I'm only a hobby welder but I'm making progress. I've recently been working on developing tig welding skills and have an idea for a small roof rack for my truck and was thinking of making it out of stainless but have a couple questions.
1. Is welding stainless any harder than welding mild steel?
2. Is the weight of stainless steel the same as mild steel?
Thanks a lot.
Kind regards,
Vic
Redlands, CA
El Cazador,
Welding SS is a little differant than welding CS. Some say harder, and it does take a little getting used to, but no real big deal for most.
Yes indeed SS is heavier than CS. :-)
jrw159
in my experience Stainless steel is easier to weld but that depends a lot on the grade, filler etc. In my opinion 304 stainless steel is some of the easiest material to weld. Also with stainless you don't have to deal with rust as much and mill scale which makes the precleaning much easier.
I can relate to that. One of my first experiances with SS was .083 and .110 wall SS tubing. Many of the welders around me found it difficult to adjust to after welding CS for some time. A very few of them were CS only welders simply because they had a hard time adjusting or just plain did not want to. As for myself, my "transition" into SS was not a problem.
jrw159
GOOD Point RANDER!
I skipped right on by the cost issue. LOL
jrw159
You can get stainless tube already polished, if polished is the look You want, this is the way to go.
As long as you get the correct filler material, it's likely you won't have an issue with welding typical stainless alloys. If you don't get the correct filler, you can have problems with solidification cracking.
Thanks for the input. It's so valuable to be able to get answers by people who have more experience and knowledge, which around this forum is everyone else but me. :-)
Since weight is an issue for me I'm ruling out stainless. I'll just powder coat it I guess, although that's certainly no guarantee against rust. I don't know if aluminum is strong enough for the purpose and besides, I'm just getting somewhat proficient at tigging steel. Haven't even begun to tig aluminum. I'm thinking the practice there will be expensive.
Thanks again.
Kind regards,
Vic
Redlands, CA
The difference in weight [between carbon steel & stainless] isn't great enough to matter. Stainless tube left bare will be lighter than the same size & wall thickness of carbon steel tube powdercoated. Aluminum COULD give a lighter structure at the same stiffness, or stiffer at the same weight, if You choose the proper section sizes. Proper section choices are required in stainless or carbon steel as well. Larger diameter & thinner wall thickness is stiffer than a smaller but thicker tube of the same weight per foot.
Edit: If You were to use aluminum, You want 6061 T6 or 6061 T651. The yield point of these alloys is a tad higher than mild steel, but the HAZ of the welds will be lower. With proper design this is not a problem.
Thanks, Dave. The use of aluminum is tempting, but my welding skill on aluminum right now is zip. Maybe I'll do it in steel, see how it works and if need be figure out a way for aluminum.
But your response referenced HAZ and after looking up its meaning am now wondering in what way the HAZ affects the weld joint in terms of its intended use?
I know, buy a book. :-)
Kind regards,
Vic
Redlands, CA
Vic,
I think for your roof rack you should just use steel tube. It is just a roof rack. If you roll your vehicle a stainless repair will be expensive as will an aluminum repair. You have experience with steel so use it. Besides you could keep enough steel in the garage to make a new one if you wanted. Check your PM I believe I know what you are looking for. You have a non critical application just use an adequate size tube.
Plain & short, the HAZ will have about 1/2 the tensile strength of the unwelded material when an amature welds 6061 T6, and a little more when a pro does it and follows all the rules. You have to design accordingly.
I would suggest You get some aluminum and stainless scraps and try them. Bare aluminum [NOT anodised] is pretty easy, wire brush immediatly before welding with a sharp clean stainless steel brush.
For really easy aluminum welding use MIG and a spool gun.
Thanks for the additional input. It's very helpful. I like the idea about the spool gun because I got one with the Millermatic but never used it. Is the wire some kind of flux core or is gas used? Just curious.
