Hi all,

I want to put on backing plates for all the stuff attached to the transom
(exhaust ports, swim platform, steering arms etc). Through continually
snugging them, the previous owner has burried a couple of nuts through the
glass! I am really new to all this but the first thing that comes to mind is
reaction between two metals. If I use stainless bolts, could I use aluminum
for backing plates or maybe I should use something else, or maybe I
shouldn't do this at all?

Still asking and not able to answer much yet.

Thanks, Steve

Use some stainless backing plates and Nyloc nuts.

"sel1" wrote in message
...
Hi all,

I want to put on backing plates for all the stuff attached to the transom
(exhaust ports, swim platform, steering arms etc). Through continually
snugging them, the previous owner has burried a couple of nuts through the
glass! I am really new to all this but the first thing that comes to mind
is
reaction between two metals. If I use stainless bolts, could I use
aluminum
for backing plates or maybe I should use something else, or maybe I
shouldn't do this at all?

Still asking and not able to answer much yet.

Thanks, Steve

sel1 wrote:
Hi all,

I want to put on backing plates for all the stuff attached to the transom
(exhaust ports, swim platform, steering arms etc). Through continually
snugging them, the previous owner has burried a couple of nuts through the
glass! I am really new to all this but the first thing that comes to mind is
reaction between two metals. If I use stainless bolts, could I use aluminum
for backing plates or maybe I should use something else, or maybe I
shouldn't do this at all?

Still asking and not able to answer much yet.

Thanks, Steve




To do it properly takes a little time but doesn't cost a single cent
more as in;

(i) Aluminium is OK say;
(a) 1/4"
(b) Size/shape of the backing is up to you, usually the available space
will dictate the shape size etc, the rule is; if it looks right it
probably is:-)
(b) it's not under water as such so dissimilar metals shouldn't be an
issue (even with stainless you'd still need to ensure the same stainless
as the bolts say 316 vs 3xx or it corrodes anyway:-)
(c) aluminium is much easier to work & you can even drill it in situ
from the outside if you have a tricky nook or cranny.

(ii) Chamfer just the outer perimeter of the plates away from where
they'll pull against the hull, if you leave a sharp edge it can cut into
the outer glass under load & leave a crack in the flow or gelcoat for
water to get in.

(iii) You should try to seal inside all the through hull holes:
(a) particularly if it's the cored transom
(b) Coat the holes right through with any of the good epoxy fillers, then
(c) push the bolts back in while it's wet, having given the bolt a good
coat of grease first (dipped in candle wax works too).
(d) Once epoxy has gelled you should be able to get your bolts back out
with a spanner, leaving a good protection for the transom core (usually
plywood) & a good fit for the bolt.

(iv) When ready to put it all together again;
(a) use plenty of any of the good sealants, sadly price is a good
indicator so any marine recommended 3M or marine sikaflex (German?? not
sure) is OK.
(b) Clean the hull, parts, holes, bolts etc with solvent so the sealant
can adhere.
(c) Put all the bolts in & tighten the nuts (don't turn the bolts if
you can avoid it, it messes up the sealant) just tight enough to get all
the parts mated & snug, don't over tighten at this stage,
(d) get rid of excess squeezed out sealant with whatever solvent.
(e) Let the whole thing set for a while at least a day but longer is
OK, so the sealant can fully cure.
(f) Now you can tighten it all up, but again make sure someone holds
the bolts so they can't turn & you just tighten the nuts.

It'll be ticketyboo:-)


K

Thanks so much for the detail K, pretty straight forward. You say aluminum
is OK. As in not the best material?

Most of the work will be above the water line but my swim platform brackets
go below the water line and they are steel angle iron (probably home made).
Any ideas on what kind of support system I could use so that the it doesn't
have to go below water line? Either that or I switch to aluminum angle
pieces and stainless bolts. Aluminum should be OK below water line? Previous
owner didn't even use stainless bolts so they were really tough to get off.

