Results from my first try.. not pretty :-)

[carl0s]

I had my first try of TIG today. I really like the process, it's much more controllable than MIG.

My first try at mild steel with filler. It needs a lot of work. I think the problem I am having is that instead of feeding filler into the pool, I am sort of pooling the filler on the end of the rod and dabbing that blob onto the material.

I had four goes here (each side), in the order of the photos. The long side with consistent-ish gaps (last photo) was the final attempt, however I did re-run the torch across to re-melt it afterwards a bit.

hmmm:

at least a little bit consistent, but still quite grim:

My first try at autogenous on stainless pipe. I really prefer autogenous I think because I can steady the torch so much better by resting my other hand against the torch hand. I didn't do any sort of purge setup because it's hardly a pipe really - just two small cut offs. Unfortunately I have discovered that the blade on my TCT saw (Dewalt 872L) is rubbish, hence the poor mating of the surfaces and thus gaps. So I've ordered a new blade:

The inside of the autogenous weld is, erm, not welded. That's called "poor/no penetration", right? and not good I guess. You can see the rough fit of the pipes too:

All done at ~75 amps, without pulse, 1.6mm tungsten, 6L/min argon.

Any tips? I think I had the arc length at about 2mm ish.

 

[FranV8]

It's a good start. The trick with TIG, I think, is to concentrate on creating a good weld pool, then putting all your energy to managing that. Only feed it when it's hungry too, if you're geting blobs on your filler wire you're too close when you've removed it, but don't move it too far away, I think you're supposed to keep it roughly in the gas shielded area. Where you'e got it on the first piece though, it looked like good start(s) of the right kind of pool. You were, I guess, correctly 'pushing' the pool as opposed to trying to pull it?

Autogenous - looks great from the outside, it's the consistent penetration you need next. You can get this either by leaving a gap between the two pipe pieces, or you might get away with lingering a bit longer. Of course, with the gap, you'll need to add filler. I'm guessing part of the draw of autogenous at the moment is not having to master the old pat head while rubbing stomach of moving the torch one way and the filler wire the other?

With the stainless, for a really nice job, you'll be looking at purging the inside, but that's for another day!

Keep up the practice, learning curve is steep at the start and very satisfying.

(Feel free to ignore what I've said though, I've done a bit but not a lot of TIG so far...)

 

[carl0s]

It's a good start. The trick with TIG, I think, is to concentrate on creating a good weld pool, then putting all your energy to managing that. Only feed it when it's hungry too, if you're geting blobs on your filler wire you're too close when you've removed it, but don't move it too far away, I think you're supposed to keep it roughly in the gas shielded area. Where you'e got it on the first piece though, it looked like good start(s) of the right kind of pool. You were, I guess, correctly 'pushing' the pool as opposed to trying to pull it?

Autogenous - looks great from the outside, it's the consistent penetration you need next. You can get this either by leaving a gap between the two pipe pieces, or you might get away with lingering a bit longer. Of course, with the gap, you'll need to add filler. I'm guessing part of the draw of autogenous at the moment is not having to master the old pat head while rubbing stomach of moving the torch one way and the filler wire the other?

With the stainless, for a really nice job, you'll be looking at purging the inside, but that's for another day!

Keep up the practice, learning curve is steep at the start and very satisfying.

(Feel free to ignore what I've said though, I've done a bit but not a lot of TIG so far...)

Thanks very much for your feedback
Yes I was pushing. I'm considering swapping hands next time though to see if that's any better. My movement just wasn't steady enough with the one hand, whereas autogenous meant I could rest my left hand against my right wrist, while the right hand was holding the torch.
I'm not sure the problem was so much patting head/rubbing stomach, more a problem of getting steady/smooth control with just one hand. I'll try resting my arm against something or swapping hands next time.

I do have a Y-piece and extra hose for purging. I think I need an additional flow meter though as I only have one, and it's on the line to the welder.

