Joe,
Well done on an ambitious project!
A few suggestions for future molding projects:
1. A new polyester mold needs to cure for at least 1 week before initial waxing/sealing to allow for complete out gassing of the styrene in the polyester. This will aid big time in how the part releases from the mold.
2. Rather than Partall PVA wax, seal the fully cured mold with a polymer sealant such as Meguires Machine Sealant, (2 applications is plenty...)
3. Use a
semi-permanent release agent over the sealant. This also requires a short, but necessary curing time.
4. Use a water based released agent over the above semi-permanent release agent. This will actually create the release happening between the two different release agents. (Here's a good source for a
variety of release agents.)
5. Create a positive draft in the mold design so that removal of part is possible.
6. include a 360º flange at the base of mold for positive stopping point for the part. About 2" is sufficient and let your layup extend well onto the flange.
7. Include at least one compressed air fitting on the mold, (more may be required depending on part complexity), so that you can used a controlled compressed air release between the part and the mold. Use a valve to control the introduced pressure.
8. Allow the polyester part to cure for a minimum of 24 hours before attemting to remove from the mold.
9. Use a rubber mallet to apply moderate blows to the part and wedges around the flange as necessary to coax the part off of the mold while under air pressure.
I remember vividly my attempts to create a polyester molded part, either before learning these steps or by trying to cut corners and ignoring one or more of them. I too have left a few molds looking like your's in the final part removal...
