Howdy! introduction and bundle o spagetti header project

[Ken the krazy one]

Hey guys, I have just discovered this forum. I have been browsing around for a couple days and there are some neat projects and conversations going on.
I like the image posting ability here. It really adds to a welding forum when you can see welds and projects I think. Neat stuff.

I love welding and fabricating things from metal, I've been at it for a few years now. I'm a computer nerd by day, welder and home mechanic at night when I need to be. I'm completely self taught, or self "poorly taught". I'm sure I have lots of bad habits. But I get by pretty well and make useful things for my cars. I am lately starting to feel like I can do some decent fabrication on stainless steel, and mild steel. Aluminum is a bit of a struggle still. Mild steel kinda bugs me, just because it is so dirty to weld, I hate watching the metal vaporize under the torch and the beads get so wide. Stainless is so clean and easy I just try to work with it whenever I can. its easy welding, but hard cutting, grinding, and everything else. I practice when I can, and I have quite a few projects under my belt now.

Here is my current stainless project. Its a turbo header for my car. Please feel free to critique my welds. I have never had anyone look at my work with an experienced eye. Most of my non-weldor friends think my stuff looks "cool". But to me its quite mediocre. My handwriting is sloppy, and I just don't have that steady artistic hand that some people seem to naturally have, that also seems to lead to beautiful welds. And my pictures weren't really meant to display the welds when I took them.

I'm not sure of the post etiquette. So sorry that this may be long winded.

My equipment is, sorry its not a Miller product, HTP USA 200 amp inverter tig machine. Tubing material is 304L stainless, the flange is mild steel. filler wire is 309, 1/32", or thereabouts. Tungsten is blue tipped, Lanthanated 2% 1/16" dia.. I backpurged when I can, especially on tubes when i can't reach the back side to clean up my messes.

And without further ado . . .

[Bert]

self-taught???!!! pretty d-a-m-n good!!!!!!!!!!!
thanks for posting pics!!
At first I thought it was a art project you were doing! Like an octopus

[fun4now]

welcome,
thats a great job you did on the headers.

[wireburner]

Welcome , those are good liking headers

[Ken the krazy one]

Guys, If you would, take a look at the welding on the "collector" in the first picture. See the little bit of burn through you see on the inside of the tubes? Is this due to insufficient gas coverage on the back of the tube? Would solar flux help this? I worry about any junk on the inside of the header that might later break free and fly through a turbo impeller.

Any thoughts on improving that?

[fun4now]

yes solar flux would fix it, or a better back gassing would also do it. you may not have a good enough flow behind the weld. beshore the back gas can flow threw the back so it can push out the air and keep the area oxygen free. the past would also take care of it, wich ever one is easyest for you to do is fine.

[JonnyTIG]

The welds in the collector pic look sugared. Not enough back purge. You can use Solar flux, for single-pass welds only, and that will provide adequate shielding. If using a back purge, put the purge into the lowest possible end of the tube, or set it up so the back purge fills from the bottom up. Close off the purge end with tape or aluminum foil. Tape the joints of the tubing so the purging gas doesn't escape through the joints, masking tape works well. Tape or foil the other ends of the tubing so the gas has just a little room to escape. Use about 8 to 10 cfh for the back purge. Too much gas casues turbulance and is as good as no backing at all, and also is a waste of gas. Use the lowest heat input possible. I use around 50 -70 amps for the tubing butts for exhaust 16-18 Ga, and of course more for the flange welds.

Something I don't know about is if the sugaring - carbide precipitation - causes weak spots and lead to cracks, in exhaust tubing weldments. Carbide precipitation is when the chromium in the stainless combinds itself to free floating carbons outside the lattice structure, producing carbide, and therefore taking the metal's stainless properties away, leading to corrosion. This plays a major factor in chemical resistant welds, however I don't know how it affects an exhasut system. Could be that the moisture in the exhaust gases rusts the welds if they are not properly purged. On that note, I've never seen a 304 stainless exhasut rust from the inside out. I'm sure their are a lot of stainless exhausts welded without the use of a purge or flux, but I do all my work an don't take the chance. So, do it right, and your system will out last some of those done on TV.

[JonnyTIG]

The welds in the collector pic look sugared. Not enough back purge. You can use Solar flux, for single-pass welds only, and that will provide adequate shielding. If using a back purge, put the purge into the lowest possible end of the tube, or set it up so the back purge fills from the bottom up. Close off the purge end with tape or aluminum foil. Tape the joints of the tubing so the pruging gas doesn't escape through the joints, masking tape works well. Tape or foil the other ends of the tubing so the gas has just a little room to escape. Use about 8 to 10 cfh for the back purge. Too much gas casues turbulance and is as good as no backing at all, and also is a waste of gas. Use the lowest heat input possible. I use around 50 -70 amps for tubing butts for exhaust 16-18 Ga, and of course more for the flange welds.

Something I don't know about is if the sugaring of your roots, - carbide precipitation - causes weak spots and leads to cracks, in exhaust tubing weldments. Carbide precipitation is when the chromium in the stainless combinds itself to free floating carbons outside the lattice structure of the metal, producing carbide, and therefore taking the metal's stainless properties away, leading to corrosion. This plays a major factor in chemically resistant welds, however I don't know how it affects an exhasut system. Could be that the moisture in the exhaust gases rusts the welds if they are not properly purged. On that note, I've never seen a 304 stainless exhaust rust from the inside out. I'm sure there are a lot of stainless exhausts welded without the use of a purge or flux, but I do all my work using a backing of some sort, and don't take the chance. So, do it right, and your system will out last some of those done on TV.

[Ken the krazy one]

Wow, thanks for the thorough explanations Jonny. I'll definitely try some of that next time. I didn't realize you had to be so careful about the leaks with the taping, and so on. Masking tape likes to burn, so, I assume you keep that a couple inches away from the heat? And I have never heard, or thought to use the aluminum foil trick for sealing. That will be helpful.

In the one picture you can see the copper tubing flowing argon to the inside of one of the tubes. And the other end has a wet rag stuffed in it to seal it off. I didn't have much sugaring in the runner sections, they were easier to seal off. And I couldn't see back there to grind, so I really tried to get a good amount of argon flowing back there. The collector was so open, I didn't see how to get gas to the backside, and seal it in. I can't remember if I flowed gas inside or not at all maybe. I figured I could reach in there to grind it smooth anyway. I'll try and see if I can't improve the backpurge next time. I certainly am 50% there now. Just missing on the execution a little.

do you have any tricks for getting the hose into the tube. When you are rotating parts around to weld them, the copper tube always seems to be falling out and fighting me. Its not copper the entire length, its tygon with a couple feet of copper on the end.

[JonnyTIG]

Sorry about the double post. Having troubles editing my posts... Your welcome for the explaination.

As far as getting the purge line to stay in the end of the tube, I use a flexable hose and just tape it real good. In the past I've flattened a piece of the ss tubing and drilled a hole in it, screwed two air fittings through the hole together, then tacked the plate to the end of the tube to be welded. Try an air chuck for air tools on the end of the purge line, then what ever type of plug you use just have the opposite fitting in it. I screw a male end air fitting through the plug/or plate, then a female (thread) air fitting on the other side, snap the hose with the air chuck on and go.

[fun4now]

you can get away with cardboard and masking tape if you put a hole at one end of the tube and the other end get the gas hose, just set the flow to keep it filled with fresh gas. you just have to keep the flow, aluminum foil is also used. lots of option, be creative and find one that works for you or you can look to the market for the many premade options. some more $$ than others but lots of options out.
great work on the pipe's