Re: [bolger] Re: Epoxy over polyester?
- Polyester peels horrible and in long flat sheets given time and water ingression between it and the wood underneath. Ring nails can help a lot, but hull shape is also important. Flat polyester sheething such as on a centerboard box will not stand. Polyester lamination on a highly curved hull, especially one with tumblehome (such as ours) will hold up much better because on curing it does shrink ever so slightly. On flat surfaces it will tend to pull free chemically even if it looks tight. On the outside of curved surfaces (convex surfaces) it will tend to pull tighter to the surface as it contracts slightly. Still, not nearly as good as epoxy but, as you and Dynamite and others have said, it is very often more than good enough.El sep 15, 2011, a las 10:42 am, daschultz2000 escribió:
--- In firstname.lastname@example.org, "etap28" <dave.irland@...> wrote:
> I have complicated feelings about polyester. It wasn't that long ago that all glass boats were built out of polyester....
Thank you for the professional input to this discussion. It certainly makes me rethink the subject. Now 60 yrs. I remember sheathing wood boats with glass/polyester resin as a teenager, and yes the resin would really set up rapidly. I don'r remember having any bonding problems. The other thing I remember doing is painting over the exposed bright wood and glass/poly with epoxy, then, after a thorough washing and light sanding, using oil based paint on the sides and lower hull and spar varnish on the bright work. That finish held up for years on a trailer boat, stored in a garage when not in use a few weeks a year.
- In his book he did restore sailing yachts with it - his stories include one being indestructable until it got cut in half by a steamer off shore.El sep 17, 2011, a las 5:06 pm, John Kohnen escribió:Vaitses's method was intended to get some more years of working out of
fishing boats and other workboats. I don't think I ever read of him
touting it for yachts.
A fellow I knew got ahold of a nice-looking British built double-ended
sailboat that had been cold-molded over. The work had been done in Port
Townsend, wooden boat capital of the west. That doesn't mean that
_everyone_ in Port Townsend knows what they're doing. <g> One day he cut
or drilled into the hull to mount something, and after he got through the
cold-molded outer shell he ran into -- compost! :o( From the outside the
boat looked great, from the inside it looked OK, in between was a layer of
very rotten wood, sandwiched between the cold-molded shell and a thin
layer of good wood on the inside of the planks. <sigh> He ground off the
cold-molded shell and discovered that just about every plank needed to be
replaced. He never got very far into the project before he lost heart, and
the boat was eventually broken up by the boatyard. If he'd never cut
through the outer shell maybe he'd have gone voyaging, and maybe the boat
would have brought him back. <shrug> After he knew that there wasn't much
of anything holding that outer shell to the rest of the boat he didn't
dare take her to sea.
The example many people give of a boat that was cold-molded over
successfully is a British cutter that spends most of its time around South
Georgia -- where it's _cold_ and the rot spores are probably in
hibernation. <g> I'd be very suspicious of any traditionally built wooden
boat that had been covered with glass, using polyester or epoxy, or had
been shelled with cold-molding.
On Thu, 15 Sep 2011 09:27:44 -0700, dave wrote:
The vaitses method always makes me cringe when I hear about it. I guess
in the case of a boat with a really terminal hull, great interior and
great rig.... it might,just might, pay to do that, but if you're going
to build a new hull over the old one, why not cold mold? The part
nobody's talking about is fairing the new polyester hull. That's a huge
labor investment, unless you just don't care and decide to paint the raw
polyester, in which case you've built yourself a totally unsaleable
hulk. Either way, you've built yourself a totally unsaleable boat, so
you better love it for the 15 or so years it'll last before that
well-sheathed rot finishes its business; but if you fair it, at least
it'll look like a boat.
A fool and his money are soon elected. (Will Rogers)
- NO "GO AWAY SPAMMER!" posts!!! Please!
- no cursing, flaming, trolling, spamming, respamming, or flogging dead horses
- stay on topic, stay on thread, punctuate, no 'Ed, thanks, Fred' posts
- Pls add your comments at the TOP, SIGN your posts, and snip away
- Plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA, 01930, Fax: (978) 282-1349
- Unsubscribe: email@example.com
- Open discussion: firstname.lastname@example.org Yahoo! Groups Links
<*> To visit your group on the web, go to:
<*> Your email settings:
Individual Email | Traditional
<*> To change settings online go to:
(Yahoo! ID required)
<*> To change settings via email:
<*> To unsubscribe from this group, send an email to:
<*> Your use of Yahoo! Groups is subject to: