I'm working on pinhole leak on a brass Chevy radiator. I have a propane
torch and a bottle of map gas. The torch fits right onto the bottle and
seems to work just fine. Is it safe to use a propane torch on a bottle
of map gas?
I've done soldering with a propane torch and MAPP without any bad results..
you don't get as much heat from it as you would if the MAPP were used with a
torch intended for MAPP.
A MAPP flame could be/probably is excessive for a radiator repair.
The typical pinpoint flame from a propane torch isn't ideal for radiator
The flame can be softened/feathered (cooler flame) by forming a sleeve to
partially cover the air holes. I made one from sheetmetal that was rolled to
a diameter slightly smaller than the propane torch so it would stay in
place, and had a long tab hanging out for a cooler place to manipulate the
It probably isn't going to hurt, but you won't get the temperature that
a MAPP-only or MAPP/propane burner will reach. If your torch was made
in the last few years, it might be a MAPP/propane unit. If it's one of
the old '50s-style Bernzomatics, dump it and get another heat source.
The newer style "turbo" units are head and shoulders above those old
torch heads, even with propane.
Usually direct flame ISN'T the way to do soldering on a project as you
describe, an old-style soldering copper works better. If you don't
have one of those, one of those clamp-on soldering tips will work. You
want pinpoint heat, not something that's going to heat up the whole
radiator and maybe loosen some joints.
This advice sounds like why I use a very small OA torch for some pewter
work I do and whenever I have to do soft soldering of brass/copper
requiring close control, it give concentrated heat allowing subtle
control when you are use to it rather than any propane torch which has
lower heat input and heats a greater area reducing control.
wrote in message
Turns out that all I need is a simple hand-held butane pencil torch
and a 50-watt soldering iron.
Absolutely right about the excessive heat from the MAPP/propane
unit. I can almost literally see my radiator go up in smoke. Not
only that, the solder refuses to cling onto the vertical
surface even after sanding and applying some cleaners.
In a word Yes. Torches like that are a bit tricky. Do you only have a single
gas input - e.g. you have a plumbing propane torch - The MAPP might be a bit
to smoky as it normally wants oxygen blend to burn very hot. They make two gas
torches - oxygen and propane or oxygen and MAPP. That is the best rig for this.
Martin [who has such a rig and does it both ways as needed ]
On Tue, 15 Feb 2005 00:55:39 GMT, the inscrutable "Tim Zimmerman"
Did you preheat with the iron and solder with the torch?
Got neutralizers and flux? ;)
VIRTUE...is its own punishment
"Larry Jaques" wrote in message
Nope. The pencil torch is used to pre heat the surface. Then the
50-watt soldering iron is used to collect the radiator solder core
and then applied to the preheated surface. This turns out to be
successful, unlike my other method below.
I use liquid flux. But in order for the surface to melt the pretty high-
temperature solder core, I nearly had to burn down the radiator before
the solder will flow onto the vertical surface. Each time I applied the solder
(with a little silver) it'll crumble and fall apart.