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  #1  
Old 02-14-2003, 07:09 PM
Yardpro393's Avatar
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Default pipe dent repair

here we go here's how to repair a dented pipe.


This will actually be in several posts because I will post pics of the "tools" that i made. I can't host them so i have to do them one at a time.


1. remove from pipe

2. clean pipe. especially the inside of both ends. use contact cleaner for the inside of the ends. You just need to get rid of the oily spooge

3. remove o-rings from large end.

4. I mount the pipe in a vise using the first tab that the pipe has

5. that mounts it to the bike.

6. using a 1/2' or 3/8' expansion plug ( size depends on bike), I plug the silencer end of the pipe. wrap safter wire over the top of the plug and secure to the rear mounting tab on the pipe.

----an expansion plug can be bought from any hardware store. It it used to temporarly plug pipes. it is a clyindrical piece of rubber with a threaded bolt through the middle and washers on the top and bottom. As you tighten the nut the rubber squeezes outward, creating a tight fit.-------

7. use a larger plug for the large end, again using saftey wire over both sides of the top and secure to the spring mounts.

---- this plug has to be modified. I switch the stock carrage bolt with a longer one that os a standard size ( 7/16 X20X4). drill the center of the bolt to create an air passage. put bolt through plug as the origional was. screw on wingnut and snug up. on the threaded end of the carraige bolt adapt to accept a male quick connect compressor fitting. see pic below.
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  #2  
Old 02-28-2003, 07:54 PM
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Default Re: pipe dent repair

Keep em comin, this is great stuff!
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Old 12-26-2003, 06:47 PM
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Default Re: pipe dent repair

NEXT, you fill the pipe with about 15-20 pounds per square inch of compressed air. (15-20 psi) then, take a propane torch and heat up the dent. once the area gets soft enough, it will pop out to normal position from the pressure inside the pipe.

correct?

Rob
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Old 06-07-2006, 11:31 AM
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Default Re: pipe dent repair

Incorrect fill the pipe with 80 lbs per square inch, heat the area to a decent temp and then drop a piece of ice on it and the metal will contract. The metal stretches when it is dented so you need to contract to make it smooth again.
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Old 08-11-2006, 11:26 AM
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Default Re: pipe dent repair

I just have to comment here. I am not bashing - I simply feel obligated to speak up here.

As a mechanical engineer at one of the world’s largest companies, I have taken numerous metallurgy courses and I deal with material properties frequently. Anyone with any amount of knowledge of metals knows that heat and then rapid cooling hardens steel. Even low carbon steels - like that used for making pipes - will be affected. Combine a brittle surface with 80 PSI internally and you are creating a very unsafe condition created by a procedure that should not be recommended on a public forum. You are also creating a pipe that is substantially more likely to fail from fracturing; this is not an opinion, it is metallurgy.

I would advise anyone against trying your suggestion with 80 PSI.

You may fill your pipes to be repaired with 80 PSI and then heat them up and shrink them with ice, but to suggest this on a public forum is asking for trouble and is not responsible as it is not exactly a very safe approach. I am sure it has worked numerous times for you without failure but I would never attempt this and I have straightened my share of pipes over the last 30 years.

Granted - when riding, the pipe can be extremely hot and then may be quenched when you go through water, but the temperature extremes are far less than heating with a torch and then quenching with ice.

A rupture at even 15 PSI can cause a severe eye injury, so make sure you wear all the appropriate protection - including heavy gloves, long sleeves, safety glasses and a face shield and wear a heavy leather apron to protect your stomach. Safety wire all of your plugs and fittings and check their condition periodically.

For those wanting to straighten a pipe, use air and heat and stay away from the ice. Use a propane torch - not oxy/acet torch. Propane will not create enough heat to melt the steel, where the O/A torch obviously can and the propane torch will not oxidize the pipe like the O/A torch will.

If 45 PSI will not push the dent out, slow down and take your time and apply the heat to a larger area. You might have to push the areas around the dent out farther than needed and then lightly tap the shape back in place with a wooden or soft faced mallet. 30-35 PSI and a propane torch will remove most average dents in OEM pipes unless they are heavily creased or folded. Some of the heavier pipes - like PC Titanium series - typically take a little more pressure - around 35- 45 PSI. If you need more than 40 or 45 PSI, you might want to re-consider the repair; at least that has been my experience.

If the pipe is really bent up and the heat/air doesn’t do it, you might have to cut it open to form it back into shape and then weld it back up or send it out to someone who does pipes and let them deal with it – they don’t charge that much and it’s a lot cheaper than a trip to the ER. Of the pipes I have repaired, I have had to cut open maybe 25% of them, but I get some pretty mangled up pipes from local dealers - many look to be beyond repair.

That’s my story and I am sticking to it. Flame away.

Scott
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Old 08-12-2006, 05:48 AM
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Default Re: pipe dent repair

Makes good sense, THANKS
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  #7  
Old 08-12-2006, 04:49 PM
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Default Re: pipe dent repair

I happen to be an experienced welder fabricator and the metal used in the pro circuit platinum pipes will handle this technique time and time again. Your point however is an issue with factory pipes that i have yet to do we all run aftermaket around here. I agree with the propane torch as well that is what I use. I have never had a dent budge until i hit 80 psi then it slowly starts coming out after 80 percent of the dent is out then i add the ice for the last little nick that is left.
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Old 10-17-2006, 11:31 PM
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Default Re: pipe dent repair

i wonder if we could send this myth to myth busters?
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  #9  
Old 10-18-2006, 08:36 AM
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Default Re: pipe dent repair

i happen to be a diesel mechanic and i deal with metal parts in motors all the time and i think fixing dented pipes is a good idea.
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  #10  
Old 07-24-2007, 11:20 PM
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Default Re: pipe dent repair

i have no proof and this is more a question than a statement but wit a perfectly normal temperature bent pipe can you just hold a peice of dry ice on the dent and it will invert?
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