Welder choice?

In order to immediately derail your tread (:, I have to ask why you would use AL. Chrome moly steel will be lighter for a given strength and much easier to weld.

A good new AL TIG welder will set you back over $2000. MIG will be considerably cheaper. I have a Thermal Arc TIG/stick and I like it.

TIG welding AL is bloody hard to learn. I pick up shop skills real fast and am very good with oxy-acc, but I'm still struggling with TIG.

Fair point, if true. I was assuming strength-to-weight favored aluminum. I haven't done that research, obviously. Though the commercially built trailers seem to use aluminum.

Good to know, and exactly the sort of insight I was hoping for. Thanks.

Bill Ranck Blacksburg, Va.

Miller Syncrowave 250, about $800-$1,000 at liquidation auctions.

i

I had some Oxy and stick welding experience, not enough to call myself a welder, but I built my own two 14 gal fuel tanks and a external oil sump for my Baby Belle helicopter. I chose to do the aluminum welding because I just wanted to learn...I took a lot of time welding scrap aluminum together. I even welded up a small match box size 2024 T3 aluminum box for the switches on the end of my collective. To date none of the welds have failed or leaked. If my shop caught on fire, my TIG welder would be rescued first. I'm on my second Miller TIG unit. I upgraded to better be able to weld thin aluminum. I could have had the tanks welded by a certified welder for a lot less than the cost of my Miller but somehow after learning to do it myself, I feel like I've expanded. Not better, but just more.

Stuart Fields

Synchrowave 250 Miller for TIG, Lincoln 175SP+ for MIG. New or used.

Steve

Find yourself a good used Syncrowave 250, preferably with water cooled TIG torch and cooler and don't look back.

Also TIG is very easy to learn on steel, particularly if you've done O/A or electronics soldering. TIG on AL is more difficult, but gets easier once you get decent at TIG on steel.

No gas change required between steel and AL for TIG, just 100% Argon for either.

Personally, for home use I wouldn't bother with MIG, it may be faster, but you're not doing production work, so speed shouldn't matter. Most of your time will be spent in the setup for each weld anyway, vs. a production line with assembly jigs.

Finally a post I know something about.

Switching from steel to alum would require a gas change. I've got no idea how you rent/buy bottles there so can't help much.(I know that here it would cost to much to be worth while) If you can ARC weld then MIG welding will be about as hard as colouring in once you have the welder set. I have always seen MigvTIG as simular to ARCvOXY/ACC. ARC is great on thick plate, but as the thickness goes down the welds get uglier so OXY/ACC takes over. I would say the change over point for MIGvTIG is around 2mm(5/64th). If most of the time you will be welding thicker then MIG, if thinner then TIG. One exemption to that rule is if you are welding lots of rusty sheet(e.g. car panels), while on new sheet with nice tight joints a TIG would be best. Tight joints can be pretty hard to get working deep inside a car and if there is much rust about you'll appreciate MIG's ability to "build bridges" easily. Also you can MIG weld one handed.

MIG Cheaper machine easier to learn faster welds rust is less of a problem one handed welding easy bridge building

TIG Prettier welds, especially on thin sheet(its pretty much the same as fusion welding with a oxy/acc) I'm sure there are more than this but I cant think of them just at the minute.

You do get f'd over on gas cylinders on that side of the pond don't you. You should mount a campaign to fix the problem.

As I do all TIG and mostly steel, my jigs are clamps and the triangular welding magnets.

oops yeah sorry I was talking about switching from a blend for MIG to Argon for TIG(my gas supplier would disagree with both of us as they seem to have a different blend for just about everything). Although one of these days I'm going to try my bend on a TIG just to see what happens. I think the tip life would be shortened, but as it costs so much to have two bottles and I'm not building pressure vessels it might be worth it.

Well now that depends on what you will be making. A lot of my "jigs" consist of holding it with one hand and tack welding it with the other.

You're not wrong, $158AU a year for one E size and don't even think about changing blend or bottle size, thats a "different" bottle and they charge you 12months rent again(with no credit for the months left on your last bottle) even if the reason you changed bottle sizes is because they couldnt supply the size you wanted!!!!

what thickness are you normally welding?

