Firescale with oxy / propane

Hi all, newbie to the forum,
I have for a long time just been using a standard canister style propane torch for soldering and annealing sterling silver with very little issues in the way of firescale. Thought I would buy a Smiths little torch which is running on oxy /propane, and suddenly firescale has become a major issue. Went back to the straight propane torch and no problems at all. So is this a common issue when using oxy / propane? By the way I had the little torch running with a neutral flame
Any help would be appreciated

Hi Techno, and welcome to the Forum.
You get firescale when you linger in one place with an oxidising flame and create hot spots.
So work in a darkened area to see this, and keep the flame moving. Dennis.

Thanks Denis, it may well be with the little torch running quite a bit hotter than the straight propane, and it could also be the flame had a little more oxygen in it than I thought.