Un-braze seatpost collar with handheld mapp gas torch?

[klunknoob]

I realized that my 41 Rollfast has the seat post collar brazed on. Is it possible to melt it away with a handheld torch using mapp gas, or is that something that the average joe should leave to the LBS? THANKS!

 

[nosferatu1381]

Technically that could work, brass melts at about 900 something and map gas burns at 2900 something I wouldn't want to do it though. Chop shop customs has a seat post that fits in there that heat treated. I don't know what the advantage of removing that collar could be

 

[nosferatu1381]

I mean I have done it and used a different collar but I rebrazing the rest of the frame anyway and mixing my gas with oxygen it burns almost twice as hot

 

[nosferatu1381]

I had to do a lot of brazing on this one

 

[nosferatu1381]

Now that I think about it I stole this one a while back and used it somewhere else.
Had to find a collar that fit here so I could put the seatpost back but I mix oxygen.

 

[us56456712]

Hard to do with mapp on most brazing. Some melts a little easier. The frame absorbs a lot of heat. On 1970s road or 90s mountain bikes all I could do is get the bracing to loosen up so that I could hammer off the canti brake pegs. I then welded them on in a different location.