AWN wrote:
I have just picked up a med duty Victor torch/cutting set and I had some
questions...

My kit doesn't come with backflow/arresters and I'm wondering if I should
worry about using the torch without them? I'm using the smallest sized O2
and acet bottles my supplier carries so I don't know if that makes a
difference from a pressure standpoint?

The manual that comes with the kit suggests using the arresters but I wanted
to ask from a 'first hand experience' perspective as to whether or not I
truly need them? I don't want to have a fire or blow myself up but I've
been using portable 1lb MAP torches for years and never had a backfire,
problem, etc...

Is there any other advice you could offer a noobie like myself? My first
two projects are going to be fixing the exhaust on an old project car and
building a welding cart. Should I use coat hanger to weld the exhaust with?
I've heard this works very well.

Can I weld the exhaust with the MAP torch or is it not hot enough? I'm
itching to get this torch fired up but I have visions of causing a problem
without the arresters in place...


Thanks for any and all advice.
Andrew.


The purpose of the backflow preventer is to prevent oxygen being forced
into the fuel cylinder (at times when the fuel cylinder pressure is
below cutting oxygen pressure) and vice versa. It's likely to be a bad
thing if this happens, especially if you're using acetylene. In my
opinion, safe working practices, adhered to scrupulously, are nearly
good enough to get by without bothering with backflow preventers on your
torch.

I see flash arrestors as more of a personal choice, I don't feel that I
need them nearly so bad as the backflow preventors but I sure ain't
gonna ridicule anyone over them.

You can weld with coathanger wire, no problem there as long as you're
not expecting too much. Pretty unpredictable alloy but adequate for an
exhaust job that nobody is going to look at.

I don't know about welding with mapp, it's not advised to weld
with propane (because it's not possible to control the amount of oxygen
and carbon available to the puddle). I suspect mapp to be the same but
nobody says you can't try and see what happens, especially with an
exhaust system.

As others have advised, careful with the torch, Eugene, 'specially under
the car. Setting your stuff on fire in the driveway is sure to make the
authorities soggy and hard to light..

John