What shape is the cowl? Are you trying to make it a one-piece mold? Be sure
the draft on the plug does not "lock-in" the female mold. Even on a round
cowl it is best to make a two piece mold. There needs to be some
flexibility(either the male plug or the female mold) to get the part to
separate. If the plug is solid balsa and the mold cures rigid, it is not
likely to release without breaking one or the other. Although I have not used
the release system you describe, I don't think it is the problem.
Norm, make sure the male forms don't have any reversed angles or edges.
if they do you will need a two piece mold. Are you painting your plug or
leaveing it in raw balsa? The plug should as smooth as possible. I use
an automotive urathane paint with good results. I let the paint cure for
a couple of days, then apply 3 to 5 coats of mold release wax. Then
spray on a thin coat of release (PVA). I use partall brand on molds
from airlane parts to 400 sqft. one piece trailer bodies with no
e-mail me if you have more questions.
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National Flying Site Directory/Database
Your site on the Internet for FREE Model Airplane Plans
Bookmark this site for the fantastic resource it is.
> +++ STARCAD PLANS +++
> National Flying Site Directory/Database
> Your site on the Internet for FREE Model Airplane Plans
> Bookmark this site for the fantastic resource it is.
++ a good crash is no accident++
12. Making a mold
13. making molds