Stainless Welding, first attempt

[Shorefun]

I have made up a brace like used on the gudgeon they sell today.

I have a TIG welder and can put in steel panels almost good enough you would have a hard time finding the seam in bare metal. I have played around with car restoration.

So I got some SS and started looking up on the web what I needed to know. One thing you have to do is passivate the weld area. When you weld you bring the iron to the surface and it can rust. It does not hurt things, but it stains. There are all sorts of acid dips that corrects this, but they require nasty chemicals that are not easy to get. So I am trying some Goof Off Rust Stain Remover which is a weaker version. Put some electricity into the mix and it is supposed to do the job.

Here is a pict of the test weld I did. What you do not see is the heat discoloration. This is after passivation. It seems to have worked. Not sure yet about the black stuff, need to look it up.

 

[BrianRobin]

Your weld is too cold on the upright piece.

 

[Shorefun]

Thanks.
In checking some on the net it also looks like do not have enough post time flow. Might have to do smaller areas and let the argon flow while it cools.

 

[Will Gilmore]

Nice post. I'm interested in getting into welding so I'm following this thread. Thanks for the pic. There is carbon in ss, so maybe that is the black stuff you mentioned.

-Will (Dragonfly)

 

[Cowpokee]

I haven't tried TIG welding but when I started to MIG stainless steel several guys recommended that I use a helium mixed gas to increase the puddle fluidity. I didn't have a big enough project to justify buying another gas bottle but I was satisfied with the results I did get with 75/25. Now I haven't tried to weld stainless steel vertically. Every project so far has been small enough to turn it over and only do flat welds. I figured after the project was completed, even an untrained eye could tell a bad vertical weld, but only a welder would know that they were all flat welds.

 

[Crazy Dave Condon]

Good report on your welding. I appreciate the reporting.. That is the way many of us started experimenting. Will is correct about the carbon. Chinese stainless steel has been known to contain too much carbon which is why some manufacturers stayed with the more costly ss here in the US.

 

[Shorefun]

Welding is easy to learn these days, well learn well enough to do basics. Youtube and the net are loaded with stuff. Catch is doing some of the odd stuff. Like welding the sheet metal on a car up to the edge and handling shrinkage.

What they do not tell you about is the fact any time you heat metal up past the plastic point you generate a shrink. Plastic point for steel is just a bit above where the metal changes color. You have to be able to correct the shrink or plan for it ahead of time. Most of the old car stuff I have to correct it. Pretty simple with lots of short welds, minimal filler (TIG or oxy act), and hammer on dolly work to stretch it out. If you are welding large stuff there is an order of welds you have to do to get a straight item in the end.

A nice trick to know is copper can be your friend. You can put some copper behind the weld area to control heat. Copper also allows you an easier time filling holes. I will sometimes put a TiG rod and start a mig weld on the tig rod to take the heat and have the puddle melt into the edges of the hole. Normally the arc burns the edge back and makes for a nasty fix.

As for welders, well you want better then cheap if you can afford it. The lower end welders usually have less settings and it is always that the setting you need is in between the welder's settings. A 220 welder is important if you need to do a lot of welding on bigger stuff as it has a better duty cycle. Deals on older TIG welders are out there. The Miller 330A/BP is a great welder (bit of an energy hog) shops are getting rid of them because all the modern aluminims need computer controller fancy waveforms to be welded. Craigslist and patience are your friend.

A note about tanks. Some are rental tanks and that can not be sold. I know in NJ the large O2 tanks are only rentals. So do not 'buy' a tank unless you can prove it is owned. Having a good relationship with a local welding gas supplier helps a lot. That is buy stuff from them and they should support you. They know you have a tank and they take care of you.

As far as the above weld. The black stuff is likely because I did not have enough Argon flowing around the weld while cooling. Likely because I am used to just pulling away as soon as I release the foot control. I have to change my habits. Also the bottom looks bad because it was exposed to air. Next time I will use some copper underneath to limit air exposure.

 

[Shorefun]

Got a chance to try some test welding again. Made sure I kept the torch on the work for the post flow. That made a difference. First go you can see I have 2 blobs. I was not getting the heat up on the vertical and so it was not doing so well. On the other side I worked at getting the tip up better on the vert and was getting my circle and rod feed better.
The first pair of picts are the two side before passivation.
Then you can see what just a little time with 12 volts and the Goof Off rust stain remover can do. I have a glass bead booth and could make the black go away too but it would make a mat finish.

 

[JimInPB]

I see a variety of things in those pictures.

The black is contamination. That can be from insufficient shield gas or from foreign material (like oil) in the weld area. Insufficient gas can be from a problem with preflow, postflow, oriface size, or local breeze.

