John P
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| posted on 3/10/06 at 01:53 PM |
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How do you clean a TIG weld in stainless?
We're just welding up some stainless tubing which has a brushed finish.
There's no real need to clean up the TIG welds which are very neetly done (not by me unfortunately) but would like to get rid of the brownish
oxidised (?) area around the weld and get back to a clean stainless colour. (Using a wire brush or sander damages the existing finish).
I seem to recall an earlier thread where someone said you could buy an acid which wiped on the weld would clean away this discolouration.
Does anyone have any info on this?
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NS Dev
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| posted on 3/10/06 at 02:28 PM |
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yep, either mechanical polishing (best option) or stainless picking acid if you cant get in with a polishing wheel.
Do a search on google for "Antox" pickling pastes.
basically hydrochloric and hydrofluoric acid mixture in paste form.
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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John P
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| posted on 3/10/06 at 03:46 PM |
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Thanks for that, I've ordered some through a company called Foster Industrial in Leicester.
John.
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tks
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| posted on 3/10/06 at 03:54 PM |
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i work daily with stainless
Look out where you apply the acid because it realy realy creates a colour difference... it creats a much lighter surrface! also clean it with a high
pressure pistol!!
Normally we grind away the weld and finally we polish it... or just vibrate it..
then you cant see the union anymore and it looks like the tube is made with its 90degrees bend 
wear handshoes as the acid will make your hands colour after some days incl. nails! its rubbish stuff!!
Tks
The above comments are always meant to be from the above persons perspective.
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JohnN
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| posted on 3/10/06 at 04:09 PM |
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Pickling paste, as said above leaves the surface matt silver in appearance, wherever it touches. It is double skull & crossbones stuff. Avesta is
the brand I've used, its a mixture of conc nitric acid & hydrofluoric acid, very toxic, great care needed in handling and washing off
afterward.
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02GF74
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| posted on 3/10/06 at 04:16 PM |
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what about the stuff sold on Frosts website - suposed to take out the blue colouring on exhausts?
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tks
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| posted on 3/10/06 at 04:18 PM |
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nahh
the blue stuf isn´t stuff
its the surface metal..
if you applie the acid it will get away, but one good run and its back again..
Tks
The above comments are always meant to be from the above persons perspective.
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Peteff
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| posted on 3/10/06 at 05:38 PM |
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The stainless firm I worked for used Nitric and Hydrofluoric in the acid baths, the stuff is lethal as stated above. It used to leave a white film on
the surface and the blokes who worked in there never looked very healthy. Rubber gloves, glasses and a mask are recommended, the hydrofluoric is
potentially lethal in any dosage.
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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Danozeman
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| posted on 3/10/06 at 08:20 PM |
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While the weld is still hot rub it with scothbrite type of stuff.
Thats what 907 did when he tigd my exhaust up came straight off...
No good as its now cold. May still work though.
Dan
Built the purple peril!! Let the modifications begin!!
http://www.eastangliankitcars.co.uk
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Boost69
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| posted on 3/10/06 at 08:52 PM |
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Yeah scotchbrite is the stuff to clean/polish stainless up with. You can get a block (bit like a pencil rubber), a cloth, or a wheel to put in a
drill. any will do, just some require more elbow grease than the others! Happy polishing.
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NS Dev
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| posted on 4/10/06 at 07:30 AM |
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As I said above, clean mechanically wherever possible (I just use a buffing wheel and compound) but there will be spots that you just can't get
to, in which case a toothbrush and pickling paste is the only way to do it.
I did 95% of this exhaust mechnically, but you just can't get between the pipes at the collectors with anything mechanical.
 
exhaust 2
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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tks
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| posted on 4/10/06 at 09:00 AM |
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yeah
applying when hot fill fasten the process...
altough saying that the damp that is created should be as toxic as you can imagine..because of the quantity..
tks
The above comments are always meant to be from the above persons perspective.
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