Greetings.

I am currently building a skin-on-frame kayak using the standard
(classic) text by Chris Cunningham. I have just reached the stage of
putting in the steam bent ribs. I realise that this stage is tricky,
especially given that he recommends that you get 50% more timber for
breakages.

I have a specific question which he does not deal with in his book.

Cunningham recommends that you start with timber 5/16 inches thick,
and that you thin the ends (maybe up to a third of the length of each
rib, depending on its length) by 1/16 inch. His instructions tell you
to take all of the 1/16 inch off one side of the rib. (In addition to
this, the ends of each rib need to be narrowed in order to fit them
into the mortices in the gunnells).

This means that when you bend the rib after steaming you have a choice
of bending it towards the thinned side or away from the thinned side.

It seems to me that it would be more likely to split if you bent it
away from the thinned side. That is, it would be better to have the
thinned side on the inside of the curve.

I have not yet broken enough ribs to know the answer to this. Does
anyone have an opinion? Or is this likely to be such a minor matter
that it will make little difference in the long run?

Yours

Norm

wrote:
On Sun, 6 Apr 2008 21:28:05 -0700 (PDT), Norm wrote:

Greetings.

I am currently building a skin-on-frame kayak using the standard
(classic) text by Chris Cunningham. I have just reached the stage of
putting in the steam bent ribs. I realise that this stage is tricky,
especially given that he recommends that you get 50% more timber for
breakages.

I have a specific question which he does not deal with in his book.

Cunningham recommends that you start with timber 5/16 inches thick,
and that you thin the ends (maybe up to a third of the length of each
rib, depending on its length) by 1/16 inch. His instructions tell you
to take all of the 1/16 inch off one side of the rib. (In addition to
this, the ends of each rib need to be narrowed in order to fit them
into the mortices in the gunnells).

This means that when you bend the rib after steaming you have a choice
of bending it towards the thinned side or away from the thinned side.

It seems to me that it would be more likely to split if you bent it
away from the thinned side. That is, it would be better to have the
thinned side on the inside of the curve.

I have not yet broken enough ribs to know the answer to this. Does
anyone have an opinion? Or is this likely to be such a minor matter
that it will make little difference in the long run?

Yours

Norm

Bend so that the thinned part is on the inside of the bend. The thinned side has
more exposed endgrain due to the thinning, so you want that side under
compression, rather than trying to pull it apart. The longest unbroken grain is
the side that can best deal with being stretched without splintering.

While the above is correct if you're going to use Cunningham's method,
my personal opinion is that his system just creates more work than
necessary. Using 1/4" ribs without any tapering works just fine. If
you've already cut your mortises to 5/16", you're stuck, but it's
something to consider on your next boat.

One thing that is very useful is his pre-bending jig. While the ribs
won't hold the shape of the jig, it does make the ends much more pliable
and easier to insert into the frame.

For other ideas, see my Webshots albums at:

http://community.webshots.com/user/brian_nystrom-reg

On Apr 7, 9:57 pm, Brian Nystrom wrote:
wrote:
On Sun, 6 Apr 2008 21:28:05 -0700 (PDT), Norm wrote:

Greetings.

I am currently building a skin-on-frame kayak using the standard
(classic) text by Chris Cunningham. I have just reached the stage of
putting in the steam bent ribs. I realise that this stage is tricky,
especially given that he recommends that you get 50% more timber for
breakages.

I have a specific question which he does not deal with in his book.

Cunningham recommends that you start with timber 5/16 inches thick,
and that you thin the ends (maybe up to a third of the length of each
rib, depending on its length) by 1/16 inch. His instructions tell you
to take all of the 1/16 inch off one side of the rib. (In addition to
this, the ends of each rib need to be narrowed in order to fit them
into the mortices in the gunnells).

This means that when you bend the rib after steaming you have a choice
of bending it towards the thinned side or away from the thinned side.

It seems to me that it would be more likely to split if you bent it
away from the thinned side. That is, it would be better to have the
thinned side on the inside of the curve.

I have not yet broken enough ribs to know the answer to this. Does
anyone have an opinion? Or is this likely to be such a minor matter
that it will make little difference in the long run?

Yours

Norm

Bend so that the thinned part is on the inside of the bend. The thinned side has
more exposed endgrain due to the thinning, so you want that side under
compression, rather than trying to pull it apart. The longest unbroken grain is
the side that can best deal with being stretched without splintering.

While the above is correct if you're going to use Cunningham's method,
my personal opinion is that his system just creates more work than
necessary. Using 1/4" ribs without any tapering works just fine. If
you've already cut your mortises to 5/16", you're stuck, but it's
something to consider on your next boat.

One thing that is very useful is his pre-bending jig. While the ribs
won't hold the shape of the jig, it does make the ends much more pliable
and easier to insert into the frame.

For other ideas, see my Webshots albums at:

http://community.webshots.com/user/brian_nystrom-reg

Thank you for this comment, and also for the reference to your Webshot
albums.

Regarding the 1/4 inch ribs, I have been trying to follow Cunningham
EXACTLY because I have a history of minor disasters and half finished
boats. However, I have not cut my mortices to 5/16, so I do have the
choice to try thinner ribs. (There have been things that I thought of
changing but I have so far resisted).

