Advice/comments for stainless welding project

[stormpetrel]

I need to weld 1/4" 316L to a 1&1/4" stainless shaft. I will be cutting out an opening in the 1/4" stainless for the stainless shaft to fit into. It's a boat rudder replacement/fix. The old 1/4" piece cracked and bent, I feel it's beyond repairing.

I just bought a Thermal Arc/Tweco Fabricator 211i. I don't want to MIG weld the stainless and buy tri-mix gas for 5 min. of welding. I din't want to scratch-start TIG weld it because I have zero TIG experience and there's still the gas issue.

I have decided to stick weld. I bought some Lincoln Excalibur 316 3/32" rods. I have only MIG welded (W/flux cored) before. Esthetics are not a big concern, as the welds will be under water.

I've run about 50 pounds of wire, and done several repairs and even fabricated stuff with success. I'm hoping that MIG welding experience will transfer to being able to learn stick welding quickly. I have ten pounds of rod, and am not afraid to burn some of it to practice. All welds will be done in the flat position.

I am looking for suggestions as to where to start amp-wise. My understanding is that stainless needs less heat. I'm also wondering how I account for the different material thickness when deciding on where to start with power.

I'm also open to any other ideas and suggestions, even though I'm positive some of them will be foolish.

Seriously though.....I'm looking forward to doing this project, and to getting your ideas.

 

[Blade Breaker]

Hi,
I have used stainless stick rod a fair amount. If stick is the process you want to use I would recommend using 1/8 rod for the base metal you describe if possible. With 1/8 rod I remember about 90 to 115 amps being close. 3/32 rod I am guessing that it would be around 70??
Don't think of stainless needing less heat. For what your doing weld it just like you would mild steel but use the correct rod.
The stainless stick rod is a smooth running rod and does not dig. If your welding the round bar flush on one side be sure to bevel the rod for a groove before welding. Fillet welds will work nice with this rod.

Let me know if you have any other questions.

 

[Sodo]

Storm if you are not accomplished at stick-welding with 1/8", I would not start with 3/32 (on a project that goes out in the water…..). I am reaching back into the dim recesses of memory but recall that 1/8" rod was about 5 times easier to use than 3/32" rod. Do you have 90-115Amps available?

 

[stormpetrel]

Storm if you are not accomplished at stick-welding with 1/8", I would not start with 3/32 (on a project that goes out in the water…..). I am reaching back into the dim recesses of memory but recall that 1/8" rod was about 5 times easier to use than 3/32" rod. Do you have 90-115Amps available?

After reading your reply I ordered some 1/8" rod. I'll practice with both. I have 90-115 amps available.

 

[jwmorris]

If you have a TIG, just get some argon and weld it. You will have a better product in the end even with scratch start, lots more control.

 

[stormpetrel]

If you have a TIG, just get some argon and weld it. You will have a better product in the end even with scratch start, lots more control.

A better-looking product, or a better-welded product? If the stick welded stainless is even 90% as strong as the TIG welded, it's worth my time to stick weld. No LWS in my town. My town is an island, you gotta fly or take a boat, but not if I stick weld it.......

 

[Brad_Blazer]

I assume it will look something like this? You can make nice fillet welds on both sides of the plate and the strength should be fine. The 308l rod I've used makes a nice weld. Position the piece so you are welding in the flat.

 

[stormpetrel]

I assume it will look something like this? You can make nice fillet welds on both sides of the plate and the strength should be fine. The 308l rod I've used makes a nice weld. Position the piece so you are welding in the flat.

Yes....like that, except that the rudder itself is rectangular. The stainless is 316 (super corrosion-proof) and so I'm using 316 rod.

 

[Gary Fowler]

316L (low carbon) rod would be the correct rod. Weld it in flat to slightly uphill and it will weld fine. If you run it too hot the slag will be hard to remove but I don't think it would hurt the weld quality as long as the edges aren't undercut. Stainless is a bit different from 7018 but not terribly so, a little practice and you should do well with it if you can make good (pretty) welds with low hydrogen. With 1/8" rods you only need just a bit of side to side oscillation, so don't try for a wide weave. If the flux slag cools before you come back across it will trap slag in the weld, therefore it is best with stainless to use just a slight side to side weave or even just drag the rod without any weave. I like the look of a slight weave weld though as it is much prettier than a simple drag with multiple passes. If you decide to weave it, don't make the weld more than 3/8" which is the allowed 3 times the core wire diameter for weave welds per most welding procedures. This produces the best and strongest weld.

 

[Gary Fowler]

Oh, yeah, make sure you have some good safety glasses on, stainless steel slag had a tendency to pop off and you sure don't want any in your eye. One to the lip will burn twice-once one the lip and once on the tongue- BTDT a lot. It is a natural reflex to tongue it off the lip.