View Full Version : suitable adhesives
02-07-2005, 01:51 PM
hi all, I have a carpenter friend doing some structural work on a 54 ft. trawler for me and he insists on useing liquid nails subfloor adhesive for all the wood to wood contacts. He also likes coated steel exterior deck screws and just nothing else will do. He also does not like the system three epoxy, prefering good old polyester resin- easier to use. Cost is not a factor but ease of use is, stength, longevity and my personal knowledge of a job done right are the most important considerations. What would you use ?
02-07-2005, 03:03 PM
Originally posted by kulas44:
hi all, I have a carpenter friend doing some structural work on a 54 ft. trawler for me and he insists on useing liquid nails subfloor adhesive for all the wood to wood contacts. He also likes coated steel exterior deck screws and just nothing else will do. He also does not like the system three epoxy, prefering good old polyester resin- easier to use. Cost is not a factor but ease of use is, stength, longevity and my personal knowledge of a job done right are the most important considerations. What would you use ?Perhaps a shipwright.. one who is more familiar with products used in the ship building trades rather than house construction etc. Some of the products will obviously overlap but there is some difference especially when considering not only exterior conditions but with salt added.
The liquid nails will probably work fine though there are others like 3M marine adhesives 5200, 4200 etc. that are proven marine products.
02-07-2005, 03:06 PM
Liquid Nails is fine for house work, but it is not rated for continous moisture. If you want a reliable adhesive in the tube for any marine application, 3m 5200 or similiar is the way to go.
Coated steel deck screws are ok for house work, but I wouldn't put anything in a boat that was not at least hot dipped galvie. Deck screws are definitely not rated for continous moisture, and I've seen them wasted away in short order when used in a boat. If it is an interior installation though, you might get away with it. Assuming it's not anywhere near where water can get in. Yes, house-decks get hit with water, but boats are a whole different animal. For peace of mind, assuming the fasteners are exposed to the air, good quality marine stainless would be good too.
Polyester resin absorbs moisture, epoxy does not (though it does transmit a small amount). If he is using poly resin to encapsulate wood surfaces, expect them to rot underneath at some point in the future, since poly resin does not form a decent bond with wood. Poly resin has been used successfully to sheathe boats, but Alan Vaistes method leaves the inside of the boat uncoated so the wood can breathe out moisture.
All that being said, people have done boaty things with all these materials in the past and they sufficed for the purpose intended. If you want a truly reliable and long lasting finish though, I would use materials more intended for the purpose.
You say 'structural work'.. what sort of structural work? And what sort of fasteners are already in the boat? What sort of wood? We'd need to know more details before being more authoritative. smile.gif
Tell him instead of using liquid nails, to use P.L.Premium it is 100% waterproof, liquid nails is not. Don't use steel screws, even the coated ones, instead use stainless steel screws.
These are on the same shelf at your local home depot, right beside the other stuff.
Much better choice.
02-07-2005, 03:52 PM
'Fraid you're digging yourself into a serious hole if the work has progressed very far and that boat will ever see salt water.
Use marine-rated and marine-proven sealants...not carpenter goo.
Fasteners should conform to what's original to the boat. Galvanized and/or bronze where they belong and SS where it belongs. Coated deck screws are literally criminal in structural applications on a salt water boat.
Good luck finding a polyester that adheres well to wood these days. Epoxy is better and wiser in every way imaginable.
02-07-2005, 04:06 PM
none of the work he will be doing is exposed to saltwater, it's almost entirely interior, mostly deck beams right now. The boat had a lot of rot at the clamp around the deck edges that also rotted the ends of the laminated deck beams, caused by deck leaks. I will be refiberglassing the deck myself and applying the sanitred deck coatings. The guy doing the carpentry is a very good friend of mine and does excellent work, I just don't think he has done his homework, or researched the products he is useing. The boat is 30 years old and built useing silicon bronze screws and anchorfast nails, I would be willing to go back with the same. I also like PL Premium adhesive and have used a lot of it on other projects with good results (but let's not tell everyone, the price might go up). I also like to use a lot of Cuprinol but he has never heard of it and doesn't like it on that basis.
