A two part polyurethane?
A two part polyurethane?
So many honey-dos . . . . . so little motivation
Gelcoat is a chemical, a polyester resin with pigments and additives like Monomers that cross link with the polymers to help setup and thixotropic agents and others that help with spraying so the gel does not sag yet will conforms to a mold.
Gelcoat is real close to polyester laminating resin in make up. Gel has about 3 x the thixotropic agents than laminating resin, cures like laminating resin exothermically , using the same catalyst MEKP.
Gee, that makes it a lot clearer..........Bazinga!
LOLOriginally Posted by rangerbobber
Gee, that makes it a lot clearer..........
It's a polyester based coating made from basically the same stuff ( polyester resin ) the rest of the boat is made from, only with pigments added to get color. they add thickening agents so it will stay on vertical surfaces when sprayed.
Gelcoat and polyester resins are cured by adding a catalyst, usually MEKP, Methyl Ethyl Ketone Peroxide which is an organic acid like material.
The catalyst increases the speed of a chemical reaction that causes the molecules in the resin or gelcoat mix to link together in a chain and change from a liquid to a solid.
When mixing resin or gelcoat with catalyst, you just have to add enough catalyst to get the reaction rate to speed up to a reasonable cure rate, but not so much catalyst that it creates extra heat in the reaction. ( the exothermic reaction )
Too much catalyst will get the resin or gel to cure fast and hot, but there is a possibility it will make the gelcoat shrink and pull away from the mold or repair.
Too fast a cure can also result in a weaker physical property for the glass part , as the faster cure rate develops shorter chemical chains, longer cure rates develop longer chemical chains which are more apt to be stronger.
Here are times in a fiberglass job shop ( not boats ) where you need a hot mix of resin to make a part or repair where the physical strength doesn't matter, you can add enough MEKP get the catalytic reaction going fast, where the resin will cure in minutes and also generate enough heat to catch the bucket of resin on fire when you are done..
Basscatz is there anything you dont know ? LOL Thanks for the info again and I get it however I still dont have women figured out what do you know about them? :)
This explains why just about every boat manufacturing facility has burnt to the ground at one time or another..
Thanks, basscatz. Don't know a great deal about this kind of stuff, but a little.
BTW, honey is viscuous, mayonnaisse is thixotropic - just thought y'all would want to know. LOL!
So many honey-dos . . . . . so little motivation
Love this answer. Major nerd props to you sir!
Tight Lines,
Andrew
This explains why just about every boat manufacturing facility has burnt to the ground at one time or another..
That's a bit of an exageration. Tell us who has burnt to the ground? If any one burnt to the ground all of the tooling would be lost, and you can't go out and buy new tooling. In my 20 years of doing this stuff no one has burnt to the ground.
Maybe, but I know the Champion Boat plant in Mountain Home burnt down and had to start over, years ago fires in boat plants were common, do the research.
Reply With Quote