Some bead looks good. Some looks cold. Some looks a bit hot with not enough filler. None show the “fish scale” look that tig beads are supposed to have, but I normally don’t go in for that aesthetic either. I don’t really believe it is necessary. If you ever send in tig specimens to get certified, then you will want proper fish scale beads. That is the only time I bother with them, unless someone asks for them. Most of the time when people ask for them, it's on aluminum, but that can vary.

The discoloration in the heat affected area is normal.

I’m curious what tungsten you are using. Pure (green stripe)? Thoriated (red stripe)? Other? I’m also curious what gas you are using. Straight Argon? I’m curious what grade of stainless your base metal is & what grade of filler rod you are using. I’m curious what polarity you are running. What is your tungsten diameter & is your torch water cooled? Do you have a pedal?

One thing about stainless in general: it warps more than almost any other metal when you put the heat to it. When I weld stainless, I make sure to put plenty of tacks on it before I start a bead. I keep my beads short. I weld a bead on the opposite side before doing a second bead on the first side & continue alternating like that all the way down. If you need a continuous bead, you can go back & fill in the blanks after the first set of stitches has cooled. I used to weld a lot of stainless, but I’ve been out of it for several years now.

I have had a variety of tanks, from the large (244cf rentals) to the tall pencil tanks (122cf, can be rented or owned) to the smaller (80, 60, 40, 20, 8 cf, all owned) high pressure cylinders to a few different varieties of dissolved storage acetylene tanks, including the old valve style on T-30 cylinders & the little plummer's bottles. Gas cylinders can be dangerous if you don’t handle them correctly, especially the acetylene. If you haven’t had tank training, get some. I also had a trans-fill hose, that let me move gas from one tank to another. It allowed me to custom blend some of my gasses, which is sometimes helpful, especially when running mig on certain grades of stainless.

An unpassivated mat finish on stainless in a salt water environment is an open invitation to suicide by rust.

 

[DayDreamer41]

Time in the saddle as they say perfects the process, the more you do the better you get.
What ever you do, don't use a steel brush on stainless steel, it will leave iron deposits etched into the surface of the stainless and it will start to oxidize.
Incidentally, the "Inside T" connection is one of the most difficult joints to weld and have it look nice, it might be the picture, but it appears like you are not moving fast enough and laying down too much filler, you don't need much of a weld to fuse stainless steel together. The black is carbon precipitated to the surface of the stainless caused by the heat, this is easily removed with passivization paste, your local welding supply store should have this on the shelf.
https://weldingsupply.com/cgi-bin/einstein.pl?PNUM::1:UNDEF:X:ARCP302
Brush it on leave for about and hour and then rinse with water, you should get a SS wire brush as well that will help cleaning the black out of the crevices. The stuff is not to bad just make sure you protect your eyes, yes it is acidic just don't apply it to bare skin it will burn, but it does a nice job or cleaning up a weld performed with the TIG process.
example of gels ability
https://www.google.com/search?q=pas...AUIDygC&biw=1366&bih=626#imgrc=yZO4kGgEewtjDM:

 

[Shorefun]

So some details....

So I am using a Miller 330A/BP from the late 60's. Got the welder tank, air cooled torch, pile of various rods for $600. Heavy as can be to move. The tank turned out to be a rental. The guy expected me to return the tank to him which was out of my way to do. Told him the tank is in front of my house and they pick up scrap in 3 days. It was gone by end of day The welder was a pain to use for a while till I figured out they wired the start/ weld current relay backwards. It had new caps ($$$) and HF arcs put in a few years before I got it. Just turned on it spins up my meter pretty fast!!
Still had troubles welding. Then I realized I could not see good cause the over 40 eyes crap. So I bought some cheaters and put them in my auto darken helmet. Now I am better.
One of the limits is I only have it on like a 50 amp breaker. I estimate that is about 1/2 what it needs for full power so I never past mid range.
It is wired normal with a foot switch/current control. I am using a Red tungsten 1/16". The rod is ER-316L 1/16" (bunch came with the welder). The stainless I am practicing on and going to use is an unknown type 1/16" thick. I was given a small sheet from a welders scrap pile. The lens is just the big ceramic thing that came with the welder.
I am using Argon gas.

I am used to doing small spot welds as that is how I do heat control and control shrinkage with regular steel. I will practice that type of welding. The 170 rudder bracket is made of a thicker stainless and will be a bit deeper of an area to do my corner welds. I am contemplating if I need to do it in an area that I can fill up with argon since I will have a couple of sides exposed to oxygen. Argon is heavier then air so I am thinking in a box.