Maybe. I have finally gotten to where I can do it with predictable results. it took a while, and there was a lot of scrap. I had a friend over who had never even SEEN a TIG welder. I set up some scraps from a recent project and made one weld to show him the general technique. Then he tried it, did a pretty passable first weld, and then proceeded to show me up totally on his second piece, producing a weld as good as my best. He has done a fair bit of stick welding in the past.

I have to admit I have a really GOOD TIG welder, a Lincoln Square-Wave TIG 300, with a water-cooled torch. I think this does make a difference, too.

Jon

Yes! I did my first project with the TIG putting together a table for a big surface plate out of

2.25" DOM steel tube, and it came out very nice. I found doing typical steel projects you'd usually do with stick to be MAYBE a little slower with TIG, but FAR, FAR better results, no cleanup, and I could even weld inside! I have to work totally blind with stick, and always burn big holes in everything. A total mess. (I did have a horrible buzz-box welder, glass filter hood, all the worst stuff.) Once I did my first TIG weld in steel, with an auto-dark hood, I sold the buzz-box! Never again.

Stick is a LOT cheaper, no tungstens, no torch accessories, and especially no Argon! But, the flux smoke REALLY gets to me, so I hated to do stick welding. Now, I jump at the chance to do some TIG welding. I have done stainless, pure copper and aluminum alloy, as well as mild steel. Oh, note some aluminum alloys are not weldable.

With steel, you can use the color of the weld area to control temperature. Mild red is good, yellow is too hot and you are getting close to having it go Blop! on the floor. With aluminum, it will go blop before the first sign of color appears. If possible, having a piece of copper bar or even steel clamped below the aluminum can prevent a melt-through. So, you have to get up close and observe the mirror-like surface when the aluminum starts to melt.

Jon

I use straight Argon on EVERYTHING! Mild steel, stainless, pure copper, Aluminum.

You do use helium mixes or straight helium when you get up to the max capacity of the welder, to imcrease heat transfer.

Jon

Oh, YEAH, one other topic -- protective equipment! When I got my TIG, I started working with the usual gloves, and heavy clothes. I got an INTENSE sunburn on my chest, THROUGH a dark work shirt! It was actually WORSE where I was covered. I don't know if the shirrt fluoresced, or whether it was just the shirt coverage matched that part of my skin that had no natural tan protection. It took two weeks to heal!

So, I went and got a massively heavy welding jacket, and use it religiously! It is annoyingly hot to wear, but I don't ever want to get a burn like that again.

Jon

That's a question I've been wondering about for a while. My choices are either in the basement of my house or in my wooden shed (wood floor and all). The wife would be really pissed if I burned down the shed OR stunk up the house.

Is it really OK to TIG indoors?

Yuck. I paid about $150US for my 80cf Argon cylinder - once. When I run out, I just do the cylinder exchange thing and get another for $25US or so for the gas. No hassles with hydro testing. Once they didn't have an

80cf on hand so they gave me a 20cf to keep my project going at no charge and had an 80cf for me the next afternoon. I'm not a big customer either, just hobby stuff.

The bulk of my projects are 16-14ga square steel tubing in .5-1" size, with some assorted other odds and ends thrown in.

Ouch. I haven't had that problem with my TIGing, but I do find that I will get a neck tan from leakage past the helmet if I do a lot of welding, so if I'm on a big project I hit my neck with spf80.

An auto-dark hood is a huge help for hobby welders, both since we don't get enough practice at helmet flipping, and since we tend to have a lot of short welds with a lot of setup in between. A good TIG machine is also an excellent stick machine so you get 2-in-1. I particularly like the "arc control" adjustment on my Syncrowave which helps prevent sticking the stick on the rare occasion I do stick.

Yes, having some material for backup bars is very helpful. I recall Ernie indicating *not* to use a copper backup bar when welding AL. Something with contamination of the weld I think, ceramic is ok.