Removing dents from 2 stroke pipes

[Buster Brown]

Just thought I'd share my first experiences removing dents. This has been on my to do list for a while, but I've been apprehensive to try due to safety concerns. After some Youtube research and a prospective pipe buyer nunge, I made the leap. I wish I had taken pictures of the first pipe I did yesterday (was just so nervous). It was a TRX 250R PSI "sea horse" pipe, dented in over an inch deep. I was so impressed with how well/easy the dent came out. My son watched from over/behind me with amazement. Creases are hard to completely remove, and are probably a weak/stress point, so I didn't want to over heat/pressurize with false hopes of making things perfect.
Anyway, I only needed 25-30 psi. Just keep in mind as heat builds psi pressure will increase. So, make sure your plugs are sound and safety wire them if you're not 100% sure they'll hold. Although all the videos I watched showed shop air use, I chose to use Argon (inert/non flammable) from my welder for added safety. Less the possible pipe bomb/boom factor! Old carbon oily spooge, + compressed air, + high heat, = . Some videos showed guys using up to 80 psi . I used a rose bud tip (oxy-propylene), so I'm not sure if that made the expansion go that much easier, but 25 psi was quite enough. A complete blow out would be very scary! Please BE CAREFUL if you try this, but I was so happy saving a bunch of pipes I almost tossed in the steel bin.

250R Jemco *BEFORE*
.



*AFTER*




Selvy TRX *BEFORE*


*AFTER*

[aldochina]

cool stuff Andy!! So you just pressurize the pipe and heat the dent and walla?? Do you heat around the dent or directly on it? do you get it red? few more details would be awsome. Looks like it worked sweet!

[El Camexican]

Very cool! Thanks for posting this, I've got a few pipes I'd like to fix.

I think water is the safe way to to this if you are concerned, but I'd go with air too if it was controlled enough to not kill anyone.

[aldochina]

Hey Andy, what size is that gas cylinder if you dont mind me asking? I had the chance to pick up a 300 for 2 hundred, but I just think it might be too big! Wouldnt be fun to have to bring it in for a fill.

[90nut]

nice work! i have also used that method with good results. no metal shrapnel yet! i have a similar cylider on my welder its awesome till its re-fill time. suuuuuuper heavy

[petesatc]

nice work Andy!!

[Billy Golightly]

That is slick, I like the idea of using an inert gas as well - that seems to make this a reasonably amount more safe than just using compressed air

[JasonB]

Very cool, I have been wanting to do this to two pipes for the last month now. I had been trying to come up with a way to plug the pipe ends and use a tire valve to get pressure into the pipe

[3WW Star-oldfart]

There is also a similar trick done with motorcycle metal gas tanks with small dents.... That is to fill it up with water and place the tank into a freezer. As the water freezes, it expands, slightly, and can displace a small dent. It may take more than one or two coolings and refills....

[Buster Brown]

Thanks guys!

cool stuff Andy!! So you just pressurize the pipe and heat the dent and walla?? Do you heat around the dent or directly on it? do you get it red? few more details would be awsome. Looks like it worked sweet!

aldochina, It's pretty much like you said. Pressurize, then heat from the outer edge of the dent and work your way to the center, all the way getting it red hot. Again not too hot. My oxy/propylene torch runs hotter than oxy/acetylene, so things went real quick. Most of the video posters on You tube used map or propane, which I guess works just fine.
I think my tanks are 200's, but I don't remember for sure. Thinking when I bought them the bill was around $450 for the two tanks filled. And on a disappointing note, I found my other bottle (Argon/CO2 mix) empty from not having the valve turned off for several months. My regulator connection must have slowly bled the tank.... Off to Prax Air today. I'll let you know my tank size for sure and cost to fill.

I think water is the safe way to to this if you are concerned, but I'd go with air too if it was controlled enough to not kill anyone.

