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Clinton1
15th Dec 2005, 10:49 AM
I went to an "Art installation" on the weekend - I'd pretend that the missus dragged me to it, but I'd be lying - and saw some art that was made from stainless steel.
The blurb said it was manufactured from 12mm stainless steel plate. The pieces were basically triangular columns up to 4 meters tall (length), curved primarily along the length, but also across the width.
I could not pick where the welds were. I know they were in the 3 corners, running down the length, but the welding quality and the polishing was so good it looked like one piece.

Hope the explanation is ok, now for the question:

What welder (machine/technique) would have produced this?

Any assistance appreciated.

Andy Mac
15th Dec 2005, 11:19 AM
Hi Clinton,
Almost definitely TIG welding, followed by judicious grinding and polishing. Its the same sort of thing thats used on with Stainless bathroom fittings, stair hand-railings and commercial end stuff (like urinal pans etc), which is so neat the joins are usually invisible. I've also had Stainless sculptures done with a stick welder using special rods, but that was on 6mm plate.

Cheers,

Schtoo
15th Dec 2005, 12:13 PM
Andy, tig on 12mm plate? Didn't know tig could crank that much juice out.

Clinton, whatever they used is anyone's guess. But I know they must have used plenty of sanding discs, scotchbrite and whatever to make the welds vanish.

A good tig driver though, the welds are practically invisible like Andy says.

Andy Mac
15th Dec 2005, 12:17 PM
No you're right Schtoo, I don't think TIG would handle 12mm. As I said an arc welder, you know, with the stick, can stitch 6mm plate no worries. I wonder what they used....??:confused:

Cheers,

Clinton1
15th Dec 2005, 01:59 PM
This was pretty industrial, with the "artist" contracting out all the work - except the really important stuff: like the vision, overseeing the installation and eating the Brie :D
With the price tags they had i.e. 12" - 18" replica of the originals were around $1000 I don't think that they would have been limited to a portable TIG bought from the Trading Post. (which is what I'm thinking of for myself). Not knocking the price - I'm sure the artist is putting $ in a lot of peoples wage packets.

Would there be Industrial TIG'S that would handle this?

Could they build up the join around an insert, i.e. a third piece between the two main side pieces...?

I been trying to figure it out - I don't even know if they did a "butt join for 8mm and left a V for the last 4mm and welded that, with internal bracing' or what. All speculation on my part.
I just admired it and couldn't get near the artist to ask any questions about the construction - heaps of rubbish on the "vision and direction and conceptual meaning" though.
I note the comment about the "good TIG driver" - yes, I thought the welds were more worthy of my admiration than the actual sculpture.

Anyway, doesn't matter -

So, last question, 3mm to 6 mm Stainless - would a good TIG handle this?

Wood Butcher
15th Dec 2005, 02:42 PM
The welds could've easilt been done with mig welding. There is a metal fab shop that I've had work done by where they only do stainless. They use tig on sheet/plate up to around 3mm then mig after that. If the welder knows well what he is doing the mig welds on thicker plate come up really good and a bit of grinding and polishing later and the welds disappear.


So, last question, 3mm to 6 mm Stainless - would a good TIG handle this?
Might, but mig would be a lot easier and even stick would do (with the right rods)

Edd
15th Dec 2005, 04:26 PM
A good tig welder could easily handle 3-6mm stainless. Even the cheaper models can do stainless. What they can't do is aluminium, which requires AC. Head over to www.fronius.com for some specs. Are you asking because you want a tig welder? If anyone is interested in buying, I recommend Fronius, followed by lincoln electric. High frequency start is a must IMO, touch or scratch starting is a pain.

Clinton1
15th Dec 2005, 09:32 PM
I am interested in buying, but $ as always gets in the way. :D
Right now I am trying to minimise the "looking like a goose" for when I try to get a job done. I find it helps when you can at least demonstrate enough knowledge to not look like someone begging to be taken for a ride.;)
Thanks fellas, I think I might have enough to at least go on with.

journeyman Mick
15th Dec 2005, 11:17 PM
The boatyard I used to contract to had a few TIGs, one was a monster that looked like a bank safe. It was moved around with the 20 ton overhead gantry and had a water tank hoilding about 40 litres with a pump that circulated water to cool the hand piece. I'm fairly sure it could handle 12mm SS plate:D . It was also used to weld Ally so I don't know about the AC-DC aspect. I only ever used the MIGs to just tack stuff together and let the boilermakers follow the sparks around all day long;) .

