M112 - 300 Build for the '56

It looks like you are still running too hot. I don't think it's gas, I think it's heat. Stainless is tricky - there's a fine line between a perfect weld and too much heat. If you have some scrap tubing, practice butt welding two pieces together with out filler rod. This is a good way to get a feel for the correct heat and you don't have to worry about dipping the rod. Just concentrate on the weld puddle - if you have your amps and fit up correct the weld puddle will flow very nice. It's a good way to get use to welding stainless without worrying about the filler rod. Looking at the picture you should always fill your craters. You have the technique, it just takes practice.
 
Let me ask you guys this...if you grind them out, can they be welded over top of to improve aesthetics like you can on mild steel, or is it ine and done?
 
I think those ground down welds should be fine just as they are. As far as rust in the welds that usually only happens when there is contaminates that got into them (carbon steel).
 
Sometimes when you put too much heat into the puddle you get segregation - separation of the alloying elements that makes stainless stainless. When this happens the weld and surrounding area can rust. That is why sometimes you'll see a stainless tank with rusty weld seams.
 
Guess what....bad gas...

After exhausting everything I knew, and trying all the suggestions...still gray. Even just a quick spot weld...gray.

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Tried it on plain steel..same thing.

Called the supplier...they have had a bunch of calls about it. Gonna swap out tanks and try again.
 
I am no welder (at all) but have read that if TIG welds are purged with inert gas (by capping the ends of the tube with tape and filling the tube with inert gas prior to welding) it helps prevents contamination, rusting and crystal formation. I am told this makes the inside of the weld more corrosion resistant.
 
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I got a bad tank of gas my first time with my tig. It was only barely noticeable that something was wrong on steel but it wouldn't even form a puddle on aluminum. I pulled my hair out for a couple weeks and was about to take the new tig machine back when I got the idea to try a new tank of gas. Problem solved after that.

Gotta love learning this stuff on your own!
 
Tip: Get a mini Nerf football, like the kind you might get at a football game as a souvenir. Punch a hole in it lengthwise and insert a shielding gas hose in it. Now jamb it in the end of the tube you are welding for back-shielding. It will make your welds sound.
 

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That's a real shame you just would expect to have trouble with shielding gas, at least from your experance you will now recognize it if it ever happens again.
 
Where should I mount the fuel pressure regulator? Right on the end of the Rail? Or Under the Cab in the frame rail?

I want to keep the engine and bay as clean as possible, but I also know I need to have easy access to it.....
 
It will need a boost reference line from the intake manifold which should be as short as possible.
You will need easy access.
Since it needs to regulate the pressure in the fuel rail it should be at the fuel rail.
 
Which regulator do I need...my pump is capable of 72.5 psi....the link below shows this one is good to 65? Or does the regulator need to handle more than the pump output?


I have 8an fuel rail... Going to adapt down to 6an correct?
 
Which regulator do I need...my pump is capable of 72.5 psi....the link below shows this one is good to 65? Or does the regulator need to handle more than the pump output?


I have 8an fuel rail... Going to adapt down to 6an correct?
The fuel pump will pump fuel to one side of the fuel rail and the regulator will return fuel from the other side of the fuel rail back to the fuel tank.

The fuel pump and regulator only have to handle the maximum pressure that the fuel will be regulated at.
Lets say you start with a base pressure of 45 psi and the intake manifold pressure goes to 15 psi at full boost, then the maximum regulated pressure will be 60 psi.

The Holley regulator posted above will work.

Yes, adapt to the fuel rail.
 
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I just haven't been able to get the pretty color to them...
I'd like to get started in TIG and just started subscribing to Pacific Art Tig Welding. One of his recent videos addressed this, and he said he struggled with the exact same thing when he first started and wished he had known. The big one was keeping the tip nearby to supply gas over the weld until everything cooled down, including the filler rod.

Edit: I see that you found it to be bad gas, but I'll leave the post for the channel links. He does some beautiful work.
 
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I have been getting very similar results. I am more confident in the quality of my gas than my abilities so I’m looking for other possibilities.
What cup size are you using? How long is your post flow set at?
 
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