I have used his jig. One of the problems I had with the first one I
made was that it broke apart while I was bending the first rib. I
then built another one which was much stronger and which works.
However, just last weekend I was wondering if I could make an
adjustable jig which would be suitable for keeping the different sized
ribs in till they cooled. I notice that your rib jig looks like just
such a piece of equipment. I will have a careful look at your photos
over the next few days.

I am one of those people who do not like to do things quickly and I
feel that I work at my worst when I have to make quick decisions. So
the description by Cunningham of the rib process had me worried from
the start.

Many thanks for your comments.

Norm wrote:
On Apr 7, 9:57 pm, Brian Nystrom wrote:
wrote:
On Sun, 6 Apr 2008 21:28:05 -0700 (PDT), Norm wrote:
Greetings.
I am currently building a skin-on-frame kayak using the standard
(classic) text by Chris Cunningham. I have just reached the stage of
putting in the steam bent ribs. I realise that this stage is tricky,
especially given that he recommends that you get 50% more timber for
breakages.
I have a specific question which he does not deal with in his book.
Cunningham recommends that you start with timber 5/16 inches thick,
and that you thin the ends (maybe up to a third of the length of each
rib, depending on its length) by 1/16 inch. His instructions tell you
to take all of the 1/16 inch off one side of the rib. (In addition to
this, the ends of each rib need to be narrowed in order to fit them
into the mortices in the gunnells).
This means that when you bend the rib after steaming you have a choice
of bending it towards the thinned side or away from the thinned side.
It seems to me that it would be more likely to split if you bent it
away from the thinned side. That is, it would be better to have the
thinned side on the inside of the curve.
I have not yet broken enough ribs to know the answer to this. Does
anyone have an opinion? Or is this likely to be such a minor matter
that it will make little difference in the long run?
Yours
Norm
Bend so that the thinned part is on the inside of the bend. The thinned side has
more exposed endgrain due to the thinning, so you want that side under
compression, rather than trying to pull it apart. The longest unbroken grain is
the side that can best deal with being stretched without splintering.
While the above is correct if you're going to use Cunningham's method,
my personal opinion is that his system just creates more work than
necessary. Using 1/4" ribs without any tapering works just fine. If
you've already cut your mortises to 5/16", you're stuck, but it's
something to consider on your next boat.

One thing that is very useful is his pre-bending jig. While the ribs
won't hold the shape of the jig, it does make the ends much more pliable
and easier to insert into the frame.

For other ideas, see my Webshots albums at:

http://community.webshots.com/user/brian_nystrom-reg

Thank you for this comment, and also for the reference to your Webshot
albums.

Regarding the 1/4 inch ribs, I have been trying to follow Cunningham
EXACTLY because I have a history of minor disasters and half finished
boats. However, I have not cut my mortices to 5/16, so I do have the
choice to try thinner ribs. (There have been things that I thought of
changing but I have so far resisted).

One of the best things you can do when building SOF boats is to read
several books (Morris, Starr, Cunningham, Petersen, Golden) to give you
a better idea of what's possible. You can then match the methods with
your tools and skills. There's no need to follow one method from start
to finish, as building a kayak is a series of discreet steps that can
easily be mixed and matched.

I have used his jig. One of the problems I had with the first one I
made was that it broke apart while I was bending the first rib. I
then built another one which was much stronger and which works.
However, just last weekend I was wondering if I could make an
adjustable jig which would be suitable for keeping the different sized
ribs in till they cooled. I notice that your rib jig looks like just
such a piece of equipment. I will have a careful look at your photos
over the next few days.

If you're interested in the jig, I wrote an article on building it for
"The Masik" magazine. You can download it at:

http://www.qajaqusa.org/newsletter/M...2004_06041.pdf

I am one of those people who do not like to do things quickly and I
feel that I work at my worst when I have to make quick decisions. So
the description by Cunningham of the rib process had me worried from
the start.

Many thanks for your comments.

Any time.

On Apr 8, 9:19 pm, Brian Nystrom wrote:
Norm wrote:
On Apr 7, 9:57 pm, Brian Nystrom wrote:
wrote:
On Sun, 6 Apr 2008 21:28:05 -0700 (PDT), Norm wrote:
Greetings.
I am currently building a skin-on-frame kayak using the standard
(classic) text by Chris Cunningham. I have just reached the stage of
putting in the steam bent ribs. I realise that this stage is tricky,
especially given that he recommends that you get 50% more timber for
breakages.
I have a specific question which he does not deal with in his book.
Cunningham recommends that you start with timber 5/16 inches thick,
and that you thin the ends (maybe up to a third of the length of each
rib, depending on its length) by 1/16 inch. His instructions tell you
to take all of the 1/16 inch off one side of the rib. (In addition to
this, the ends of each rib need to be narrowed in order to fit them
into the mortices in the gunnells).
This means that when you bend the rib after steaming you have a choice
of bending it towards the thinned side or away from the thinned side.
It seems to me that it would be more likely to split if you bent it
away from the thinned side. That is, it would be better to have the
thinned side on the inside of the curve.
I have not yet broken enough ribs to know the answer to this. Does
anyone have an opinion? Or is this likely to be such a minor matter
that it will make little difference in the long run?
Yours
Norm
Bend so that the thinned part is on the inside of the bend. The thinned side has
more exposed endgrain due to the thinning, so you want that side under
compression, rather than trying to pull it apart. The longest unbroken grain is
the side that can best deal with being stretched without splintering.
While the above is correct if you're going to use Cunningham's method,
my personal opinion is that his system just creates more work than
necessary. Using 1/4" ribs without any tapering works just fine. If
you've already cut your mortises to 5/16", you're stuck, but it's
something to consider on your next boat.

