Pipe Repair

[maddoggy]

i think you're right on point there BDI. the pipe is almost the same as a petrolium holding vessel considering the stuff that runs through there all the time. the inert gas will work to fill the chamber safely lowering the explosion danger when you heat the pipe from the outside. however, if you only have small dings is it really worth it to risk life and limb to remove small dents? a couple hundred $ for a new pipe seems like a good buy compared to what could happen when pressurizing with air or some of the other things i've seen mentioned in this thread. by the way, if you use the method described by BDI, fill the pipe with inert gas then heat your dinged area if it doesn't pop out then while still hot, place a piece of ice in the center of the ding. the rapid cooling of the small area will shrink it thus popping the ding out while the rest of the pipe around the ding will remain in an expanded state till cooled off. i've done this with hail dents on an old truck i used to have, done on a 100 degree plus day and ice on the hail dent. worked great. MADDOGGY

[KXcam22]

I read somewhere that guys have been using frozen water to undent their pipes.  Basically fill the head pipe with water and prop it up in the freezer.  The frozen water expansion pushes out the dent.  I haven't tried this myself yet. Cam.

[BDI]

I read somewhere that guys have been using frozen water to undent their pipes.  Basically fill the head pipe with water and prop it up in the freezer.  The frozen water expansion pushes out the dent.  I haven't tried this myself yet. Cam.

   I'm scared to try it I think the forces would  not just push on the dent but rather the whole tube and could split it open like a beer can.

[KXcam22]

Yeah you would think so.  I think what happens is that the round pipe is quite strong and contains the force but the dent gets bulged back out until it matches the round.  I would have to test it on an unimportant header pipe first.  The air pressure, plugs and heat is a tried and true method. I would certainly feel more comfortable since it is also a controlled thing (with you controlling it). I am planning to fab up my own kevlar header pipe guard.  Hopefully it can handle the heat since it is more than a 2-stroke pipe. Cam.

[Dutch-K5 Fan]

http://www.rino-racing.be/cat/
Then page 224/225 of the Catalogue.

Have one at home and works great. Easy to make self.
Save way is to first heat the pipe, than pressurize the pipe.

 Dutchie

[Jeeks]

I would have to see the freezing method first hand to believe it.  Think about it, how does the water know exactly where to push out the dent?

The air/torch method pinpoints the dent for precise removal.

[Hillclimb#42]

It works. The ice quickly contracts the metal that is only held in the dent by the slightly stretched metal around the dent. In a body shop they use a shrinking hammer that looks like a waffle iron on the face. It tightens the stretched metal by putting a bunch of small dents in the same area. It actually doesn't fix it, but makes the dent shallow as possible for bondo or in the old days, lead. Hail damage or that size of dent is often fixed with this method of heating and cooling.
 The torch spiraling into the dent also will work. Then you need to put cold water on it to keep it popped out. At least thats how it works on body work. Sometimes it will make the dent pop up too high and you need to file or hammer and dolly back to shape.
 Its been my experience that dents thay can be fixed like this are very minor dents. Ones that would only matter, if they were on your hood of a new truck. Tiny dents on the pipe probably don't affect performance as much as they take away from the look of the bike. Dents that are real big have stretched the metal enough to stay distorted and the best you can hope for is to help it.
 I like the heating and cooling methods that I recently discovered that helps setting gears and tight tolerance bearrings. Heat the outside or housing, freeze the bearring or inner gear (clutch hub) and pieces seem to fall into their place without a press.

[Jeeks]

Sorry, still not sold on the freezing method. I call BS on that.

Using water during autobody repair does not keep the dent out, it keeps the panel from warping around the work area.

The "dents" your referring to sound more like DINGS.  A dent to me would be a good WHACK with a baseball bat.  Dings I can live with, not dents.  I have formed many pieces of metal by hand, there are many ways to remove dents and dings.  Heat will help return the molecules to their original state.

[Hillclimb#42]

I agree, "dings." Like hail damage. Have you watched paintless dent repair on hail damage? I agree too, that any dent big enough to cause performance problems would be tough to fix. Maybe you could make it better, and what's to lose if it doesn't work? It seems obvious though that heat alone wouldn't help or they would pop out while riding.
 I've heard about some local guys pressurizing their pipe with air pressure and  popping out dents in aftermarket pipes, but think stock pipes would be also tough. Plus you would probably need to weld up a crack 1/2 the time on a sizeable dent. This is just evryone's first thoughts when you put the first dent in a new pipe.
 

[BDI]

The stock four stroke end caps are made out of two pieces then epoxied together. A buddy of mine gave me a brand new muffler off of a 07 crf that was taken off at his shop because the end cap had a dent from shipping.To put it on my 05 crf450x I had to move the lower mount 10mm. What I wanted to show is the end cap. I took it off fixed the dent and welded the end cap together. I blended the welds and refinished the end cap so that it looked like it was made as one piece.This is the end cap before dent removal, after dent removal,after refinishing and then after welding.

[Hillclimb#42]

The dent I just fixed in my pipe was a half inch deep and you can't even tell it was there and I just fixed my buddies pipe that was smashed over two thirds.When I was done it still had all the scratches in it from the rock that smashed it flat but it was round and usable again. All the theorys and speculations are a crack up. I just go ahead and fix them stock after market stainless titainium or other.

Obviously, you have pics about fixing them and I'm talking about some guy I know that knows somebody. At least I start with "I think" sometimes. Looks good BDI. Too bad you don't live closer, I have a PC platinum with nice one to fix.

[BDI]

You know what sucks I do stuff like this all the time but I never think about taking pictures. I'm going to do a two stroke pipe soon and I will show my home made tools and before and after pictures So it will be a productive post.You know lots of people have posted this ice thing lets try it doesn't any one have something to try it on find a piece of tubing smack it with a hammer and do it and post it. I looked around and I do not have any thing right off hand. I would like to see less talking and more doing. We need to do some myth busting around here. Some one could screw up his pefectly saveable pipe trying stuff like this.