To do it properly takes a little time but doesn't cost a single cent
more as in;

(i) Aluminium is OK say;
(a) 1/4"
(b) Size/shape of the backing is up to you, usually the available space
will dictate the shape size etc, the rule is; if it looks right it
probably is:-)
(b) it's not under water as such so dissimilar metals shouldn't be an
issue (even with stainless you'd still need to ensure the same stainless
as the bolts say 316 vs 3xx or it corrodes anyway:-)
(c) aluminium is much easier to work & you can even drill it in situ
from the outside if you have a tricky nook or cranny.

(ii) Chamfer just the outer perimeter of the plates away from where
they'll pull against the hull, if you leave a sharp edge it can cut into
the outer glass under load & leave a crack in the flow or gelcoat for
water to get in.

(iii) You should try to seal inside all the through hull holes:
(a) particularly if it's the cored transom
(b) Coat the holes right through with any of the good epoxy fillers, then
(c) push the bolts back in while it's wet, having given the bolt a good
coat of grease first (dipped in candle wax works too).
(d) Once epoxy has gelled you should be able to get your bolts back out
with a spanner, leaving a good protection for the transom core (usually
plywood) & a good fit for the bolt.

(iv) When ready to put it all together again;
(a) use plenty of any of the good sealants, sadly price is a good
indicator so any marine recommended 3M or marine sikaflex (German?? not
sure) is OK.
(b) Clean the hull, parts, holes, bolts etc with solvent so the sealant
can adhere.
(c) Put all the bolts in & tighten the nuts (don't turn the bolts if
you can avoid it, it messes up the sealant) just tight enough to get all
the parts mated & snug, don't over tighten at this stage,
(d) get rid of excess squeezed out sealant with whatever solvent.
(e) Let the whole thing set for a while at least a day but longer is
OK, so the sealant can fully cure.
(f) Now you can tighten it all up, but again make sure someone holds
the bolts so they can't turn & you just tighten the nuts.

It'll be ticketyboo:-)

K

"sel1" wrote in message
...
Thanks so much for the detail K, pretty straight forward. You say aluminum
is OK. As in not the best material?

I tried both 1/8" ss plate and 1/4" aluminum plate this summer. Unless you
have a drill press forget the ss. damn hard to cut or drill. On sume of
the aluminum backing plates, wehere the ss bolts and washes came in touch, I
used cutout plastic washers made of ice cream containers and liquid
electrical tape.

Use a cutting oil when drilling the SS.

"Don White" wrote in message
...

"sel1" wrote in message
...
Thanks so much for the detail K, pretty straight forward. You say
aluminum
is OK. As in not the best material?

I tried both 1/8" ss plate and 1/4" aluminum plate this summer. Unless
you
have a drill press forget the ss. damn hard to cut or drill. On sume
of
the aluminum backing plates, wehere the ss bolts and washes came in touch,
I
used cutout plastic washers made of ice cream containers and liquid
electrical tape.

Assuming "Starboard" is similar in strength to Corion, or its many
copy-cats.......You may be able pickup free sink cut-outs from a local
kitchen cabinet dealer. A lot of Corion style sinks are molded-in these
days, but some people still prefer the drop-in sink...leaving a Corion
cut-out to be thrown away. RichG TX

--
RichG manager, Carolina Skiff Owners Group on MSN
http://groups.msn.com/CarolinaSkiffOwners
..

On Sun, 12 Dec 2004 23:41:28 GMT, "RichG"
wrote:

Assuming "Starboard" is similar in strength to Corion, or its many
copy-cats.......You may be able pickup free sink cut-outs from a local
kitchen cabinet dealer. A lot of Corion style sinks are molded-in these
days, but some people still prefer the drop-in sink...leaving a Corion
cut-out to be thrown away. RichG TX

I'm surprised you've never heard of it - it's used on fiberglass boats
for cabinet/storage/baitwell covers/doors and is the stuff used in
electronic boxes.

http://www.kingplastic.com/Products/...ardFamily.aspx

Later,

Tom

I didn't say I haven't heard of it.

