Brian Whatcott wrote:
On Mon, 21 Nov 2005 10:49:53 +1100, "d parker"
wrote:


"News f2s" wrote in message
...

///


Well, once a month I take a swim with a wire brush, take a few deep
breaths and the see how long I can stay underwater hanging on to the prop
shaft. But then I'm in warm water (never less than 18C) and it's clean and
clear.

Sorry, didn't really answer your question, but that's my conventional
wisdom on the subject.

JimB


hmmm... Ever thought of attaching a regular snorkel to some larger hose?
Vacuum hose is great with a float at the loose end. You can stay down a lot
longer. Some of the co2 you exhale will get re-inhaled each time. I havent
passed out yet though.. Fingers crossed.

DP



How about a y fitting from the snorkel to two vacuum hoses, the float
on one would have a caged ping pong ball for an outflow only
and the float on the other would have a soft sprung flapper for an
inflow only??

Brian Whatcott Altus OK


All you need is an exhalation valve at the mask, and an iron lung to
enable you to suck air below about 4 feet. Try it, just suck in
through the mouth using a harden hose and exhale through your nose.
Good luck.

Or a powered snorkel pump on a float on the surface, know as a
hooka, and some dive weights.

Terry K

"Terry Spragg" wrote in message
...
Brian Whatcott wrote:
On Mon, 21 Nov 2005 10:49:53 +1100, "d parker"
wrote:


"News f2s" wrote in message
...

///


Well, once a month I take a swim with a wire brush, take a few deep
breaths and the see how long I can stay underwater hanging on to the
prop shaft. But then I'm in warm water (never less than 18C) and it's
clean and clear.

Sorry, didn't really answer your question, but that's my conventional
wisdom on the subject.

JimB


hmmm... Ever thought of attaching a regular snorkel to some larger hose?
Vacuum hose is great with a float at the loose end. You can stay down a
lot longer. Some of the co2 you exhale will get re-inhaled each time. I
havent passed out yet though.. Fingers crossed.

DP


How about a y fitting from the snorkel to two vacuum hoses, the float
on one would have a caged ping pong ball for an outflow only
and the float on the other would have a soft sprung flapper for an
inflow only??

Brian Whatcott Altus OK


All you need is an exhalation valve at the mask, and an iron lung to
enable you to suck air below about 4 feet. Try it, just suck in through
the mouth using a harden hose and exhale through your nose. Good luck.

Or a powered snorkel pump on a float on the surface, know as a hooka, and
some dive weights.

Terry K


Yeh the harden hose is difficult at longer lengths. So is garden hose. Thats
why, in my initial post, i recomened a larger diameter hose you see

DP

On 20 Nov 2005 20:44:21 -0600, Dave wrote:

I did just what you're proposing last year. When the boat was hauled both
the bottom paint and the barrier coat were gone, and the prop covered with
barnacles.

=============================================

There are primers and paints that work well, even here in SWFL, so do
not take a defeatist position. My props and running gear were done by
Olsen's in Ft Myers Beach last year and they have done extremely well.
The primer they use is multi-step and bright yellow as they are
applying it. Other than that I don't know what it is.

Here are the Interlux recommendations:

http://tinyurl.com/8mdqx

On Sun, 20 Nov 2005 19:08:32 -0500, "Garland Gray II"
wrote:

"Bil" wrote in
On 20 Nov 2005 08:46:07 -0800, "beaufortnc"
wrote:

Hi,

I'm prepping the bottom of my sailboat for barrier coat then ablative
bottom paint.

I'm thinking, however, that it might be a good idea to paint the prop
with something like Trinidad instead of ablative. It seems to me that
the ablative won't last long on the prop.

What's the conventional wisdom here?

What you use on your prop depends on your pattern of boating. Regular
boat use, eg once or more a week, can mean no special treatment
(depending on your local level of fouling). And on your prop: whether
bronze or stainless steel or plastic etc. And on other characteristics
of your prop, eg whether it's a surface prop, such as a Levi drive; or
a deep prop; whether it's spinning at around 1,000 rpm or two or three
times faster.

If you have a new bronze prop, waxes applied during the polishing
process can mean that no permanent treatment works until that wax is
removed and, perhaps, an etch primer is used.

Some treatments that do work:

* Grease the prop: if you are cruising, but anchor or berth for up to
a month, coating the prop with a salt-water resistant grease works
(for about a month). I use a German-made grease, Bechem SW2, and send
the cook over the side after taking a berth or anchorage. The grease
spins off, taking any slime etc with it. No chance that it can change
the balance of the prop.

