Welding Tips and Tricks

Hi welders,

I designed these aluminium monkey bars for my kids.(all in mm i'm afraid)
It's made mainly from aluminium 6060 round tubing ø30x2mm and Rectangular box profile 60x20x2mm. I'm planning on tig welding this frame.

Anny tips in what order to to assemble, tack weld and finish weld this ladder? I'm afraid that if i go by the wrong order the frame will twist.

Welcome to the forum! One of the great things about AL is that it doesn't distort and move when you weld/tack it. We have all seen what mild steel does if you don't restrain it. Stainless is even worse. Aluminum behaves itself but should still be restrained. Proper clamping and/or jigging will ensure you won't have any movement. Good luck and send us some pics of the finished project.

exnailpounder wrote:One of the great things about AL is that it doesn't distort and move when you weld/tack it.

Not sure what AL you weld, but AL surely DOES warp/shrink/twist due to heat. And it does move A LOT.

It is my opinion that you will want to fully restrain the rails while tacking and position and tack the tubes within the rails. Once each tube is tacked 2x on one end (I'd use a 180* opposite tack) swap to the other side and lay down tacks. Ultimately 4 tacks per tube.

Then I would set the bars up so the tubes are vertical, welding the rail/tube connection for one side completely, flip over, then weld the other side. But, I would have the rail I'm welding against fully clamped during the welding process. Let cool, then complete it.

Sidebar:
I do not wish to offend you, but, if you are uncertain about how to weld this, then I would suggest to you that AL is NOT the correct material to use. AL is prone to cracking at the weld if done improperly, and not the best material to choose for such an apparatus, especially when live loads (human weight) is involved. At the very minimum, you should confirm that the section strength of the tubes/rails exceeds the strength requirements. AL will fail without notice under load stress and you certainly want no responsibility for injury to a small person.
-Just meant as a safety concern-

cj737 wrote:

exnailpounder wrote:One of the great things about AL is that it doesn't distort and move when you weld/tack it.

Not sure what AL you weld, but AL surely DOES warp/shrink/twist due to heat. And it does move A LOT.

It is my opinion that you will want to fully restrain the rails while tacking and position and tack the tubes within the rails. Once each tube is tacked 2x on one end (I'd use a 180* opposite tack) swap to the other side and lay down tacks. Ultimately 4 tacks per tube.

Then I would set the bars up so the tubes are vertical, welding the rail/tube connection for one side completely, flip over, then weld the other side. But, I would have the rail I'm welding against fully clamped during the welding process. Let cool, then complete it.

Sidebar:
I do not wish to offend you, but, if you are uncertain about how to weld this, then I would suggest to you that AL is NOT the correct material to use. AL is prone to cracking at the weld if done improperly, and not the best material to choose for such an apparatus, especially when live loads (human weight) is involved. At the very minimum, you should confirm that the section strength of the tubes/rails exceeds the strength requirements. AL will fail without notice under load stress and you certainly want no responsibility for injury to a small person.
-Just meant as a safety concern-

The only AL I have ever seen warp or distort is flat plate, round and square tube and angle usually dont . It will distort when it gets really hot but nothing like other metals that's why everything needs to be restrained. For those little welds the OP has to do...a simple jig or clamp set up will be fine and I highly doubt his box tubing is going to warp uncontollably from those small welds. I wish I has taken pics of the AL diamond plate square tubes I just finished. Fully OS corner welded and not so much as a wrinkle...and not restrained or clamped whatsoever.

Found a pic of the sample I made for the customer of the project I just finished. Corner tacked and full welded on all 4 corners...no restaints. No warping or distortion either ...weird huh?

https://www.youtube.com/watch?v=HY30i_t1Da8
Here's a very helpful video that Jody made about welding AL box tube. He doesn't bother to restrain his tubing for tacking or welding other than third hands. No warping, no lifting, nothing other than aluminum behaving pretty nicely.

I must have some junky aluminum because I can't make it warp or twist or distort no matter how much I heat it up. Sorry for my crappy aluminum welds...haven't welded AL in a little while and I'm hangin pretty good but these were done this morning by just holding the pieces together and tacking, then setting them on the table and welding them..no clamps..no restraints. I guess it's only my aluminum that doesn't distort.

I've had serious problems welding AL plate (like it looks more like a bowl than a plate when I finish), but I can weld 4x4 1/8th inch square tube on a mitered 90 degree corner top and bottom, inside and outside corners with zero distortion.

WoodpeckerWelder wrote:I've had serious problems welding AL plate (like it looks more like a bowl than a plate when I finish), but I can weld 4x4 1/8th inch square tube on a mitered 90 degree corner top and bottom, inside and outside corners with zero distortion.

Admittedly I don't do alot of AL plate or even alot of AL at all but my last AL job was 1/8" diamond plate cut into 4"x5' strips and full corner welded into square tubes to slip over some bollards at my friends bar. No distortion or problems at all...just put a few tacks on them, made sure they were square and started welding. I had to let my torch cool off a bunch of times so I didn't really heat soak them but they were nice to work with. Plate is a problem...especially thin plate. Thin ANYTHING will warp when you heat it but to suggest that all AL severely distorts or warps is plain wrong. Other than AL having it's own characteristics to deal with, aluminum is a pleasure to work with. Now stainless steel will do some amazing things when you get it hot and thin mild square tube will teach you a lesson but AL is nice to work with.

