Polyester Resin and Temp ?

[jonesg]

Re: Polyester Resin and Temp ?

A lot has to do with resin quality, the stuff available at the street level can be junk, one retailer won't give kick times, they say their economy resin is variable from batch to batch.

West marine poly resin is very expensive but I have read they sell good product, I can't afford it anyway so I'll never know.

It would be neat if I could lay my hands in some CN , I suspect the cheap resin isn't promoted to my liking.

Anyways, none of this should be necessary, mix it right the first time.
Amateurs fix it 12 different ways then trash it, the pro's throw it out the first time.

It also depends where the resin is being used, if its in the first matt layer in the mold and its not right the hull/gelcoat will blister, so it needs to come out.

On the deck in my boat?
who cares, throw sand on it and slosh more resin on.

Life is sooo simple down here on the redneck riviera.

 

[ondarvr]

Re: Polyester Resin and Temp ?

Jonesg

You're correct many won't give you a gel time or any other specs for the product they sell, because many times they don't know. None of the retail suppliers make their own resin and some don't even have, or require a spec for the resin other than it to be low cost. This doesn't mean its junk, sometimes it a very high quality product, just with different specs than the last batch they had. What happens is very large producers of resin sometimes have stock that may not meet the spec of the fabricator it was made for, this spec may or may not be that important as far the quality is concerned, but may be important to the customer's method of production. Since resin has a shelf life, this product needs to find a home fairly quickly, so some retailers can buy these resins at a reduced cost, they then repackage it and sell them to you.
During this recent slow down in boat and RV building, there was a great deal of resin, gel coat and everything else that goes in into building these toys sitting in warehouses all over North America. Stuff that doesn't have a shelf life can sit for a while until needed, but resin, gel coat and catalyst need to be used up before it drifts too far out of spec to be usable.

 

[jonesg]

Re: Polyester Resin and Temp ?

I just read theres only a small handful of poly resin mfgers, shell industrial chemical being one.

I got a book by a chemist from "aircraft spruce" last week.
http://johnawills.com/indpu.html

He gives a lot of formulas for cobbling different putty's/resins.
Some of the homemade recipes are funny, dissolve old movie film in acteone to make parting film for molds.
Other books are how to make gel coat paint.
Bottom paint etc, around here they just use cayenne in paint.

I recall yrs ago being told I could drop a foam cup in acetone to make a sealing compound for fabric covered planes, never tried it. Probably not good for nylon fabric.