Welding Stainless Steel?

whisper · 28 February 2012, 16:37

Hi, I've never welded before but I've seen it done several times, I have access to quite a large SIP 240 Mig welder which is connected to a large cylinder that says argonsheild universal on it.

I guess to weld Stainless I will need to change the wire from the 0.8 wire in there to stainless steel and on the SIP website it's 0.7 so I'll need to change the nozzle too???

Can anyone give me any tips and also any ideas where I can find some offcuts to practice with such as pipe and plate.

Thanks in advance.

Alex

whisper · 28 February 2012, 16:45

Sorry I made a mistake the SS wire is also 0.8 so the nozzle should be ok.

martini · 28 February 2012, 16:51

Mig welding stainless won't give the nice looking welds you see on people's a frames etc, that's done with a tig.

If you did want to weld ss with your mig you'll need to buy ss wire, 0.8mm is ok for light/medium fabrication and a contact tip of the same size. Gas needs to be changed to pureshield, universal is for carbon steels.

Cutting, drilling, bending etc of ss is a pita requiring lots of heavy duty tools, there's a lot more to it than just wire and gas. Then there's all the polishing kit as well.

My advice is think hard about how deep in you want to go before spending any money.

whisper · 28 February 2012, 18:47

Hi Martini, thanks for the info

Yep I am defiantly sold on the idea of learning how to weld stainless steel and I have just looked at the tig welding method and I am confident that I can do it.

Fortunately I also have access to cutting, drilling and bending equipment but sadly no polishing tools here

I am all up for buying a tig welder so if anyone can recommend one it would be much appreciated

The main use will be to build an a-frame and winged seat backs etc....

martini · 28 February 2012, 19:24

I can recommend a British manufacturer called R-Tech, very nice quality kit, prices are good and they're very knowledgable and helpful.

They have a website and also sell on eBay.

A DC only inverter is all you need, AC output is for welding aluminium, much more complicated and expensive!

Just make sure it has a high frequency start, not scratch start (quite rare these days anyway)

Their bottom of the range 160A would be more than capable for what you propose, tbh you could get away with something smaller and cheaper

Mollers · 28 February 2012, 20:11

New Arc. Brit firm based in NE with Cheryl Cole on reception.

Well built kit, great people to deal with.

Nos4r2 · 28 February 2012, 20:34

Quote:

Originally Posted by whisper

Hi Martini, thanks for the info

Yep I am defiantly sold on the idea of learning how to weld stainless steel and I have just looked at the tig welding method and I am confident that I can do it.

Fortunately I also have access to cutting, drilling and bending equipment but sadly no polishing tools here

I am all up for buying a tig welder so if anyone can recommend one it would be much appreciated

The main use will be to build an a-frame and winged seat backs etc....

Make sure you've got plenty of scrap to practice on. You'll make a lot of failed attempts to start with.

Give me a bell if you want to learn.

whisper · 29 February 2012, 21:38

Thanks for all the info and thanks for the chat tonight Nos

Just a couple more questions.....

What pipe bender would I need to bend tube for seats and an A-frame?

Also with regards to polishing I was planning on pickling the welds after, however the cost of the equipment may be to much for occasional use?

I can now see how the costs can over weigh the advantages of doing it yourself even though it would be very rewarding....

Bigmuz7 · 29 February 2012, 21:56

Quote:

Originally Posted by Mollers

New Arc. Brit firm based in NE with Cheryl Cole on reception.

Perving is still alive and well in welding

.....

Downhilldai · 29 February 2012, 21:58

Welders use an acid called 'pickle paste' to clean the welds - not expensive, but a jar will probably last you forever as a DIY user!

You can use a conduit bender on 1" OD tube for the backrests, but it's hard work and you (& the equipment) will struggle to do a full 180 deg backrest hoop. A hydraulic tube bender would be best, but lots of money unless you can 'steal' one at a plant/tool sale.

guernseylee · 29 February 2012, 22:06

http://youtu.be/yigRgG_NIyU

this should do you ............

kerny · 29 February 2012, 22:10

Quote:

Originally Posted by guernseylee

http://youtu.be/yigRgG_NIyU

this should do you ............

Wow!! that machine is amazing.

martini · 29 February 2012, 22:46

Pickling will passivate the weld area and bring back it's corrosion resistance but leaves a matt finish which still needs polishing. Unless you use a machine like the Anapol but they're well pricey.

The best DIY way to get polishing is to get a car polisher/buffer and make or buy? An adaptor to fit a tapered spindle (used for metal polishing mops) onto the M14 male thread on the polisher. That would be a fairly versatile tool able to get into most places with more power than a dremel or summat.

ukprometheus · 29 February 2012, 22:56

that is an amazing machine

i used to work in fabrication and have done a fair amount of tube bending and things have obviously come a long way

Quote:

Originally Posted by guernseylee

http://youtu.be/yigRgG_NIyU

this should do you ............

whisper · 29 February 2012, 23:00

How about this... Watch the video

Rems Curvo Electric Pipe and Tube Bender

ukprometheus · 29 February 2012, 23:05

very sweet

mach rather copper to all that plastic rubbish plumbers use these days

biffer · 01 March 2012, 06:28

To bend stainless you need a former and a guide otherwise youll crush the pipe. You can put small polishing mops in an angle grinder. Don't forget the soap to dress the mop

Rokraider · 01 March 2012, 12:43

I bought a Tig welder to do some stainless fabrication. I did a lot of research before buying a Lorch T220 (German) AC/DC, (as I am doing some aluminium stuff as well). The machine is the dogs doodads,it is the upper end in price, but has excellent support and is good value in my books.

LORCH - So geht Schweissen

However, learning to use it is another story. I have been Mig welding for 25+ years but that is a doddle compared to Tig.

I would say the key is in getting all the settings right before you start. Once it is set up to suit what your doing, it is not too bad. I would advise getting on a course somewhere and learn how to do it properly. I am paying a qualified Tig welder to come and teach me on site and I am still crap at it!
It is worth paying attention to how the settings work. I hate menus where one knob and display does 100 different functions. I find I am constantly referring to the handbook as I can't remember where to locate the setting I want. The Lorch is very good and intuitive on this front.

I found this site to be very informative with lots of vids showing what to do.

Welding Tips and Tricks - TIG, MIG, Stick and a pantload of other info

Good luck.

biffer · 01 March 2012, 13:32

You should have said last time you were here. You could of played with large Kemppi welder up the end of the shed
It's not too bad when doing stainless as long as you've got slope in and out of gas and amps. You'll only be using about 50 amp for normal boat stuff. You can also get different size guns and tungstens

whisper · 01 March 2012, 17:52

I wish I had paid more attention now but there were so many things to look at in your rather awesome workshop.