Alternatives to sheet lining wax?

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#1

Does anyone know of any alternatives to sheet lining wax for replicating part thickness (for making mold inserts)?

I have never liked using sheet lining wax. It’s expensive and it never conforms that well to complex curves. I have to apply heat to make it conform to my mold cavity without breaking and this spoils the uniformity in thickness. I also get little indentations from my fingers or whatever I use to push it down against the mold surface.

Recently I have started casting full size parts and sanding them down to reduce the size until they fit as mold inserts.

I was wondering how other people make inserts and if there is a better alternative to sheet lining wax?

#2

Layup a fibreglass part using cloth layers for uniform thickness.

Prep and finish back surface for moulding when used as insert??

#3

Sounds like you need that CNC router up and running Zebra!

#4

I thought about using fiberglass. The obvious problem is that I would need the insert to make the fiberglass part thickness replica. I could potentially get around the problem by using a super fast cure resin and stand over it holding the fiberglass fabric down against the mold.

Fiberglass does conform to a complex mold surface a lot easier than cf. I tried using for this purpose on a simpler mold about a year ago and I struggled to achieve a uniform usable rear surface without a male mold.

I might try again and use my silicone vacuum bag (under vacuum) to see it if deliver the desired result. Fiberglass would certainly be a cheaper alternative to sheet wax and if I can find a repeatable process, it would be a better solution.

I came across another idea this morning too. smooth-on sells a product that apparently shrinks silicone casts or molds by a uniform amount. In theory, I could cast a silicone insert and use their product to shrink it by 10%.

#5

You are so right!

I have most of the parts just sitting there waiting to be assembled. Instead of messing around with all this manual trial and error, I could have just clicked my mouse and put my feet up while a robot made pristine aluminum tooling with perfectly sized inserts…

It’s time to start building!