Hey gang, quick question. Im about to restore the stringers and the deck on my 85 Vl475 as was wonder if you guys would recommend Epoxy or Polyester resin for the glass work. I know epoxy is typically the best but I wasn't sure if the original was polyester. I was under the impression that Epoxy wouldn't stick to Polyester or is it the other way around??? Thanks gang any additional thoughts would be greatly appreciated!!
The boat was originally built with Polyester resin. Either resin will do the same job, Epoxy will bond fine with Polyester resin. Now, if the area need to be gelcoated on top of the repair, then Polyester will be the best bet as gelcoating over Epoxy resin does not form as strong of a bond as it does over polyester resin.
Either resin will bond strong to the original polyester as long as the prep work is good. Advantage with Epoxy is it is more glue like than polyester, but also has to be mixed fairly accurately to achieve this. Polyester is more forgiving in the catalyst/resin mix.
Epoxy resins also can be 2 - 4 times the cost of the polyester resin.
Carpet glue does not like to bond to epoxy resin either, I use vinyl ester resin for everything I do. Bonds better than polyester and is stronger than polyester or epoxy.
Les Mahan - STROKER 250 MERC
Actually, Epoxy is the strongest resin you can use for either building or repair work. The tensile strength is beyond that of any of the Polyester resins,( laminating or Vinyl.)
The drawback is the price essentially double for the products as you go up the strength ladder.
Polyester being the cheapest, Vinylester 50 % more than Polyester and Epoxy generally 50 % more .
If both type resins are prepped correctly and cured right, Epoxy resin has more than twice the strength of Vinylester resin.
but at twice the cost.
Epoxy resins have advantages over polyester and vinylesters. Better adhesive properties (the ability to bond to the
repair)
Superior mechanical properties, much stronger.
Improved resistance to fatigue and micro cracking
Epoxy is also the best to use in any area where sitting water will be a problem, as it is almost impermeable to water vapor.
Vinylester is a step above Polyester, but below Epoxy resin.
The strength on a secondary mechanical bond for Vinylester is around 500 PSI, for Epoxy it is around 2000 PSI.
I agree the mechanical bond of epoxy resin is much better but the tensile strength of vinyl ester is stronger. West systems epoxy resin is about 8,000 psi tensile strength, us composites vinyl ester resin is about 12,000 psi tensile strength for example.
Ps, make sure you use epoxy resin for all your bonding (vinyl ester has to be exposed to cure correctly) then use vinyl ester to lay up. I would call uscomposites, they are very helpfull and the cheapest around that I have found.
Les Mahan - STROKER 250 MERC
Vinylesters where great for boat hulls to prevent stress cracking ( and Osmosis ), but since being outlawed by the EPA a few years ago for use by boat builders because of High VOC's they have not yet found a suitable replacement that does not cost a fortune.
Last edited by BASSCAT7; 12-10-2012 at 06:43 PM.
Erubash, I would call us composites (561)588-1001. They will walk you through everything you need and everything you need to do, and you can ask them what is stronger and best for your application. Good luck with your project, those older hydrasports are runners.
Les Mahan - STROKER 250 MERC
Vinylester resin is still available for consumers, your custom boat builders, bullet - allison - stroker etc are using epoxy modified vinyl ester (very expensive) most boat companies still use polyester.Originally Posted by BASSCAT7
Les Mahan - STROKER 250 MERC
Hey guys, thanks a bunch. I apologize for not responding my father in-law had a heart attack and i've been at the hospital all week. Anyhoo, based on this information you guys have said I could realistically do the entire project with polyester but for maximum strenght and adhesion epoxy or vinyl ester is a better alternative. Based on this info here's my plan:
1. Prep Hull for bonding by sanding down to org fiberglass with 80 grit. Vacuum and clean with Acetone let dry completely.
2. Coat and Seal all wood including Stringers new bulkheads and deck with Polyester thinned with Acetone
3. Bond in Stringers with Epoxy
4. Use vinyl ester for layup and tabbing of Stringer to hull.
Anything You guys can think of IM leaving out?
Thanks again for the response's, you guys rock. FYI my Father in law had Quintuple bypass Friday and is doing great in case you wondered!
Hey guys, thanks a bunch. I apologize for not responding my father in-law had a heart attack and i've been at the hospital all week. Anyhoo, based on this information you guys have said I could realistically do the entire project with polyester but for maximum strenght and adhesion epoxy or vinyl ester is a better alternative. Based on this info here's my plan:
1. Prep Hull for bonding by sanding down to org fiberglass with 80 grit. Vacuum and clean with Acetone let dry completely.
2. Coat and Seal all wood including Stringers new bulkheads and deck with Polyester thinned with Acetone
3. Bond in Stringers with Epoxy
4. Use vinyl ester for layup and tabbing of Stringer to hull.
Anything You guys can think of IM leaving out?
Thanks again for the response's, you guys rock. FYI my Father in law had Quintuple bypass Friday and is doing great in case you wondered!
Glad your FIL is doing well.
On the boat rehab, there is no reason to use 3 different resins, pick one that is in your cost range and use that one, as long as the prep work on the area you are bonding to is done right, any of them will work and do the job.
Your prep work list looks good.
The question was what should be used to do the repair, epoxy or polyester, in reality it will make no difference which one gets used, they are both up the job.
You can under or over build either one, and as far as the bond, the prep work is the same for each product and while the bond with epoxy is slightly better, the bond with Polyester isn't bad, it is actually quite strong and durable with proper prep.
If you are going to gelcoat on top of the repair, I would use the Polyester as gel is easier to lay over polyester. if you are going to paint over the repair, I would use epoxy.
THanks, I was under the impression that you couldn't laminate Wood with Epoxy resin only Polyester thinned with Acetone will penetrate the wood fibers?? If i can laminate with epoxy I'll just use that throughtout. Guys got any good links to Deck Extension Ideas as well! Would love to see them! Also Im not painting or Gelling the Deck, once finished I've decided to put truck bed liner down for an extra layer of protection. I ripped up the carpet on my father in laws boat last year and sprayed his entire deck with it, topped it with two coats of clear and still looks brand new today. FYI just to be clear when I say Deck I mean "Floor Deck" not "Top Cap Deck".
Thanks again you guys rock!
I have laminated with epoxy and had good results.
If at first you don\'t succeed,dont take up skydiving
Epoxy is an excellent wood sealer.
I would use epoxy for laminating, if you are going to use polyester I would thin with styrene. Some times when you thin polyester with acetone it does not cure quite as hard.
Les Mahan - STROKER 250 MERC
I used epoxy resin for my complete restoration. It worked really well. I used us. composites.
You might check, but hydrasports used kevlar in vl465's and x270's in the mid 80's,not all hulls but alot of 'em
If you aren't gelcoating, then epoxy is prolly your best chit for fabricating/layup, personally , i think it covers anything and everything better.,as in compatible with various putty's /epoxy primers /paints etc. And seals wood and composites just fine, and as stated earlier is impermeable to water intrusion in bilges and core areas.
They did but it was more for Marketing of the boats than it was a structure strenght idea. My understanding is they put kevlar in 4 different spots on the boat and as long as they had a certain amount of Kevlar, Kevlar would allow them to Stamp the boat. It worked, they sold a lot of boats because of that stamp. Great boats with or without the stamp in my opinion! Thanks for the input though!
Thanks again guys, Im starting the project in January. I'll post some pics before I do. Still looking for Deck Extension plans if anybody has any input! I got a $250 Bass Pro gift card for Christmas, that's burning a hole in wallet!
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