Welding Stainless Steel

[Metal Troll]

We have got a new job that requires us to weld up some 16ga 304 stainless steel with a #4 finish on it. This will be my first stainless job and was wondering if any of you had any tips on setting speeds, pierce delay and amps up on my Plasma table to cut . We have a Hypertherm Powermax 1000 plasma cutter and are plasma runs on compressed air and we are not really set up for using any shielding gases.

We use 25% argon/ 75% CO2 mix for are MIG welding. Will this work for TIGing these parts or will we need to get a different gas to insure beautiful clean welds that you wont be able to see with as little grinding as possible?

This is for a new customer that is building a multi-million dollar home for some doctor who is a real stickler for details (for the kind of money he is spending I would be too) and I am hoping to use this job as a in with this contractor and architecht. Any help or advice would be greatly appreciated and if everything works out I will post some pictures for everyone here to check out.

Thank you

Nick

[plasmajoe]

Hi Nick,

I would not reccomend your mixture gas for tig welding Stainless. I highly reccomend using 100% Argon. That is all I use and the welds are immaculate and no grinding at all. Be very careful on your heat, tigging such thin stainless is tricky, if you have the spare material do a few practise runs before doing the finish product. As for you plasma setting I cannot help you there I use a Thermal Dynamic plasma pak. Hope the tigging information helps you out and best of luck on the new client.

Plasma Joe

[boodog710]

Nick, I have a hyperthern 1250. We do a lot of stainless work. I use the cutting tables in the manual. They are a good starting point. The fine cut consumables work best on thin stainless. On the 1250 they recommend (for 16 ga) the arc voltage set at 64. I increase all voltage settings by 5. I reduce the published speed by 25%. In this case it would be 110 ipm instead of the 150 on the chart.

Your owners manual has the cutting chart for your machine. I copied mine, laminated them and stapled them to the wall by my computer.

[Metal Troll]

Thanks for information gentlemen it helps me out alot. With the price of stainless I want to limit my chance of error but so far everything on this job has been visited by "Murphys Law" and this information should help keep him at bay.

Thanks

Nick

[awt112]

I also use 100% Argon for SS it comes out very clean.... Goodluck

[Metal Troll]

Well we started fabricating are piece and we are TIGing it up right now. The welds are looking great with the 100% Argon.

I was wondering if anyone had any suggestions on how to clean the weld and get it to match the #4 finish on the finished part. We spent a half a day yesterday trying different grit sand paper, various Scotch bright pads with very limited sucess . The customer wants it to look seamless when finished.

Once again thank you all for the all the information that you provide.

Nick

[Chopper John]

The best thing I've found for blending the finish on stainless is a Dynabrade Dynisher Finishing Tool. It's a bit pricey though. I just borrow the one I use when I need it, it's good to have friends with cool tools.

[Metal Troll]

We ended up getting a 3M Inline Sander3500 RPMs and 1HP with a 5" x 3 1/2" rubber slotted wheel to put the finish on and I have to say WOW what a tool you smooth with a 60grit then 120 grit to put your grain back in , then finsh with the 3M scotch brite belt on this bad boy, and then take you 3M Hand pad to shine it up with a very fine scotch brite pad. You can put any finish you want on with this sucker in seconds and you save about $50 dollars a sheet for the stainless because you dont have to get the finish on it. I figure it will pay for it self after about 10 sheets of stainless. Really works good on radius. I still want to get the Dynafile with 3/8" by 18" belt for tight spots and fine detail work but for this project this turned out to be the ticket.

We also got the job after they saw are test piece that we made for them so thank you all for your information you all helped alot. We still have a long way to go before I would consider us a "Stainless Shop" but we are on are way.

Everyone have a Happy Thanksgiving and this year I am thankful for Plasmaspider.

Nick

[wcgrady]

where did you get the sander and wheels. i am working on setting up a peanut roasting plant and have done alot of stainless work but have no idea how to polish any of it. our customers are happy with the raw stainless but it kinda hurts your pride to set raw conveyors and hoppers next to polished machinery.

[MQUICK]

wcgrady, try Unitec csunitec.com Look at their surface finishing tools. I have found that they have the right tools and pads to do the job right. They also have some pads for a grinder that can grind and polish stainless welds faster than anything I have ever used. (poly-magis-wheel) This wheel can also get into tight corners. I made a big mistake and started off using a company called walter. That was a big mistake. Stay away from them. Also look at PFERD pferd.com they have a flap disk that is made to grind fillet welds. works great on coped welds and tight corrners. Just find out who their suppliers are in your area. Just my 2 cents worth.

[wcgrady]

thanks mquick ill definitly check them out.

[Metal Troll]

We go are tool and belts from a company called R.S. Hughes Co., Inc. www.rshughes.com . It was kind of all the stars aligning at once. We were standing over these stainless pieces that we had welded up scratching are heads on how to get the finish into them and a salesmen walks in and say "Hey I got just the thing for that." he called up 3M sales and talked to them and got us the right grits and the tool to use it. We ordered the tool and Friday and it was here on Monday. We had to pay some extra for the quick ship but it wasn't to bad.