Pipe Repair

[Mhardee]

Got a rock ding in upper part of 2003 KX500 pipe and a log ding on the very bottom. Anybody had good results in pipe repair? A shop near Memphis?

[Platypus]

http://www.piperepair.com/

I have read a lot of good reviews for these guys.  I have not personally used them.

[alan]

I have a premo stock pipe and a FMF Gnarly pipe for sale!

Alan

[alan]

I have heard of various ways to straighten out dents in pipes. The first way involves heating the area with a torch and pressuring up the pipe and popping out the dented area.  I'm not sure how you would seal up both ends to apply the pressure. The second way would be like popping out a dent in a car, by drilling a small hole in the area and using a slide hammer to pop out the dent and then welding up the hole.

Anyone else have any other ideas?

Alan

[Arigato]

You can use freeze plugs to plug each end.  I have a friend to has a schraeder valve in the middle of one so he can use heat and compressed air to get the dents out.

[mdw471]

Hi All

plugging the ends of the pipe and using air pressure or heat to 'expand' the dent out works great......but a bit of a heads up

heating a chamber with trapped air can be dangerous. the air expands to the point where if something fails or is torched thru the whole thing can go 'BOOM'....actually i have never seen/heard anything more than a decent 'pop', but holy cow that was enough!!

instead, fill the chamber with water and as little air as possible. the water will expand enough to force out dents, but not enough to pop. any failures result in a 'pisser' until the pressure balances out

for whatever it is worth

Mark

[Johnniespeed]

 Hi Mhardee
   A friend of a friend who lives nearby has jigs set up for pipe repair. I had him extract several. He has some type of plugs for the ends, pressurized it with air and gently heats the area. This works perfect. The surface was only slightly discolored but the dents were gone. I am sure there is someone near you who has perfected this craft also.  I am grateful this guy lives close and only charges $25.   
   I have seen adds in magazines for pipe repair too.
   John

[don46]

instead, fill the chamber with water and as little air as possible. the water will expand enough to force out dents, but not enough to pop. any failures result in a 'pisser' until the pressure balances out

I've poped dents   many pipes, in fact I made some trick adapters to plug the ends of the pipe, even though I've always been leary of the blow up, and as such I tried the process described with the water, it was the only time I've had a pipe rupture. The water dissipates the heat, once you have enough heat to expand the dent the water is so hot it turns to steam and expands rapidly and ultimately I had a hole. I work in the Industrial gas business and have a real appreciation for what compressed air/gas can do which leads to my healthy respect for the possibility of a failure, always wear gloves and safety glases, I even use a leather welding jacket wrapped around the pipe except where I'm working.

[mdw471]

Don46

so no problems with just air??

hmmmmmm

Mark

[don46]

Think about the expansion rate of air, OK now think about the expansion of water. To get the dent out you have to get the area hot enough to make the metal pliable, and in doing so the water gets hot enough to boil at the are being heated, turning to steam and since you have no room to expand because of the water the pressure rises rapidly. I thought this was a good idea as well, if there was a rupture it would be hydralic rather than pressure leak.  I think there is the poetential for failure using air as well, I haven't had a problem. 

I have heard of water being used, but rather than heat the pipe is put in the freezer, when the water freezes it expands and pops out the dent.

[Platypus]

Water expands 1600 times when it is converted to steam.  Seems like that would be a good way to pop out a dent.  Just learned that the other day reading this article about a 6 stroke engine this guy developed.

http://www.autoweek.com/apps/pbcs.dll/article?AID=/20060227/FREE/302270007/1023/THISWEEKSISSUE

[Arigato]

I have also hear that the freezing method works too.  You'd have to have a big freezer!

[don46]

Water expands 1600 times when it is converted to steam.  Seems like that would be a good way to pop out a dent.  Just learned that the other day reading this article about a 6 stroke engine this guy developed.

http://www.autoweek.com/apps/pbcs.dll/article?AID=/20060227/FREE/302270007/1023/THISWEEKSISSUE

The idea of using water is to minimize the air volume trapped in the pipe, if a rupture occurs there is minimal energy. As you say water expands 1600 times, where does the volume go? BOOM

[MadKaw]

if water expands 1600 times, then the calculation should be pretty streight forward.

total volume the pipe can contain /1600=how many ml of water to use to fill the space with steam upon liquid to gas change.

taking into consideration the displacement of the volume the dent subtracts from what the total volume would be. possibly by filling the dent with water from a syringe on the outside for estimation.

[BDI]

I think you are going to wind up with a big split in your pipe before you ever pop a dent using the freezing method. The ice  is going to apply pressure to the whole pipe equally not just the dent. Messing with steam sounds dangerous to me. (like mentioned before) What I have thought of  but have never tried Is putting plumbers plugs in the pipe, one with a schrader valve. Then pressurize the pipe with a inert gas like Argon to about six psi then heat the dent with a torch until It pops out. I think using air definitely runs the risk of explosion do to the gas and oils inside the pipe. I have successfully welded gas tanks by purging them with Argon while welding.