On Wed, 6 Mar 2019 11:57:34 +0000, newshound
wrote:

On 05/03/2019 09:53, Jon Fairbairn wrote:

I have a slotted turner (cookery) with a thin stainless steel
blade, which I really like, but the handle is made of a plastic
that bubbles and swells if you rest it on the side of the pan
(or get it too close to the flame or similar).

I’d like to replace the handle, but that requires a material
that:

* is D-I-Y workable
* has low thermal conductivity
* resists exposure to high temperatures
* is dishwasher proof

any suggestions?

Tufnol, PTFE

Neither of these will withstand particularly high temperatures and
when overheated produce some nasty fumes. 250degC is about the start
of the degradation temperature pf PTFE, at 350degC it starts to
decompose and releases fumes which cause polymer fume fever in humans
and are lethal to birds.

Tufnol has a range of temperature maximums depending on the grade but
most have an upper limit of 120 to 140 deg C.

Leaving the turner on the side of the pan on a gas cooker as the OP
does will expose the handle to temperatures higher than 250deg.