Doing a welding course - notes as I go

[FridgeFreezer]

25 minutes ago, landroversforever said:

Just looked back through to the pictures... how is she holding the torch?

"With difficulty" basically the college machines have quite chunky torches as I guess they're teaching heavier industrial stuff to the BTEC lot or possibly just need idiot-proof gear - my home torch is smaller & lighter even though it's 160A water-cooled, and the lead is more flexi.

H having quite dainty hands finds it difficult to grapple the thing into a comfortable position but I think the tutor got her into the swing of it eventually - we ALL found that TIG is VERY sensitive to torch position, height, and angle as you're very finely controlling what's going to melt, a bit like pointing a laser but the laser is mounted at an angle on the end of a big unwieldy snake of cables

I was finding a definite knack to getting the exact angle where the edges of the material would both melt evenly at a point a little ahead of the torch - tutor calls it a keyhole shape of molten metal, I might call it a horse-shoe, but that's what you aim for and then you have to poke the filler into the middle of the "U" to make a nice little blob.

I even found a picture of it...

[landroversforever]

I'll grab a picture later, its the best way I've found of holding it. What also doesn't help is some torches have really stiff buttons, you go to press it and dunk the tungsten  

[Cynic-al]

2 hours ago, landroversforever said:

For the grinding, what orientation are you grinding? The marks need to go along tungsten.

For the resting, a flexi torch really really helps, but if you haven't got that, and even with one, I often stick a g-clamp or similar on the workpiece just as a hand rest. Sometimes when you're in the groove and the height is right I can do it without but 8/10 I stick something on there as a rest.

I have it pointing up to the sky with the wheel coming down if that makes sense. 

I need to spend a bit more time on it. I find the torch a bit difficult to hold. I think when I went to R-tech they had me holding it right up at the top rather than on the handle to make it easier, I will have to try that again as I did some really nice welds there! 

[lo-fi]

I've not had much luck holding the torch like a MIG torch. Nowhere near enough control. Holding it with hand shaped like a gun with the tungsten running between fore and index finger is my favoured way. A TIG finger is almost essential with this, though, as is a pedal. 

[FridgeFreezer]

Had a spare moment in the shed today so fired up the TIG and plugged in the foot pedal to have a go - after I'd worked out to switch it to AC for ali and enable the foot pedal current control it came out quite well, definitely easier to keep it under control as you get near the end although I'm still not going to win any awards for stacking dimes!

 

This was ~2mm ali, I thought I'd tempt fate and revisit my previous nemesis of 1mm ali...

OK it's just running a bead along a folded edge so it's way easier than a joint but I'll take it!

 

[discomikey]

On 3/20/2020 at 9:11 AM, Cynic-al said:

I shaped it to a point, usually I dull the end but with that I kept it sharp as I thought it might concentrate the weld a bit. I was at 50 amps but with a foot pedal so less than 50 amps depending on how I was trying to stop it blowing whilst still welding. The joint wasn't perfect, there was a gap to fill as it was something I had folded so the radius of bend left a gap, maybe that and my speed were the problem. I think the other problem I had was it was a box so I couldn't rest my hand on the bench like I could with a flat piece. I had it resting on the end of a brick and was a bit wobbly. The welder does have pulse but I will have to read into it to use it. I will have another go!

I don't think you can complain at that welding FF, I would be happy with that. In the real DIY world you can just let the job cool between welds. 

 

 

As Ross states, sharpening to a point is the thing to do but sharpen so the grinding marks run down the length of the taper as opposed to round the taper. It makes a massive difference. I think weldingtipsandtricks did a video on the correct methods. 

Youre definitely on the right track. Comfortable propping can overcome a lot of issues. Get creative with things around you to prop and make a dry run before you hit the pedal. Propping is NOT cheating! 

And welding gaps is tricky. Gaps on outside corner joints, and butt welds are particularly sensitive to heat. 

If you feel it's all getting out of hand, sometimes it's a good idea to back off the footpedal until you're barely lit up, readjust your filler hand and get back into it. 

One of the big advantages of TIG is stop/starts aren't an issue in terms of lack of fusion so use that to your advantage. Get comfortable, reset and continue. You'll get further and further as you go and your muscle memory catches up with you. 

TIG is hard. But so rewarding too.

I hope this helps

[FridgeFreezer]

I have noticed ali is incredibly sensitive to the oxide layer forming, and of course that forms in seconds on bare ali. Even just picking a fresh clean rod out of the tube rather than the dull one that's been sat on the bench made a difference.

Also very much finding that going in hotter and moving quickly is better on ali, otherwise by the time you've got a puddle going the workpiece has gone like T-1000 and starts dribbling off the bench

[discomikey]

For sure. 

I had to do something for a customer last week. Puddle weld aluminium slot and tabs in 1.5mm 5056. 

Try and ease in and the slot lifts away from the tabs from the heat. You have to just get in and make sure you're ready with the filler! 

[FridgeFreezer]

Had to share this... we're sat on the sofa eating tea, watching Car SOS welding up a BMW 2002 and they show the finished weld and both of us look at each other and go "Ugh, that's nasty!" she's definitely learned some stuff then

[discomikey]

My other half isn't in the slightest bit interested in learning. You're a lucky man. 

[Blanco]

Inspired by all the above, and having a small stainless job to do, I thought I would try my hand.

All of the above now makes much more sense. I spent the afternoon  altering a piece of 28g 316, probably should have started with something easier, the last half of the second run went more quickly, if not better! I am glad I just got stuck in, but I will play with something heavier next time!

[landroversforever]

On 3/21/2020 at 2:30 PM, FridgeFreezer said:

Even just picking a fresh clean rod out of the tube rather than the dull one that's been sat on the bench made a difference.