Tell him that you are going to ask him and his first born to go on the shake down cruise when you finally launch this. He might find that he will be more comfortable with the best materials that are to be found. Remember " nothing too strong ever broke."
02-07-2005, 04:53 PM
You should print this thread out and show it to your good carpenter friend, maybe he will see the light. The marine hardware, goo and epoxy suitable for your project is most likely very little more money than the non marine type stuff he is useing. I can't imagine anybody actually wanting to use polyester resin instead of epoxy.
02-07-2005, 05:51 PM
HEY CLEEK. These guys are being gentle with kulas44. It might help to have a little of your, um, conciseness.
Everyones being so polite... read between the lines.
If you don't listen to the advice given here, then you will regret it...or make a total nightmare for the next owner. Its pretty straight forward, use the proper materials or your just making a temporary fix...that will not last.
Using polyester resin on any wooden boat repair compared to epoxy is absurd. Epoxy is very easy to use. If done properly she will last longer than you will be alive.
When glassing the deck you should use epoxy...period...perhaps sheath with dynel cloth atop a layer of fiberglass cloth even better.
I think you need to do a bit of homework to get the "boatbuilder mindset" which pushes one to superlative methods simply because they are necessary in boatbuilding.
[ 02-07-2005, 06:00 PM: Message edited by: RodB ]
I'll repeat a statement that I made somewhere sometime back " How comfortable will you be with these repairs when you are weathering a storm at night?"
02-07-2005, 08:34 PM
The words between the lines:
He's about to screw your boat up.
02-07-2005, 09:55 PM
I guess I do not have anything to add except refer to all of the above.
Anything more said will be like trying to potty train a duck.
It either takes or it don't.
As the Coasties say,"Please wear your PFD, it makes it easier to find your body."
02-09-2005, 03:11 PM
Can polyester resin work when applied to wood on seagoing vessels? Absolutely. Can such vessels be long lived? Yes they can. Commercial boats have proven this since at least when I apprenticed as a Shipwright in the early 70's.
But you got to know what you are doing: To give long life, polyester resin must be correctly mixed, correctly formulated, correctly applied, correctly cured and correctly protected from UV light damage.
Incorrect mixing will lead to osmotic blistering.
Incorrect formulation may be too brittle, allowing cracks to develop as the wood moves due to temperature changes and moisture changes. This means you have to choose the right polyester resin.
Incorrect surface prep and application will lead to poor bonding and delamination as well as potential water intrusion. If not cured at the correct temperature and humidity for the correct amount of time, un-bonding from the surface can occur as well as porosity that allows water intrusion.
Failure to protect polyester resin from UV light will seriously damage it in a matter of weeks. (Most epoxies too)
So why use epoxy when polyester will work?
1) Epoxy requires less stringent surface prep.
2) Epoxy is a more tenacious resin. This allows many flaws in preparation and application without reducing bond to the surface too much.
3) Epoxy swells less with water absorption producing less degradation of mechanical properties. i.e. it is stronger when wet.
3) Many epoxies are better moisture barriers than polyester resin.
In a nutshell, application of epoxies formulated for boat building is less demanding than using polyester. So unless your carpenter is an expert at building marine structures with polyester resin (i.e. a Shipwright), he should stick to epoxy.
02-09-2005, 04:52 PM
A house is but a poorly built boat so hard aground as to be totally immovable.
And if there is any doubt about this just look at how quickly a house disintegrates in a hurricane. A (wooden) boat may sink but it generally stays in one piece. Unless, of course, it is driven onto the rocks or a seawall.
/// Frank ///
[ 02-09-2005, 04:53 PM: Message edited by: Frank Wentzel ]
02-09-2005, 05:36 PM
Now SSOR....dunno make the bad remarks like the duck one...won more than a few bbq dinners from my brother the minister over such things.
A while back a member of his church wuz gonna potty train his new chimp...I bet him he wouldn't succeed...and we extended his training time twice...finally i told him why it wuz impossible.........and the BBQ wuz really more better that way.....
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