Stainless welding options

[dstig1]

So I am thinking ahead to next year.

I am going to weld up some SS railings and mesh for a 3 decks/porches on our new house. My power supply is a Miller XMT304, run on single phase 220. It can do MIG, TIG (DC only) and stick. So far I have only done MIG with it on plain steel, though I did a bunch of stick on my Lincoln stick welder before that. I have a 12 or 15' 300A Tweco gun on it (I think it is 12') and currently a C25 gas cylinder, but I also have a helium cylinder I picked up from CL for almost nothing that I might convert to something else as needed. No spool gun. I am going to have to weld a good number of inches of SS. I could set up TIG, but know it is slow. Can I reasonably feed SS through my current gun or do I really need a spool gun? Not really considering stick SS in this case as I don't want to fight with the slag. Obviously I would need a new tank of gas to MIG the SS too (Trimix?).

I guess I'm just looking for suggestions and discussion at this point. Then I can figure something out from there. I guess the big question is TIG vs MIG and if MIG then spool gun or not? I kinda hate to get a spool gun for this as the ones that are compatible are pretty pricey. Just looking to get thoughts from the collective...

Thanks!

 

[Blade Breaker]

No spool gun needed . Just get the wire and a tank of stainless mix 90%He/7.5%Ar/2.5%CO2. Your standard drive rollers and liner will work fine. Guessing .035 wire is what you have in mind. Xmt runs ss great.

Let me know if you need anything else.

 

[Gary Fowler]

If and only if you can do pretty TIG welds, that is what I would use. The welds on porch rails will always be in sight so they need to be pretty. A TIG weld when done right is the best looking weld and will use less $$$ worth of gas. It is a bit slower than MIG but I think the quality and beauty will win out for the vote.

 

[dstig1]

BB- Nice to know it will run through the gun as is. Though I am probably due for a new liner. Bought this setup used a few years back at auction and they had been running fluxcore or dual shield or something nasty through it.... But getting back on topic... That may help the decision a lot as if all I need is a new cyl of gas and some wire, that may be just the ticket. 035 is what I was thinking would be about right. It seems to be a sweet spot for a lot of stuff that one can do at home. Works on 12 ga up to 1/2", more or less...

Gary - My TIG experience is all of one evening. My welding class a couple years back we had some time the last day and the teacher was very helpful and showed me how to TIG and I did a couple 2" cubes out of steel and SS. Mixed results... I could get better at it if I invested in it with some time, and I do want to, but time is the big problem with the house build. Coupled with my realization that TIG is quite a bit slower, pushes me towards MIG if it works, and per BB's points, that looks like the best option for me.

Thanks for the input! Curious what others have to say...

 

[mrmikey]

I'm with Gary, Tig. It is substantially slower but when you take into account the finishing time and the finished appearance there's no comparison, just my two cents worth....Mike

 

[nybirdman]

I have done tons of Tig Stainless in breweries and paper mills on pipe.Only way to go for a quality looking job.Mig may be faster but you are going to have a lot more clean up afterwards(splatter).

 

[Gary Fowler]

Cleanup is the big killer for having nice looking welds. My employer prior to me retiring did some production studies as to manhours required to do TIG root & hot pass welds on carbon steel vs using stick rod, then grinding out the impurities on the root pass and running a hot pass with carbon steel electrodes. It was found that time wise, dollar wise also figuring in consumables, it was much faster and much better quality to run TIG than stick. MIG quality is not going to be there either. I always said that a malfunctioning MIG gun can make a mess in 1 minute that will take you one hour to grind out.

If you can weld everthing flat or nearly so, just about anyone can make a descent TIG weld and with just a couple hours practice you can be turning out some pretty fillet welds on the stainless. YES it is a bit slower but that is too your advantage in making a pretty weld unlike MIG where you have to move pretty fast and on small pipe that means fast rotation of the MIG gun to keep the wire feeding at optimum angle or you are going to have a lot of grinding to do for cleanup.

 

[Gary Fowler]

OH yeah, lets not forget the cost of equipment for MIG vs TIG. A good TIG torch with 25 foot hose can be bought for less than $200 with regulator. What is the MIG gun going to cost (unless you already have one that is)

 

[dstig1]

Well, yes, I already do have a MIG gun, which is part of the equation. There would be minimal additional cost to adding SS to MIG, but more if I were to go TIG. But on the plus side, I do want to get TIG capability for the long run, so that is a factor here too. Maybe this is the time to do it... I hadn't thought about spatter with SS MIG as I see so little currently on steel. That is a good point.

 

[mikefromnh]

Got a pic of the railing style you want to make?

 

[Arc weld]

How thick is the railing and deck you want to weld?

 

[dstig1]

I don't really have a pic at this point, just some ideas in my head. Here is a description, if you can follow my meanerdings. I'm thinking mostly 1/8" thick for the main structural elements, but it could go a little thinner too. 12 -14 ga is about the min. for some parts of it, I would think.

