Pattern Mold Part release question

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#1

Hello, I am planning on building this wood pattern approx 2’x1’x1’. And then making an epoxy/fiberglass mold from the plugs outer side. Then building my composite in the female mold.

My question is am I going to have a terrible time trying to get this to release from its mold having a 0 degree camber on the sides. Is this something I should be using a split mold with.

The bottom edge are a small rounded corner like the sides.

I thought maybe making something from the bottom that I can then remove after infusion to put some wedges in to aid.

Any help or ideas would be fantastic, I don’t really want to camber the walls due to visual aspects.

#2

Well once you’ve got the mould made, if you’re using a high slip chemical release agent, then I doubt it will be too hard to release the parts from it. The issue is releasing the mould from the plug, which may be a bit difficult.

I’m building a similar thing, but I’ll be doing it as a 2 part mould. Easier to get the mould off the plug without damaging it that way, and then it can be layed up and infused as one part. If you put the parting line on one of the edges then it will be even easier to sand away the line on the final part, essentially making it invisible.

#3

you could always split at the radius to have two L shaped moulds, but Im not sure what exactly you are trying to achieve, so this may not be feasible

#4

look into high slip zyvax release.
ideal in zero draw moulds

#5

I have a mold just like that and in a single piece, but I have a little “draw” built in to it and a flange that helps a lot to remove the part.

#6

If you do it in one piece try to incorporate an air line fitting on the underside ,valved of course , to aid in part ejection when your done .With non-existent draft angles it can be difficult to get that separation without flexing in the sidewalls and possibly damaging your parts . Even an 1/8 air fitting will work if you just cover the hole with clay or a removable plug .

#7

sounds great i think i will try to make a it with like a 2 degree draw. And also use a removable plug at the bottom to aid in removal.

and will look into high slip zyvax release, but I read on this forum somewhere it can create fish eyeing