 

[malcolm]

Try autogenous on a fillet. That forces a good tight arc, and when you've cracked that the other stuff will be much easier. TIG tutorial linked from the top of the page is worth running through.

 

[carl0s]

Try autogenous on a fillet. That forces a good tight arc, and when you've cracked that the other stuff will be much easier. TIG tutorial linked from the top of the page is worth running through.

Thanks Malcolm. I am just reading the TIG tutorial again as it happens!

By the way, is it auto-genous, or au-todg-enous (pronounciation)?

 

[carl0s]

Oh yeah, can anybody guess what my first mistake / thing I forgot to do was ?

 

[FranV8]

Turn the gas on?

 

[inchpincher]

That pipe looks mighty thick to be autogenously (sp?) butt welding or is that just me? I need to add filler on anything over 1.5mm really because i like to crank the amps but don't want to leave the surface undercut...

Good work btw, nothing that a bit of practice won't soon fix!

 

[carl0s]

Turn the gas on?

No. I forgot to hook up the earth clamp. I had the workpiece in a metal vice so the HF start went through me, even through the gloves

 

[carl0s]

That pipe looks mighty thick to be autogenously (sp?) butt welding or is that just me? I need to add filler on anything over 1.5mm really because i like to crank the amps but don't want to leave the surface undercut...

Good work btw, nothing that a bit of practice won't soon fix!

It's 1.6mm which seems to be about the norm for exhaust pieces from what I can see (eBay). When it arrived, I did think it a bit hefty for an exhaust system.

 

[inchpincher]

wow, looks at least 3mm in the pics! You're not far off full penetration from the pics but as mentioned back purging if your doing a serious manifold, on a diy exhaust i think you'll get away without.

 

[carl0s]

wow, looks at least 3mm in the pics! You're not far off full penetration from the pics but as mentioned back purging if your doing a serious manifold, on a diy exhaust i think you'll get away without.

Yeah I think it's just the horrible chop-saw cut that's made the ends look chunkier than they are.

 

[saintnz]

Not to bad. I think you'll find it much easier to weld tube with a purge.

You can always drill a hole in your work bench the same diameter as your purge hose and push the hose up from underneath the bench poking through the top just enough to seal it with tape. As long as the tube is sitting flat, you shouldn't have any problems - It's not ideal, but this is how I weld small components by rotating by hand as I weld - or you could build a turn table

Tips:

Fit up is important for a nice looking weld - you can place the tube on a flat surface and scribe around it to show high spots - then grind flat...

Deburr and clean the surfaces (inside and out) with acetone - you'll find your weld pool will wander around with a dirty surface - plus it will make your weld look like crap.

A few skin tacks to hold the tubes together ( no penetration ) - run your purge 2 to 3L max... slower the better. ( you can run some tape around the joint ) - fully tack tube - tacks 10mm spaced.

I would also drop your amps to around 40-45 using .9 wire


If I remember correctly you mentioned exhausts, then definitely add wire.. A fused joint (no wire) may crack overtime through vibration and thermal expansion and contraction..

Good luck

 

[carl0s]

Not to bad. I think you'll find it much easier to weld tube with a purge.

You can always drill a hole in your work bench the same diameter as your purge hose and push the hose up from underneath the bench poking through the top just enough to seal it with tape. As long as the tube is sitting flat, you shouldn't have any problems - It's not ideal, but this is how I weld small components by rotating by hand as I weld - or you could build a turn table

Tips:

Fit up is important for a nice looking weld - you can place the tube on a flat surface and scribe around it to show high spots - then grind flat...

Deburr and clean the surfaces (inside and out) with acetone - you'll find your weld pool will wander around with a dirty surface - plus it will make your weld look like crap.

A few skin tacks to hold the tubes together ( no penetration ) - run your purge 2 to 3L max... slower the better. ( you can run some tape around the joint ) - fully tack tube - tacks 10mm spaced.

I would also drop your amps to around 40-45 using .9 wire


If I remember correctly you mentioned exhausts, then definitely add wire.. A fused joint (no wire) may crack overtime through vibration and thermal expansion and contraction..

