I recently purchased a 1975 Lancer 25. Overall the boat is in good condition for it's age, but it does need some fiberglass repair in the aft well. I am also considering permantly glassing in the "door" in the stern where the outboard mounts. Question, which resin sould I use? epoxy or polyester?
Which resin to use for repairs
- Thread starter mmsaws
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Either will work fine. Polyester is cheaper and requires you to remove the "blush" between layups that have hardened. It is also effected by water more than epoxy.
I prefer epoxy on boats because of better water resistance and removing the blush in those crazy curvy parts at the bottom of the locker while standing on my head is just a real PITA.
Defender.com has good deals on fiberglass scraps and resin. Also get the dispenser pumps. They take almost all the pain out of mixing correct dosages of resin and hardener. They also provide a resin that sets up consistently and does not harden faster or slower than the last batch. Takes the "time to set" venerable out of the equation.
I prefer epoxy on boats because of better water resistance and removing the blush in those crazy curvy parts at the bottom of the locker while standing on my head is just a real PITA.
Defender.com has good deals on fiberglass scraps and resin. Also get the dispenser pumps. They take almost all the pain out of mixing correct dosages of resin and hardener. They also provide a resin that sets up consistently and does not harden faster or slower than the last batch. Takes the "time to set" venerable out of the equation.
Just a few words on the differences between polyester resin and epoxy. When it comes to fiberglass repair polyester does not have the adhesive strength that epoxy has, but epoxy will break down under UV if it isn't painted or in someway protected from the sun. Also, gel coat and polyester resins will not adhere to epoxy. That is; You can apply epoxy to polyester surfaces, but you can not apply poly to epoxy surfaces. I recommend the FIBERGLASS BOAT REPAIR MANUAL by Allan H. Vaitses or SAILBOAT HULL & DECK REPAIR by Don Casey. Both of these books give a good how-to for fiberglass repair.
Duke
Duke
epoxies
Tow places to learn about epoxies are West Systems and their epoxyworks magazine on the web.
Another is a crazy web site but good source of marine epoxy,
http://www.epoxyproducts.com/
Progress makes a epoxy cleanup product worth getting. It is their TA 661.
That stuff cleans up good. It allow getting two or three uses from chip brushes, which is handy when making small repairs and cleaning up between projects.
They sell a plastic quart bottle which I tried and then got the gallon jug. Also works cleaning bottom paint brushes and varnish brushes. Worth a few shekels.
This subject has been discussed many times on this forum with many offering good input. Check out archives by subject.
Ed K
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Tow places to learn about epoxies are West Systems and their epoxyworks magazine on the web.
Another is a crazy web site but good source of marine epoxy,
http://www.epoxyproducts.com/
Progress makes a epoxy cleanup product worth getting. It is their TA 661.
That stuff cleans up good. It allow getting two or three uses from chip brushes, which is handy when making small repairs and cleaning up between projects.
They sell a plastic quart bottle which I tried and then got the gallon jug. Also works cleaning bottom paint brushes and varnish brushes. Worth a few shekels.
This subject has been discussed many times on this forum with many offering good input. Check out archives by subject.
Ed K
I just completed a full recoring and reglassing of my entire deck this year. Gelcoat over epoxy works fine IF the surface is prepared correctly. See http://www.westsystem.com/ss/assets/Uploads/Ew22Polyester.pdf for a full description and test results. I also reimprinted the original nonskid surface in gelcoat and after seven months there has been no indication of bond failure. The temperature has ranged from 17 through 97 degrees.
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All good information with personal preferences. Polyester with chopped strand mat will allow more complex shapes because the resin desolves the sizing in the mat and lets you coax it around. If you wanted to you could cover a golf ball with polyester resin and mat. Vinyl ester resin is a choice that combines the adhesion of epoxy with the user flexibility of polyester. If you buy wax free polyester there is no prep needed between layers because the surface remains tacky. They sell liquid wax to add to the last layer to get a completely dry tack free last coat. Painting the last coat with oil based paint will serve the same purpose.
This has been shown to be false. I have personally applied gelcoat to epoxy resins many times with 100% success. West Systems has a white paper that dispels the myth. Like anything proper prep is key which entails removing the blush, if it is a blushing resin....
Maine Sail comment
Thank you for the link on butyl tape for sealing deck hardware. Many of these guys are using 5200, 4200, Life seal products, etc.
Bytyl sealant works on fiberglass to metal seals and allows fixing or resealing later.
The reasons have discussed many times over years. Sail boaters need to understand.
Cheers for Maine Sail.
Ed K
Maine Sail,
Thank you for the link on butyl tape for sealing deck hardware. Many of these guys are using 5200, 4200, Life seal products, etc.
Bytyl sealant works on fiberglass to metal seals and allows fixing or resealing later.
The reasons have discussed many times over years. Sail boaters need to understand.
Cheers for Maine Sail.
Ed K
ur boat has survived 35 years so far and i gurrantee its most likely polyester resin,i would stick with that as it also has the advantage of being way more economical then any other resin out there
Thanks for correcting me. It is never my intent to give false info. Plus, this will be my approach on a couple repairs I'm facing.
Duke
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