TIG welding: need some clear info please
TIG welding: need some clear info please
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Discussion

911hillclimber

Original Poster:

486 posts

219 months

Saturday 19th December 2009
quotequote all
I am about to embark on making a set of very custom exhaust manifolds for my Porsche engined Lola race car.

The tube are all here etc and i have a good MIG welder with the right gas/wire etc.

I plan to tack weld the mirriad of tubes together with the MIG, but the final welding of the tubes needs to be by TIG.

Are there any affordable TIG units available?
I have a good old arc welder which has'lost' its range control. so welds just right for 12 SWG rods, but can an Inverter be used for TIG.

I cannot seem to find clear info on TIG welderd for the petrol head.

Graham

rdodger

1,089 posts

227 months

Saturday 19th December 2009
quotequote all
Rather than invest in a TIG welder, why not tack it together then take it to a specialist to have fully welded? I see you are West Midlands so JPS won't be a million miles away and are very good.

http://www.jpexhausts.co.uk/

theconrodkid

372 posts

284 months

Saturday 19th December 2009
quotequote all
try this lot http://www.mig-welding.co.uk/

i have an inverter i use for tig,you need pure argon tho and it aint cheap

Steve_D

13,801 posts

282 months

Saturday 19th December 2009
quotequote all
Why do you believe it needs to be TIG welded?
MIG welding, done properly, will be fine.

Steve

Gulf -LS2

1,922 posts

228 months

Saturday 19th December 2009
quotequote all
Tig is the only way to go, imo mig can never look as good!!

I would take it to a specialist, the motorsport boys next door use a mobile tig welder he is awesome do you want his details?? I think he works all over the Midlands.

I used to have a little exhaust business and we tried the top MIG products from gases through wire and it never looked as good as the tig welded units. Tig is slow but well worth the effort.

Toltec

7,179 posts

247 months

Saturday 19th December 2009
quotequote all
You might find this site useful too http://www.millerwelds.com/resources/improving-you...

One of the docs on there http://www.millerwelds.com/pdf/TIGBuyersGuide.pdf

If you are just welding exhaust tube you can probably get away with one of the cheaper sets, 130amp should be plenty as you will probably need around 80-100A. Watch out for the duty cycle though as some cheaper sets will overheat at higher current quite quickly. Go for a set with high frequency start not lift or scratch as you will be forever regrinding the tungsten otherwise.

It is mentioned on the docs on the Miller site, when welding SS you ideally need to back purge the piece, i.e keep the air purged out of the inside of the tube you are welding. It will weld without doing this but you will need to grind the inner face of the weld as it will be rough, almost furry looking.

Lastly, tig is more like gas welding than mig, you heat the work with the arc and feed in the filler rod with your other hand. If you can gas weld you should pick up tig reasonably quickly.

I am not a pro, just did a basic level one course covering arc, mig, tig and gas last year. The mig-welding site above has a really good forum and covers tig too despite the name.

911hillclimber

Original Poster:

486 posts

219 months

Saturday 19th December 2009
quotequote all
I had my chassis welded by Roy Wilding, quite a welder! (drag race car chassis etc)
Roy I'm sure would TIG them gas tight, but the cost of this and I could (?) have the tig myself for the future.

I can gas weld well, so think I can get used to TIG quickly.
Trouble with MIG on these tubes is the weld can be very untidy inside the tube.

Steve_D

13,801 posts

282 months

Sunday 20th December 2009
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Steve_D said:
Why do you believe it needs to be TIG welded?
MIG welding, done properly, will be fine.

Steve
Can I withdraw this statement.
Somehow mis-read the OP and thought we were welding a chassis.

For thin wall pipes like headers TIG is the sensible option.

Steve

911hillclimber

Original Poster:

486 posts

219 months

Sunday 20th December 2009
quotequote all
Thanks to all contributing!
I have gas welded for about 30 years of car building/restoration so comfortable but not sure it is worth the investment of about £250 or more to get the right bits.
Must have a careful look on those Miller sites and a good chat with Roy.

Steve_D

13,801 posts

282 months

Sunday 20th December 2009
quotequote all
Not done it myself but from what I'm told if you can gas weld then you should get on well with TIG.

Steve

GTRCLIVE

4,193 posts

307 months

Sunday 20th December 2009
quotequote all
Remember if you weld a Stainless tube tube you need to use a Sanitary gas technique. Stainless Steel will fur up on the inside with a very hard slag if you don't flood it with Argon. So you need to have argon inside the pipe and outside at the nozzle.

I have worked with allot of Stainless pipework in 2 food companies and TIG is the standard for stainless pipe welding....

If you have ever Gas welded (Oxy/Ceth) you can Tig weld easy.

GTRCLIVE

4,193 posts

307 months

Sunday 20th December 2009
quotequote all
http://cgi.ebay.ca/SIMADRE-520D-50A-PLASMA-CUTTER-...

This is what I bought and it works great, and the Plasma is a bonus...

eliot

11,989 posts

278 months

Sunday 20th December 2009
quotequote all
GTRCLIVE said:
Remember if you weld a Stainless tube tube you need to use a Sanitary gas technique. Stainless Steel will fur up on the inside with a very hard slag if you don't flood it with Argon. So you need to have argon inside the pipe and outside at the nozzle.

I have worked with allot of Stainless pipework in 2 food companies and TIG is the standard for stainless pipe welding....

If you have ever Gas welded (Oxy/Ceth) you can Tig weld easy.
With food stuff - I can understand why backpurging is nessesary - but for an exhaust does it matter?
As others have said, if you can gas weld - you will be able to TIG. Just google around to learn how to grind (and select) your tungstens.
I probably only use my tig 3-4 times a year - but I still pay the rental on the bottle, because it's so handy to be able to weld up any material neatly.

Toltec

7,179 posts

247 months

Sunday 20th December 2009
quotequote all
eliot said:
With food stuff - I can understand why backpurging is nessesary - but for an exhaust does it matter?
Gas flow and hot spots, though how much difference it really makes?? How about the satisfaction from just doing the job properly?


CNHSS1

942 posts

241 months

Monday 21st December 2009
quotequote all
if you decide to not buy the gear yourself, theres Shropshire Stainless on Cartmel Drive shrewsbury, not far from Loton either ;-)
ive used them and they can weld neater than i can draw! owners also a car nut which helps a lot

CorseChris

332 posts

257 months

Monday 21st December 2009
quotequote all
Just done this job myself....only I took the bits to a local chap for final TIGing after I'd MIG tacked it with stainless wire. Total cost for very roughly 50 welds was just over £200. No way could I have done as nice a job myself even under ideal conditions, and some of the welds were really awkward. He did all the welds with Argon both sides too - very little to see on the insides of the tubes.

I get the idea of having your own TIG at the end of it, and did briefly consider that myself, but I don't intend doing lots of welding (TIG or MIG) so figured I'd leave it to an expert.

Just my vote for leaving it to the experts! YMMV smile

911hillclimber

Original Poster:

486 posts

219 months

Sunday 3rd January 2010
quotequote all
At last I'm ready to tig it all.

I will send this to a pro though. I am noe an official Hater of stainless!

I will never tig this lot myself!

Thanks for all the help, Piston Heads as it should be!