Anyway, thanks so much for the suggestions. I'm more comfortable doing this now.
Kind regards,
Vic
Redlands, CA
Hello Vic, actually the spoolgun can be used to run any type of wire that is available on a 1 pound spool. Depending on the type of wire, you will need to consider the various types and mixtures of shielding gas that you will want to use with it. If you select a wire that is a "self-shielded flux-cored wire" you won't need any shielding gas to use it. If you use this wire you will also likely need to change the polarity to "straight polarity" meaning the the gun is -/negative and the ground is +/positive. I don't know of any other wires that use a shielding gas that don't operate on reverse polarity, meaning that the gun is +/positive and the ground is -/negative. If you are already aware of this information please forgive me for including it. For some information on shielding gases use the search function of the forum and type in shielding gases or go to the web and type in the same topic. You will find that there are many different choices for shielding gases. With certain wire types there are limited choices for correct gas, for other types of wires there are a wide variety of choices, so do a little homework and it is likely that you'll end up with a combination that will suit your purpose and not break the bank in the process. Best regards, aevald
For aluminum in the thicknesses You will most likely use, pure argon is the shielding gas to use. You will probably find .035 diameter 4043 alloy wire the easiest to learn with. .047 - 3/64 wire works well too, but it puts down a lot of material really fast, and takes a little more getting used too. If Your Millermatic is one of the little guys, You might be better off with .030 wire. Don't forget to use that stainless brush, and don't use anodised tubing.
Having said all this, if the rack is for a work truck that looks like a work truck, as oposed to the spiffy rigs these guys are posting pictures of, and You know will be rough on it, use carbon steel or mill finish stainless steel. Carbon steel is by far the cheapest, rust assured.
aevald, DaveBoyer, and all the rest of you, thanks so much. Being a hobby guy y'all know so much more than I do that even simple questions and answers usually send me searching for more answers. LOL. But it's a decent way to learn if your livelihood isn't on the line.
I invested in a water cooled torch and got it up & running yesterday. It was just sheer coincidence that when I fired up the tig to run a couple beads on some mild steel my technique took a giant leap forward and it looked 50% decent as far as appearance. Penetration has always been good. For some, beyond stupid, reason I had been picking up the torch, allowing the puddle to cool, then dipping it down again, like I was starting to weld all over again with each action. I have no clue where I got that from but now it's cured and I can see that what I've done with the past 10 hours of practice was all but a waste of metal, filler, tungsten, and argon. About the only thing that got better was my patience and determination for get better. Oh well, I'm a lot happier now.
As I sit here I wonder what got others into welding. For me it was a visit to my dad's shop, which he owned with his brother and another man. Turned into a pretty big business. Back around 1962 they were making missile parts and they had a guy who used Heliarc to weld and I loved the result he was able to produce. Beautiful welds. It helped that my dad, who was a master tool & die maker in his day, said this guy was the best welder he'd ever seen. And it was nice that he said it in front of the man. So the guy took some time to explain what he did and then gave me a quick lesson. Of course afterward I removed the gloves and I inadvertently touched the metal I'd just been welding. Another quick lesson learned. :-)
After that I always wanted to learn to weld. Took me almost 40 years to get around to it. My cousin, a heck of a good metal worker himself now, said the guy I am talking about was a great artist and taught him to weld.
Enough of the past. Looking forward to getting better in the future.
Kind regards,
Vic
Redlands, CA
Hello Vic, glad to hear of your newfound success. It is really fun to enjoy those times when things start coming together. I believe everyone can tell that you are "hooked". If you want to hear of some of the stories of others "starts" there is a thread in the Off topic Bar and Grill section that is titled: How did you get your start?, it contains a bunch of really interesting and encouraging stories of success and personal enjoyment. I believe it is currently located on page 4 of the available backpages. Best regards, aevald
Hmmm, guess that personal history is off topic, huh? Sorry. Thanks for the point to the right location.
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