Thanks for all the replies particularly Keith.
I the past I have used carbide from blunt cutters but as this one needed 3/32" rod the suggested TIG electrodes seemed the better option and I just wanted to know if the lack of carbon in the metal needed a different approach.
As you can see the small round contact on the hammer wetted well, the longer rod comming out of the conical part not quite so well but I could not pull or twist it out so must be OK.

For those that are not sure how an ignitor works this shows it being tripped by the pushrod.
J