Advice on finishing a mold cavity

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#1

Hello,
I have CNC’ed a clam shell mold. The material I used is a filled casting resin system from Alumilite; Replicator 400. There are machining marks that I would like to minimize(remove if possible) and then seal the surface of the cavity. This is my first attempt at this and I am seeking advice as to the general process of getting a “class A” type finish. I assume I need to lightly sand the surface and then seal with some sort of sealer followed by a release.

Can someone please lend me their expertise? Attached is a picture of the molds.It’s difficult to see the machining marks.

Thanks in advance,
PT

#2

Look up Duratec products. They have surface finishing resins for moulds like this.

Is there a reason this mould needed to be this material?

Could you have just machined aluminium and polished it? This would give a great finish and very durable mould.

#3

it looks like its been done on a cnc router rather than a cnc mill

trying to do aluminium on a router is a mission

i would imagine that replicator 400 is quite a hard material , i dont see any reason a semi perm release system not working … apply the sealer as per instructions , 4-6 layers etc
then apply the release

i use Zyvax no 5 and man the stuff is awesome !

#4

Thanks to all for their input. It’s made on a CNC router not mill.
These are one-off molds. After each part is pulled from the mold, the mold will be cleaned to remove residue and refilled with additional material R400. Process is repeated for subsequent parts with different dimensions. All custom stuff.