Hotcoat Question

just one more question, what exactly is the purpose of sanding if you dont plan on doing a gloss coat. What is the harm in undersanding,what sort of texture should I be looking for after sanding.

Most guys like a smooth shiny finish but if cosmetics are of no concern and you don’t plan to gloss, you could ride it unsanded. I doubt if any overlap ridge or zits are going to affect the ride much.

It is primarily a matter of asthetics to get a decent finish. Definitely knock off any sharp edges or stray glass strands that could slice or stab you.

I recently saw a polyester resin/fiberglass sample that was probably good enough to go with no sanding. The sample I saw hadn’t even been hotcoated - just some cloth that had been wetted out on a cardboard tube and wrapped in plastic. It was at the Fiberglass Hawaii store in Santa Barbara.

When i think about the three resin applications, lamination, hotcoat, and glosscoat, it has always been the hotcoat that’s given me the most trouble. And of the times I’ve screwed up it’s always been the catalyst %. That, and working it too much on the first couple of boards. Now I thin the hotcoat with about 2% added styrene to the sanding resin and about 3-5% catalyst depending on the environment, brush it down and get out as soon as I can. I have the luxury of waitng days before I have to sand as my boards are personal use and not for customers. Sanding is easier after proper curing for sure. I’ve only done 6 boards so far, experimenting and learning more each time. This forum is invaluable for information. Thanks to all.

Ride on.

Tom

Howzit tkelly, I add SA by eye and use 15 cc’s catalyst for all quantities since the bigger the board the more resin and time needed to apply the hot coat. As for waiting before sanding the optimum time to sand is 1 or 2 days after hotcoat for easy sanding.Aloha,Kokua