Thread: Welding stainless

Hi All,

I need to weld some stainless tube for a boat hand rail. It doesn't have to be pretty as there a cover that goes over the top of it.

I have a lincoln 250amp mig. I have a bottle of argoshield(mild steel) and a bottle of pure argon(aluminium). I dont want to get another bottle for stainless. Can i use either of these.

Also what wire do i need. I''m not sure what the grade of stainless is, but assuming it is 316 grade what wire would i need.

Is there anything else i need to weld stainless. What shade of lens is required for welding stainless.

Cheers
Michael.

use pure argon for stainless and any stainless wire will weld it. but being a marine aplication i would recommend 316 wire also.
Also a tig would be my choice for welding.

Originally Posted by mcchaddy

I need to weld some stainless tube for a boat hand rail. It doesn't have to be pretty as there a cover that goes over the top of it.

I have a lincoln 250amp mig. I have a bottle of argoshield(mild steel) and a bottle of pure argon(aluminium). I dont want to get another bottle for stainless. Can i use either of these.

Also what wire do i need. I''m not sure what the grade of stainless is, but assuming it is 316 grade what wire would i need.

Is there anything else i need to weld stainless. What shade of lens is required for welding stainless.

the weld may not need to be pretty, but surely it needs to be strong and not corrode
especially if it will be covered

Hi all,

Thanks for the feedback. I realise it has to be strong but it doesn't have to look like its TIG welded for an art display either.

Do the same techniques apply to welding Stainless as they do for Mild steel. Can you use the same tips. power setting etc.

Cheers

Michael.

The contact tip will be fine as long as it suits the wire size.
As for settings similar but you would have to adjust to suit material.

Originally Posted by mcchaddy

I realise it has to be strong but it doesn't have to look like its TIG welded for an art display either.

Michael
my apologies, I should have been more explicit
the welding I'm most familar with relates to my day job where welds have to be strong, with no defects or obvious stops and starts that might act as sites for corrosion or stress/fatigue cracking. To my eye, that quality of weld is "pretty"

For a boat rail, my expectation (especially where the weld is covered) is that a similar defect free weld would be required.

The most common sheilding gas for stainless mig welding was/is a trimix. Seeing how that you dont wont to get a different bottle and you are not too concerned about the finish just use the argosheild. The more preferred argosheild mix should be argon 97-98% and co2 2-3%. Do not use straight argon as this is best suited for GTAW (tig) which can be used for tig welding stainless steel and aluminium. I would practice a bit before the actual job.

Originally Posted by Dobre

The most common sheilding gas for stainless mig welding was/is a trimix. Seeing how that you dont wont to get a different bottle and you are not too concerned about the finish just use the argosheild. The more preferred argosheild mix should be argon 97-98% and co2 2-3%. Do not use straight argon as this is best suited for GTAW (tig) which can be used for tig welding stainless steel and aluminium. I would practice a bit before the actual job.

Curious as to why you say don't use straight argon? Argon will work fine, you just won't get as good penetration and you will get a wetter puddle.

Argoshield, c25, 75-25 or whatever blend you like, will work too! The c02 in the blend helps stabilize the arc. The helium in the tri-mix will help with deeper penetration.

thanks to everyone for the advice.

I will try some test runs on some scrap.

Cheers
Michael

Originally Posted by method m

Curious as to why you say don't use straight argon? Argon will work fine, you just won't get as good penetration and you will get a wetter puddle.

Argoshield, c25, 75-25 or whatever blend you like, will work too! The c02 in the blend helps stabilize the arc. The helium in the tri-mix will help with deeper penetration.

Yes you are right argon gas will "work" and so will most of the other gas combinations. The option of renting another cylinder is not one that he wants to take on for a small one of job, then go no further and play with what he has got. If there are 2 different gas bottles at his disposal then get some scrap, fire up the welder do some welds with each bottle of gas and settle on the preferred one.

Different gas combinations are put together for the purpose of achieving the best end results for the intended base metal for its strength, holding ability, purpose, longevity and appearance. The theory behind welding gases and metallurgy is mind blowing and well beyond the best of welders but it is well watered down for the end user with fairly easy/simple guidelines to work from. So, for the occasional welder and the job that they want to do they just want the pieces to stay together and have a sense of pride and achievement, which is great in my opinion. I am not having a go but simply answering your question.

I think that I need a lie down.

Don't forget that you could also stick weld if you have access to a stick weld setup, DC is better I think.
I have welded up such things fairly successfully with 2mm 316 SS rods and if you have the machine available it would be a lot cheaper than buying a roll of SS wire.

If you think that that you will have more use for the wire later on or you can borrow a roll or you are happy to have it sit around till next time then the MIG may be the easiest.

Good point johncar about the roll of stainless wire. A 9kg spool of stainless wire would set you back a lot of folding. Maybe graeme could lend you his compact kemppi 180 adaptive and then buy a 1kg roll from bunnings or somewhere. Stick welding is another cheaper option if you can get your hands on a small inverter arc welder as Johncar mentioned. Even with the stick welder you will need to run a few practice passes to get the feel of the electrode to minimize blowing big holes in your material. If you can get your hands on either one of the above mentioned machines this would be your best way of doing the job. Good luck and pics would be great if possible.

Hi All,

It turns out that the guy I am doing the job for has an inverter stick welder!!!. I saw it in his shed today but he is not real good with it. I must say i haven't used one for a long time either. Will go and buy some 316 rods and see how we go.

Cheers
Michael.

Sounds like a plan and maybe the planets are lining up for you. What type of inverter stick welder has he got? If it is any good maybe a trade of your labour for the welder may end up been a good deal. As I said in a earlier post that straight argon will work with the mig. We need to keep in mind cost. Getting the roll of stainless mig wire won tbe cheap even if you get the smallest roll to fit your machine unless you can borrow some. The cost of argon is much more expensive than a argon co2 mix. I guess the bottom line is try all the options and use the one that suits you best. I am now keen to see the results.

Originally Posted by mcchaddy

Hi All,

It turns out that the guy I am doing the job for has an inverter stick welder!!!. I saw it in his shed today but he is not real good with it. I must say i haven't used one for a long time either. Will go and buy some 316 rods and see how we go.

Cheers
Michael.

Sounds like a good plan, hope it goes well for you. It should give you a decent result but practice on a few scraps in a similar position first.