Fabrication Everything From JBwelded/Fluxcored downpipes to Equal length SS Manifolds.

why are welds porous

Old Jul 10, 2006 | 11:02 PM
  #11  
z1guy's Avatar
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Default Re: why are welds porous

Originally Posted by Engloid
As mentioned above, JB weld will NOT work. It will burn off slowly, and stink like hell as it does.

My advice is to throw that manifold in the garbage and start over. You cannot weld over JB weld, and it's a total bitch to grind out.
reading correctly owns you. :P
Old Jul 11, 2006 | 12:23 AM
  #12  
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Default Re: why are welds porous

An way this is how I pressure tested the pipes cost me NOTHING. found some old paint can tops and screwed them down....punched a hole in one and added air tons of bubbles. somebody may have done it before but it hit me like a ton of bricks when I figured it out, the pipe is 2.5".









Question is how long do I have before the JB starts giving up on me? I would like to to the pipes over again but I don't trust the Cambell Shitfeld Welder.



Old Jul 11, 2006 | 12:30 AM
  #13  
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Default Re: why are welds porous

Originally Posted by jagojon3
I had the same thing happen to me on my downpipe and charge pipes I made with my flux core. Here is my super-awesome pressure test method:

Go into a completely dark room (I used the bathroom since every other room had windows) and shine a flashlight through it. Weld up the pinholes, repeat until they are gone.
I'm gonna try that, I already put the stuff on two of the welds.....

Originally Posted by z1guy
grind the welds down almost smooth and then apply jb weld, when the jb weld is ALMOST cured hit it w/ a file to smooth it down. fills the holes and doesnt look like ***. then paint.
so I'll try this on the ones that have JB on them. I really didn't want to use the stuff but I kind of got desperate because it's been a month since I've driven my baby and it wasn't boosting after all that damn work, I'm taking deep breaths now.

I can't throw the pipe away(isn't cheap) so I'm going to grind down the welds and weld up the pin holes.



what do you guys thing about the spray can tops?
Old Jul 11, 2006 | 01:30 PM
  #14  
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Default Re: why are welds porous

For charge pipe back when I was using a mig for them I would wld them best I could. Grind them smooth and then lay a coat of bondo over it and sand it smooth. Bondo is much easier to work with and cheaper than jb weld. And for a pin hole it will hold back a ton of pressure.
As for the heat, bondo holds up under the paint of black cars sitting in the sun, so it should be fine no matter how hard you spin your turbpo out of it's effeciency range

Later
Randy
Old Jul 11, 2006 | 01:35 PM
  #15  
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Default Re: why are welds porous

It seems to me as though your metal wasn't prepped properly to begin with. On the lincoln 135 that I have used for flux core I generally keep the wire feed speed between two and three on the dial. For manifolds I use the high amp setting (A-D....D being the highest) and on charge pipes I generally use B.
I've tried various methods over the years and I prefer to make little circles as I push the bead along. You've heard it before but WATCH THE PUDDLE!

We all know flux core is a band-aid for using gas and not the best approach but when done properly I have great results. Thicker material always turns out better for me than the thin walled stuff.
Old Jul 11, 2006 | 02:20 PM
  #16  
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Default Re: why are welds porous

Originally Posted by Heath
It seems to me as though your metal wasn't prepped properly to begin with. On the lincoln 135 that I have used for flux core I generally keep the wire feed speed between two and three on the dial. For manifolds I use the high amp setting (A-D....D being the highest) and on charge pipes I generally use B.
I've tried various methods over the years and I prefer to make little circles as I push the bead along. You've heard it before but WATCH THE PUDDLE!

We all know flux core is a band-aid for using gas and not the best approach but when done properly I have great results. Thicker material always turns out better for me than the thin walled stuff.
I'm going to try to weld on the lower setting, but I still end up moving at the speed of light to keep from burning a hole in the stuff.

If I could only put a potentiometer on the heat setting I could probably buy more time to look at the puddle, because on anything 3/16 - 1/4" I can see teh puddle fine and it turns out wicked nice with good penetration.

I'm considering the bondo since I don't really need that much.
Old Jul 12, 2006 | 07:24 AM
  #17  
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Default Re: why are welds porous

JB weld and Bondo?

damn, I'll stick to the ****. *click*
Old Jul 13, 2006 | 04:36 PM
  #18  
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Default Re: why are welds porous

Lemme guess...the campbell hausfield unit only has 1 adjustment and for amperage only? Last time I threw some fluxcore in my lincoln it worked almost as good as the mig setup, but I also have amperage and wire speed adjustments. Does yours have the reversible polarity? Maybe check to see if they're correct for fluxcore. My Lincoln uses negative at the electrode, and positive at the clamp for fluxcore and it does make a difference if you reverse them. Try dragging the bead in a circular motion too and see if that works for ya.
Old Jul 14, 2006 | 01:39 PM
  #19  
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Default Re: why are welds porous

I have adjustment for wire speed which is very adjustable, the amperage only has HI/LO. I thought dragging was something done on thicker material. I'll look into the polarity question while there isn't an option on the front panel it might be as simple a reversing some leads inside the unit. Thanks slocrx
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