Plug materials for mould heated up to 85-90C

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#1

Hey guys , I have such problem i need make a heat resistant part.
That means I have to build heat resistance mould…
and that means I need to build plug from materials that will held higher temperatures.

The questions are:

1.What to use instead of plasticine to smooth the edges at flanges and to seal them

  1. What kind of putty should be used to smooth surface and build some shape.

Plasticine is good up for 50-60c , typicall polyester putty wont held more than 60C - it will deform much

#2

I have a polyester putty loaded with carbon fibre If I remember right…I know that is used also in autoclave. I didn’t remember now the name, next days I will check

#3

I’ve used this: http://www.ptm-w.com/index.asp?pgid=11

High temp filler.

#4

This is also very good: http://www.adtechplastics.com/pc-15-643-p-17-high-heat-resistant-filler.aspx

#5

Thanks , so one problem get solved , what about plasticine or some substitutes?

#6

I use clay. Handles 120 degrees just fine.

I don’t like using it as much as plasticine because you need to use it with water and it makes a mess. It also has a tendency to crack if you move it around too much. So I use plasticine where I can, but on things that need a post-cure I use clay.

#7

There are likely tooling systems that can be released from the plug and post cured so that the mould is suitable for a higher temp.

If so then no need for high temp plug materials.

#8

A clay might be ok , got to check, fasta - heating mould without plug is risky , when system get soften while post cured it probably won’t stay at its original shape.

#9

The opposite is true: Unless you use a plug made in an isotropic material that matches perfectly the CTE of your mould material, you will get a distorted mould for sure.
The safest way to get accuracy, is to use a proper resin suitable for the task: to reach a TG higher then the temperature of curing.
With such resins, 45°C is usually enough for an initial cure.
Then you can postcure it following the appropriate ramp & cycle.
If the part is big or heavy you can help yourself with jigs and/or slowing down the heating ramp.

#10

For what it’s worth, I didn’t post cure my mould before post curing parts in it and it didn’t distort at all. Given it was made with Airtech Infusioncoat.