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forteh

Tig Welding

152 posts in this topic

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Edited by f**megently

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Spent most of yesterday clearing out loads of crap from the back of the shed, took an almost complete gsxr750 motor to the tip along with a whole box full of suspension bits, brake levers, calipers and bodywork! OK I could have weighed it in (about 120kg worth or aluminium and steel but that's just not as simple as taking it to the tip :D

The upside is, I now have space in the shed, put some carpet down (which will make it far more comfortable in the colder months), have allocated an area for welding in and finally mounted my bench grinder (after having it for over a decade!). At the moment it is just a plywood bench, I was planning on sheeting it with some steel (although stainless would make more sense regarding keeping it rust free) for heat protection.

Looking at the size of the return/earth clamp, there is no way that I would be able to clamp it onto the bits of tube I actually want to weld up. I mentioned clamping onto the bench earlier but how is best to transfer the earth to the piece? Could I conceivably use an old pair of molegrips, weld an angle bracket onto them and bolt them to the table/earth sheet? Alternatively should I use some hold down clamps as below and have them bolted through the bench? Multiple holes through the bench would mean slightly more flexibility with clamping the work.

hold_down_clamp_pic.jpg

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That engine would have made a gocart for me but heyho.. how thick is the flat bed? you could always tack the peice to the bench if you needed to. I assume you'd use a fairly substantial piece

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It needed a fair amount of work, at least new pistons, bores cleaned up and a complete rebuild. I have an 1100 motor going spare though ;)

I hadn't considered the thickness of the bed plate to be honest, I was initially looking at a fairly thin sheet, probably 3mm stainless but I can see the advantage of thicker. Would a mild steel plate be ok? I can get an offcut of 10mm from work for nowt but not sure if it would just turn into a bed of rust bearing in mind it is in a shed (not a damp shed mind). I presume that keeping the surface oiled would not be a good idea :D

If working with stainless would there be issues with having the mild table? I know you're not supposed to mix and match stainless and mild steel forming tooling (pressbrake etc) but does the same apply for welding?

edit: price back from BoC for the half size tank is 6.45 rental with 48.49 refill cost, gonna make much more sense to go for the bigger tank. Might see if I can wing the rental cost ;)

Edited by forteh

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I don't think there's any problems with dissimilar earthing? I've never had trouble, but I've only welded stainless a handful of times in 5 years. I'd defo go for the thik stuff from a jig point of view. If you can get it pre drilled even better. Keep it oiled if you have to but degrease when you use it... fire/fumes is a twat.

Hmmm, an 1100cc go cart... AWSOME!! Farrari killer

Edited by f**megently

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I can get an 18"x12"x3/8" plate from work for nowt, get a bunch of holes punched through it in a grid pattern and then bolt it to the bench. I can then use any old nuts and bolts with strips of slotted steel to clamp :)

Will have to see how badly it might rust, I can always make a wooden sheet cover for it to try to stop most of it and a quick wipe over with emery cloth should clear the worst surface rust up.

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I doubt it'll rust too bad. A bag or two of silica gel under the wood cover? That's a quite small bed, I'd go 2×4 but I guess I'm thinking of it earning a proffit on it rather than home projects :S

That go cart is still turning me on (Y)

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Aye, this is only for small home projects, besides which in an 8x10 shed, a 2x4 is going to take up a bit too much room considering there are two motorbikes and a full length workbench in there as well ;)

Just picked up a lanthanated 1.6 electrode off the bay for 1.99 posted so a step closer. Intending to get some gas lenses as well.

I know I'm unlikely to be able to weld aluminium properly, only having a DC set but would I likely be able to tack it? Eventually I want an aluminium fuel tank, constructed a cardboard and solidworks model years ago and reckon I could do the fabbing side of it without too much hassle - if I could at least tack the bits together would make it a lot cheaper!

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Bionic balls said its possible, I've never tried personally though I expect it would have to be clean as a nuns twat if its going to work. You do know I have a nice tig for ally and I'm not too far away ;)

*you may need a differnt tungsten, you do with ac

Edited by f**megently

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Some photos of Al welded on DC- http://weldingweb.com/showthread.php?51165-Anybody-here-good-with-DCEN-Alum-Tig-welding

Does indeed need to be clean..a decent scrape on the bevel prep with a rasp and not hanging about is apparently the secret! Al in general is prone to porosity so a fueltank might not be the best thing to start with.. AC would probably be a better bet (on another set by the sounds of it) but might be worth a go for tacking?? No promises!

Get the stainless plate..no-one wants a rusty bench :P

Adam

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Beer bottle glasses tastic!

Seems the gas is the key to a decent ally weld on dc.

The bed is small enough to take in doors at night, you could even put it under your pillow like leigh :P

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Unfortunately we don't deal with much stainless sheet/plate at work (non ferrous gets subbed out) so I have a mild steel welding plate. 500 x 320 x 10thk, will be bolted down to the bench and the earth clamped onto the side of it.

For clamping the parts down I have a bunch of 25 x 150 x 10thk strips with a 10 x 20 slot through about 2/3rds of the length along; the plate will be punched through with a series of 10mm holes so I can use M8 bolts to turn them into machine bed clamps.

The MD at work has OK'd me putting the gas bottle on the schedule, I'm sure he won't notice an extra 7 quid a month on the rental costs ;)

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I tryed a dc ally weld today... :S it's not that bad to be fair, but dirty black soot every where! I think you could tack with it maybe..

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From what I've read, using helium transfers more heat into the piece which I think can help with the cleaning and the shoot can be brushed off easily. Because I don't have a pedal to fine control the amperage I think relying on the 2t button might cause problems actually welding DC aluminium. Did you use DCEN or DCEP?