Give the rods a rub over with a bit of scotchbrite, then an alcohol or acetone wipe. I do it with my mild and stainless rods (no AC for Ali here sadly) and it does make a difference.

[FridgeFreezer]

On 3/21/2020 at 5:48 PM, Blanco said:

All of the above now makes much more sense. I spent the afternoon  altering a piece of 28g 316, probably should have started with something easier, the last half of the second run went more quickly, if not better! I am glad I just got stuck in, but I will play with something heavier next time!

Aye, heavier is a LOT easier as it can take a lot more heat and you don't *need* to be as accurate to get something that looks like a weld - thin stuff is always a knife-edge of blowing a hole, and (so far) hole filling with TIG is a lot harder than the squirty MIG gun

[Cynic-al]

On 3/20/2020 at 11:57 PM, FridgeFreezer said:

This was ~2mm ali, I thought I'd tempt fate and revisit my previous nemesis of 1mm ali...

OK it's just running a bead along a folded edge so it's way easier than a joint but I'll take it!

I'd be over the moon with that, looks good enough for a water tank or whatever. 

[landroversforever]

Here you go Jon/Fridge, and anyone else!

This is how I hold the torch 99% of the time. This way the control of the button and the hold of the torch are separate. 

 

Excuse the poor selfie! This is how I have the torch leads which makes life so much easier. It means the weight of the leads is taken by the arm and not the hand. Especially important when I’ve used a water cooled torch in the past. 

 

Hope that’s of some use  

[Blanco]

22 hours ago, FridgeFreezer said:

thin stuff is always a knife-edge of blowing a hole

...yep, being very second hand in the first place and quite wany edged,  holes and hole filling were the bulk of the job.

[FridgeFreezer]

Well, as it looks like that's the end of it I'll give a few thoughts to sum up...

Overall I think the course is well worth it - especially if you've not welded before. Sometimes it could feel like you're not getting huge amounts of tuition, but what you ARE getting is a couple of hours of good solid practice in an evening - good quality machines, set up well, as much steel , wire, and argoshield as you can burn through, and a tutor on hand to tell you what you're doing wrong or demonstrate how to do it right.

For those newbies who might otherwise find themselves alone in a shed with a newly acquired hobby MIG and no clue about how to fly it, I'd say the course is an excellent idea.

However, it IS very very basic and doesn't cover some stuff that Jez and Vince beat into me - proper metal prep, good grounding, stitching and weaving (touched on but not really demonstrated/practised), and of course it's not a metal fabrication course.

I can't complain, as you can learn most of that for free from YouTube or indeed this very forum and they have to try to get a wide range of abilities over the finish line of being able to run a neat bead of MIG by week 8, which some were still perfecting last Wednesday. Also, I definitely learned stuff even though I've been MIG welding for a decade and watching more than enough welding videos online since acquiring my TIG set.

Another point: As I cajoled my better half into joining, I'd say that aspect worked very well - I'm sure I'd have been a bad teacher, and having a proper tutor, a course structure, and some proper "exercises" set up was definitely better than any teaching at home would've been. And domestic harmony remains intact

There were a couple of guys there who were aiming to restore cars and I feel they might get a bit of a shock when they move to crusty old wafer-thin bodywork, but then half of that is about prep and fabrication rather than the actual welding.

 

And in case you're wondering, things I was taught by Jez and Vince:

Proper metal prep;

CLEAN CLEAN CLEAN, flappy wheel in grinder until you've got at least 5-10mm SHINY metal both sides of the joint.

Chamfer edges on thick parts.

Mega-clean anything that's zinc coated giving a BIG (20mm+) gap between the SHINY CLEAN metal and any remaining zinc.

Tack stuff firmly, you'll be amazed how far and how strongly stuff can move/warp with the heat

For aluminium, a dedicated stainless wire brush for ali ONLY, ideally a cheap bench grinder for tungstens ONLY, any abrasives used on the part should be kept for ali ONLY so you're not rubbing steel particles into the surface.

Good grounding

The pressed-tin croc-clamp that comes with your welder belongs in the bin, a good solid ground is everything - I use the G-clamp style.

Heavy objects not only stop the work piece from moving around but also help make good solid contact to the bench, when the bench is the ground. Big lumps of steel, ali or brass/copper are amazingly helpful to hold stuff down, prop stuff up, and take heat away (esp. thin stuff & ali).

Stitching and weaving

For thin stuff, stitching is essential - I've posted UrchFab's video on it elsewhere in this thread and it's still the best I've seen.

Weaving - just basic forward-back or a line of e's, can give a good result and I find it helps to create a rhythm that keeps you moving at a steady pace rather than trying to just move in one continuous line like a robot. For relatively big stuff with a relatively small welder it's very useful.

 

HobNobs

Essential.

[Blanco]

It has all been very interesting and entertaining, thanks FF. I can't help wondering whether your better half has her own welding project in the pipeline or whether it was simply for insight on her behalf?

[FridgeFreezer]

15 minutes ago, Blanco said:

It has all been very interesting and entertaining, thanks FF. I can't help wondering whether your better half has her own welding project in the pipeline or whether it was simply for insight on her behalf?

She sort of fancies a few projects - we've made a couple of tables (which I welded, natch) and I ribbed her that I'd make her weld the next thing she comes up with her mum's already demanding a sculptural steel owl for her garden although she's had it explained that the hard part of that is not the welding!

Also sort of fancies building a Cobra replica one day (although I suspect it's a very distant day!)

[miketomcat]

5 hours ago, FridgeFreezer said:

Also sort of fancies building a Cobra replica one day (although I suspect it's a very distant day!)

Not if I've got anything to do with it. 

Mike

[FridgeFreezer]

1 hour ago, miketomcat said:

Not if I've got anything to do with it. 

You've got enough silly plastic cars of your own to build!