Good luck

Thanks for the advice. I should have an extra regulator here by Wednesday, and some pipe clamps and magnetic clamps, oh and a new TCT blade for the chop saw. I'll have a go with less amps too.

Today I decided to try to make a battery clamp, because the universal one I have been using sticks up in the middle and has been knocking against the boot plastics. The battery was originally in the front.

I first of all practised a few beads on some mild steel that I bought from B & Q, and a butt weld too (I think).

Then after removing the paint off some shelving L-brackets with a propane torch and wire brush, I had a go at welding them together.
There are some signs of hope here, at last, although still a long way to go! It would have helped if there weren't holes in the material. I think I will have another go out of some flat bar like what I used for the practice beads above.

It all ends in disaster however!
I'm starting to wonder if this bar wasn't even mild steel after all. I just found it floating around the cellar. It did have a little bit of corrosion on it, which I took to mean it was some form of mild steel, but it was kind of light and weak, and I made a terrible mess trying to weld it.

Hmmmmmm

 

[carl0s]

Tomorrow I will play with less amps. Most of the above was at 55 - 60 amps.

Oh, and today's schoolboy error (after yesterday's earth-via-me), was to forget to switch on the speedglas helmet and start welding. D'oh! Thankfully they sort of shade a little bit anyway.

 

[saintnz]

To me it looks like youre putting to much heat into the rod..

This is what I would do:

Hold the bracket in the vice - vice grip the bar to the bracket - tack the end of the rod - remove the vice grip and tack both sides of the bar at the top of the plate.

Then, use a couple of c-grips and clamp the bracket to a solid bench or a thick piece of Ali plate (help suck the heat out of the bracket and to help keep it straight).

Stitch weld 20mm at the top of the plate (both sides). and then do the same at the end of the rod. weld it in segments - alternating from one side to the other - when its cooled down, back weld or give it a knock with a hammer in the vice to straighten

Welding:

Clamped to the bench - 45 to 50 amps. 1.2 wire. weld size: 3mm max

Direct most of your heat into the plate.

Start by creating a weld pool on the plate. with small up and down movements, wash the weld pool into the bar while dipping a tiny bit of wire at the top of the movement.

 

[carl0s]

To me it looks like youre putting to much heat into the rod..

This is what I would do:

Hold the bracket in the vice - vice grip the bar to the bracket - tack the end of the rod - remove the vice grip and tack both sides of the bar at the top of the plate.

Then, use a couple of c-grips and clamp the bracket to a solid bench or a thick piece of Ali plate (help suck the heat out of the bracket and to help keep it straight).

Stitch weld 20mm at the top of the plate (both sides). and then do the same at the end of the rod. weld it in segments - alternating from one side to the other - when its cooled down, back weld or give it a knock with a hammer in the vice to straighten

Welding:

Clamped to the bench - 45 to 50 amps. 1.2 wire. weld size: 3mm max

Direct most of your heat into the plate.

Start by creating a weld pool on the plate. with small up and down movements, wash the weld pool into the bar while dipping a tiny bit of wire at the top of the movement.

Thanks. I need to get some rod to try with, since that was just some hook that I found in the cellar and straightened out in the vice.

I started on the 2nd-try L-brackets (more like Z-brackets with the bit that sticks out the side, like above). I have only done one so far and I made it out of some of that flat bar above. It's rough, but I have learned a little from some mistakes that I made on it.

The two main things I have learned are: Where the two pieces meet at an L-joint, the inside is a fillet joint, and the outside is a lap joint, so the amp requirements are different.
I also learned that the reason I wasn't getting a puddle going on the inside was because I needed the tungsten out more, to get a shorter arc gap, because of the ceramic cup size. I was using the smallest cup I have (#5). Once I did that, it fixed the problem I was having (no pool..).

So, two things sunk in anyway. I know I should have done a corner weld instead of laying them onto each other in an L-shape, but I don't have any magnetic holders yet and am having to do everything in the vice.