Topic: Pulling Exhaust Pipe Dent

[billstron]

Anyone pulled the dent out of an exhaust pipe before?  I have a 78 cb550 with 4into4 exhaust.  My previous #1 pipe was rusted out, and I just bought a used replacement in pretty good condition except for a dent about 6in from the back.  Do I have any options besides living with it?  I was thinking about trying one of those dent pullers you can by at the auto parts stores.  The one where you glue something to the dent and turn a screw to pull it out.  What do you think? 

Thanks,

[puppytrax]

By 6 inch from the back, do you mean in the muffler cannister?? Or 6 inch from the muffler/pipe weld??

[CB360T]

Anyone pulled the dent out of an exhaust pipe before?  I have a 78 cb550 with 4into4 exhaust.  My previous #1 pipe was rusted out, and I just bought a used replacement in pretty good condition except for a dent about 6in from the back.  Do I have any options besides living with it?  I was thinking about trying one of those dent pullers you can by at the auto parts stores.  The one where you glue something to the dent and turn a screw to pull it out.  What do you think? 

Thanks,

I realize this is a little on the esoteric side, but take a look here http://www.tomyang.net/cars/ferrari.html and click on 2/18/07 RPM Party Continued.

I quote. "I was more interested in some of the details of the car, and while I was taking a closer look, I saw this air hose fitting on the end of one of the exhaust headers. I couldn't come up with a logical explanation, so I asked Steve. It was part of a little trick they used to get the dents out of the leading edge of the exhaust headers. With about 100 pounds of air pressure, and enough heat to get the steel cherry red, the dents came out of the header like a plastic bottle! A very neat trick!"

The cherry red part may be the part that doesn't work for you . . . 

[kghost]

Those kits are made for relatively thin gauge and wide area repairs.

Exhaust pipes are much thicker.

[ProTeal55]

Alittle black exhaust wrap will make that dent dissapear ! 

[billstron]

Thanks for the prompt replies.  Upon closer inspection, the dent is in the muffler about 1 foot from the tip or exit. 

I bought the pipe for $25, and it came will the second pipe because the guy (Charlie from Charlie's Place in SF) didn't think it was worth it to remove.  I am lucky that it did, because I noticed that my other pipe was getting to be in pretty rough shape.  The second has a small hole in the side of the muffler around toward the bottom.  It doesn't really affect the sound, but I think I am going to try to epoxy it closed (probably JB Weld). 

I just got done cleaning them up and putting them on, and I'm tellin ya, for those who say "you can't polish a turd"...  That may be true but you can sculpt it into a pretty nice form. 

Any more thought on the dent removal? 

[puppytrax]

Any more thought on the dent removal? 

Just on the heated dent...I thought that would be a neat trick for popping a dent out of a Norton gas tank...I closed off all the openings, installed a Schrader valve in the filler plug, put 3psi in it, and heated the dent...nothing...10psi...still nothing...at 15psi, the tank spread its wings like a duck taking off...   

The torch to the dent superheats the compressed air inside...you're actually getting hundreds (if not thousands) of psi...   

The tank was ruined...and that damned dent never did come out...   

I imagine a pipe would do the same...maybe straighten it out, or if it was the muffler, bulge it like a football...   

[clarkjh]

Any more thought on the dent removal? 

Just on the heated dent...I thought that would be a neat trick for popping a dent out of a Norton gas tank...I closed off all the openings, installed a Schrader valve in the filler plug, put 3psi in it, and heated the dent...nothing...10psi...still nothing...at 15psi, the tank spread its wings like a duck taking off...   

The torch to the dent superheats the compressed air inside...you're actually getting hundreds (if not thousands) of psi...   

The tank was ruined...and that damned dent never did come out...   

I imagine a pipe would do the same...maybe straighten it out, or if it was the muffler, bulge it like a football...   

Would have worked great if you would have had a mold to hold it together.  

James

[Hop on a Honda]

Try filling the pipe wit distilled water and freezing it .
Note !!!
Make sure that the pipe ends are blocked off and all air is out.
Freeze the dented area with a plumbers liquid ice fitting and turn on the liquid oxygen.
Ice will expand when frozen and should take out a mild dent This will work If the pipe is rusty it could stuff the pipe be carefull as it may go bang in the very thin places..
Good luck
Dave in Australia.

[puppytrax]

Would have worked great if you would have had a mold to hold it together.

Ah! Yes, I remember that from my University days...explosive deformation or somesuch...using C4 or similar explosive to blow thick steel sheet into a formed cavity...   

My neighbors might take a dim view of that, though...   

[hymodyne]

if the metal in the center of the dent was scrubbed bare and a small piece of steel rod or something was tack welded to the center point, then you attached that rod to the business end of a slide hammer dent puller you might be able to get the dent out after heating the steel in and around the dent  so it would give... then one would just have to grind off the attached rod.

just a thought,
hym

[billstron]

I guess, long story short, this is not an easy task.  It sounds like the cheap easy auto glue type dent puller won't work.  Everything else may be too much effort for my bike.  Header black spray paint, header wrap, or living with it will be the way I go.  Thanks for all of your help.