Any ideas on how to fix this ?

sparkwizard

sparkwizard

#2
#2
Do you have a torch hot enough to make that pipe red hot?
I would remove the pipe, find something that would reach inside from the engine side with a smooth end on it. Maybe a tire spoon, anything strong and rounded. Then start heating the dent around the edge and push the dent out from inside.

OR seal one end, put air pressure in the other end and heat the dent until it looks smooth.
 
f4radar

f4radar

Well-Known Member
#3
#3
sparkwizard said:
Do you have a torch hot enough to make that pipe red hot?
I would remove the pipe, find something that would reach inside from the engine side with a smooth end on it. Maybe a tire spoon, anything strong and rounded. Then start heating the dent around the edge and push the dent out from inside.

OR seal one end, put air pressure in the other end and heat the dent until it looks smooth.
Click to expand...
I knew I'd get some use out of that tire spoon one day.
 
Bird Brain

Bird Brain

Active Member
#6
#6
Any chance the i.d. of that pipes close to the o.d. of a golf ball? Put a few hose clamps around the damaged section drawed up tight to retain that outside diameter and play them through! A homemade flexible mandrel similar to one for elec. conduit pulled with a dent puller slide hammer could be another option might be worth a shot next time.
 
f4radar

f4radar

Well-Known Member
#9
#9
sparkwizard said:
Do you think a 1 7/8 hitch ball would go in there?
Click to expand...
something like that might have been an idea. Once I got the primary dent out I could have done more with some type of inside dolly and a hammer. I've been watching Forged in fire.. I think I would have been sent home after the first round.
 
Augiedoggie

Augiedoggie

Well-Known Member
#10
#10
Common expansion chamber is done with secure plugs for both ends and provision for regulated compressed air to pressurize pipe. Once pipe is pressurized to 35 to 60 psi the damaged area is heated with acetylene torch to yellow glow and outer edge is tapped with flat faced dent hammer. Pressure should not exceed 70 psi for safety. Pressure has to be monitored during heating process as pressure increases with heat applied. There is also a hydronic method now used which uses a Pressure pump to remove dent once pipe is filled with water. Both methods require plugs to seal tightly and use secondary retainer in the event plugs blow out. Plugs will blow out like a bomb if not secured. I have scar to prove it. Pictures show some plugs used and a recent repair performed in my shop during Honda CR125 restoration 20210222_072321.jpg 20210222_072321.jpg 20200216_112645.jpg
 
f4radar

f4radar

Well-Known Member
#11
#11
Augiedoggie said:
Common expansion chamber is done with secure plugs for both ends and provision for regulated compressed air to pressurize pipe. Once pipe is pressurized to 35 to 60 psi the damaged area is heated with acetylene torch to yellow glow and outer edge is tapped with flat faced dent hammer. Pressure should not exceed 70 psi for safety. Pressure has to be monitored during heating process as pressure increases with heat applied. There is also a hydronic method now used which uses a Pressure pump to remove dent once pipe is filled with water. Both methods require plugs to seal tightly and use secondary retainer in the event plugs blow out. Plugs will blow out like a bomb if not secured. I have scar to prove it. Pictures show some plugs used and a recent repair performed in my shop during Honda CR125 restoration View attachment 311847 View attachment 311847 View attachment 311848
Click to expand...
Nice work.
 
Augiedoggie

Augiedoggie

Well-Known Member
#13
#13
I don't prefer the high pressure needed with the hydraulic method. It can cause pipe to deform and can straighten the required bends needed to fit into its mounting. It sort of unscrews and straightens the curves. I have seen idiots on YouTube attempting similar method using pressure washer. This is a foolish and dangerous method and should be avoided. There are still a few shops around that can restore dented expansion chamber.
 
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