Well, I finally have some good news...
It occured to me to take the tip off my hand piece and run gas
through to see if it was getting through that far. It turned out it
was and that it had to be my torch tips - even my new ones... In
the past I've had to return tips that were blocked straight out of
the packet so I guess I shouldn't be too surprised about that.
Anyway, having discovered online that BOC stocks all the Primus
torch gear I went to my local store today and asked them if they
sell anything that I can use to unblock my tips. The lovely sales
staff there told me that there are no tools to unblock those tips
because the hole is too small but one of them also told me that he
had heard (but not tried) that a soaking in a glass of coke
overnight unblocks these tips.
I went back to my studio and took out an ultra pinpoint tip that was
discarded long, long ago and took out the end bit (the piece with
the hole) and soaked it in a glass of coke for two hours. I then
rinsed it in water and gently heated it (along the sides) with
another tip on my torch to make sure that all of the water dried off
it. I put it onto the torch and lit it up - it was a perfect
flame... the likes of which I have very rarely seen come out of my
I mentioned all of this to my father who raised a concern that on
the leading surface it is very important to have a square edge on
the hole and that soaking in acid (coke) will blunten this. I guess
its okay once or twice... but after that could it become a problem -
does anyone know? I had an idea to remedy that problem and am
wondering what you guys think - what if I masked that surface with a
plastic adhesive tape before putting it in the coke - then the acid
couldn't touch that edge but could still open the hole out from the
back. Would this work? And is it necessary?