Mick

bsrlee
16th Dec 2005, 01:17 AM
There are some specialised industrial machines that can weld huge bits of just about anything, but they are robotic 'handpieces' that weld at the bottom of a bed of flux - sort of like a 'gasless' MIG, with the flux laid down as a powder as the welding head motors along the weld line.

I'd suspect that they either 1) scarfed the edges of the plate pretty close to finished size & shape, then TIG or MIG'ed it inside and out without worrying about long term strength & full penetration -OR- used a big bit of rod welded across the joint & ground back as Clinton1 said.

Clinton1
16th Dec 2005, 09:40 PM
Thanks people. As usual, good value.

Grahame Collins
17th Dec 2005, 12:00 AM
I have been almost tearing my hair out reading the feedback.
Crikey fellas! This is stuff boilermaker tradesmen would not take on without a well equipped workshop.
I don't want to seem negative but it might be a project that is far too much to undertake without training of experince

The situation that is described above with 12 mm thick stainless steel plate can only be welded properly with MMAW ( stick to you ) or GMAW ( mig).

A stick machine of 200 amp capacity running 4mm diameter electrodes to get the build up. Alternately ,if you have too muh money grab a GMAW machine with the correct gas mix- No argon won't do it - far too cold.Do some costing on that and on 15kg rolls of stainless mig wire as well.

Now while you into it,take more money and buy the plasma cutter you shall need to cut the 12mm plate. You are unlikely to find a enginneering shop that has a guillotine that will have a capacity for 12mm stainless. A guillo that will
cut 10 mild steel won't have the grunt to cut anything but very short pieces of 10mm stainless.

What grade of stainless are you talking about? Do some research - there 's more than a few.Your electrode filler will need to match this grade of stainless for colour match after polishing.

But wait! There's more -no steak knives here- but a whole host of problems exacerbated by the nature of stainless steel when it is welded incorrectly and out of sequence - mainly distortion. Sorry to sound negative ,but your artist would not have made a lot of money out of what you have described.

For last something postive. If you are still determined start small 6mm plate welded with stick or mig. Get as much info as you can and then look at it again.Send me a private email if you would like help.
I would have replied sooner but :-
I have had intermittment problems logging into the board and staying here but I think I am back for a while.

best of luck then
Grahame

Clinton1
17th Dec 2005, 11:17 PM
Thanks Grahame.
I'm not sure if you read the thread, I think you are assuming I intend to cut and weld 12mm stainless plate in the shed? That was the artist's material, and it made me realise the finish possible on stainless welds.
Thanks anyway.

Edd
18th Dec 2005, 06:57 AM
...correct gas mix- No argon won't do it - far too cold.best of luck then
Grahame
I'm guessing the 92%/5%/3% of Argon/Co2/Oxygen would be the one for stainless, as oxygen is oxydising and would make it a li'l hotter?

boilermaker
25th Oct 2006, 12:50 AM
For 12mm stainless they most definitely would have used a mig clinton1...given the size u described they probably dogged it down and utilised sequence welding. With the right grinder discs etc (possibly milling)and pickling (a chemical process to clean the stainless) it would have come up a treat. I would also hazard it a guess given the thickness the "art" was, industrial stainless (soft)was used as opposed to your kitchen variety (had).

General rule of thumb in guillotining stainless is add one third of the thickness to approxiamate mild steel thickness... therefor 12mm stainless is like 16mm mild steel.

Chances are they CNC plasma cut the metal and not by hand.

Argon gas or a mix was no doubt used as it has a low thermal conductivity and is most suitable for stainless welding ... it produces a hotter weld ..hence the argon/co2 mixtures for mild steel welding.

fabricating/welding stainless is not unlike mild steel but u need to know a lot of tricks...from start to end...eg don't use a grinding disc/wire brush thats been used on mild steel...>>> sequence welding>>.pickling>>> and so on. good luck if you do.


boilermaker

Clinton1
6th Apr 2007, 01:58 AM
thanks Boilermaker.... didn't see your post till now!
Sequence welding, I understand the concept, but reckon it would take a little while to learn to do well. More power to you if you can do it.