Arkmage

iTrader: (3)

For those folks who know about fabricating manifolds... what's the minimum RELIABLE thickness for the tubing? I was thinking .065 stainless would be sufficient but what about mild? .095? Any thoughts?

Markp

I prefer to use at least .120" wall, .095" is still a little thin for the job, but will work. It will just fail earlier. Optimally you'll just go buy schedule 40 weld-els, I believe the wall thickness is on the order of .125", but I don't remember.

Remember, this is going to heat cycle alot, and the penalty you'll pay for using thicker steel is worth EVERY hit in weight and "performance". So go with the thickest stuff you can find. My weld-el manifolds would typically last several years but eventually would fail from heat and oxidation stresses. Usually a quick patch and weld would restore the manifold to it's former glory.

Mark

TheBandit

iTrader: (8)

I use sch 10 stainless weld els, or you use sch40 mild steel weld els.
-Michael-

Arkmage

iTrader: (3)

gotcha... the weld ells are what I'm planning to use, but i was curious what the thinnest was I could go without failing it in a year or so... I just wish my quest for weld ells local was more sucessful... cheapest i've found is $12/90* for sch 40 mild an $10/90* on sch 10 stainless.

Markp

Yes, the stainless sch 10 will work fine.

Mark

TheBandit

iTrader: (8)

acestainless.com
Your welcome
-Michael-

bripab007

I used .140" sch 40, FWIW.

www.mcmaster.com

kyle242gt

Hi guys - interested in the homemade header option. I've got the image of the flange and a client with a CAD mill, and a 140A MIG.

All I've ever welded was steel, but I was thinking of trying my hand at aluminum (for IC piping). SS would be "interesting" as well, for manifold and exhaust.

For those who have done both, how much harder is SS than mild steel to weld, and can it be done with a 120V140A MIG?

I'd be interested in doing it myself to A) save a few bucks and B) learn something new. Cosmetics aren't real important. I'd just make a log instead of an equal length, if that matters.

TheBandit

iTrader: (8)

Stainless isn't much different, You just need stainless wire, and possibly a different gas (argon)? Welding aluminum with a Mig won't work that I know of. If you have the capabilities a TIG would really be what you need to make a nice manifold or weld aluminum. If you decide you want a mani. made, let me know and maybe I can help you out.
-Michael-

kyle242gt

I dig that smiley!

http://www.lincolnelectric.com/knowl...compactmig.asp

When I was buying my welder, there was a dude who was doing his best to weld some AL battery boxes for his boat. Welds looked like ***, but they were functional. So I know that AL is hard to deal with (hence my interest - never been one to shy away from a challenge) but not impossible.

TheBandit

iTrader: (8)

Well, like I said, theres not any way that I knew of. Al is hard to weld with a Tig, I couldn't imagine it with a Mig. Good luck.
-Michael-

Arkmage

iTrader: (3)

Thin aluminum is very difficult with a MIG, but thicker stuff is not out of reach for beginners. You will HAVE to have an argon tank for aluminum and stainless, weld quality with CO2/Mix is crap for anything but mild steel. 140A should be more than enough for stainless, aluminum however tends to require a lot of current so depending on thickness you may want a beefier unit. For IC pipes I'd think 140 would be adequite.

Markp

Yes, it can be done with the right gas and flux or backpurge. Stainless is harder than mild steel to weld but not as hard as aluminum. You can weld stainless even with CO2 (not the blend but pure CO2), you just want to backpurge the pipes to keep O2 out of the weld. As others have noted, other gases (Argon) may be more appropriate but CO2 will make the weld "hotter" which is needed sometimes with a small welder.

The power requirements are well within what your MIG welder is capable of. You'll also want to get a spool of stainless wire to do the welding.

Mark

Markp

Actually you can MIG weld aluminum nicely with a nice spool gun, still it's no match for the TIG welder. Keep your intercooler piping steel unless you want to tear your hair out trying to weld aluminum with an underpowered welder for the job. The little that you'll lose from using the mild steel piping isn't really that big of a factor if your intercooler is doing it's job properly.

Mark