I made my first mold and everything seems to have turned out better than I thought expect for the fact I have a handful of small pin holes in the gelcoat. They weren’t visible after taking the mold off the plug then after polishing the surface it exposed the holes. I’m assuming they were air bubbles trapped in the gelcoat?
How should I fix them or will the wax release fill them in? I was thinking of just dabbing a small amount of gelcoat onto each one and then sanding smooth.
A toothpick or sewing needle will apply gelcoat to pinholes while avoiding excess buildup to sand down .
How do you cure such a small amount of resin? Do you have to heat it externally to get enough heat to fully cure?
Sorry , I meant to say mix up a small batch and then apply the smallest amount possible . If he has a sensitive enough digital scale , wasting a bunch of gelcoat can be avoided .
After reading another thread with similar issue I have decided to fill the pin holes with wax and see if that works.
Thanks for the suggestions.
Wax is only a temporary solution… Is the part outdoors? Or what is its intended application ?
The final part is an auto interior trim piece. The pin holes are in the mold.
Did you do the mould yourself? I think it’s sometimes best to look at what could be done to prevent this next time. I myself sometimes have pin holes in my tooling gel coat so I’m wondering the same thing.
Does anyone degas your tooling gel? And I have been brushing it on as well, I don’t have a dump gun.
Did you use any heating element to speed the cure when you layed down the gel coat?
Yes I made the mold myself and no I did not degas my gelcoat.
No heating element was used although I did use too much catalyst as it started to go off in obout 10-15 min.
I pulled my first parts from the mold tonight and they turned out pretty darn good for a first time epoxy infusion newbie. Better than I thought they would I’m very pleased.
Degassing tooling gel coat I don’t think is necessary, especially if your brushing it on.
The catalyst might be your problem, using too much and having it kick off quickly can trap bubbles in your gel coat.
From your description, im thinking too much catalyst caused the gel coat to “boil”. When resins and gel coats cure they give off heat… I’m sure you found out if you had any extra gel coat sitting in the cup. Too much catalyst can cause the gel coat to heat to the point where it will boil and cure.
You want to make sure to mix correct amounts of catalyst and gel coat. If you really want to speed the cure you can use a space heater in your work area. Just don’t put the heater directly in front of what your working on.