Compression Molds

General Composites Discussions Composites Talk
#1

I’m wanting to make some good pressure molds for small parts. Just wondering how you guys do it that have done this? I need a 30 mil or 1/32" free space between the male and female mold halves, so there is a space for the laminate/part.

Thanks guys. We tried parafin wax today but it just causes lots of drips and runs without leaving an even coat. Maybe we are doing it wrong? We bought a small crock pot and dip the part in the wax but like I said, it doesn’t leave an even coat of wax.

I’m open to good suggestions.

#2

Sheet bees wax…

#3

Bees Wax? well mind your own…! LOL :smiley: just kidding.

What is the difference between Bees Wax and Parafin Wax?

#4

http://www.freemansupply.com/SheetWax.htm

Are you doing RTM?

#5

Sheet Bees wax comes in machined thickness to the thousands…

#6

you can make a part the thickness you want in your mold then pull the second mold off the inside of that. this will offset your second mold the correct thickness

#7

The mold will duplicate the ugly backside of the composite part. That would be a waste of time, as there would be no point in compression molding.

#8

Thank you guys. I emailed them for a quote.

#9

Get a catalog also from www.kindt-collins.com too!

#10

The thinnest mcmaster.com has is 1/32inch - but is only about 10 bucks for a 12x24 inch sheet. (Available in High temp and with/wo sticky back).

No Joy on the kindt-collins web site 404 Not found.
Cheers - Jim

#11

thats why you would finish the backside of the part so it has a smooth finish.

#12

I’ve bought several times from McMasterCarr (metal hardware) so i’ll probably order the wax sheet from them. That’s awesome someone came up with that idea of precision rolled wax! :cool:

#13

I bagged plys of fiberglass to make the core molds in my finish molds for one of my projects and it worked well. slightly different than what your doing but might work. i think thats what Hojo said

#14

Of course, but then you waste a lot of time applying filler and sanding it smooth. It will also increase the thickness anyways.
With sheet wax, just apply it and go.

#15

apply and go… after sealing with lacquer, wax, pva, wax

#16

I wasn’t disagreeing with using sheet wax at all, for most applications it is the best choice… But if you do it right you can easily sand the back of a part down smooth and seal it with Huntsman high performance sealer then semi release, without the use of fillers and primers to thow off the proper offset. with a tricky shape part, or varying thickness part this would be the more reliable method of off-setting the mold.