I don't know its density and strength relative to Corion or other molded
plastic flat stock.
--
RichG manager, Carolina Skiff Owners Group on MSN
http://groups.msn.com/CarolinaSkiffOwners
..
************************************************** *****************
"Short Wave Sportfishing" wrote in message
...
On Sun, 12 Dec 2004 23:41:28 GMT, "RichG"

I'm surprised you've never heard of it - it's used on fiberglass boats
for cabinet/storage/baitwell covers/doors and is the stuff used in
electronic boxes.

http://www.kingplastic.com/Products/...ardFamily.aspx

Later,

Tom

sel1 wrote:
Thanks so much for the detail K, pretty straight forward. You say aluminum
is OK. As in not the best material?

If you're talking 3/8 bolts 1/4 should be OK but go to 3/8 if you have
reservations; or go to dinner:-).

Most of the work will be above the water line but my swim platform brackets
go below the water line and they are steel angle iron (probably home made).

Is it a trailer boat?? I thought it was a trailer boat but now I'm
wondering if it's a moored for the season type boat??? Getting wet while
being used is OK but if it's permanently in the water then stainless
might be better below the waterline.

Remember the stern drive or OB itself is make of aluminium & put
together with stainless bolts & what nots. They are wet whenever the
boat is in the water, even worse the top of the gearbox is blasted with
very hot exhaust driven salt water when the engine is running (they
always corrode from the inside the outside paint etc is just fluff for
the punters:-)), so your 1/4" plates are not such a worry really.

Any ideas on what kind of support system I could use so that the it doesn't
have to go below water line?

Lots of people have stainless cables, chains or even heavy stainless
rod (me:-)) from the top of the transom to the duck board (swim platform).


Either that or I switch to aluminum angle
pieces and stainless bolts. Aluminum should be OK below water line?

Again only if it's a trailer type boat that comes out of the water most
of the year, a few weeks at a time would be OK but full time???, creates
antifoul problems also because you need the aluminium suitable stuff
which doesn't work too well:-)

I notice below some comments about maybe the transom is rotten?? be
careful here because replacing the transom core is just as you suspect a
big job to do yourself or an expensive one to have done for you. If you
have no other symptoms than those you've detailed & just want to tidy up
a bit then new stainless bolts, properly installed is the go.

Hope you don't mind but I've pasted one of my previous howtos on
transom repairs below; just so you can get some better understanding of
what a really big job it is, most older boats have a low value because
the cost of repairing the transom is not worth the money or owner effort.

All the best.

K


Previous
owner didn't even use stainless bolts so they were really tough to get off.


Paste of transom howto;

I'm making some assumptions (again) but indeed it sounds like the
transom has failed, probably because the core was plywood & over time
has rotted.

It's a big job, but not too complex & even if you choose not to do it,
it might help to know what needs to be done.

The transom from the outside in is, fibreglass, plywood then
another layer of fibreglass. Sounds like the load from the motor has
actually broken the inner & outer skins along with the plywood
obviously. Have a really good look at it & you will see what
has happened, don't be shy about poking/drilling holes to be absolutely
sure it is a rotten transom, it might have hit something & not been
properly repaired, not likely but
be sure.

On the assumption it is the transom, to repair you need to strip all
the machinery off the stern of the boat, motor, steering, wiring, fuel
filters/lines etc. etc. also peel the rubbing/cover rubber off for a few
feet along the hull.

Using a 4in. grinder (wear goggles & dust mask) with a metal cutting
disc;

(i) you'll probably need to remove the outboard well, this will need to
be cut where the deck is bonded onto the hull (don't try to remove any
fastenings just cut them) & unfortunately you'll need to continue the
cuts along each gunwale until level with the forward end of the outboard
well, then across to deck into the inside, now the outboard
well should lift out,

(ii) cut all around the inside of the transom where it joins the hull,
but not too deep, you only want to remove the inner skin, (if the floor
goes all the way back, cut & remove enough out to give yourself plenty
of room)

(iii) now with hammers & chisels remove the transom inner skin (try not
to destroy it too much as you can use it as a template to cut the new
transom core later on), then continue chiseling getting all the old
plywood out, now with a metal grinding disc, completely grind the entire
area until there is no trace of the old wood or it's bonding
agent attached to the transom which you will be leaving in situ, grind
along the hull sides bottom etc for a good distance to give plenty of
fresh cleanly ground area to bond to, also tidy up around the gunwale
where you removed the O/B eng. well & under the well where it bonds to
the gunwale. (keep everything all dry & clean)

(iv) Find your local fibreglass supplier, commercial not a hardware
store or such & get your materials. You will need all that is mentioned
below, except the woven cloth should be heavy, at least 800 gsm, plus
you need a new core for the transom, there are new materials
now that are very strong, bond well, don't rot & are specifically
designed for transoms, your supplier can advise, but if you are stuck
use ply again, you'll need enough to make the core 2 in thick min, you
will also need some bonding agent, (a fair bit actually) use a brand
"probond" but be guided by your supplier.


