Joint Strength - Free Aluminum Score

[Stefan S]

Hi all,

I scored some extruded aluminum and I am wondering how strong it will be when welded.

My plan is to make a welding cart from this stuff and I have a Miller 211 MVP. I will miter the corners on the 90° bends. Do you think I need to Gusset with some sheet aluminum? I'm concerned because I won't be able to do a full weld around the tube which is roughly 2x2.

I am a decent welder but a very novice fabricator.

Thanks in adavance

 

[koditten]

Do some test welds. put the pieces in the vice and see what happens when you try to bend the aluminum. That looks like some stout Al, so you should be able to get some good welds.

KO

 

[kald]

I agree that is some strong stuff. I think you have to find out what type of aluminum that is and see if it's weldable.

 

[bimmer1980]

Remember that it is only a welding cart..... it's not going to fly and it's not going to go screaming down the highway at about 70mph....

Just try to get the best penetration that you can. Do note that welded aluminum looses some strength due to the loss of temper.

That particular style of extrusion is meant to easily bolt together using special connectors and gusset plates. You may be able to source those online for a decent price. At the end of the day, it may be much easier than welding.

Have you welded aluminum before?

Gussets would be very helpful and would probably allow you to get better welds.

Your mileage may vary, but I think for a welding cart, you will be fine.....

Worst case, if it breaks, just reweld it and add some gussets or reinforcements....

 

[Stefan S]

Thanks for the replies!

I have tig welded aluminum quite a bit but never have I had an opportunity to mig weld it. Mig welding is the only machine I have. I agree it is only a welding cart but that said I might cry if I discovered my welder crashed on the ground!

How does one determine the type of aluminum? melting point?

 

[383 240z]

A GOOD scrap metal dealer should have a "gun" the can shoot it with that will give you the alloy. Keith

 

[bczygan]

That profile would be excellent to use to assemble something without any welding at all. It would also lend itself to easily sliding panels into the slots for top, bottom, back and sides. Panels could be perforated for air flow. Casters or wheels could also attach by sliding into the slots and tightening. Don't know if they are the standard T slot. You could check. I know you are dying to weld it, but check what connectors would work, and what they cost.

 

[elvee]

That looks like 80/20 framing system material. You can find out about their stuff on their website - www.8020.net. Should be 6061T6 aluminum.

You can also get all the hardware to just bolt / clamp it together.

 

[Kevin54]

I looked in my 80/20 catalog and although the above pic looks similar, I don't think it's an 80/20 product. One reason is that the 80/20 material has a hole through the center that is either round or it has an ear on each corner of the center hole.

But anyways, the 80/20 site shows that their extrusions are 6105-T5 material. The extrusions are also clear anodized. Whether that is a problem or not, I'm not 100% certain, but I think you need to remove the anodize before welding.

As far as adding gussets, I really don't think you would need them. Once you have everything welded, it should be rigid enough for what you want to do. If it isn't, you can always add a couple of gussets later on.

 

[Stefan S]

That profile would be excellent to use to assemble something without any welding at all. It would also lend itself to easily sliding panels into the slots for top, bottom, back and sides. Panels could be perforated for air flow. Casters or wheels could also attach by sliding into the slots and tightening. Don't know if they are the standard T slot. You could check. I know you are dying to weld it, but check what connectors would work, and what they cost.

You are right about wanting to weld it! that said it is perfectly suited to being bolted together. I actually have a bunch of connectors and feet as much of the material was still assembled. That said if there is anyone who knows the manufacturer I would like to know who makes it so I can potentially order more. My 5 x 10 trailer is loaded with this stuff.

 

[larry_g]

You may have Bosch strut there, http://www13.boschrexroth-us.com/Framing_Shop/Product/Default.aspx?Group=101 . There are many manufactures of this extruded strut and and do not all take the others t-bolts and other fittings. So if you decide to buy some of the fittings to assemble this make sure that you get the correct brand and profile size. I see some connectors on some pieces in the background and they should have a part number on them or a brand. I've worked with a lot of this and if you structure your joints correctly I would think that bolted would be as strong as welded. Take a bit of time to research what connector fittings are available.

lg
no neat sig line

 

[racingtadpole]

Regardless of who the manufacturer is its almost certainly guaranteed to be clear anodised. Will this cause you problems? Yes, lots of them. You will need to meticulously sand/grind off all the anodising before attempting to weld anything, PITA on a profile like that.
If it were me, I'd be inclined to find out who made the profile and buy the bolt things that slot inside. If time is plentiful and money scarce (or you just want to build something for the sake of saying you did it ) you can fab your corner gussets out of plate to hold it all together and save the cost of those. You might even find a dome or cheese head bolt that fits in there if you want to do it without buying expensive proprietry parts.
Plenty of ways to give this feline a trip to brazil.

Edit: BTW you **** for getting all that for free

 

[jhelrey]

Looks like you could just use a carriage bolt...

 

[NASTYZEN]

If it has a coating on it. Sandblasting is fastest. Followed by a wire brushing, preferably S/S.

 

[Stefan S]

I ground the anodization off and welded it up with some 4043 filler rod covering only the flats, inside and outside corners. It was plenty strong as I was hanging off it but aestetically it looked kind of dumb because you could see the seems through the valleys. I may just bolt everything together.

Thanks again for all the great advice!

 

[fivespdcat]

Man, I would kill for a truckload of that stuff! So much you could build with them and very strong! It's used in industrial settings for things like workbenches, fixtures, etc. plenty strong bolted together.

 

[isaac338]

You found that stuff in a dumpster? You really ****!

 

[Stefan S]

You found that stuff in a dumpster? You really ****!

 

[Kevin54]

You may have Bosch strut there, http://www13.boschrexroth-us.com/Framing_Shop/Product/Default.aspx?Group=101 . There are many manufactures of this extruded strut and and do not all take the others t-bolts and other fittings. So if you decide to buy some of the fittings to assemble this make sure that you get the correct brand and profile size. I see some connectors on some pieces in the background and they should have a part number on them or a brand. I've worked with a lot of this and if you structure your joints correctly I would think that bolted would be as strong as welded. Take a bit of time to research what connector fittings are available.

lg
no neat sig line

To go along with Larry's site, here is the 80/20 site for comparison http://www.8020.net/Default.asp

 

[zr1nsx]

There are many producers of this type of strut. Specifically disigned for building modular benches, robot stations, custom machinery, etc, etc. It is anodized. It would be a crime to weld on this material. Buy the proper joining hardware and assemble with some pride. You'll have the best looking structure and it will be strong as hell. Saves a lot of time as well. Most all of the manufacturers of this material show time studies of how much more efficient and strong this type of material is verses a weldment. It cuts very easily with a good mitre saw with a fine tooth carbide blade. Use a WD 40 as a cutting lube and it goes real easy. Please don't weld it.

 

[Bobhdus]

I've welded the 80/20 stuff before. Welds fine and structurally never had any problems. A lot of people tend to "over weld" things. We usually bolt what we can but in an emergency, or prototype build with no spare parts, we weld it. Never had any issues. I was thinking about making a Pool Table with some of the heavier sections we used to throw out where I work (I still have the plans, somewhere). You can get it in about any color and the 80/20 Company can do any special machining or customization you may need. They will even cut to length and build your project for you. Like everyone else though, I would fab my own brackets and bolt this though (or buy stuff on ebay/ craigslist). With a simple drill and or holding jig you could spit out quite a few and enjoy welding some un-anodized Aluminum brackets. That way as your needs change it takes no time at all to loosen a bolt and move a piece to where you need it

 

[uniballer]

That is called item, yes you can weld it. It is strong! But you have to tig weld it.