* Bagging the prop: a physical barrier, such as a plastic bag, works.
But you have to send the cook (or the cook's assistant) over the side
twice, once to install the bag, once to remove it.

* Painting with an antifouling. Whether you use a hard or ablative
antifouling matters little; the problem is getting the paint to
adhere. New props are a problem, because of the waxes. Older props
work better. And the primer/paint combination is important.

One technique that works is to use an epoxy primer and to follow,
within the prescribed recoating time (usually about an hour, before
the epoxy primer has completely hardened) with antifouling. The next
step is important: then leave to harden completely (ie about one week
- any sooner and the primer will spin off).

I've also used a zinc chromate primer, with some -but not complete -
success.

* Commercially applied silicon coatings. Expensive (applying yourself
is not a good as paying the experts to apply). But works in many
conditions, especially if the boat is used fairly often.

Bil,
This was very informative.
Regarding your suggestion of epoxy primer followed by antifouling, which
expoxy primer do you recommend, and what kind of antifouling ?
I have saildrives with folding props. At last haulout I followed each of the
many steps (Interlux Primecom as one layer comes to mind) required, but this
seems simpler.
Thanks.

Garland:

I always beg epoxy primer from the yard which has hauled me out - the
prop does not need much and I usually have no other use for it. So I
take whatever the yard has in terms of left over epoxy primer.

My sailboat is currently wearing International Micron Extran
(International is called Interlux stateside), so that's the antifoul I
use.

To reiterate, the important steps a 1. to apply the antifouling
onto the epoxy primer before the epoxy has dried (usually the
manufacturer will detail the timing on the package); and 2. to leave
the epoxy/antifoul to harden for at least a week.

I have two props, a 2-blade and a 3-blade, so I antifoul whichever is
not on the prop shaft (because I am usually on the hard for only 3
days - and that is not long enough for the primer/antifoul coatings to
harden).

Cheers

"Terry Spragg" wrote in message
...
Well, once a month I take a swim with a wire brush, take a few
deep breaths and the see how long I can stay underwater
hanging on to the prop shaft. But then I'm in warm water
(never less than 18C) and it's clean and clear.

hmmm... Ever thought of attaching a regular snorkel to some
larger hose? Vacuum hose is great with a float at the loose
end. You can stay down a lot longer. Some of the co2 you exhale
will get re-inhaled each time.

How about a y fitting from the snorkel to two vacuum hoses, the
float
on one would have a caged ping pong ball for an outflow only
and the float on the other would have a soft sprung flapper for
an
inflow only??

All you need is an exhalation valve at the mask, and an iron
lung to enable you to suck air below about 4 feet. Try it, just
suck in through the mouth using a harden hose and exhale through
your nose.

OK. Full story. Snorkel is attached to a long hose which goes up
to the deck. Mask covers nose and eyes only. I breath out through
the nose (which then bubbles out through the edges of the mask,
good one way valve) and breath in through the snorkel. No need for
any balls (unless the alligators are hungry). I've scrubbed a
whole bottom this way.

But I don't recommend anyone doing this unless they do some
shallow water practice first, sitting in a pool. Ask a friend (!)
to disconnect/block/duck the hose end into the water at random
times to familiarise yourself with recovery routines. Then do this
deeper. The purpose of these practice sessions, which you should
do several times, is to get the feel of an imminent mouthful of
water coming down the line, and develop routines to reduce your
panic levels when it happens. Otherwise, feeling that gurgle in
the pipe when you've just breathed out is quite a downer . . .
don't ask.

Oh, and have someone on deck looking out for you, with a bit of
string to give you a couple of tugs if you should quickly come up
for some reason.

JimB

This stuff will work, but is expensive: http://www.propspeed.com/

In article . com,
says...


Hi,

I'm prepping the bottom of my sailboat for barrier coat then ablative
bottom paint.

I'm thinking, however, that it might be a good idea to paint the prop
with something like Trinidad instead of ablative. It seems to me that
the ablative won't last long on the prop.

What's the conventional wisdom here?

If you dispense with zincs, the copper ions migrazting into the water
will keep your prop totally free of growth. Of course, pretty soon you
won't have any prop at all. Problem soilved.

In article ,
d parker wrote:
All you need is an exhalation valve at the mask, and an iron lung to
enable you to suck air below about 4 feet. Try it, just suck in through
the mouth using a harden hose and exhale through your nose. Good luck.

Or a powered snorkel pump on a float on the surface, know as a hooka, and
some dive weights.