One thing that is very useful is his pre-bending jig. While the ribs
won't hold the shape of the jig, it does make the ends much more pliable
and easier to insert into the frame.

For other ideas, see my Webshots albums at:

http://community.webshots.com/user/brian_nystrom-reg

Thank you for this comment, and also for the reference to your Webshot
albums.

Regarding the 1/4 inch ribs, I have been trying to follow Cunningham
EXACTLY because I have a history of minor disasters and half finished
boats. However, I have not cut my mortices to 5/16, so I do have the
choice to try thinner ribs. (There have been things that I thought of
changing but I have so far resisted).

One of the best things you can do when building SOF boats is to read
several books (Morris, Starr, Cunningham, Petersen, Golden) to give you
a better idea of what's possible. You can then match the methods with
your tools and skills. There's no need to follow one method from start
to finish, as building a kayak is a series of discreet steps that can
easily be mixed and matched.

I have used his jig. One of the problems I had with the first one I
made was that it broke apart while I was bending the first rib. I
then built another one which was much stronger and which works.
However, just last weekend I was wondering if I could make an
adjustable jig which would be suitable for keeping the different sized
ribs in till they cooled. I notice that your rib jig looks like just
such a piece of equipment. I will have a careful look at your photos
over the next few days.

If you're interested in the jig, I wrote an article on building it for
"The Masik" magazine. You can download it at:

http://www.qajaqusa.org/newsletter/M...2004_06041.pdf

I am one of those people who do not like to do things quickly and I
feel that I work at my worst when I have to make quick decisions. So
the description by Cunningham of the rib process had me worried from
the start.

Many thanks for your comments.

Any time.

Thanks for the general advice. I have read Morris and a book on
kayaks by Chappell and another person. I am always trying to be more
flexible in my approach, but I do worry about adopting two
incompatible approaches. For example, Morris describes doing the deck
beams before doing the ribs, whereas Cunningham does the ribs first.
As a consequence of this, Cunningham takes measurements for his masik
by sitting in the already ribbed kayak, whereas Morris uses another
method.

I have downloaded your article on the adjustable jig, and lost sleep
reading it the night before last. It looks great, and I will have a
serious think about it this weekend. Thank you also for referring me
to the journal The Masik. Despite a lot of web browsing over the
years on issues relating to kayaks and canoes I have never come across
it.

Many thanks. I'll try to get back to you over the next few weeks
about how the steam bending is going, and whether or not I end up
using your jig.

Norm wrote:
On Apr 8, 9:19 pm, Brian Nystrom wrote:
Norm wrote:
On Apr 7, 9:57 pm, Brian Nystrom wrote:
wrote:
On Sun, 6 Apr 2008 21:28:05 -0700 (PDT), Norm wrote:
Greetings.
I am currently building a skin-on-frame kayak using the standard
(classic) text by Chris Cunningham. I have just reached the stage of
putting in the steam bent ribs. I realise that this stage is tricky,
especially given that he recommends that you get 50% more timber for
breakages.
I have a specific question which he does not deal with in his book.
Cunningham recommends that you start with timber 5/16 inches thick,
and that you thin the ends (maybe up to a third of the length of each
rib, depending on its length) by 1/16 inch. His instructions tell you
to take all of the 1/16 inch off one side of the rib. (In addition to
this, the ends of each rib need to be narrowed in order to fit them
into the mortices in the gunnells).
This means that when you bend the rib after steaming you have a choice
of bending it towards the thinned side or away from the thinned side.
It seems to me that it would be more likely to split if you bent it
away from the thinned side. That is, it would be better to have the
thinned side on the inside of the curve.
I have not yet broken enough ribs to know the answer to this. Does
anyone have an opinion? Or is this likely to be such a minor matter
that it will make little difference in the long run?
Yours
Norm
Bend so that the thinned part is on the inside of the bend. The thinned side has
more exposed endgrain due to the thinning, so you want that side under
compression, rather than trying to pull it apart. The longest unbroken grain is
the side that can best deal with being stretched without splintering.
While the above is correct if you're going to use Cunningham's method,
my personal opinion is that his system just creates more work than
necessary. Using 1/4" ribs without any tapering works just fine. If
you've already cut your mortises to 5/16", you're stuck, but it's
something to consider on your next boat.
One thing that is very useful is his pre-bending jig. While the ribs
won't hold the shape of the jig, it does make the ends much more pliable
and easier to insert into the frame.
For other ideas, see my Webshots albums at:
http://community.webshots.com/user/brian_nystrom-reg
Thank you for this comment, and also for the reference to your Webshot
albums.
Regarding the 1/4 inch ribs, I have been trying to follow Cunningham
EXACTLY because I have a history of minor disasters and half finished
boats. However, I have not cut my mortices to 5/16, so I do have the
choice to try thinner ribs. (There have been things that I thought of
changing but I have so far resisted).
One of the best things you can do when building SOF boats is to read
several books (Morris, Starr, Cunningham, Petersen, Golden) to give you
a better idea of what's possible. You can then match the methods with
your tools and skills. There's no need to follow one method from start
to finish, as building a kayak is a series of discreet steps that can
easily be mixed and matched.

