TIG Alley

[Mullet52]

Your argon flow or balance is off. Or both.

What torch setup you running? Gas lens or standard?

Are you cleaning the edges of the material and wiping with acetone?

The 4043 is looking grainy because of heat build up. I’d use 1.6mm filler rod on 2mm material

 

[Dr.Al]

Pressure blowing back as there is no where for the gases to escape when you try to button it up on last corner.
Drill a tiny hole in one of the faces and it should resolve this
Then dot a bit over the hole when done.

Thanks, that's useful advice. I'd been keeping the corner free as a vent hole, but maybe I'm making it too big. It would certainly be easier to use a drilled hole in one of the faces. Hopefully I'll be able to seal that without the same problem but I guess if the hole is a lot smaller it'll help.

Your argon flow or balance is off. Or both.

What torch setup you running? Gas lens or standard?

It's a #6 gas lens on a CK9 torch. Flow is set to somewhere in the region of 6 lpm (I think).

Are you cleaning the edges of the material and wiping with acetone?

Yes. On all of the joints I've done so far the edges have been milled (I haven't mastered getting a good finish on aluminium with the plasma cutter) and then wiped with acetone. The next lot are as provided by the supplier so probably guillotined. I'll clean them up (either with a hand file or a carbide burr) and then wipe with acetone.

I also wipe the filler rod with acetone before starting.

The 4043 is looking grainy because of heat build up.

Interesting to know that's the cause of the 4043 problems. I hadn't managed to get my head round what was causing it to look so blotchy.

I’d use 1.6mm filler rod on 2mm material

Thanks, I'll give that a shot. I've got some 1.6 mm 4043 filler rod. I might have to order some 5356 in smaller sizes as well sometime soon - I'm sure I'll need something much smaller to do the 1.2 mm sheet. Do you think 1 mm is best for this (assuming it's available - not listed on weldequip, but I haven't looked anywhere else yet)

 

[Mullet52]

6lpm sounds good for a gas lens. I have mine between 5 - 7lpm on a number 7.

For me I like the balance to be between 60-70%

I definitely prefer 5356. Especially on thinner material

 

[Richard.]

Thanks, that's useful advice. I'd been keeping the corner free as a vent hole, but maybe I'm making it too big. It would certainly be easier to use a drilled hole in one of the faces. Hopefully I'll be able to seal that without the same problem but I guess if the hole is a lot smaller it'll help.

Outside corners are always prone to shielding issues and a blow back full of nitrogen/oxygen is obviously gonna make the problem worse. Right on a corner is probably the worst place to have your last vent to button up.
Drill a small hole (2mm or so) right in the middle of the face. Allow it to cool right down then quickly spot it in when done. Dress and polish it back to suit.
Colour match may be off so put it in a less visible place.

 

[Dr.Al]

Outside corners are always prone to shielding issues and a blow back full of nitrogen/oxygen is obviously gonna make the problem worse. Right on a corner is probably the worst place to have your last vent to button up.
Drill a small hole (2mm or so) right in the middle of the face. Allow it to cool right down then quickly spot it in when done. Dress and polish it back to suit.
Colour match may be off so put it in a less visible place.

Thanks again; shame the original video from welding tips & tricks didn't cover this bit! I've had a go (with the 125 mm squares this time rather than the 90 mm squares), just waiting for it to cool down. I went with a 1.6 mm hole in the middle of a face. It doesn't matter that much to me if it looks a bit shabby: it's not as if these cubes have any function beyond TIG practice.

I think the joint welding went okay. I had to change the tungsten after the first bead as I'd somehow dropped the post-flow from 5 seconds to 4 seconds and ended up with a colourful tip. After that I managed to use the same tungsten for all the rest of the beads with no changes or dips and it still looks good.

Two joints were a bit shabby in one place each. I'd managed to get some contamination into one of the tack welds but hadn't noticed at the time. I saw it as the weld pool melted it but there wasn't much I could do about it at that point, so I just carried on. That's in the first photo below. On one joint it got a bit hot in one place but otherwise I think it was okay. I was generally happy with the rest of them (not that I'm claiming they're good, just that they're good by my welding standards!), but I might change my mind once it's cooled down enough to properly inspect it.

A few photos of the progress so far:

Hopefully I won't completely wreck it when I come to plug this hole:

 

[Dr.Al]

Fluffed it up again, but I think I learnt something, so that's a positive, isn't it? Maybe?

Lit up on the hole and immediately everything went nasty quickly so I lifted my foot up quickly:

Close-up:

So I attacked it with a carbide burr and cleaned off all that nastiness:

I then carried on to get rid of that last little bit and lost control of the carbide burr (several times) and made a complete mess of the top surface

To try something different, I sharpened the filler rod to a fine point on the belt sander. I then cut a short (4–5 mm maybe) length off and pushed it into the hole, followed by a few taps of a hammer to get it firmly in there.

Lit up on the end of the banged in filler rod and it went all lovely and puddly and settled.

That black dot is dirt (exaggerated by the photo - it didn't look that bad in practice) as I hadn't fully cleaned it, it isn't a hole .

I then tried to add a bit of extra filler to make up for all the carbide burring and promptly blew a huge hole in the face

Anyway, I'll have another go (probably tomorrow) on a new cube and that time I'll try the filler-rod-hole-plug technique straight away. Who knows, it might work! Whatever happens, it's all good practice at outside corner joints.

If, once I've done a couple more cubes, I want to really ruin my week and try doing this with 1.2 mm aluminium, what size filler rod should I go for and what sort of current? I can't find anything smaller than 1.6 mm in 5356 at the moment; is that too big? Or is this just a damn fool idea and I should walk away now?!

 

[Richard.]

It’s air blowing back and contaminating your shield. If it continues drill another hole near to it and fill it with argon (second hole to vent out the air) at least then the gas pushing back will be inert.
Then quickly dab them both shut.