<VV> Cutting Torch

[Dale Dewald]

At 17:50 12/17/2009 -0500, Bill Strickland wrote:

> >>reply to:
> >I'd like to get a torch setup for occasional use and would like to be
> >able to cut, bend, and weld.
> >
>
>For welding, unless you are really weird, or learned how to gas weld
>Back When, when there weren't a lot of alternatives, forget learning
>oxy-acetylene for welding -- buy a little wire feed with a gas bottle --
>great for general welding of both sheet and plate, and almost no
>learning curve -- if you want something more challenging, get a TIG. For
>any arc, get one of the new automatic electronic hoods -- the ones that
>are not the very cheapest work quite well.

I have to agree with Bill here, the technology for wire and stick welding 
has pretty much made gas fusion welding obsolete.  However, it is helpful 
to have the option of a torch for cutting, brazing or soldering--see below.

>As for cutting, the new battery powered Sawzall things are really nifty
>for carving up cars (they seem to cut "better" than the corded ones) --
>just get a pack of metal cutting blades, a couple extra long ones, an
>extra battery, and a good pair of leather work gloves and have at it.
>It's like having a portable band saw!  And they are great for cutting
>out patch panels at the yard/where ever, exhaust work, pruning trees,
>and of course construction/demolition.  The newer lithium battery packs
>are expensive, but light weight, and there are some new nifty looking
>"one handed" models.

For thin metal, the next step up would be a plasma cutter.  The price of 
imported versions of these rigs is approaching the point of being an 
alternative to oxy/fuel cutting.  The big advantage is that they work well 
on thin metal and will also cut stainless, aluminum, etc.

>That leaves heating -- well, oxy-acetylene does work well for that, but
>so does a propane torch, if you are the patient sort, and there are
>other gas mixes in those little disposable cylinders that burn hotter
>and they are way more affordable.  And you *can* use an arc welder to
>heat things up.  Richard Finch, yeah, that Richard Finch - he does have
>a "real" job - (see, there is a Corvair connection here) has a pretty
>good Welder's Handbook out by your old HPBooks friends.

For general heating and brazing I simply use oxygen/LPG (propane). This 
mixture is not as hot as oxy/acetylene but is fine for these purposes. I 
fact, this is what I use (along with thousands of scrapping yards) for my 
cutting torch. I simply got a set of tips for use with LPG and a standard 
Blue Rhino 20lb tank (which are now only filled to 15lbs).  There are no 
insurance hassles with regard to having an acetylene tank lying around.

>But, if you want oxy-acetylene, by all means, go get one -- buy a couple
>good fire extinguishers at the same time, and check the fine print in
>your fire insurance policy.  Check with your gas supplier to make sure
>you can get the mini-tanks refilled/exchanged locally.  There is little
>point in buying tanks, imo -- just get exchangeable bottles at the
>welding supply. (Things may work differently elsewhere than my upper
>left coast experiences on this.)

Check out the long term lease deals for commercial tank exchange. I paid 
only about $250 to get 20 year leases on an oxygen tank and an argon/CO2 
tank for my MIG welder.  When one of them runs low, I simply order an 
exchange for a full one from stock--same day service.  An owner's tank 
needs to be shipped back, inspected, filled and returned--about two weeks 
in my neck-of-the-woods.

Dale Dewald
Hancock, MI