Anyway no rush. The bracket works as it is, but it clearly needs some bracing as it was curled down some at the top. I am going to stop at my local welding shop and ask them about my welds.

 

[JimInPB]

There is nothing wrong with those old blue machines. I'd be happy to have one in my shop. Aside from the difficulties involved in moving them around, I actually prefer them to the modern inverter welders. The old points based HF systems are a lot more durable (& cheaper to repair) compared to the modern stuff. Your air cooled torch will overheat long before that machine will. You can probably run 3/16” tungsten without worrying about blowing a 50 amp breaker. I doubt that your air cooled torch even has a collet any bigger than that.

If you notice yourself getting headaches, or if you feel a sandy, gritty feeling on the back of your eyes when you go to sleep at night, then check that the lens on your hood is up to snuff. A lot of the tig guys like to run shade 12 rather than 10, because the tungsten arc is brighter than a stick arc. Also, some auto darkening hoods change faster than others. Speedglass is what I used to use when I did a few thousand welds a day, but others may also be good. If you have a solar lens, charge it up before you start. If you have battery power, then keep spares around. When the battery gets low, the lens gets slow on some brands.

BE CAREFUL when you grind red stripe tungsten. Have very good ventilation & clean up the grinding area as soon as you are done. The red stripe denotes 2% thorium. That stuff is radioactive. If you inhale the dust, you can get a committed dose of radiation that is many times greater than the OSHA max. Normal handling of red stripe sticks is generally not a problem. Keeping a box of them in your shirt pocket 24/7 might not be a good idea. I usually store them in a metal box. Green stripes (the ones that you ball up for welding aluminum) are no problem. They are pure tungsten. There are also some newer blends out there now that are not dangerous like the old school red stripes.

I haven’t needed to do any reinforcement on the rudder bracket on my 170. If I made the bracket any stronger, I would be worried about breaking off the little transom post that it screws to.

 

[JimInPB]

Oh yea, check that the incoming power to the welder is connected to the proper tap. Those old blue boxes usually had separate taps for 208vac, 220vac, etc. There should be a wiring diagram on the inside of the panel that you remove to get access to the area where primary power connects.

 

[Shorefun]

My welder happens to be on some really heavy duty wheels so moving it is not such a big problem. The guy we got it from ended up with it from a friend of his that had died. That guy was last using it to tig weld super thin stainless bellows used in some kind of pressure gauge. The guy that died was so good with that welder he could weld together to razor blades, don't know if it is true, but it sounds good.

Honestly after my test welds I was debating if I would go through with adding a brace. I got some bend in the metal and I am worried about keeping the back sides clean and pretty. I am leaning towards leaving it alone. I know I can get it welded in place, but I am afraid what the part will look like when I am done. A lot of extra work I do not need to add to my list.

Thanks for your comments.

 

[JimInPB]

I've seen an aluminum beer can welded with an old Miller Gold Star of similar vintage to your machine. Razor blades should not be any more difficult. Yep, that machine can do it.

As for the bracket, I've always been a big fan of the philosophy - If it ain't broke, don't fix it.

 

[Shorefun]

At the car flea markets the guy with the alumaweld and a propane torch welding together beer cans.

 

[JimInPB]

Yea, that's cheating. That's not actually welding. That's actually brazing. The difference being that when you braze, the base metal is not melted, the filler is just whetted to the surface of the base metal. It's like soldering. When you weld, you actually melt the base metal. Welding on thin cross section material without blowing holes in it, can be difficult.

 

[sailnoproblem]

I ran a shop in Jersey that welded thousands of Bow rails, bow and stern pulpits, ladders , bridge rails, etc.. The majority of work was 18ga. SS tubing type304 if I remember right. 316 on occasion but that was for purely custom work. We did the work for Silverton, Egg Harbor, Ocean Yachts, Sea Ray and many others.
All of the joints were machined to fit at a specific angle, and the welds were always fused rarely did we need wire filler. The welds were all buffed after straightening. If I remember correct we used a 1/8 tung., @ 50 amp setting on the machine, with straight argon. I don't remember the flow rate. Old Miller blues were used and then we graduated to Syncrowaves.
This is 30 year old info. It was a very enjoyable business until the Luxury Tax hit.

 

[Mechone]

I have welded many broken ,cracked stanchions, for people. I've removed the heat marks and have the welds look chromed by buffing with a white wheel and white bar compound for s/s

 

[Shorefun]

I have welded many broken ,cracked stanchions, for people. I've removed the heat marks and have the welds look chromed by buffing with a white wheel and white bar compound for s/s

Yes that removes the discoloration. During welding the iron comes to the surface for some stainless (all?) and you need to remove that iron so it does not rust stain.