> >
> > > I would add that using a TIG welder is very much like using an
> OxyAcetylene
> > > torch, but the heat is supplied by an arc. The arc supplies the heat
and
> you
>
> I should have noted It's also more concentrated.
>
> > > feed in the rod just like brazing or torch welding. As with MIG
welding
> you
> > > need a nice calm day outside.
> >
> > So far I am seeing TIG welders for $900. - $4,000! Out of my range
> > for sure! Perhaps something used/refurbished?
> >
> > I have yet to find any reference to copper and references to
> > only certain models sufficient for aluminum. Hmmm.
>
> They may not reference it, but any TIG welder that has the heat capacity
> should work on coper and aluminum. You'd probably need to use a different
> cover gas though.
> >
> There are several problems using an arc on Aluminum and copper. As I
recall
> the big difference is between the voltage necessary to establish the arc
and
> that required to carry the current to melt the metal. It takes a *lot* of
> heat (BTUs) to melt Copper and Aluminum copared to steel even though steel
> has a much higher melting point..That is one of the things that raises the
> price.
I find that one reason aluminum is so hard to do good welds on is that it
melts well below "red heat" color. With steel, the color of the metal tells
you when it's about to melt so you can move the torch/arc/take your foot off
the TIG pedal. With aluminum, one moment it's nice and solid, the next, it's
running on the floor.
>
> Also "to me" TIG welding is much more of an art than MIG, or stick welding
> and a class on welding would be a good idea.It usually takes most people
> quite a few hours before they can run a good horizontal bead/weld joining
> two flat plates with any type of welding.
Very, very true. However, TIG is a lot like soldering in some ways, because
you're feeding in the rod from outside, and the torch/workpiece distance is
separate from the feeding. You have separate control over how fast you feed
the rod and how much heat you're putting in. With stick and wirefeed,
they're sort of combined. Of course, once you do MIG a couple times, you
get the feel for how far to hold the wire from the work and how fast to
move. It's more like spray painting that way.
Hey folks, all these metal joining things are pretty hard core craft skills.
They are not something you go out and buy the gear and the next day you're
welding up pressure tanks. They require good hand/eye/brain coordination,
and a fair amount of practice (and regular use) to be reasonably good at it
(to the point where you'd trust your life to the welds). For the vast
majority of situations, you're much better off finding a buddy or some
guy/gal in town who is willing to do your little jobs for you. Check the
local places that do iron fencing or muffler work as a start.
Auto/motorcycle fab shops (not body repair, but places doing serious custom
work) are a source of very skilled welders who are great at improvising.
(Oh, can you put this little tab over here, and burn a bolt hole through
there) Of course, if you live on a deserted island, or on a boat, or just
want to be totally self-reliant, then learning to weld is an exceedingly
useful skill. As has been pointed out, once you know how, you'll find all
sorts of things that need to be welded, and there is definitely a visceral
satisfaction to melting and joining metal (it's that holding fire in your
hand thing, I think)! Why, Humphrey Bogart found fusion welding skills
handy in "The African Queen".
Most community colleges have classes, and it's well worth it. Yes, you'll
have to learn some useless stuff too, and it is sort of aimed at folks who
are going to make a career of being a welder. The other alternative is to
find someone willing to teach you. Plan on spending 4 or 5 days with 3 or 4
hours at a crack. It helps a lot to be able to use someone else's shop at
first (because they'll have all the clamps, saws, grinders, chipping
hammers, and all around junk.. just like we have multimeters, clipleads,
antenna analyzers, coax adapters, etc.) Get yourself a pile of scrap steel
in various shapes, and start welding. Once you know how to weld, make sure
you tell your fellow hams, because there's probably a whole raft of projects
that you can help on.
One further warning... be careful welding galvanized steel, because the zinc
vaporizes and is toxic. All the commercial welders hate welding galvanized
stuff for that reason.
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