Terry K


Yeh the harden hose is difficult at longer lengths. So is garden hose. Thats
why, in my initial post, i recomened a larger diameter hose you see

When I was a kid, we decided to try this at the bottom of a swimming
pool. I volunteered to be try breathing with the hose. There were four
of us. I went below with the hose, then the other three kids took deep
breaths and blew into the hose topside. I was able to extend my bottom
time by about 2 minutes, until they got winded and I got dizzy. Well,
I'm still hear and probably didn't damage too many brain cells.


--
"j" ganz @@
www.sailnow.com

Jonathan Ganz wrote:
In article ,
d parker wrote:

All you need is an exhalation valve at the mask, and an iron lung to
enable you to suck air below about 4 feet. Try it, just suck in through
the mouth using a harden hose and exhale through your nose. Good luck.

Or a powered snorkel pump on a float on the surface, know as a hooka, and
some dive weights.

Terry K


Yeh the harden hose is difficult at longer lengths. So is garden hose. Thats
why, in my initial post, i recomened a larger diameter hose you see


When I was a kid, we decided to try this at the bottom of a swimming
pool. I volunteered to be try breathing with the hose. There were four
of us. I went below with the hose, then the other three kids took deep
breaths and blew into the hose topside. I was able to extend my bottom
time by about 2 minutes, until they got winded and I got dizzy. Well,
I'm still hear and probably didn't damage too many brain cells.


Damaged them enough to use hear instead of here.

Thanks !

"Bil" wrote in message
...
On Sun, 20 Nov 2005 19:08:32 -0500, "Garland Gray II"
wrote:

"Bil" wrote in
On 20 Nov 2005 08:46:07 -0800, "beaufortnc"
wrote:

Hi,

I'm prepping the bottom of my sailboat for barrier coat then ablative
bottom paint.

I'm thinking, however, that it might be a good idea to paint the prop
with something like Trinidad instead of ablative. It seems to me that
the ablative won't last long on the prop.

What's the conventional wisdom here?

What you use on your prop depends on your pattern of boating. Regular
boat use, eg once or more a week, can mean no special treatment
(depending on your local level of fouling). And on your prop: whether
bronze or stainless steel or plastic etc. And on other characteristics
of your prop, eg whether it's a surface prop, such as a Levi drive; or
a deep prop; whether it's spinning at around 1,000 rpm or two or three
times faster.

If you have a new bronze prop, waxes applied during the polishing
process can mean that no permanent treatment works until that wax is
removed and, perhaps, an etch primer is used.

Some treatments that do work:

* Grease the prop: if you are cruising, but anchor or berth for up to
a month, coating the prop with a salt-water resistant grease works
(for about a month). I use a German-made grease, Bechem SW2, and send
the cook over the side after taking a berth or anchorage. The grease
spins off, taking any slime etc with it. No chance that it can change
the balance of the prop.

* Bagging the prop: a physical barrier, such as a plastic bag, works.
But you have to send the cook (or the cook's assistant) over the side
twice, once to install the bag, once to remove it.

* Painting with an antifouling. Whether you use a hard or ablative
antifouling matters little; the problem is getting the paint to
adhere. New props are a problem, because of the waxes. Older props
work better. And the primer/paint combination is important.

One technique that works is to use an epoxy primer and to follow,
within the prescribed recoating time (usually about an hour, before
the epoxy primer has completely hardened) with antifouling. The next
step is important: then leave to harden completely (ie about one week
- any sooner and the primer will spin off).

I've also used a zinc chromate primer, with some -but not complete -
success.

* Commercially applied silicon coatings. Expensive (applying yourself
is not a good as paying the experts to apply). But works in many
conditions, especially if the boat is used fairly often.

Bil,
This was very informative.
Regarding your suggestion of epoxy primer followed by antifouling, which
expoxy primer do you recommend, and what kind of antifouling ?
I have saildrives with folding props. At last haulout I followed each of
the
many steps (Interlux Primecom as one layer comes to mind) required, but
this
seems simpler.
Thanks.

Garland:

I always beg epoxy primer from the yard which has hauled me out - the
prop does not need much and I usually have no other use for it. So I
take whatever the yard has in terms of left over epoxy primer.

My sailboat is currently wearing International Micron Extran
(International is called Interlux stateside), so that's the antifoul I
use.

To reiterate, the important steps a 1. to apply the antifouling
onto the epoxy primer before the epoxy has dried (usually the
manufacturer will detail the timing on the package); and 2. to leave
the epoxy/antifoul to harden for at least a week.

I have two props, a 2-blade and a 3-blade, so I antifoul whichever is
not on the prop shaft (because I am usually on the hard for only 3
days - and that is not long enough for the primer/antifoul coatings to
harden).

Cheers