El Camexican, I agree and have tried the water freeze method. Maybe just my error/lack of patience, but I didn't have any luck and it seemed like a waist of time for me. I know others have had success though. I saw the "Myth Busters" do some hydroforming with their power washer wand and it looked pretty cool. That would require brazing/welding fittings to seal and looks like a lot of more effort. This went much quicker IMO. Here's a couple picks of the "sea horse" PSI pipe after the fact. This was a big deep dent. The dotted line is where it had a sharp crease.

Very cool, I have been wanting to do this to two pipes for the last month now. I had been trying to come up with a way to plug the pipe ends and use a tire valve to get pressure into the pipe

JasonB, You might have to do some searching, (as I did) at your local home improvement store. I found these thick rubber plumbing adapters, and heavy vinyl tube at Menards. I've done about 8 pipes in total now. With varying stinger OD sizes, I chose this reinforced clear vinyl tube rated at 125 psi. It's nice because after some heat it is malleable enough to melt/slide over some of the double wall stinger flanges. Obviously the tighter fitting the better. I tried to slip this clear hose past the larger diameter of the flange so I could get a clamp on the narrower section, therefore locking the melted vinyl from ever sliding off. In fact I had to cut it off with a utility knife when finished. PVC and rubber work fine as long as the heated/dented areas to be worked are well away from the ends. PVC in small diameters will withstand high psi, but NOT high heat. If heating closer to the ends, I would use a water drenched towel/rag to help keep temp in check. Regardless, I suggest wrapping safety wire around your plugs and anchor the wire back to your pipe's spring hooks/eyelets. I did have a couple hissing leaks start after heat buildup. Pressure got to about 40 psi. I just stopped, retightened my clamps, bled off some pressure and started again. Defiantly not a beer drinking afternoon.....

[tri again]

25-30 psi?
really?
I could steal that from one of my truck tires, right?

but also have a neighbor who, well, almost lost an arm when a
tire rim blew, most likely his fault but still.
I'd do it behind a stack of cement or sandbags.
or around a corner.

I been whipped by a failed airline but that was around 100psi
and it HURT.
Did I learn anything?
probably not.

I wonder if,say 1/2 or 3/4 full of water and then air or gas pressure would be safer and / or yield the same great results?
Water won't compress but the gas pressure should come up the same.
May not heat properly or may create steam which could be worse safety wise.

[Orangecnty250r]

I watched some of the you tube videos this past week and then just found this post. I was going to try my MAP gas and the kits sold on line to plug the ends with the air inlet. I have a few OEM pipes I want to fix. Has anyone else bought the plate kits?

[C.J]

25-30 psi?
really?
I could steal that from one of my truck tires, right?

but also have a neighbor who, well, almost lost an arm when a
tire rim blew, most likely his fault but still.
I'd do it behind a stack of cement or sandbags.
or around a corner.

I been whipped by a failed airline but that was around 100psi
and it HURT.
Did I learn anything?
probably not.

I wonder if,say 1/2 or 3/4 full of water and then air or gas pressure would be safer and / or yield the same great results?
Water won't compress but the gas pressure should come up the same.
May not heat properly or may create steam which could be worse safety wise.

Exactly it.

There's a big back-and-forth when it comes to repairing pipes. The more pressure you use, the less heat is needed. The less pressure you use, the more heat is needed. And there's a point where you just don't have enough pressure or heat on either side on the rainbow.

25-30 psi is right around the sweet spot. You aren't going to blow the pipe apart for NOTHIN at that level unless it's just a REALLY REALLY crappy pipe lol

I've done about a dozen or so pipes like this and they've all came out well except for big creases or dents that go across a seam. But that was just because I didn't wanna put a LOT of heat on a sharp corner. Corners + pressure + heated metal = bad time.

[Buster Brown]

Sorry, just fixed the missing/moved Photobucket pics from my previous posts. Didn't realize I'd messed the pics up....

Bill, The map gas should work real good (for heating). I originally looked at the eBayed plate/plug kits, but during a trip to the hardware store just made my own to save a few bucks. A little work with a drill & welder, a guy could easily fab up some plates too. I'm sure they'd work pretty slick. Good luck!

[Orangecnty250r]

Thanks, I am hoping to give it a try in the next 2-3 weeks!