molding replacement pocket liners

[Dark57]

The pocket liners on my fiberglass sailboat were plastic moldings that were glassed into the sides of the cockpit, and served to keep out rain, and to hold small items during sailing. 20 years later, the plastic deteriorated and shattered. Yesterday I cut out the remainders, and plan on building a wooden mold, and laying up replacements, one each for right and left. The mold will be a female mold in that the finished side will face the mold. The liners are shaped like a cube that is open on the top and one side.I plan on using polyester resin, csm and cloth, no gelcoat, rather autobody fine scratch filler as a surfacing agent (snofine or the like), and a painted finish.

I have a couple of questions:
1) Is there an inexpensive commonly available material I can use as a mold release?

2)Is there a decent source for materials and supplies in the Austin TX area, or is mail order the best source? If mail order which?


This is a one time job, my goals are economy and restoration of original function.


Thanks in advance for any wisdom!

Dark57

[wet feet]

Your intended use of a fine scratch filler may or may not work.It is possible that the styrene in polyester resin will attack it.Try a small test piece before the real thing.For a release agent,you ought to be all right with several coats of a good silicone free wax.The silicone free part is important.I can offer no advice on your local suppliers as I am rather a long way from them.

[Dark57]

Thank you for the reply. I'd planned on adding the filler after the parts are molded, similarly to the way male molded boats are finished, mainly to smooth the finish, and prevent glass splinters.

I'd hoped that once the resin cures, the body filler would adhere without problem. I'm not against using gelcoat, I just already have some fine filler from another project, and it sets to a nice white color, and sands well.

Thanks again.

[SamSam]

Originally Posted by Dark57

The pocket liners on my fiberglass sailboat were plastic moldings that were glassed into the sides of the cockpit, and served to keep out rain, and to hold small items during sailing. 20 years later, the plastic deteriorated and shattered. Yesterday I cut out the remainders, and plan on building a wooden mold, and laying up replacements, one each for right and left. The mold will be a female mold in that the finished side will face the mold. The liners are shaped like a cube that is open on the top and one side.I plan on using polyester resin, csm and cloth, no gelcoat, rather autobody fine scratch filler as a surfacing agent (snofine or the like), and a painted finish.

I have a couple of questions:
1) Is there an inexpensive commonly available material I can use as a mold release?

2)Is there a decent source for materials and supplies in the Austin TX area, or is mail order the best source? If mail order which?


This is a one time job, my goals are economy and restoration of original function.


Thanks in advance for any wisdom!

Dark57

Johnson's Paste Wax will work. 100% Carnuba wax is what it is, maybe there are others. 4-5 coats. You'll have to seal the wood first with a few coats of $1 a can spray enamel. If you can get some formica covered sink cutouts from a cabinet shop (for nothing) that will work real well, you won't need the paint, 1 coat of wax will work. Modeling clay for a dollar or so from a toy store can be rolled into pencil sized sticks, stuck in the corners of the mold and formed into filets by using an appropriate sized tool socket dragged along, putty knife like. The filler will work. If you first brush resin in the mold, then csm, then more resin and csm you won't have so much to fill. You'll have to get the wax off the part before painting. Scrub with acetone, sand, scrub again. Sam

[Dark57]

Thank you for the suggestions, they'll really help to make a successful project.

Dark.