Remember I'm sure no expert but:
Are you now going to make a female mold or are you making a one shot
final piece. If going for the final piece it only matters that you seal
the foam so that the gel coat and resin doesn't dissolve it as you will
chip it/sand it out later. Use car wax or whatever.
I made a female mold and then the final piece from that. Spackling
compound worked fine for me and then numerous layers of the mold release
wax that seemed identical to paste car wax to me. I wondered about the
numerous layers as my understanding is that one can not build thicker
layers of wax on wax but -hey even I follow directions occasionally. No
biggy as again you are going to again destroy the foam to separate it.
If you are making a female fibreglass mold, the fun part is that you are
right and it was not easy to separate the final piece from that. I used
the mold release wax again. Some sources also recommend spraying PVA on
the mold but I did not as several sources said it was a waste of time.
I'd probably try it anyway if the part is deep. I had to hammer cedar
wedges in to get the two parts to separate. I think it really depend on
how deep the nose bowl is as to how difficult this will be. Oh and I
used some coloring in the gel coat of the final piece to make an obvious
distinction between mold material and final part material.
I was actually pleased to get over some of my trepidation with
fibreglass as I had a few parts that almost had to be made with the
stuff such as an intake duct for engine air. I still avoid it if I can
though ;)
Ken
Mike Kimball wrote:
I'm getting close to being ready to lay fiberglass over my "mold" built in
place for the nose cowl on my Super Rebel. The mold is currently sculpted
foam. I was planning on covering the foam with either wall spackling or
bondo. Then I would sand the mold smooth and cover it with a mold release
agent. Then the glass would be laid up on the mold and hopefully will
release from the mold after curing. I have experimented with wall spackling
because it cures fast and is easy to sand. I have used it to fill gouges
and other mistakes and then I can sand the foam/spackling area nice and
smooth. I don't know if the spackling would be suitable for the final
surface to apply the mold release to. Anybody know? I know bondo works but
it's harder to sand. The other question I have is about the agent.
Aircraft Spruce lists a product called Plastiease 512B which is to be
brushed or sprayed on and also a product simply called mold release wax
which comes in a can that looks like a car wax can. That makes me think
that it is thicker and would be applied like car wax. The Plastiease sounds
easier. Any opinions on the Plastiease versus the wax?
Sure doesn't seem right for this to be a topic on a list for builders of all
metal airplanes but I'll gratefully accept any thoughts.
Mike
044SR
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