I have used his jig. One of the problems I had with the first one I
made was that it broke apart while I was bending the first rib. I
then built another one which was much stronger and which works.
However, just last weekend I was wondering if I could make an
adjustable jig which would be suitable for keeping the different sized
ribs in till they cooled. I notice that your rib jig looks like just
such a piece of equipment. I will have a careful look at your photos
over the next few days.
If you're interested in the jig, I wrote an article on building it for
"The Masik" magazine. You can download it at:

http://www.qajaqusa.org/newsletter/M...2004_06041.pdf

I am one of those people who do not like to do things quickly and I
feel that I work at my worst when I have to make quick decisions. So
the description by Cunningham of the rib process had me worried from
the start.
Many thanks for your comments.
Any time.

Thanks for the general advice. I have read Morris and a book on
kayaks by Chappell and another person. I am always trying to be more
flexible in my approach, but I do worry about adopting two
incompatible approaches. For example, Morris describes doing the deck
beams before doing the ribs, whereas Cunningham does the ribs first.
As a consequence of this, Cunningham takes measurements for his masik
by sitting in the already ribbed kayak, whereas Morris uses another
method.

Although I build largely using Morris' method, I fit the masik and the
foredeck stringers after the rest of the boat is completed. I can't see
any advantage to doing it earlier in the process where the potential for
error is substantial.

I have downloaded your article on the adjustable jig, and lost sleep
reading it the night before last. It looks great, and I will have a
serious think about it this weekend. Thank you also for referring me
to the journal The Masik. Despite a lot of web browsing over the
years on issues relating to kayaks and canoes I have never come across
it.

Many thanks. I'll try to get back to you over the next few weeks
about how the steam bending is going, and whether or not I end up
using your jig.

Make sure you build a good steam box and have an adequate steam source.
The latter is especially important. I built my first boat using a teapot
on a hotplate, but it was far from ideal. Using a wallpaper steamer as a
steam source is a much better way to go.

On Apr 11, 8:46 pm, Brian Nystrom wrote:
Norm wrote:
On Apr 8, 9:19 pm, Brian Nystrom wrote:
Norm wrote:
On Apr 7, 9:57 pm, Brian Nystrom wrote:
wrote:
On Sun, 6 Apr 2008 21:28:05 -0700 (PDT), Norm wrote:
Greetings.
I am currently building a skin-on-frame kayak using the standard
(classic) text by Chris Cunningham. I have just reached the stage of
putting in the steam bent ribs. I realise that this stage is tricky,
especially given that he recommends that you get 50% more timber for
breakages.
I have a specific question which he does not deal with in his book.
Cunningham recommends that you start with timber 5/16 inches thick,
and that you thin the ends (maybe up to a third of the length of each
rib, depending on its length) by 1/16 inch. His instructions tell you
to take all of the 1/16 inch off one side of the rib. (In addition to
this, the ends of each rib need to be narrowed in order to fit them
into the mortices in the gunnells).
This means that when you bend the rib after steaming you have a choice
of bending it towards the thinned side or away from the thinned side.
It seems to me that it would be more likely to split if you bent it
away from the thinned side. That is, it would be better to have the
thinned side on the inside of the curve.
I have not yet broken enough ribs to know the answer to this. Does
anyone have an opinion? Or is this likely to be such a minor matter
that it will make little difference in the long run?
Yours
Norm
Bend so that the thinned part is on the inside of the bend. The thinned side has
more exposed endgrain due to the thinning, so you want that side under
compression, rather than trying to pull it apart. The longest unbroken grain is
the side that can best deal with being stretched without splintering.
While the above is correct if you're going to use Cunningham's method,
my personal opinion is that his system just creates more work than
necessary. Using 1/4" ribs without any tapering works just fine. If
you've already cut your mortises to 5/16", you're stuck, but it's
something to consider on your next boat.
One thing that is very useful is his pre-bending jig. While the ribs
won't hold the shape of the jig, it does make the ends much more pliable
and easier to insert into the frame.
For other ideas, see my Webshots albums at:
http://community.webshots.com/user/brian_nystrom-reg
Thank you for this comment, and also for the reference to your Webshot
albums.
Regarding the 1/4 inch ribs, I have been trying to follow Cunningham
EXACTLY because I have a history of minor disasters and half finished
boats. However, I have not cut my mortices to 5/16, so I do have the
choice to try thinner ribs. (There have been things that I thought of
changing but I have so far resisted).
One of the best things you can do when building SOF boats is to read
several books (Morris, Starr, Cunningham, Petersen, Golden) to give you
a better idea of what's possible. You can then match the methods with
your tools and skills. There's no need to follow one method from start
to finish, as building a kayak is a series of discreet steps that can
easily be mixed and matched.

