I am making a plug for a fiberglass mold. It is primed and ready for paint. A friend is painting a car with 2K urethane paint. Is this ok for the plug?
Thanks,
Chris
you want to use a polyester primer. I would not do anything in urethane!
what type of paint would you recommend?
i would not paint it. Almost all paints will have a chemical reaction with tooling poly gelcoats. Sometimes it happens sometimes it doesnt. It is not worth the chance. Just use a polyester primer and you can sand and buff it like a clear
I shoot all my plugs with Eurothane single stage with the flange installed. Wetsand and polish like REAL glass when needed, not usually needed.
Polyester primer will always result in a mold surface that requires polish/sanding…whereas the surface is perfect when the part is pulled in the slick finished plug.
What you skip on up front, will only be replicated effort later on…on each part.
…V’
i guess it is just what you want to do, but i have had 2 plugs that were sprayed with urethane fuse to the mold and most of the boat shops that I know of always preach STAY AWAY from it when you can just use a poly primer and never have to worry about it. It is too risky in my book. I don’t have the time to remake a plug and a mold because it fuses to the mold. The duratec primer you can buff it and be glossy as hell, I have NEVER had to sand a mold with the duratec primer. You are using the wrong poly primer if you have to sand the mold. But again it is personal preference. I have over 160 molds that were made with poly primer that didn’t need surfaced after I popped the plug. Maybe it was just the way I was taught. Never needed to change a process that has been really successful to me. Here is a mold that the plug was sprayed with duratec primer. Surface turned out awesome, no sanding or buffing. I did buff it after the pic. I buff all my molds no mater the surface just to have even an even more glossy surface
they even have a high gloss additive to make it even more shiny but I have found that it fish eyes easily. Maybe I just don’t know how to spray lol
Rell, Are you using polyester tooling or epoxy tooling?
yeah I probally should have asked that too
This is my first plug/mold so I have not yet decided. I would assume polyester unless you recommend epoxy.
Rell
Wonder what difference there is between std gel-coat and the “tooling” variety?
our plugs are painted with 2k solid… it gives us a perfect glossy finish from the start, we have never had problems with the paint bonding to the mould…
the same difference as ortho poly resin and iso poly resin. Better HDT, hardness, etc…
Tooling gel coat is formulated to take the heating cycles of making parts better too.
maybe my mold got too hot and that is why it fused? If people are having success with it then use paint
“Tooling” gel-coat doesnt seem to be available in the UK for some reason, although I can see there may be some advantage to using it for making some moulds.
I have used 2K vehicle paint for surfacing plugs, and never had any sort of problem. However as with any paint if you try putting something over it before it has fully hardened, then its possible that there may be difficultys with it.