The Fiberglass Resin Stayed Sticky

I was ask by a friend who was working on his old boat what I would suggest doing to bet it back so he could use it for fishing. It was a boat that was to a point that it could be junked or fixed. It needed a lot of work, but a new boat is a lot of money.  He decided to work on it since he had it and he owned it outright. 

I gave him so fiberglass material that we had siting around for about ten years and some other stuff that would let him work on the boat to help him out. His dad gave him free labor and advice and the fix up began.  

He bought laminating resin and did the fiberglass work that needed to be done. He called and said that the resin set up but the surface was still just a little sticky after two days. What had he done wrong? He said he could not sand it because it was sticky. 

There are two types of resin for fiberglass work. Laminating resin for laying down and building up layers and finishing resin for the top coat.  The sticky surface lets you get a better bond between layers when you are building up the fiberglass layers. For the surface of laminating resin to harden up you need to cover the surface so air cannot get to it. Finishing resin has a wax in it that floats to the surface and forms an air proof coating on it so the surface will cure and then it can be sanded. 

There are sprays that you can get to spray on laminating resin to it will dry tack free. It then can be sanded so you can finish it.

Finishing resin can be used to build up and layer glass, but you need to let it cure and sand between layers to get good bonding of layers. No sanding is needed between layers when laminating resin is used. You just let the layer cure and add another layer.