I have used his jig. One of the problems I had with the first one I
made was that it broke apart while I was bending the first rib. I
then built another one which was much stronger and which works.
However, just last weekend I was wondering if I could make an
adjustable jig which would be suitable for keeping the different sized
ribs in till they cooled. I notice that your rib jig looks like just
such a piece of equipment. I will have a careful look at your photos
over the next few days.
If you're interested in the jig, I wrote an article on building it for
"The Masik" magazine. You can download it at:

http://www.qajaqusa.org/newsletter/M...2004_06041.pdf

I am one of those people who do not like to do things quickly and I
feel that I work at my worst when I have to make quick decisions. So
the description by Cunningham of the rib process had me worried from
the start.
Many thanks for your comments.
Any time.

Thanks for the general advice. I have read Morris and a book on
kayaks by Chappell and another person. I am always trying to be more
flexible in my approach, but I do worry about adopting two
incompatible approaches. For example, Morris describes doing the deck
beams before doing the ribs, whereas Cunningham does the ribs first.
As a consequence of this, Cunningham takes measurements for his masik
by sitting in the already ribbed kayak, whereas Morris uses another
method.

Although I build largely using Morris' method, I fit the masik and the
foredeck stringers after the rest of the boat is completed. I can't see
any advantage to doing it earlier in the process where the potential for
error is substantial.

I have downloaded your article on the adjustable jig, and lost sleep
reading it the night before last. It looks great, and I will have a
serious think about it this weekend. Thank you also for referring me
to the journal The Masik. Despite a lot of web browsing over the
years on issues relating to kayaks and canoes I have never come across
it.

Many thanks. I'll try to get back to you over the next few weeks
about how the steam bending is going, and whether or not I end up
using your jig.

Make sure you build a good steam box and have an adequate steam source.
The latter is especially important. I built my first boat using a teapot
on a hotplate, but it was far from ideal. Using a wallpaper steamer as a
steam source is a much better way to go.

Yes, I do have a good steam source. A few months ago I was at a
market where a chap sells cheap tools and he had a 15 litre urn for
sale. I have made a new lid for it with marine ply and an old vacuum
cleaner tube acts to take the steam to the steaming chamber. I have
made a steam box out of old floor boards. It is just the right length
for my kayak ribs, and has a rack inside to keep them completely
suspended in steam. That part of the process seems to be working
well. I have started working on the new jig.

On Sun, 13 Apr 2008 21:19:48 -0700 (PDT), Norm
wrote:

On Apr 11, 8:46 pm, Brian Nystrom wrote:
Norm wrote:
On Apr 8, 9:19 pm, Brian Nystrom wrote:
Norm wrote:
On Apr 7, 9:57 pm, Brian Nystrom wrote:
wrote:
On Sun, 6 Apr 2008 21:28:05 -0700 (PDT), Norm wrote:
Greetings.
I am currently building a skin-on-frame kayak using the standard
(classic) text by Chris Cunningham. I have just reached the stage of
putting in the steam bent ribs. I realise that this stage is tricky,
especially given that he recommends that you get 50% more timber for
breakages.
I have a specific question which he does not deal with in his book.
Cunningham recommends that you start with timber 5/16 inches thick,
and that you thin the ends (maybe up to a third of the length of each
rib, depending on its length) by 1/16 inch. His instructions tell you
to take all of the 1/16 inch off one side of the rib. (In addition to
this, the ends of each rib need to be narrowed in order to fit them
into the mortices in the gunnells).
This means that when you bend the rib after steaming you have a choice
of bending it towards the thinned side or away from the thinned side.
It seems to me that it would be more likely to split if you bent it
away from the thinned side. That is, it would be better to have the
thinned side on the inside of the curve.
I have not yet broken enough ribs to know the answer to this. Does
anyone have an opinion? Or is this likely to be such a minor matter
that it will make little difference in the long run?
Yours
Norm
Bend so that the thinned part is on the inside of the bend. The thinned side has
more exposed endgrain due to the thinning, so you want that side under
compression, rather than trying to pull it apart. The longest unbroken grain is
the side that can best deal with being stretched without splintering.
While the above is correct if you're going to use Cunningham's method,
my personal opinion is that his system just creates more work than
necessary. Using 1/4" ribs without any tapering works just fine. If
you've already cut your mortises to 5/16", you're stuck, but it's
something to consider on your next boat.
One thing that is very useful is his pre-bending jig. While the ribs
won't hold the shape of the jig, it does make the ends much more pliable
and easier to insert into the frame.
For other ideas, see my Webshots albums at:
http://community.webshots.com/user/brian_nystrom-reg
Thank you for this comment, and also for the reference to your Webshot
albums.
Regarding the 1/4 inch ribs, I have been trying to follow Cunningham
EXACTLY because I have a history of minor disasters and half finished
boats. However, I have not cut my mortices to 5/16, so I do have the
choice to try thinner ribs. (There have been things that I thought of
changing but I have so far resisted).
One of the best things you can do when building SOF boats is to read
several books (Morris, Starr, Cunningham, Petersen, Golden) to give you
a better idea of what's possible. You can then match the methods with
your tools and skills. There's no need to follow one method from start
to finish, as building a kayak is a series of discreet steps that can
easily be mixed and matched.

