Simple Tig Cooler

[Paul.]

Clamp it down hard on a heatsink, a piece of aluminium or copper will be ideal, then weld round it at about 70 + amps, having the current too low will work against you, it make you move slower and increases the heat input,

Bigger job here but same principle, there is a lump of 1/2" copper plate under there.

 

[dazza]

Clamp it down hard on a heatsink, a piece of aluminium or copper will be ideal, then weld round it at about 70 + amps, having the current too low will work against you, it make you move slower and increases the heat input,

Bigger job here but same principle, there is a lump of 1/2" copper plate under there.
View attachment 98180

Thanks Paul, i cut up some of my practice aluminium so so thats 16mm of aluminium bolted through the middle.

Tack it up first? Then weld between the tacks pausing to let it cool?

70amps for the tacks?

 

[Richard.]

Paul has pointed out a classic mistake made by many when they first go to weld thick to thin.
It's too easy to tickle the pedal at low current hoping the pool will grab between the two parts and it won't. You'll have no where near enough current to get the thick bit started and before you know it your 0.5 will be straight through.
You need a very sharp tungsten. You need to set your current to your thickest metal and you focus the arc on the thick metal too. Strike up straight on that current as soon as the pool shows get filler (1-1.2mm) in then wet it down onto the thin and straight off the power. This is your tack.
I would probably go a little lighter than Paul about 60 amps for me (he's a better welder than me though.)
This is now tacked. I would then drop my current to around 50 amps start on that tack and dip it round. Keep heat focused on the thick and it will wet onto the thin.
Focused tungsten is absolute essential. If you dip it in any way STOP and redress it.

 

[dazza]

Paul has pointed out a classic mistake made by many when they first go to weld thick to thin.
It's too easy to tickle the pedal at low current hoping the pool will grab between the two parts and it won't. You'll have no where near enough current to get the thick bit started and before you know it your 0.5 will be straight through.
You need a very sharp tungsten. You need to set your current to your thickest metal and you focus the arc on the thick metal too. Strike up straight on that current as soon as the pool shows get filler (1-1.2mm) in then wet it down onto the thin and straight off the power. This is your tack.
I would probably go a little lighter than Paul about 60 amps for me (he's a better welder than me though.)
This is now tacked. I would then drop my current to around 50 amps start on that tack and dip it round. Keep heat focused on the thick and it will wet onto the thin.
Focused tungsten is absolute essential. If you dip it in any way STOP and redress it.

Thanks Richard, the fittings i've got are v'd out at the bottom would it be easier for me if they were flush?

 

[Paul.]

I would take the chamfer off the fitting, that is designed as a prep for butt welding the fitting to a pipe end, a small filler rod say 1mm will melt quicker and allow you to move faster, if you have some 0.8 mig wire would be ideal for that joint, as Richard says a sharp tungsten is essential, keep a very tight arc to keep the heat concentrated, weld a short section, say a quarter off it, and immediately hit it with a blast of compressed air (air quenching) then move to another part of the joint, and do the same.
Practice on a piece of scrap if possible to find the amps that suit your welding style, there is no right or wrong current, just starting point guidelines, all that matters is the result.

 

[dazza]

The filler neck is actually 3mm so i will need more amps, 80/90??

I have no scrap thats that thin. I do have the bit i cut off the filler neck i could try welding this to something but i only have 3mm mild steel.

 

[Richard.]

You don't want a chamfer it's a fillet joint and full pen isn't essential. What is essential is a water tight joint in 1 pass.

 

[Richard.]

80/90??

For the tack go with 90.
For the run 75-80.

 

[Richard.]

1.2mm filler would be my choice in this case.

 

[dazza]

1.2mm filler would be my choice in this case.

I only have 1mm or 1.6mm stainless filler.

 

[Paul.]

Use the 1mm then, 1.6 will take too long to melt

 

[dazza]

Please cover the eyes of pets and small children .

Tacking up with no filler went ok.

The rest not so much.

I cant get comfortable with the torch, at first i was dragging the cup on the metal but my brain was confused at the extra friction and i made a mess.

Learnt a few things though, don't accidentally press the pedal when your taking the tungsten out .

I will just keep using the bucket. Left the pump running the hole time, your right Richard the motor is really hot.

 

[Paul.]

See, easy aint it,
I've seen a lot worse than that, and done by people being paid for it, well done

 

[dazza]

Thanks Paul i feel a bit better now, i was going to bin it. I had a few good runs but could not keep it going. If it holds water i will use it until my skills improve and i can make a better one.

 

[WorkshopChris]

Its always a problem trying to weld a thread of that size. if you can grind or machine back to flat material life is much simpler.

 

[dazza]

Its always a problem trying to weld a thread of that size. if you can grind or machine back to flat material life is much simpler.

The end bit was flat but i cut it off as it was too high .

 

[Brad93]

That's a good effort I'd of liked to achieve that when I first started out. You've got good colour no oxidised areas, so we know your heat input wasn't too high. That's just a control/practice & patience thing now.

 

[dazza]

That's a good effort I'd of liked to achieve that when I first started out. You've got good colour no oxidised areas, so we know your heat input wasn't too high. That's just a control/practice & patience thing now.

Thanks brad i'm my own worst critic sometimes, im going to make a gasket like Richard suggested so i just need to weld the inlet and outlet. Whats the best way to clean the welds up?

 

[Brad93]

Scotchbrite will remove all colour. If you want to grind them I'm not sure, probably some sort of scotchbrite disc or belt.

 

[Paul.]

No need for machinery on that, just scotchbrite, use it wet with a bit of soap if you like,