2t Exhaust Dent Removal

[swazi_matt]

Have any of you made a bracket to block the ends of the expansion chamber to allow it to be pressurized for dent removal?

I have found these http://www.24mx.com/pipe-repair-kit

but as i am intending to remove the dents using water pressure i am not sure if these will seal properly. Any of you made any other tools for this - and any of you using water pressure? see the video link below:
https://www.youtube.com/watch?v=LTPhjaKfQRA

 

[pscook]

I used heat (propane torch) and air pressure. The advice I will give is to secure the end caps as well as drape a towel (or other restraining device) over them to slow down their velocity when they pop free. The dent in my garage door tells a better tale than I could.

Here's what I did, in order:

• Capped ends
• Heated the dents (one at a time) to red hot
• Applied pressure (50 psi to start)
• Slowly and carefully added more heat until dent started working out

I tried air pressure first before any heat, and found that the pressure rise during heating operations caused everything to explode. Unsafe. That's when I figured out that I should prewarm the air in the sealed pipe, then add air pressure a little at a time, then add a touch more heat until the dent slowly smoothed out.

I'll look for pics later today.

Be safe!

 

[Zman]

Yes this is dangerous! Pressure increases in direct proportion to temperature. Double the air temp and you will double the pressure.

 

[swazi_matt]

Yes this is dangerous! Pressure increases in direct proportion to temperature. Double the air temp and you will double the pressure.

This is why I am intending to do it with water, it is incompressible so there will be no explosions just a bit of spray

 

[Rick]

Not a chane I'm messing with this........I'm more than happy to send my pipe out for repair.

 

[Zman]

So what are you using for the hydraulic pump?

 

[pscook]

Here's the setup that I cobbled together-

 

[pscook]

And here are the before and after pics-

 

[pscook]

You can see the towel that I draped over the entire contraption to protect life and limb.

I forgot to add- I bought an extra long schrader valve from the auto parts store and used it in place of the compression bolt in the smaller plug. I had to shave the rubber plug down a bit to allow the threads on the schrader valve to engage, but it worked.

So, my process was:
Plug pipe
Heat dent (one at a time)
Add air pressure until dent walked itself out
Add heat as needed, slowly and carefully

It was pretty cool to watch the dent disappear as I added heat. Very easy to control. Just DO NOT stand in the path of the plugs, because they will hurt you when they pop out.

 

[swazi_matt]

So what are you using for the hydraulic pump?

Something like this:
http://www.rothenbergertools.us/20-RP30_RP50_&_RP60_Hydrostatic_Hydraulic_Test_Pumps.html

There are other options like modifying a 100bar power washer but I think that is a bit too uncontrollable to risk on a $300 pipe

https://m.youtube.com/watch?v=llhcATrmsBg

 

[Zman]

That youtube link was AWESOME! Thanks for sharing!

I think the challenge will be sealing the plugs at each end when using water.