I have used his jig. One of the problems I had with the first one I
made was that it broke apart while I was bending the first rib. I
then built another one which was much stronger and which works.
However, just last weekend I was wondering if I could make an
adjustable jig which would be suitable for keeping the different sized
ribs in till they cooled. I notice that your rib jig looks like just
such a piece of equipment. I will have a careful look at your photos
over the next few days.
If you're interested in the jig, I wrote an article on building it for
"The Masik" magazine. You can download it at:

http://www.qajaqusa.org/newsletter/M...2004_06041.pdf

I am one of those people who do not like to do things quickly and I
feel that I work at my worst when I have to make quick decisions. So
the description by Cunningham of the rib process had me worried from
the start.
Many thanks for your comments.
Any time.

Thanks for the general advice. I have read Morris and a book on
kayaks by Chappell and another person. I am always trying to be more
flexible in my approach, but I do worry about adopting two
incompatible approaches. For example, Morris describes doing the deck
beams before doing the ribs, whereas Cunningham does the ribs first.
As a consequence of this, Cunningham takes measurements for his masik
by sitting in the already ribbed kayak, whereas Morris uses another
method.

Although I build largely using Morris' method, I fit the masik and the
foredeck stringers after the rest of the boat is completed. I can't see
any advantage to doing it earlier in the process where the potential for
error is substantial.

I have downloaded your article on the adjustable jig, and lost sleep
reading it the night before last. It looks great, and I will have a
serious think about it this weekend. Thank you also for referring me
to the journal The Masik. Despite a lot of web browsing over the
years on issues relating to kayaks and canoes I have never come across
it.

Many thanks. I'll try to get back to you over the next few weeks
about how the steam bending is going, and whether or not I end up
using your jig.

Make sure you build a good steam box and have an adequate steam source.
The latter is especially important. I built my first boat using a teapot
on a hotplate, but it was far from ideal. Using a wallpaper steamer as a
steam source is a much better way to go.

Yes, I do have a good steam source. A few months ago I was at a
market where a chap sells cheap tools and he had a 15 litre urn for
sale. I have made a new lid for it with marine ply and an old vacuum
cleaner tube acts to take the steam to the steaming chamber. I have
made a steam box out of old floor boards. It is just the right length
for my kayak ribs, and has a rack inside to keep them completely
suspended in steam. That part of the process seems to be working
well. I have started working on the new jig.

You probably know this but it is not "steam" that makes the wood
flexible, it is heat. The old Maine boat builders quite frequently
boiled the oak timbers for boats to make them flexible enough to bend
into the forms. For some reason they used soapy water for this - never
did understand why.

Bruce-in-Bangkok
(correct email address for reply)

On Mon, 14 Apr 2008 07:00:22 -0400, wrote:

On Mon, 14 Apr 2008 12:41:27 +0700, Bruce in Bangkok
wrote:

On Sun, 13 Apr 2008 21:19:48 -0700 (PDT), Norm
wrote:

On Apr 11, 8:46 pm, Brian Nystrom wrote:
Norm wrote:
On Apr 8, 9:19 pm, Brian Nystrom wrote:
Norm wrote:
On Apr 7, 9:57 pm, Brian Nystrom wrote:
wrote:
On Sun, 6 Apr 2008 21:28:05 -0700 (PDT), Norm wrote:
Greetings.
I am currently building a skin-on-frame kayak using the standard
(classic) text by Chris Cunningham. I have just reached the stage of
putting in the steam bent ribs. I realise that this stage is tricky,
especially given that he recommends that you get 50% more timber for
breakages.
I have a specific question which he does not deal with in his book.
Cunningham recommends that you start with timber 5/16 inches thick,
and that you thin the ends (maybe up to a third of the length of each
rib, depending on its length) by 1/16 inch. His instructions tell you
to take all of the 1/16 inch off one side of the rib. (In addition to
this, the ends of each rib need to be narrowed in order to fit them
into the mortices in the gunnells).
This means that when you bend the rib after steaming you have a choice
of bending it towards the thinned side or away from the thinned side.
It seems to me that it would be more likely to split if you bent it
away from the thinned side. That is, it would be better to have the
thinned side on the inside of the curve.
I have not yet broken enough ribs to know the answer to this. Does
anyone have an opinion? Or is this likely to be such a minor matter
that it will make little difference in the long run?
Yours
Norm
Bend so that the thinned part is on the inside of the bend. The thinned side has
more exposed endgrain due to the thinning, so you want that side under
compression, rather than trying to pull it apart. The longest unbroken grain is
the side that can best deal with being stretched without splintering.
While the above is correct if you're going to use Cunningham's method,
my personal opinion is that his system just creates more work than
necessary. Using 1/4" ribs without any tapering works just fine. If
you've already cut your mortises to 5/16", you're stuck, but it's
something to consider on your next boat.
One thing that is very useful is his pre-bending jig. While the ribs
won't hold the shape of the jig, it does make the ends much more pliable
and easier to insert into the frame.
For other ideas, see my Webshots albums at:
http://community.webshots.com/user/brian_nystrom-reg
Thank you for this comment, and also for the reference to your Webshot
albums.
Regarding the 1/4 inch ribs, I have been trying to follow Cunningham
EXACTLY because I have a history of minor disasters and half finished
boats. However, I have not cut my mortices to 5/16, so I do have the
choice to try thinner ribs. (There have been things that I thought of
changing but I have so far resisted).
One of the best things you can do when building SOF boats is to read
several books (Morris, Starr, Cunningham, Petersen, Golden) to give you
a better idea of what's possible. You can then match the methods with
your tools and skills. There's no need to follow one method from start
to finish, as building a kayak is a series of discreet steps that can
easily be mixed and matched.

