[cboy]

Anybody ever come up with an simple but effective method of checking for welding pinholes in U-Weld header kits?

[BMM]

Just an idea, dont know how cost effective or efficient it may be....

Cover all holes so they are watertight. Maybe even just duct tape would work. Submerge under water, in a bathtub or the like?

[matt167]

water under preassure. plug all exhaust port holes, little water in them, put a peice of rubber in the collector, cut hole in it, stick blow gun in. leaks will be found

[kruzr]

Try this....make a piece for end of collector,drill a hole in plate to accept a tubeless valve stem, or weld a piece of pipe to the plate so you can attach your air hose to it with your fittings.(depends how much faith you have in your welds)bolt it to collector with rubber gasket.If you have good flat table to clamp header in several places with rubber gasket again. You wont need a lot of air pressure(4/5 pounds steady )in header,then do a soap test.
A little dishsoap in water and paint the soap on your welds.If it leaks you have no problem to find them.

[cboy]

This is sorta responding to ALL of you who made suggestions. Bascially I think everybody is saying that the headers need to be sealed off at both ends (head flanges and pipe tips or collector flange). As best I understand KRUZR's plan (or at least how I see it) one could clamp a piece of flat stock (tall enough and wide enough to cover the head flange end of the headers) and clamp it tightly to the flange with a rubber or cork gasket in between.

On the other end, if you have individual header tubes, you could find a simple cork which will fit tightly into each header tube. Drill out the center of the cork just enough to fit the end of your air nozzle from your compressor. Soap up the weld joints for that particular tube and hit the button on your air nozzle to get a couple lbs of pressure in that particular tube. If you have holes, they will bubble up. If no holes, move on to the next tube to test.

If you have a collector and flange on the other end rather than individual tubes, you would need to make a plate which could be bolted to the flange to seal it off (again with an appropriate gasket material). Drill a hole in middle of that sealing plate to insert your air nozzle...and you are in business.

Does that sound about right?

For those of you who have done this in the past, I'm sure this question sounded pretty silly. But for the life of me I couldn't figure out a way to do this until I read through all of your suggestions.

[kruzr]

Not silly at all cboy, good question to ask .
I wasnt sure if you had collector or not at the end.
If you want to do each pipe separate,I've seen like little balloons the plumbers use in checking for leaks,cant think of proper name right now.

[dinger]

Would magnafluxing work? Dan

[Beenaway2long]

Dewey-

Find an old head with good valves. Bolt the header on with good gaskets. Tip it so the collector is up. Fill it with soapy water. Pressurize the collector or individual tube. They make pipe plugs that will seal the collector. I assume 3"? Home Depot Plumbing dept. Round rubber plug with metal backing and wingnut. Drill hole through, and use your blower tip to fill with air.


Or Use the torch method.

A soft tickling clean flame (even propane) around the joint , in a darkish room. Look into the header tube, look for light.

[novajohnb]

When welding exhaust pipes (not headers) I've used a long tube fluorescent drop light inside the pipes in a dimly lit room to instantly find the pinholes. Moving the light down the tubes and rotating 360 degrees covers every square inch of weld joint.

My drop light wouldn't fit though small headers, but a bright glow stick would, and it's flexible enough to pull through all the tubes.

[Hodaphile]

You can use the expandable rubber stopper plugs that they sell at plumbing stores to seal it up. Drill a hole in one to mount the valve stem to pump it up.