Epoxy VS Polyester Resin
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Boat Maintenance
Forum Discription: Discuss maintenance of your Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=17758
Printed Date: November-18-2024 at 12:41pm
Topic: Epoxy VS Polyester Resin
Posted By: 80tiquefan
Subject: Epoxy VS Polyester Resin
Date Posted: May-27-2010 at 6:16pm
Just wanting to know opinions on epoxy and polyester resins and which to use for stringer replacements and why.
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Jason Murray
http://www.correctcraftfan.com/diaries/details.asp?ID=4217" rel="nofollow - 1980SkiNautique
1993 Sport Nautique
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Replies:
Posted By: horkn
Date Posted: May-27-2010 at 7:44pm
Well, polyester resin is hydrophyllic, and epoxy resin is not.
So when polyester resin wants to absorb water, epoxy resin will not.
I would go with epoxy resin in a heartbeat over polyester, although when I redid the floors of mine, I used polyester. I did not have the stringer rot like many here have.
I built a 200 gallon aquarium out of epoxy resin and plywood with a glass front panel last spring, and the epoxy was a snap to use compared to polyester resin. Plus epoxy once cured is inert, meaning it can't leach crap into the water. That's not an issue with a boat, but it was on a coral reef tank.
I got mine from UScomposites. They have great prices and great customer service.
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78 martinique- refloored, reinforced, stringers re glassed, re engineered interior
GT40P heads Edelbrock Performer intake acme 4 blade
http://img.photobucket.com/albums/v64/horkn/fish/nautique.jpg
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Posted By: Waterdog
Date Posted: May-27-2010 at 7:54pm
The only reason to use polyester resin is you can't afford epoxy. If you use epoxy amine cured epoxies and the tuffest, sometimes a pain (amine blush) but the best for wet lay-up.
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- waterdog -
http://www.correctcraftfan.com/diaries/details.asp?ID=3896&sort=&pagenum=2&yrstart=1978&yrend=1978" rel="nofollow - 78 Ski Tique
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Posted By: srbranum
Date Posted: May-27-2010 at 8:15pm
I would never use poly based on my past experience. Another non Correct Craft project was almost ruined when the poly delaminated after numerous times getting wet. I had bought it at home depot and did not know what I was doing.
I spent about $1000 from Larry at www.raka.com and they too are great. You can discuss your project with them and they ship almost immediately. Larry even comes in on saturdays and sundays and I have called him with questions on weekends and he is more than happy to talk with me.
Scott
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I have to keep her running 'cause I can't afford a new one
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Posted By: form&function
Date Posted: May-28-2010 at 12:41pm
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Boats have been made from poly since the dawn of fiberglass boat building and remained king until the advent of vinyl then epoxy in the early nineties.Poly may be hydroscopic but very mildly so and cannot take on water in any measurable amount.Epoxy can also have problems with adhearing to other resins and is not as flexable as poly making it more suseptable to cracking.I use the rule of thumb that whatever the boat was made of is what should be used for repair.
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Posted By: sanity
Date Posted: May-28-2010 at 1:19pm
Ryan,
I agree with you to some extent. We used both on the 66 Mustang when doing the stringers and I made repairs to the hull using only the poly with cabosil. My thoughts, as silly as they may seem, was that the poly would adhere to poly the best. When that cured, epoxy was used. The important thing is to remember that epoxy will adhere to poly/ poly will not adhere to epoxy.
Chelle'
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Posted By: DrCC
Date Posted: May-28-2010 at 2:57pm
There is more to it than just epoxy vs poly. Mat vs cloth. If you want the optimum "stick" you have to use mat.
I will not use fiberglass cloth for anything.
AT
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Posted By: 80tiquefan
Date Posted: May-28-2010 at 7:05pm
Still a long way from needing the epoxy or polyester. Just getting started pulling the floor to see the amount of damage. I'm still not a hundred percent sold though on which to use. Will the epoxy adhere to the hull very well? What are the disadvantages of using the poly. Is it that much more difficult to use.
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Jason Murray
http://www.correctcraftfan.com/diaries/details.asp?ID=4217" rel="nofollow - 1980SkiNautique
1993 Sport Nautique
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Posted By: form&function
Date Posted: May-28-2010 at 9:49pm
For the floors I might consider epoxy but if your regelling poly is my choice.Like dr.cc said theres alot more to it than gell.
I could be wrong but the last two new boats I owned had very poor gell with visible repairs all over them.Sometime in the later part of this decade epoxy was required to meet voc compliances and as a result I beleive it suffered in quality.
I have the same problem with the deisel they sell nowadays.
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