What foam for polyester resin? - Page 2 - RC Groups
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Nov 16, 2012, 03:11 AM
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chester2240's Avatar
It looks like your trying to mold a pickle!
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Nov 16, 2012, 08:47 AM
gallfer's Avatar
No, actually a pic of a REALLY old Hostess Twinke
Last edited by gallfer; Nov 16, 2012 at 08:37 PM.
Nov 16, 2012, 08:36 PM
gallfer's Avatar


Mold after plug removed, lousy pics. Blowing high PSI air through a small hole did pop the plug loose, but had to pry it out anyway. Found 2 small voids that are easily repaired. Mold surface was not perfectly smooth, thought I sanded a lot! Used some W/D 320 paper to smooth it out. Can I now wax the mold and apply PVA to make the actual part after fixing the voids?
Nov 16, 2012, 09:10 PM
Just fly it!
wyowindworks's Avatar
The surface of polyester molds made with strand mat always have print-thru issues. You could have a perfect plug finish but have a less than perfect mold finish due to resin shrinkage.

You can wax and PVA when the mold surface is fixed.
Nov 16, 2012, 09:14 PM
gallfer's Avatar
You are a BIG help to me sir! Please check your PMs
Nov 19, 2012, 05:35 AM
Registered User
If I'm only making a few, I make it right off the wood. This is a helicopter canopy I made that way.
Dec 07, 2012, 09:53 PM
gallfer's Avatar

Finished Part

I think this will work.

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