could you elaborate on this? Did you mean break up the binding agent of the matt or the epoxy? What is the polyester based product?
thanks, rondane
The glass fibers in mat are held together with a kind of "glue", called a binder. This binder is dissolved by the chemicals in polyester/vinylester resins after the mat is "wet out". It was not dissolved by the chemicals in epoxy resin, creating issues where the resin would not "stick" to the fibers. But- most mat on the market today is compatible with epoxy resins.
Sorry I didn't check back on this thread. Dave is right. Most fiberglass mat is manufactured with a polyester binding agent that dissolves when wetted out with resin. The epoxy doesn't break down the binder which makes it want to stay flat instead of conforming to corners. Gougeon brothers (makers of West System) makes a mat that is binder free, but it's difficult to work with because it shreds apart so easy, and it's expensive.
US composites has a stiched mat for use with epoxy. http://www.uscomposites.com/mat.html
I have seen it both ways, stitched and unstitched binder-free. Both are $400-$500 a roll as opposed to $180 for the normal stuff.....
Thanks for the tip on another source though
One guy hit it on the head. Use West System Epoxy. 105 resin/205 or 206 hardener depending on temp. It's the only thing I use at my shop to repair PWC. I have had too many comebacks using the "SMC Resin"
To do it right, you should fix it on both sides. Lay a nice patch on the inside with at least a 2 oz mat and 6oz cloth (I prefer mat and 1708 or 2415 woven composite if you can find some) several inches beyond your repair in all directions. Then grind that Kitty-Crap off the outside and replace it with mat. The trick to using fiberglass mat with epoxy resin is wad it up and work it over really well before wetting it out to break up the binding agent they use during manufacture. It's a polyester based product that normal resin will break down...Epoxy won't break it down. Good Luck!
Or you could just use a good vinyl ester. I have yet to have anything come back. But I also don't remember any PWCs that I have worked on being made of plastic. If you are using epoxy it doesn't make sense to use glass designed for polyester. Why wouldn't you just use mat designed for use with epoxy?
www.bowkersfiberglass.com
Or you could just use a good vinyl ester. I have yet to have anything come back. But I also don't remember any PWCs that I have worked on being made of plastic. If you are using epoxy it doesn't make sense to use glass designed for polyester. Why wouldn't you just use mat designed for use with epoxy?
www.bowkersfiberglass.com
I am not trying to start a war with you here Martan, but I can assure you from personal experience the the vinylester idea does not work on anything that is subjected to abuse. I used it for several years on PWC with little trouble. Then I landed a contract with a PWC rental company and the comebacks were a problem to say the least, simply due to the abuse that the ski's were put through. Epoxy cured that problem 100%
And on using the mat desigined for epoxy...it's just one more product that I would have to stock, which increases my overhead. If I were using epoxy more often, I probably would stock it, but I probably use it about 10-15% of the time which doesn't make it cost effective.
I think maybe you must be referring to ONLY the jet ski brand made by kawasaki. I tend to lump all PWC together. I have to admit in the last 10 years I have only worked on maybe 5 kawasakis. I do however know that my repairs on several pwc have held up quite well under some heavy use and even new accidents. In fact I remember one that was repeatedly drove up onto the beach all summer and the kids got in the habit of hitting the beach at speeds and learning to time it just right so they could do jumps. When it came to the shop it was pretty beat up, but none of my repairs had let loose. I wonder if epoxy does good on plastic? This is one area where vinylester will not bond at all and I have had several people try to talk me into doing repairs on plastic.
As for trying to start a war with me, I didn't think that at all. I assume you are talking to me from your own personal experience. Please assume that I am doing the same.
www.bowkersfiberglass.com
Kawasaki and Sea-Doo hulls are fiberglass so you might get away with it on those, but Yamaha and Polaris hulls are SMC. Polyester and vinylester do not stick to SMC at all.
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