I have used his jig. One of the problems I had with the first one I
made was that it broke apart while I was bending the first rib. I
then built another one which was much stronger and which works.
However, just last weekend I was wondering if I could make an
adjustable jig which would be suitable for keeping the different sized
ribs in till they cooled. I notice that your rib jig looks like just
such a piece of equipment. I will have a careful look at your photos
over the next few days.
If you're interested in the jig, I wrote an article on building it for
"The Masik" magazine. You can download it at:

http://www.qajaqusa.org/newsletter/M...2004_06041.pdf

I am one of those people who do not like to do things quickly and I
feel that I work at my worst when I have to make quick decisions. So
the description by Cunningham of the rib process had me worried from
the start.
Many thanks for your comments.
Any time.

Thanks for the general advice. I have read Morris and a book on
kayaks by Chappell and another person. I am always trying to be more
flexible in my approach, but I do worry about adopting two
incompatible approaches. For example, Morris describes doing the deck
beams before doing the ribs, whereas Cunningham does the ribs first.
As a consequence of this, Cunningham takes measurements for his masik
by sitting in the already ribbed kayak, whereas Morris uses another
method.

Although I build largely using Morris' method, I fit the masik and the
foredeck stringers after the rest of the boat is completed. I can't see
any advantage to doing it earlier in the process where the potential for
error is substantial.

I have downloaded your article on the adjustable jig, and lost sleep
reading it the night before last. It looks great, and I will have a
serious think about it this weekend. Thank you also for referring me
to the journal The Masik. Despite a lot of web browsing over the
years on issues relating to kayaks and canoes I have never come across
it.

Many thanks. I'll try to get back to you over the next few weeks
about how the steam bending is going, and whether or not I end up
using your jig.

Make sure you build a good steam box and have an adequate steam source.
The latter is especially important. I built my first boat using a teapot
on a hotplate, but it was far from ideal. Using a wallpaper steamer as a
steam source is a much better way to go.

Yes, I do have a good steam source. A few months ago I was at a
market where a chap sells cheap tools and he had a 15 litre urn for
sale. I have made a new lid for it with marine ply and an old vacuum
cleaner tube acts to take the steam to the steaming chamber. I have
made a steam box out of old floor boards. It is just the right length
for my kayak ribs, and has a rack inside to keep them completely
suspended in steam. That part of the process seems to be working
well. I have started working on the new jig.

You probably know this but it is not "steam" that makes the wood
flexible, it is heat. The old Maine boat builders quite frequently
boiled the oak timbers for boats to make them flexible enough to bend
into the forms. For some reason they used soapy water for this - never
did understand why.

Bruce-in-Bangkok
(correct email address for reply)

I think the soap was supposed to soften the outer fibers a little more to help
reduce splintering. It probably also helped with the sap that came to the
surface from the heat.

Certainly the boats were built of green oak as aged oak doesn;t bend
very well.


Bruce-in-Bangkok
(correct email address for reply)

Bruce in Bangkok wrote:
On Mon, 14 Apr 2008 07:00:22 -0400, wrote:

On Mon, 14 Apr 2008 12:41:27 +0700, Bruce in Bangkok
wrote:

On Sun, 13 Apr 2008 21:19:48 -0700 (PDT), Norm
wrote:

