Ridiculous...

[Sean]

The price of Metal these days is Crazy. The 4" to 2" reducer on this fitting I made today cost $90! It is a food grade part, but geez...

I had mentioned Purge Welding on somebodys Header Post a while back (nzsimon?) so I took a couple pics to illustrate how we cap and purge the Tubing. The cap on the 45 is solid, but the one on the far end has a few holes poked in it so the Argon is able to flow through and carry out all the oxygen.  On this piece, I was running about 40cfh on the purge Gas.

You have to balance the flow and pressure by the exit holes in the other end. Too much pressure will make the weld Hump up, not enough will let it sag. No Filler rod is used with this process, it is butted tight and fused with 100% penetration. If done right, the bead looks exactly the same on the inside as it does on the outside.

The reason for all this trouble is so there are no cracks or oxidation on the inside of the Tubing to trap bacteria. It also makes an extremely strong joint because of the full penetration. Probably too much trouble to go through for anything on a car, but this could give you all something to play around with next time you are bored...

[Charlie Chops 1940]

Very pretty and quite tidy. Wouldn't an exhaust system done that way be a bit over the top?

Charlie

[SKR8PN]

Very pretty and quite tidy. Wouldn't an exhaust system done that way be a bit over the top?

Charlie

Ya......but it would SURE be PRETTY,and you wouldn't have to worry about bacteria in it !!!

[Sean]

Very pretty and quite tidy. Wouldn't an exhaust system done that way be a bit over the top?

Charlie

Oh yes, way over the top. But if a person wanted a seamless look to the exhaust, this is the way to do it.  

Say you were building exhaust for a show car. If you ran regular Beads with filler Rod, then ground the joints smooth, you are removing most of the strength in the joint and asking for cracks. With this method, you have a nearly flat surfaced Bead with 100% penetration. The little bit that would have to be ground off would not affect the strength of the Joint.

[river1]

very nice :!:  :!:

i hope to get that good someday

later jim

[river1]

VERY NICE

You have to balance the flow and pressure by the exit holes in the other end. Too much pressure will make the weld Hump up, not enough will let it sag.

did you weld that all at one time or did you do say  1/4 at a time? did the ability of the weld to sag/hump change as you welded more of the seam up? i'm think as the seam was closed less argon would leak past and the pressure would build.

thanks jim

[Sean]

very nice :!:  :!:

i hope to get that good someday

later jim

Thanks. I've been doing it daily for 10 years, so I have had plenty of practice.

Looks like the end of it for me though. The Boss came out a couple days ago and informed me that I was getting transferred to the HVAC side of the Company. Apparently they think that me setting on my Butt in the shop welding all day is a waste of a good Foreman, so they are sending me out to run work in the Field.

He brought the subject up by saying... "I have two Foreman retiring this month, the other guys like working for you, and you've been riding the Gravy Train long enough."    Didn't bother to ask if I actually wanted to do it, he just informed me that the decision had been made.

Now I have to go out and work in the weather, and learn an entirely new Job. Won't get any more money either, since I was already a Foreman. I reminded him that I didn't know anything about HVAC and he told me they wanted me because of my "People Skills". I wonder if that means I can get away with wandering around BS'ing all day like he does...  

On the plus side though, I get a Company truck. At least I'll save some money on Gas...

[Sean]

did you weld that all at one time or did you do say  1/4 at a time? did the ability of the weld to sag/hump change as you welded more of the seam up? i'm think as the seam was closed less argon would leak past and the pressure would build.

thanks jim

We have a special saw that cuts the tubing perfectly square, so when its tacked together, there is very little leakage. I run the bead all the way around when possible, but since that had the 45 on it, I had to stop to roll it. On the heat issue, I have basically just learned through experience that it takes 80 amps to match my travel speed on 4" Sanitary tubing. On 2" the heat catches up faster so I back it off to around 60 amps.

The real trick to this is in the Torch manipulation. You have to "Jiggle" the molten metal enough to break the surface tension on the inside surface of the tubing. In the Shop, I use the pulse feature on our square wave TIG to do this. In the field with a basic TIG Welder, I accomplish it by weaving the Torch  rapidly in very small circles, with a fairly slow travel speed.

After you learn the basics of it, its really not that hard. I know some of you guys own TIG welders, so I mainly brought this up as something for you to play around with...

[enjenjo]

That sounds like the same way you do it with a Henrob. You can back shield the Henrob with purge gas too.

I did a complete welded, polished SS exhaust one time, it was near $1000 just for materials. Sure did look pretty.

[Sean]

That sounds like the same way you do it with a Henrob. You can back shield the Henrob with purge gas too.

I did a complete welded, polished SS exhaust one time, it was near $1000 just for materials. Sure did look pretty.

I believe it, especially if you were using pre-made 90's and 45's to do it. Sanitary stuff is higher because its a different grade, but just regular Stainless fittings are pretty crazy in price too.

[enjenjo]

I recently bought some type of heat exchanger at the scrap yard, because it was made from 304 SS 2" 16 ga. tubing, with the straight lengths about 3 ft, and 180's on each end. About 30 ft in all. Enough there to do a complete dual system in brushed SS. I think it came out of the Campbell Soup plant. Cost me $26

[Sean]

I think it came out of the Campbell Soup plant. Cost me $26

We do a lot of Stainless work for Kraft, but they won't let us keep any of the stuff we tear out. I think they have some kind of Contract with a scrap company.

[enjenjo]

I got that heat exchanger at the scrap yard. I hit it every couple weeks or so, I pick up aluminum, Stainless, copper, anything that looks useful. I also check the cast iron pile, I get a lot of SBS exhaust manifolds there. Most of the factories and machine shops in this area use this yard, I can usually find what I need.

[EMSjunkie]

I got that heat exchanger at the scrap yard. I hit it every couple weeks or so, I pick up aluminum, Stainless, copper, anything that looks useful. I also check the cast iron pile, I get a lot of SBS exhaust manifolds there. Most of the factories and machine shops in this area use this yard, I can usually find what I need.

Hey Frank, that's a pretty good idea, we have two big scrap yards here. I have two non-matching ram horn exhaust manifolds, reckon if I was to get the numbers off them, you might be able to find me a mate up there?
:?

Thanks

Vance

[enjenjo]

I might even have one. I also have a buddy who used to have a salvage yard, the cars are gone, but he has many parts yet.