(v) The repair is as follows;
(a) using the old inner transom as a template, cut the new core to the
correct shape,
(b) completely coat the inside of the old outer transom with catalysed
probond & the outer (stern) side of the new transom core, then place the
new core into the boat, drill some holes through where the old engine
mount bolts were & bolt pre-prepared timbers inside & out, to act as a
press to get the new core well bedding in against the old outer
transom & hull perimeter, if it doesn't look right, drill some more
holes & use more bolts/wood or whatever, you only have 15-20 mins & any
extra holes in the transom can be simply repaired later.
(c) after the probond has gone off, a final tidy up with the grinder,
you can glass a new inner transom in, being careful to ensure that each
layer is glassed to the old hull & not just the layer under it. (i.e.
each successive layer travels slightly, say 1.5in. further along the
hull) Inside there is no need to "finish" it off too much.
(d) using probond, as with the transom core, replace the outboard well &
put new fastenings into the deck shelf, where you had to cut across the
deck there will be a gap the thickness of the cutting disc, put some
small nuts & bolts with biggish washers on to align the two edges, under
the deck, put some glass between the bolts, later remove the bolts
(grind them out) & glass over the holes from underneath, this area is
more than cosmetic so don't skimp under the decks.
(e) the only "finishing" needed is the two small cuts across the deck,
the original holes left in the outer transom & any additional holes you
put in the transom to help draw the new core into place.
(f) in your travels if you come across any other rot or problem in the
boat, the repair is much the same & by this time it'll be a doddle for you.

Don't hesitate to ask, the NG or your fibreglass supplier if you have a
problem with what & how it's done, "before" you start:-)


To do it properly takes a little time but doesn't cost a single cent
more as in;

(i) Aluminium is OK say;
(a) 1/4"
(b) Size/shape of the backing is up to you, usually the available space
will dictate the shape size etc, the rule is; if it looks right it
probably is:-)
(b) it's not under water as such so dissimilar metals shouldn't be an
issue (even with stainless you'd still need to ensure the same stainless
as the bolts say 316 vs 3xx or it corrodes anyway:-)
(c) aluminium is much easier to work & you can even drill it in situ
from the outside if you have a tricky nook or cranny.

(ii) Chamfer just the outer perimeter of the plates away from where
they'll pull against the hull, if you leave a sharp edge it can cut into
the outer glass under load & leave a crack in the flow or gelcoat for
water to get in.

(iii) You should try to seal inside all the through hull holes:
(a) particularly if it's the cored transom
(b) Coat the holes right through with any of the good epoxy fillers, then
(c) push the bolts back in while it's wet, having given the bolt a good
coat of grease first (dipped in candle wax works too).
(d) Once epoxy has gelled you should be able to get your bolts back out
with a spanner, leaving a good protection for the transom core (usually
plywood) & a good fit for the bolt.

(iv) When ready to put it all together again;
(a) use plenty of any of the good sealants, sadly price is a good
indicator so any marine recommended 3M or marine sikaflex (German?? not
sure) is OK.
(b) Clean the hull, parts, holes, bolts etc with solvent so the sealant
can adhere.
(c) Put all the bolts in & tighten the nuts (don't turn the bolts if
you can avoid it, it messes up the sealant) just tight enough to get all
the parts mated & snug, don't over tighten at this stage,
(d) get rid of excess squeezed out sealant with whatever solvent.
(e) Let the whole thing set for a while at least a day but longer is
OK, so the sealant can fully cure.
(f) Now you can tighten it all up, but again make sure someone holds
the bolts so they can't turn & you just tighten the nuts.

It'll be ticketyboo:-)

K