I’ve wanted a simple flame spreader tip for a propane torch for many years. I recently got around to looking on Ebay etc, but couldn’t find a cheap one. It helped when I saw a picture of one that wasn’t fully enclosed. I figured I could make something with an open back like that, so I did.
A piece of 3/4″ copper pipe slit open should provide good starting material, so I found a scrap. To help me understand what I’d be doing in bending it up, I first made the shape up from scrap cardboard. That was a very useful exercise.
A couple of cuts with a hacksaw and some flattening and I had the basic starting shape. I can’t believe I was dumb enough to make the cuts by eye without measuring. I really do know that I can’t get away with that, and now I have yet another embarrassingly asymmetrical physical reminder of that. Maybe someday I’ll learn.
Another surprise (that I should have foreseen) was that it gets really hot. That means it oxidizes a lot and is unpleasant to handle after it cools down. So it’s asymmetric, ugly, and dirty. But at least it works about as I’d hoped.
It’s not like a bunsen burner flame spreader where the flame is all outside the spreader. Here the hot inner cone of the flame directly hits the spreader. I even reshaped the spot it hits so it would spread out a little more. Flame pictures are always a challenge, so I used the CHDK firmware in my little Canon to get widely bracketed exposures and picturenaut HDR software to make this one.
The spreader is basically successful and certainly functional, and it also serves to remind me (again!) to never cut anything without measuring first.