mixing resin

[SgtMaj]

Well everything for the transom came in today, so now I'm ready to finish the job. One thing is confusing me though. I thought resin came with just resin and hardener, but when I got my resin, it also had surfacing wax that says to mix 2oz per gallon of resin. What is this do?

 

[drewpster]

Re: mixing resin

What you have is probably a resin kit that can be used as a laminating resin and as a surfacing resin.
Polyester resin will not fully cure when its surface is exposed to air. It is used without the wax as a laminating resin. That way when the next coat of resin and glass is added, no sanding will be needed to bond the next coat with the previous one.
The wax is then added to the last batch of resin to make surfacing resin. As the last coat cures the wax rises to the surface, sealing it from the air, allowing it to fully cure.
Maybe somebody else has a clearer explanation but that is how I understand it.
I am clearly no expert. :redface:

 

[Robj]

Re: mixing resin

You probably got laminating resin, when it cures it will remain sticky. If you are going to do another lay-up on the same area the next day, you just wipe the area with acetone and you are good to go. You add the wax to the resin on your final lay-up, then when the resin sets it is no longer sticky, it will be smooth and glossy. However if you want to add another layer once you have used the finishing resin, you will need to grind the surface of the area before as resin will not stick to resin with wax in it. The wax stays on the surface so once you grind it you are good to go.

i.e. no wax = laminating resin

wax = finishing resin

Hope my explanation makes sense.

Have a great day,

Rob.

Rob.

 

[SgtMaj]

Re: mixing resin

Cool, thank you both. Makes perfect sense now.