The main railing is a panel made up of a simple SS angle frame and SS mesh inside that. I would weld the mesh to the angle. This is where TIG would be a lot easier, I'm sure. That is the structural part of it, and t would span between posts. I would also be adding a screen to this for bugs. So I will need to figure out a way to make a mount for screen frames. The screen frames will need to be custom, so I may be welding those up too. For a cap railing, I was thinking of something a bit wider, like 6" so that it has some beef to it. Probably nothing thicker than 3/16" or 1/4" flat stock, perhaps. Or maybe some rect tube in a 6x2 form (if that even exists). I will need to attach bug screen above that too, so will need mounting for that. Again, probably some angle or even just flat stock welded on vertically. Will need to frame above for bug screens and mounting that with angle.

On one deck/balcony I will need to make a door out of this for roof access to clean the chimney, so I will be framing up a SS screen door in similar format.

Hopefully this made some sense...

 

[dstig1]

Going to resurrect this for another question. As I seek equipment to set up for TIG on these railings, am I OK sticking with air cooled torches, or should I look into water cooled? I doubt I will weld very fast, as I am slower than molasses in january, but if I really need water cooled, i want to get that set up from the get go. I am thinking getting a HF box might also be a wise move given the amount I have to do. CL/ebay and we'll see what comes up...

 

[Walkin Horse]

No you do not need a W/C rig. They are very awkward to use. I used to weld out a 12" pipe joint without stopping. I kept cut wire in my pocket and kept going. All you need is the standard 200 amp. Your money would be better spent on other things for this project.

Something that hasn't been mentioned is rust protection. You will need to be very careful about carbon contamination. I would buy a better grade of ss than 304. Go with 316L if it's available. Get some SS sheet metal to work on. Change all your grinding wheels to a new one. Limit your cuts with a saw blade and use a 6" metabo cutoff wheel. Use only a SS wire brush. Watch spatter and grinding sparks from other carbon projects. Reject any steel that has been bundled with carbon wire.

You are going to po 3 days after you put it in and see it rusting after the first dew. However if you want to buy a water cooled rig, think aluminum.

 

[Gary Fowler]

No you do not need a W/C rig. They are very awkward to use. I used to weld out a 12" pipe joint without stopping. I kept cut wire in my pocket and kept going. All you need is the standard 200 amp. Your money would be better spent on other things for this project.

Something that hasn't been mentioned is rust protection. You will need to be very careful about carbon contamination. I would buy a better grade of ss than 304. Go with 316L if it's available. Get some SS sheet metal to work on. Change all your grinding wheels to a new one. Limit your cuts with a saw blade and use a 6" metabo cutoff wheel. Use only a SS wire brush. Watch spatter and grinding sparks from other carbon projects. Reject any steel that has been bundled with carbon wire.

You are going to po 3 days after you put it in and see it rusting after the first dew. However if you want to buy a water cooled rig, think aluminum.

I agree with everything except the wire type. Actually 304 grade has more chromium in it than 316 but either of those will work fine and never rust unless contaminated with CS dust or particles from a brush previously used on carbon steel.
If you use all new brushes made from stainless steel, new grinder wheels and cutoff wheels, work off a plywood table top cover and you should be ok. Clean your shop well prior to starting so any steel dust is sweep and blown out before starting.
Should you get rusting on the stainless steel, a phosphoric acid treatment (like a brand name WEDAC) will remove the carbon steel contamination.

 

[dstig1]

Thanks, Guys. I suspected WC was not needed, but wasn't sure if there was some advantage I was missing. I've heard they are smaller and easier to maneuver, but that had me scratching my head as there are 3 tubes plus a wire vs 1 tube and wire for air cooled. Also good points on avoiding contamination. Will make sure to keep things clean.

What size torch? Is the #17 that is the common one? I've heard good things about the CK brand lately somewhere (probably over on WW).

 

[Walkin Horse]

When I said 316L I was referring to the stock and not so much the wire. I have never seen 304 wire. I thought it started at 308.

Is the higher grade SS more for chemical corrosion than for rust? I work one place and they had a machine made by George Ficsher. It used a chemical to clean the metal with a tungsten and a scrubby. It would even take some of the discoloration out of the welds

 

[dstig1]

316 is typically used in highly corrosive environments in industrial settings. There is no real advantage to using it for railings or where other typical SS (303, 304) is used. I may not know how to TIG weld this stuff yet, but I know what it's used for. Typical Engineer...

 

[Cord]

I have some stainless rods that I use for these projects. They work great. Slag peels right off and the weld bead is super pretty. Almost as easy as using a 7014 rod. Wish I had the number or I'd give it to you.

 

[bigdeano]

I have some stainless rods that I use for these projects. They work great. Slag peels right off and the weld bead is super pretty. Almost as easy as using a 7014 rod. Wish I had the number or I'd give it to you.

Sounds like the E308L-16 rods I use to weld 304 stainless.