Thanks for the replies guys!

I'll take mky time tacking and welding. As i read your posts i'm not that afraid that i'll get a helicoil.

I'll start in a week or two, and i will keep you informed. Till then i'll keep practicing. I started Tig welding three weeks ago. I got some box and round to practice the bulk of the welds.

Here a sample of my lastest test weld. I'm not at all disapointed. Hope i can get most of the welds like this. I'll keep you informed of the progress.

BramR wrote:Thanks for the replies guys!

I'll take mky time tacking and welding. As i read your posts i'm not that afraid that i'll get a helicoil.

I'll start in a week or two, and i will keep you informed. Till then i'll keep practicing. I started Tig welding three weeks ago. I got some box and round to practice the bulk of the welds.

Here a sample of my lastest test weld. I'm not at all disapointed. Hope i can get most of the welds like this.

Test weld.JPG

I'll keep you informed of the progress.

That is beautiful! Three weeks??? WOW! If you drill your bars into the box tube so that you're not relying on welds then you'll be fine. Most in-the-know welders won't make treestands or ladders out of AL because of the liability. Even ladder manufacturers use mechanical fasteners on their rungs or they bore and crimp them to eliminate the weak link, which is a weld. Unless you have 400 lb. kids I wouldn't worry You obviously have welding and mechanical knowledge so I say weld on...and let us see the final product.

The raw materials have arrived.

BramR wrote:The raw materials have arrived.

Ok lets see this go together with photos of your process

If you drill your bars into the box tube so that you're not relying on welds then you'll be fine.

^^^^^^^^^^^
That is excellent advice, eliminates the single point of failure of the weld.
Good luck and remember no photos, it didn't happen

Feel free to comment.

Pretty damn nice welds for doing ally for only 3 weeks! Nice job! Just make sure youre getting the weld bead down into the joint and penetrating. I only say this because I have made this mistake when I first started on ally and tried to weld pipe. It looked great on the surface, but when I cut it in half, there was a lack of penetration in the root of the joint. Kinda like it bridged over, and not down.

I would do as other have suggested though. Drill holes in the box tube and insert the crossbars. will be much stronger, and make life a bunch easier when youre jigging it up.

I sliced a box section in halve to check the weld. As you look close there is a line in the bead. Is this the residue of the oxide that floated on the penetration?
This is the inside of the tube.

This is the same weld from the outside. I think I started to cold, that is were there is lack of penetration.

(The black blob on the right tube is were I ran out of gas )

BramR wrote:I sliced a box section in halve to check the weld. As you look close there is a line in the bead. Is this the residue of the oxide that floated on the penetration?

1493399734973403799610.jpg

This is the inside of the tube.

1493399805033758253074.jpg

This is the same weld from the outside. I think I started to cold, that is were there is lack of penetration.

(The black blob on the right tube is were I ran out of gas )

Opps...we've all run out of gas.

Pictures make it hard, but are you sure that is not a crack running up the bead, that is what it looks like to me? Crank the heat up and burn it in...

Like others if I was building this Id drill holes, run fillets on the inside and button weld the outside if your go all the way through with the bars. Drilling as long as you can drill straight (LOL) will make alignment much easier.

That sure does look like a crack on the bottom of that weld. Even though it looks like you got great penetration, that bulging metal is your base metal that is sagging down and never fused together. Make a small gap between your pieces so when you weld, you will melt in on both sides and that will make a little keyhole that you will dip into. What you did was the same as welding over the top of a crack. Your welds sure look nice though.

exnailpounder wrote:That sure does look like a crack on the bottom of that weld. Even though it looks like you got great penetration, that bulging metal is your base metal that is sagging down and never fused together. Make a small gap between your pieces so when you weld, you will melt in on both sides and that will make a little keyhole that you will dip into. What you did was the same as welding over the top of a crack. Your welds sure look nice though.

Sure does and crack kills, so be careful with that. Before hanging anybody or anything on any item I build, I tend to put it to the ultimate retard test to make sure its all good.

BramR wrote:As you look close there is a line in the bead. Is this the residue of the oxide that floated on the penetration?

That's blistering on the back of the weld, from too much heat. It should look like the start of the weld where it was colder and you just see the original joint between the two pieces of material. Excess heat is also what causes the longitudinal cracking along the weld. I'd try moving a bit faster and/or reducing the current.

Guys, it's finished.

The good news is the welds are fine. The bad news is I probably should have used a bigger box profile. For the girls it's fine, for me it's a bit to flexible.
Could be that I'll make another one.

What a learner!!! There are some peppery joints. Mostly I think from my filler rod that got to far from the puddle. Or me trying to fill com a wrong angle.

Had a lot of fun & learned a lot.

I would have buttressed that angle with some 1/4 plate. Don't have my trig table out but hang 100 lb on it and the forces at that weld are likely over 1000 lb.