I'm completely unfamiliar with welding, so I'll be sending my things down to the local shop to have them welded. But, will I run into problems welding aluminum to steel?
no you cant weld aluminum to steel, unless you use some very specific filler rods and a lot of experience. even then you would have to push the alu into the steel...or you could get a thermite reaction when the iron oxidizes and reacts with the aluminum and melts your entire part, as well as a large hole in your concrete floor.
How about aluminum to aluminum? Is it just when you mix the metals? I would use only steel, except that part of it needs to be bent and I don't think I'll be able to do that to steel.
How thick is the part that needs bending? If it is so thick that you can't use a bending brake then you may be able to hammer fold it. Aluminium to aluminum welding is common. mixing metals is when it gets tricky.
yes, it is almost as easy to weld aluminum as it is steel. iirc, aluminum requires that you use AC to weld rather than DC+ or DC-.
It's still in the planning stages, but my other modding section topic, Capsule - Concept is what I'm working on. The bent aluminum cylinders will be welded to the base. To bend the aluminum, I'll just be using a ton of clamps to bend it around a wood mold the exact size of the bend. Once it's in place, I'll bolt the metal together, holding it in place. I'm hoping that I'll be able to get a smooth bend without any creases in the aluminum, but not sure if I'll be able to. If anybody else has any suggestions, I'm open to them.
i wouldnt be so sure, around here, there are very few ppl who can do aluminium welding(without turning the piece into a mess) my dad happens to be one of them its a lot different from steel, with steel you can just weld some patch kind of surface to hold 2 parts together, with aluminium you have to melt the whole edge so the 2 parts would become one. not so sure about the ac/dc thing, he uses his standard steel welder, maybe theres a button or something. you also need argon gas and different wire for it though. aluminium welding will probably be much more expencive for you, and if you want to attatch aluminium to steel then use rivets . Btw, how thick are those aluminium tubes you want to bend? aluminium is not very good for bending, if its over 3mm, i think it might rip or something.
Steel and aluminum can only be brazed together, or soldered, depending on how big the part is and what it does, that could be strong enough. Rivits, screws, or epoxy might be a good method to join the two.
I just happen to be going into my 4th year as a welding engineer and right now I'm working 2 welding jobs and I've seen strange things like this. aluminum and steel can't really be welded together what with the large difference in melting points and grain structure you'll end up with bubbly mess generally. There are some speciatly processes and ways to fit em but it's not a practical thing. They can however be easily brazed with brass. I will note that I weld aluminized stainless steel everyday and it will never look good. Aluminum to Aluminum isn't hard to weld for any decent welder but the welding pool isn't self cleaning nearly as much as steel so any contamination or oil, or even cut edges where it touched a steel blade will make it a little harder to weld. However any fab shop should have experienced welders on hand who can handle aluminum no problem. Steel to steel is very easy in my book and just about anyone off the street can MIG two things together. anyways to answer you question I looked at what your trying to make and in the long run, cost etc it might be easier to form out of steel. looking at the design right now, you won't be able to hand form it with clamps over a pattern, it would be a nightmare to keep smooth and it will want to spring back. Alternatively any fab shop would be able to roll that on a 3 ring roller in a few minutes. OR you could buy a length of pipe in the diameter you wanted and have it cut to length the problem there being pipe is generally much thicker and more expensive. if you wanted to hand fab it, you would find 2 rings or a pipe or what ever that was the exact diameter you wanted then clamp the sheet to the form and roll it and then clamp or bolt or weld it together and you would have a nice cylinder. that's just my suggestions, but I like this work and I recently had to fab some cylinders out plastic in much the same way
Its pretty hard to answer questions about fabricating things without the specifics, but can share this with you... bending aluminum isn't difficult, but to do it straight is best done with the proper tools. You would be amazed how quickly and smoothly bends can be made with a good hydraulic press brake. These parts were made for me like that out of .100" aluminum without any special tooling whatsoever, just a knife die on top and a "v" die beneath... meaning the guys running the brake determined where to press the dies onto the parts, how far and how often. They did change the bottom die to make the tight 90 degree bends. They were made on a twelve foot long, 250 ton hydraulic press brake. A detail shot... About welding aluminum... its all about who's doing it. I know that's a vague answer, but its the way it is. Personally, I would suggest avoiding any welding unless you like the look of it (can be gorgeous if its done right) because aluminum is just so easy to make parts out of that screw together (more accurate and no distortion... also much easier to finish).
For round forms you could always just try to find something that is already round (like a pipe or something) and adapt it to your purpose. I think you've heard enough about welding/soldering so I won't get into it anymore. If you are dead set on turning sheet alu/steel into a cylindrical form, the best way I know of is through a process called forming and planishing. This involves working your material with a hammer, lightly, over something like a steel bar. It takes a bit of practice to get it right, so maybe you should go with another option, but really the best round forms come from planishing and polishing. (My brother is a jeweler and metal sculptor.)
Thanks for all the replies. I've got a lot more information now. I like the idea of trying to find something that is already the size that I need. I'll see what I can find. If anything, I can probably find a website that will make custom cylinders. After looking at dutchcedar's images, I'll consider some other way of attatching them. I'm still open to welding, but I'll do some more looking.
sorry to bring a thread back from the dead but if all else fails jb weld it then sand and paint no one will ever know
