Looks like you have gotten some good advise from others in the group.
I'll back up some of that. MIG would be great for assembling a swing
set, but it is not a good choice for assembling a 4130 tube fuselage. It
is not just about control of the weld on thin tube but also about final
strength and durability of the welds. The skill you develop with the
oxy/acet torch will serve you well if you ever wish to convert to TIG.

A TIG unit would be a possible choice, requiring only a bit more skill
that the oxy/acet torch. Its primary drawback is the cost. There are
some very good deals out there these days on units like the Lincoln 175
or 185 Pro series of TIG welders....but you can buy 3 or 4 of the best
acet. outfits available for that kind of money. And in the end the welds
will not likely be superior to the oxy/acet welds.

As for tools: A good hacksaw and/or a tubing cutter; a bench grinder
with at least an 8" wheel; I really like a 4.5" angle grinder to help
with coping the fit up; a few clamps and a magnetic positioner is a good
investment. A 6" bench vise.

I would also suggest a good quality dressing tool for the bench grinder.
Dress the grinding wheel so it has a radiused face rather than the
normal square face. This will really help shape the fish mouth weld
joints. As for the grinder itself, someone suggested, I think it was
Orval, getting a good bench grinder. I used to agree with that idea, but
twenty five years ago I bought the least expensive Taiwan bench grinder
I could find. I have used it in two metal fabrication businesses and
years more in my garage shop. I have replaced the electrical push/pull
switch once with a toggle. The unit still runs strong. I have been lucky
but the cheapest bench grinders will probably out last 5 or 10 projects.

Ed wrote:

Eventually I plan to build a tube-n-fabric aircraft, but now isn't the time.
However, I would like to start developing the skills that I will need.

I've been looking at kids playsets for our yard. Most of them are made from
redwood, and are quite expensive. Several thousand dollars for the more
complex ones. Pressure treated lumber is much cheaper, but I don't want my
kids crawling on it.

Today I got an idea. I could build a frame out of steel tubing, get it
powdercoated, and then deck it with the composite synthetic decking that is
becoming popular for backyard decks. Such a structure would be strong,
durable, impervious to the elements, and would give me an excuse to learn to
weld.

What are the minimum set of tools I'd need to buy to complete the project?
I know I'd need an OA torch. What tools would I need for the cutting,
shaping, and prepping of the steel tubing? Any other suggestions on
construction and materials, especially steel type?

--
Bruce A. Frank, Editor "Ford 3.8/4.2L Engine and V-6 STOL
Homebuilt Aircraft Newsletter"
| Publishing interesting material|
| on all aspects of alternative |
| engines and homebuilt aircraft.|
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0 0 TIG welding

While trying to find the time to finish mine.