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Got it all hooked up this afternoon, had to reterminate the gas hoses because they were leaking loads but all good now.

Laid about 12" of bead before the two little argon bottles ran out, some of it almost looks good (I think!). Got a problem with it though, after releasing the button in 2 stroke mode, the arc flares up and blows the end off the tungsten, I guess that the post gas isn't flowing for long enough or the ramp down time is too long. It's about 6 seconds from button release till gas stops flowing, unfortunately the post gas and ramp down times are fixed.

I'm not 100% sure that the flow meter is calibrated for argon or are they not gas specific?

I also seemed to struggled to get any heat into it and had to turn it up to max amperage to get a puddle going, my electrode gap may have been too great though. Additionally whilst I cleaned the corrosion off the tungsten, I guess that the collet is still dirty and that will affect the current transfer?

Will get a big bottle of gas from work next week and play some more, got some photos of my attempts which I will upload later :)

Edited by forteh

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The gap between the tungsten being and the pool being too big will make the metal hotter as its a bigger arc? Just a few mm away is cool, takes some practice not to take a dip in the pool though, haha. emptying bottles that quickly means too much pressure. I've never blew the end off a tungsten unless its on DC+ , no gas and it just burns. My guages have argon written on them.. not sure if it makes a difference though? Clean the bits as best as you can, and only sharpen or clean the tungsten long ways.

Pics or it didn't happen ;)

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Mostly the gap seemed about right, the arc was beautifully controllable (whilst the tungsten still had a tip on it!) and formed a tiny little weld puddle. Once or twice I dipped it in and it just welded the tungsten to the plate. So if I need more heat into it then I pull the torch off a bit?

When it flared up, it was like the arc grew in size 4-5 times and the end of the tungsten fell off, as I said, I'm not sure if this is lack of gas or it not closing the arc off properly. Either way it caused a massive crater at the end of each weld :(

I will pick up a gas lens to replace my corroded collet, at 85 amps on the dial it wouldn't penetrate 1.6mm stainless so I guess that the current just isn't getting through.

Don't forget that they were disposable bottles with less than 29 litres in each ;)

And as you asked so nicely :D

This is the bench set up, excuse the crap photo, was dark when I took it and phone camera + flash never works well :(

Tig%20welding%20setup.jpg

This was the first test plate, just a bunch of beads to see how the pool behaves, the huge craters are from where it flared up. This was my first ever attempt at welding, it didn't really penetrate through the back of the plate but I guess that is mostly due to the dirty collet.

2013-11-16_16-50-08_833.jpg

Had a play with a lap joint and got some reasonable looking beads, most of these were done with a burnt off tungsten so the arc was all over the shop :D
I really struggled to get enough heat into the lap joint to melt both bits of stainless, I guess it just isn't putting the amps in that it should be.

2013-11-16_16-51-25_41.jpg

None of these plates were degreased, cleaned or prepped in any way (probably should have to be honest).

Any comments would be appreciated although I will be much happier producing beads once I have a better gas supply and have figured out why it's blowing the tungsten to bits :D

edit: seems I might have had the tungsten too close to the piece, I was working with an arc about 2mm long, miller say 1/8-1/4" which is 3-6mm;if I was too close then the arc would be cooler correct?

Edited by forteh

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Yep the arc is cooler, but you could just move slower? (Dam as I'm writing your post has disappeared :l ). To be fair a few of your welds are either too hot or not enough gas.(bottom left of last pic).

A tip when practicing is to start close to an edge and run the pool like writing lines, you'll get more practice out of one test price of steel, rather than at random ;)

Try the 4step, see if that is any better. Or try whipping the torch away before it gets a chance to blow a hole, probably won't do it much good but he weld might fair up a bit better.

The set up piece in my pic was about 1.6 thick and at about 60-80 amps I think so at 85 you should be able to weld stainless fairly well. Thought your welder went higher?

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The gas had run out on the one weld in the last picture, I hadn't noticed that the flow meter had stopped tinkling and wondered why the arc was all over the shop!

The set is 160A and I needed it set full to get that lap weld to actually form. I will get a gas lens and new collet along with an argon specific flow meter, and that should hopefully help with getting the current to the electrode.

With the new gas and bits I will be more frugal with the stainless, this was more a random test play around with settings :)

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The easiest way for you to learn would be to make a T fillet then you can just sit the ceramic between the two plates at an angle and walk the dog (basically just moving the torch up and down on a fillet) and the torch really does the rest.

Once you have a consistent weave between both plates start introducing filler wire into the equation.

Ive been welding for 10 years now ( im 29 ) and im still learning just be patient and it will come to you.

When you have got a pipe to weld on a 45° restricted and is 100% radiograph welding with a mirror then its tricky!

I have finished my last contract now probably till after xmas but I will add some pictures and so on when I can.

Edited by i like cunning stunts

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I had a go at walking the cup on the lap joint and it sort of worked, material was a touch too thin to do it properly though.

Ordered a gas lens, collet and cup off Ebay and should have gas again by mid week so will all being well be able to have a better bash at it later in the week :)

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Be harder in the lap due to not enough surface area for the ceramic,, what size ceramic are you using?

I would go for a size 8 or 10 easier to learn with plus better gas coverage. You would need the correct size gas lense also though.

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Currently got a size 5 cup on there (what was fitted) with a 1.6 tungsten. Going to stick with these sizes as I am learning on thin material for the moment, not entirely sure what size cup is coming with the gas lens but I guess it will be sized correctly for the 1.6 electrode.

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There isn't a set size ratio as far as I know, its kinda job dependant. I use an 8 on steel and a 5 on ally, seems to work best for me. But tight angles ect demand different techniques and ceramics.

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