Gas weld aluminum for a horse stand

[BeezFun]

I need to make a stand for my wife's horse to stand on with her front legs for a trick show, something similar to the stands you see in a circus that the animals get up on. So it needs to be strong, but weight's an issue since we have to move it around. Been using something made out of wood, but it weighs more than the horse.

I'm a pretty good gas welder but have only welded steel, and have brazed a bit. What's involved butt welding square aluminum tube, probably 1-1/2" square, maybe 1/8" wall or so? The stand is 3' feet square, 2' off the ground. I assume the aluminum alloy will determine the rod to use? I'm not sure where to buy this material. I buy steel from a local supplier, they don't carry aluminum. My friend's an engineer, he'll check the structural design once I figure out what material to use.
thanks

 

[deereman75]

You can gas weld aluminum, but it is kind of hard, due to the low melting point. Since this thing is going to be holding up a horse, it needs to be strong and safe. I would recomend making it out of 4130 steel tube, that will be very light and strong. If it needs to be aluminum, I would take it to a shop to get it done, so there is less risk of the horse getting injured.

 

[CharlieS]

heat is critical, if its not hot enough, you get no penetration, if it's too hot, you end up with a huge hole where molten metel fell out of your work piece, special rod, special flux, the metal has to be super clean. in other words there's not much temp latitude to prevent problems.
It can be mig'd with the proper gas and wire but a better option would be get your layout and fitting done, take it to someone who has a tig, then you should be assured of a strong, safe assembly.

 

[BeezFun]

You can gas weld aluminum, but it is kind of hard, due to the low melting point. Since this thing is going to be holding up a horse, it needs to be strong and safe. I would recomend making it out of 4130 steel tube, that will be very light and strong. If it needs to be aluminum, I would take it to a shop to get it done, so there is less risk of the horse getting injured.

Hmm, maybe I should figure out how much it would weigh made out of 4130 tubing. That might be a better solution. I'd be comfortable welding that.

 

[BeezFun]

So I went and looked at square 4130, a WAG at what size I need shows it's about 1/2 pound per foot and I need about 50' of material, so that's only 25#. Definitely luggable. Especially if I keep the wood piece of the top removable. I'll have my friend start looking at what size tube would actually be needed.
tnx

 

[yomax4]

Tig weld it for maximum strength ( on aluminum ) If you Have to use aluminum and can not tig weld it.. You can torch solder it with a Harris product called CORAL. a flux cored aluminum rod. Or my favorite is to use an Aluminum Stick Welding Rod but apply it with a torch..Works very good, Very strong too. There are a dozen ways to fix this but Tig is still the best.

 

[deereman75]

I would use round 4130 tube, the same stuff used for stunt aircraft frames, alot stronger for the weight then square. Just make sure you dont use copper coated welding rods, it makes a 4130 weld very weak.

 

[BeezFun]

I would use round 4130 tube, the same stuff used for stunt aircraft frames, alot stronger for the weight then square. Just make sure you dont use copper coated welding rods, it makes a 4130 weld very weak.

I don't have any way to radius the ends of the round tube, don't want to do all that with a grinder and file.

 

[deereman75]

I don't have any way to radius the ends of the round tube, don't want to do all that with a grinder and file.

I dont think you would need to radius the ends for thin wall 4130 tube. But if you use thick wall (which I wouldnt) you can just quickly do it with a grinding wheel.

 

[BeezFun]

I'm talking about putting what I think is called a fishmouth in the end of the tube so it butts cleanly against the outer diameter of another tube. Maybe radius was the wrong word. I have a drill press and I've read you can do this with a hole saw. I would have thought you need a pretty strong fixture to get started cutting on the round edge of a pipe with hole saw. I have a vise clamp on my press, maybe that's enough.