On Apr 11, 8:46 pm, Brian Nystrom wrote:
Norm wrote:
On Apr 8, 9:19 pm, Brian Nystrom wrote:
Norm wrote:
On Apr 7, 9:57 pm, Brian Nystrom wrote:
wrote:
On Sun, 6 Apr 2008 21:28:05 -0700 (PDT), Norm wrote:
Greetings.
I am currently building a skin-on-frame kayak using the standard
(classic) text by Chris Cunningham. I have just reached the stage of
putting in the steam bent ribs. I realise that this stage is tricky,
especially given that he recommends that you get 50% more timber for
breakages.
I have a specific question which he does not deal with in his book.
Cunningham recommends that you start with timber 5/16 inches thick,
and that you thin the ends (maybe up to a third of the length of each
rib, depending on its length) by 1/16 inch. His instructions tell you
to take all of the 1/16 inch off one side of the rib. (In addition to
this, the ends of each rib need to be narrowed in order to fit them
into the mortices in the gunnells).
This means that when you bend the rib after steaming you have a choice
of bending it towards the thinned side or away from the thinned side.
It seems to me that it would be more likely to split if you bent it
away from the thinned side. That is, it would be better to have the
thinned side on the inside of the curve.
I have not yet broken enough ribs to know the answer to this. Does
anyone have an opinion? Or is this likely to be such a minor matter
that it will make little difference in the long run?
Yours
Norm
Bend so that the thinned part is on the inside of the bend. The thinned side has
more exposed endgrain due to the thinning, so you want that side under
compression, rather than trying to pull it apart. The longest unbroken grain is
the side that can best deal with being stretched without splintering.
While the above is correct if you're going to use Cunningham's method,
my personal opinion is that his system just creates more work than
necessary. Using 1/4" ribs without any tapering works just fine. If
you've already cut your mortises to 5/16", you're stuck, but it's
something to consider on your next boat.
One thing that is very useful is his pre-bending jig. While the ribs
won't hold the shape of the jig, it does make the ends much more pliable
and easier to insert into the frame.
For other ideas, see my Webshots albums at:
http://community.webshots.com/user/brian_nystrom-reg
Thank you for this comment, and also for the reference to your Webshot
albums.
Regarding the 1/4 inch ribs, I have been trying to follow Cunningham
EXACTLY because I have a history of minor disasters and half finished
boats. However, I have not cut my mortices to 5/16, so I do have the
choice to try thinner ribs. (There have been things that I thought of
changing but I have so far resisted).
One of the best things you can do when building SOF boats is to read
several books (Morris, Starr, Cunningham, Petersen, Golden) to give you
a better idea of what's possible. You can then match the methods with
your tools and skills. There's no need to follow one method from start
to finish, as building a kayak is a series of discreet steps that can
easily be mixed and matched.
I have used his jig. One of the problems I had with the first one I
made was that it broke apart while I was bending the first rib. I
then built another one which was much stronger and which works.
However, just last weekend I was wondering if I could make an
adjustable jig which would be suitable for keeping the different sized
ribs in till they cooled. I notice that your rib jig looks like just
such a piece of equipment. I will have a careful look at your photos
over the next few days.
If you're interested in the jig, I wrote an article on building it for
"The Masik" magazine. You can download it at:
http://www.qajaqusa.org/newsletter/M...2004_06041.pdf
I am one of those people who do not like to do things quickly and I
feel that I work at my worst when I have to make quick decisions. So
the description by Cunningham of the rib process had me worried from
the start.
Many thanks for your comments.
Any time.
Thanks for the general advice. I have read Morris and a book on
kayaks by Chappell and another person. I am always trying to be more
flexible in my approach, but I do worry about adopting two
incompatible approaches. For example, Morris describes doing the deck
beams before doing the ribs, whereas Cunningham does the ribs first.
As a consequence of this, Cunningham takes measurements for his masik
by sitting in the already ribbed kayak, whereas Morris uses another
method.
Although I build largely using Morris' method, I fit the masik and the
foredeck stringers after the rest of the boat is completed. I can't see
any advantage to doing it earlier in the process where the potential for
error is substantial.

I have downloaded your article on the adjustable jig, and lost sleep
reading it the night before last. It looks great, and I will have a
serious think about it this weekend. Thank you also for referring me
to the journal The Masik. Despite a lot of web browsing over the
years on issues relating to kayaks and canoes I have never come across
it.
Many thanks. I'll try to get back to you over the next few weeks
about how the steam bending is going, and whether or not I end up
using your jig.
Make sure you build a good steam box and have an adequate steam source.
The latter is especially important. I built my first boat using a teapot
on a hotplate, but it was far from ideal. Using a wallpaper steamer as a
steam source is a much better way to go.
Yes, I do have a good steam source. A few months ago I was at a
market where a chap sells cheap tools and he had a 15 litre urn for
sale. I have made a new lid for it with marine ply and an old vacuum
cleaner tube acts to take the steam to the steaming chamber. I have
made a steam box out of old floor boards. It is just the right length
for my kayak ribs, and has a rack inside to keep them completely
suspended in steam. That part of the process seems to be working
well. I have started working on the new jig.
You probably know this but it is not "steam" that makes the wood
flexible, it is heat. The old Maine boat builders quite frequently
boiled the oak timbers for boats to make them flexible enough to bend
into the forms. For some reason they used soapy water for this - never
did understand why.

Bruce-in-Bangkok
(correct email address for reply)
I think the soap was supposed to soften the outer fibers a little more to help
reduce splintering. It probably also helped with the sap that came to the
surface from the heat.

Certainly the boats were built of green oak as aged oak doesn;t bend
very well.

It depends on what you call "aged". My experience is that air-dried oak
bends pretty much as well as green oak. It requires a little more
steamer time (20-30%), since the lower moisture content doesn't carry
heat into the wood as fast.