It is vastly easier to learn on a good machine. I good weldor can get good results from a crap machine since they know how to compensate for all it's faults. When learning it's much easier to only have to compensate for your faults.
That is interesting. I used to do assembly line soldering on MIL-Spec electronic equipment, so electronics soldering I can do in my sleep. In fact I think that's why I picked up stick welding fairly quickly, a molten puddle is a molten puddle to some extent, although I know aluminum has very different melt characteristics.
Bill Ranck Blacksburg, Va.
I would like to say thanks to everyone who has responded to my questions. I've read all the responses so far and it's been interesting and informative. I now know what sort of questions to start asking at the local welding supply. Cost of gas, etc. This is a long term project/hobby so I can take my time looking for good used equipment and learning to use it.
I will keep reading the group, though I'm mostly a lurker if I don't think I can add anything to a discussion.
Bill Ranck Blacksburg, Va.
TIG is very much closer to electronics soldering than stick, with no sparks, smoke or spatter so you can get in real close to see what you're doing, and heating with a torch in one hand while adding filler with the other.
I'll certainly concede that some people might be able to pick it up quickly. OTOH, to do thin AL sheet requires another level of physical and hand- eye coordination far above most shop skills. I'd put it right up there with learning to land an airplane.
Haven't done it myself, but the hot ticket for MIG on Aluminum is supposed to be a spoolgun...
That way you don't have to worry about the aluminum wire kinking in that 20' - 30' of liner from the welder out to the gun - it goes straight from the bulk roll, to the feed rollers, then straight out to the nozzle tip. Or it makes one turn if you use a curved tip to get around an obstruction.
Well, you can do a LOT better for stick than a tombstone buzz-box. A lot of the old Miller gear does stick beautifully, very controllable. And you can do much heavier work in one pass, especially with an engine drive so you aren't worrried about blowing the main fuse.
Big problem with stick is the huge learning curve, where you'll be making a LOT of hole and a LOT of cold dauber welds till you get it all figured out and build a touch. And it's even worse if you are welding a thin tab to a thick beam, or vice versa - getting the penetration divided right is nasty.
Whereas you can pick up MIG or fluxcore wire-feed a LOT faster, and be making good structural welds in a few hours of practice.
You can buy or build a fume extractor for welding, to get the smoke out of your face. Simple as a boat bilge blower or a large muffin fan, and a length of aluminum foil dryer hose for the inlet.
You can use the vinyl flex hose for the exhaust end of the fan, getting the fumes out of the garage, but the molten dingleberries will light vinyl duct on fire at the weld end. With the aluminum foil flex on the suction side the spatter might melt a hole, but that's it.
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Make friends with your local Fire Extinguisher shop. When the horn, hose, or valve are damaged on a CO2 unit, or the seals need replacing, they have to use OEM parts to maintain them. And if the company that made the extinguisher is out of business there are no more Factory Parts. As an extinguisher, it's trash.
All you have to do is have the shop change the valve to the proper CGA form (renew the Hydrotest if it's due) and refill the bottle, and now you have a perfectly good CO2 shielding gas bottle. For a /very/ reasonable price.
Straight CO2 is cheaper than any of the blends, just fine for MIG around the home shop.
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Indeed. And it wont rot as fast as Aluminum
Gunner
"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.
Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner
Ive done a bit of welding myself over the years. Stick weld like a pro. Mig weld like a regular... Fumblefuck around on TIG. It sticks..every other weld often looks nice....but its HARD for me.
Ive got some nice welders...Esab SquareWave 200, Airco 300 SquareWave, Synco350....just the machines for TIGing..and thats the best I can do. Ive got neighborhood rug rats that Ive worked with for an hour, that can TIG like pros now. But..its still Hard for me. Some folks are better on one method than others. Shrug..you just have to find out what your style is.
If you can do all 3..you are Da Man
Gunner, tickled to get 2 out of 3
"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.
Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner
Indeed. Ive got 6 MIG bottles. 4 of them are C25. Two of them are CO2. I use the C25 maybe 3 times a year. The rest of the time, both of my Migs have a Co2 bottle on them. And I weld a lot..... Most of my C25 bottles get filled every couple years...
Gunner
"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.
Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner
I'm inclined to let this one go, but it looks like something that might leave someone confused, so I'll be the contrarian.
Aluminum, generally 6061, will be a bit lighter than 4130 "chrome moly" steel in a space-frame tubing structure, as has been shown in the Bobsy racecars of the 1960s, the Porsche 917 series (which eventually went from steel, to aluminum, to aluminum-magnesium alloy tubing), and some recent Lotus 7 clones reproduced in aluminum from the original design in steel tube. If you aren't going to triangulate the structure but are going to make a cage or platform without diagonal bracing, aluminum can, with proper design, be a lot lighter.
But it's difficult to get really strong joints in aluminum tube unless you're one very good TIG weldor. Welding 4130 is a snap by comparison.
There are two issues: stiffness and strength. There is some advantage to aluminum over steel in a true space frame in terms of strength. There is none in terms of stiffness if you replace the steel piece-for-piece with aluminum of equal weight. However, given the thicker tubing walls in an aluminum structure of similar or slightly less weight, or the larger tubing diameter (take your choice), there is an advantage in buckling resistance under compression, which can lead to a structure with longer spans between joints and, possibly, fewer tubing members.
It's not what I would choose for a motorcycle trailer of welded construction, however. I'd go with steel. But I see no reason to go to the expense of 4130 over mild steel. It won't be any stiffer, and stiffness is likely to be the limiting design parameter, as it is in racecars. It will be stronger, which might matter if you expect to crash into something with it.
As for internal rust, ask Richard (cavelamb) for the current thinking in light aircraft tubing structure. Linseed oil is the traditional treatment. Foam-in-place urethane foam is used by some. There may be something better today.
-- Ed Huntress
Ditto here. I can x ray on stick and MIG, but can hardly put two pieces together with TIG. I can do stainless so it sticks, and it looks decent. Never got the hang of AL. But give me some 6010 and 7018 and tell me what you need done. Everyone is good at something, that's the way of the world.
Steve
Another huge consideration is fatigue life - Motorcycle trailers are light, and are going to bounce around a lot. When streel is flexed a lot it will fracture, but a lot slower - you'll see the swayback. When aluminum hits it's fatigue life it'll rip like paper.
If you don't design and build it perfectly, you will eventually end up with a two (or more) piece trailer chassis. If you do a really good job you'll hear a lot of crunching noises, see an axle and wheel passing you and go "Hey, that looks familiar..." >_<
You could make the body out of Aluminum tube with a monocoque skin riveted on for strength,think Airstream trailers. Or better yet, hand laid Fiberglas over sculpted foam board (like a surfboard) with Aluminum tube reinforcement rings around the door openings, and on the doors themselves.
But I'd still make a steel chassis to tie the axle and spriing perches securely to the coupler. KISS.
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You nearly have to. If you have even a slight draft, it blows your shield gas away. At the price of Argon these days, I want to get by with the MINIMUM flow I can.
It is a bit messy to TIG anything galvanized, otherwise I haven't had any problem with it.
Jon
Do the math. Welding produces smoke.
Steve
If you are TIG welding AL and you've done proper surface prep, there's hardly anything to create smoke.
That's what I thought. Is that also true with steel?
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