Welding close to bonded plastic - advice

[Pistom]

I've got a welding job to do which is about 50mm from an epoxy bonded plastic component which is attached to the steel I'm welding.

I'm wondering if MIG welding this is a good idea and how to prevent the heat destroying the epoxy bond? I believe the epoxy is the limiting factor as that can only take up to about 120 to 140 deg C.

Is using a heat blocking putty an idea?

I'm thinking of welding short tacks to minimise heat build up.

[Pistom]

JohnMcL said:

Can you not cut the epoxy bond, move the plastic component out of the way, do the weld, let cool, redo the epoxy?

That's a really good idea in principle but the difficulty is cutting the bond. It's very difficult to get at.

I think the best idea is very short stitches which are allowed to cool.

The heat resisting putty won't do any harm.

[Pistom]

Other than an infra red contactless thermometer, I wonder if there's some device I could use to log the temperature the metal gets closest to the bonded part?

[Pistom]

Yes, TIG is a good idea.