Author Topic: Who can get dents out of my expansion chamber  (Read 8976 times)

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Offline kurraboy

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Who can get dents out of my expansion chamber
« on: August 29, 2016, 05:09:02 pm »
Hi all,

Does anyone know of someone that can dings out of my shiny new 2 stroke pipe?

Many thanks,
James

Offline jimg1au

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Re: Who can get dents out of my expansion chamber
« Reply #1 on: August 29, 2016, 05:17:31 pm »
or plenty of dents in my1973 cr250 pipe

Offline Rossvickicampbell

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Re: Who can get dents out of my expansion chamber
« Reply #2 on: August 29, 2016, 06:05:19 pm »
try Geoff Morris
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Offline bigk

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Re: Who can get dents out of my expansion chamber
« Reply #3 on: August 29, 2016, 07:30:29 pm »
Um, not me anymore. Last one I did (have done many over the years) exploded @ 35psi & took out 3 bones in the back of my hand. Very lucky it went sideways & not upwards into my face. Not worth it when new pipes are available at pretty reasonable costs & only an option for something unobtainable. That's just my opinion gained from personal experience.
K

Offline davidmc

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Re: Who can get dents out of my expansion chamber
« Reply #4 on: August 29, 2016, 09:04:15 pm »
Where are you located?

Offline Barra

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Re: Who can get dents out of my expansion chamber
« Reply #5 on: August 29, 2016, 11:15:18 pm »
Bloke i knew used water.  Plugged ends, filled pipe with water and applied heat sparingly.  Good method for smaller dings.

Was relatively safe  - but you wouldn't want to melt the metal with high pressure steam behind it! He always used caution and full cover safety gear!

Offline rocketfrog

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Re: Who can get dents out of my expansion chamber
« Reply #6 on: August 30, 2016, 07:59:33 am »
How about that, I was pumping out some dings with compressed air @50psi and using oxy/acetylene to heat on the week end.

The whole time I was wondering if the juice was going to be worth the squeeze as you warn of in your reply Big K.

It is a sketchy process, even small pressures can make a big bang. So 50 PSI is going to go big.

Any how, moral of the story is that it is potentially catastophic heating a vessel under pressure while observing the process at arms length - especially a thin metal chamber not rated or built for these pressures.

The result was very impressive in any case, nicely repaired pipe for minimal effort. I will build a cage to do this in the future. Similar to a tyre inflation cage, the concept is to contain the pipe if it blows.

There is still scope for the pipe to blow fragments and the potential for injury is still very present but hopefully the hazard can be reduced with the use of protective devices and protective gear.

I would be very interested to hear a blow by blow recollection of events from Big K to assist in designing a cage to contain a blow out. Maybe a Ned Kelly suit?

Hydroforming using high pressure water - you tube it. Looks real good and the operator can stay at a respectful distance from the pipe.



« Last Edit: August 30, 2016, 08:03:14 am by rocketfrog »
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Offline Brian Watson

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Re: Who can get dents out of my expansion chamber
« Reply #7 on: August 30, 2016, 09:55:40 am »
There is a guy over here in WA called Pipe King.. look him up..he is on Friend Face.. pretty impressive work.. and will build to your needs also..

Offline Rossvickicampbell

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Re: Who can get dents out of my expansion chamber
« Reply #8 on: August 30, 2016, 12:21:28 pm »
Pipe King = Richard - very good but thought maybe long way away?
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Offline Momus

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Re: Who can get dents out of my expansion chamber
« Reply #9 on: August 31, 2016, 02:32:44 pm »
I, ve done a couple of dint repairs on chambers lately using compressed air and oxy. You need to organise tethered bungs and a calibrated leak which can be as simple as a bolt loosely screwed into a tap.ped hole in one bung. When the air pressure rises from the temp and probably the burning carbon yit will not go over about 25psi. I use a air line connector and the line from the compressor with the reg. Set at no more than 25
If you love it, lube it.

Offline rocketfrog

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Re: Who can get dents out of my expansion chamber
« Reply #10 on: August 31, 2016, 03:08:59 pm »
Thats interesting Momus, I could not get the dents to budge at 25 PSI. Initially I thought that it would not take a great deal of pressure, I estimated 10 PSI with heat. I actually needed the 50 to do the job.

Pro circuit Platinum, FMF Gold series and a stock YZ - all took 50 Pounds
Political correctness is a doctrine,fostered by journalists and politicians, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end."

Offline bigk

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Re: Who can get dents out of my expansion chamber
« Reply #11 on: August 31, 2016, 04:33:50 pm »
There's lots of theories on pressure but I always used 40psi & never had an issue till the one that went pop. Took off like a missile & one of the mounting tabs sliced the back of my hand open, breaking 3 bones. Shit injury, 6 weeks with 18 gauge pins (nails) in them sticking out the end. I know people who regularly use 100psi, maybe I was just unlucky but never again for me.
K

Offline rocketfrog

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Re: Who can get dents out of my expansion chamber
« Reply #12 on: September 01, 2016, 02:14:10 pm »
Thats a major bummer what happened to you K, I suppose the result could have been lethal given the force and the damage to your hand.

So the pipe spun or shot forward and smashed into your hand? Did the seam split or did a bung let go? Do you think a cage would have prevented your injury?
Political correctness is a doctrine,fostered by journalists and politicians, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end."

Offline bigk

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Re: Who can get dents out of my expansion chamber
« Reply #13 on: September 01, 2016, 04:45:08 pm »
Bung let go @35psi, didn't even get the hot spanner near it. I usually clamp them in a vice but was only putting the air in (gently) & had it sitting on the bench. Yes a cage would have probably restricted the damage.
K

Offline ol490

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Re: Who can get dents out of my expansion chamber
« Reply #14 on: September 01, 2016, 04:55:17 pm »