HOW-TO: B13 ES control arm bushing installation. - Page 2

Yahnozha · 08-11-2005, 10:45 AM

Quote:

Originally Posted by Peter

The cryo treatment people claims it's all
about better alignment of the iron atoms, so does that mean that
annealing creates a BAD alignment of the atoms?

Not necessarily *bad*, just different, but you have to consider the part that your trying to burn out a bushing. On a stamped piece of metal (ie: lower control arm, trailing arms etc on our cars) the metal is actually work hardened thru the metal forming process, making it a stronger piece.

Now annealing is a controlled process, but applying significant heat to an object tends to soften the metal. To what extent in an uncontrolled environment like this? Who knows. But burning out bushings on a cast steel/iron I beam on a 75' Ford Truck, I doubt your gonna affect that any.

Peter · 08-11-2005, 06:41 PM

Okay, now I'm somewhat confused. Typically, if you heat something,
like a bolt and then try to drill it, it breaks carbide bits. Same with trying
to drill something like an SS bolt.

I had also thought that the reason the bolt 'work hardens' while
attempting to drill it was because of the heat generated, and if
you go slower, using a little more lubrication, it doesn't generate
as much heat, and therefore doesn't 'work harden' as much.

From what you're saying, this is basically false. The metal should
soften up when it gets overheated. For some reason, even drilling
mild steel, it always seems to harden, or maybe it's just that the
drill bit is getting dull?

Peter

Peter · 08-11-2005, 06:47 PM

Quote:

Originally Posted by BigB

as to the torch method.. that is why i use a propane torch.. it will not heat the metal signifcantly enough to worry about softening the metal.. and i keep a bucket of water close by...

I am ASSuming you mean a relatively standard propane plumber's
torch. Oxy-propane generates a significant percentage of the
heat oxy-acetylene generates. The only reason I never used
propane or even MAPP torches is that I was never patient enough
to want to wait the 1/2 hour per bushing it seemed to take. I
remember trying it with a MAPP gas torch, and it didn't seem to
want to even begin to slag the rubber. Which is great for the
metal, but sucks if you want to get it done!

I know that I never had the control arms actually glowing with the
torch, the main benefit of the oxy-acetylene torch is that it's a
*highly* directed heat. With LP, or MAPP, I always found
that the gas didn't have the force behind it to really push the
soft rubber out of the way.

Peter

Yahnozha · 08-11-2005, 07:53 PM

Quote:

Originally Posted by Peter

Okay, now I'm somewhat confused. Typically, if you heat something,
like a bolt and then try to drill it, it breaks carbide bits. Same with trying
to drill something like an SS bolt.

I had also thought that the reason the bolt 'work hardens' while
attempting to drill it was because of the heat generated, and if
you go slower, using a little more lubrication, it doesn't generate
as much heat, and therefore doesn't 'work harden' as much.

From what you're saying, this is basically false. The metal should
soften up when it gets overheated. For some reason, even drilling
mild steel, it always seems to harden, or maybe it's just that the
drill bit is getting dull?

Peter

Well drilling and flame produce two different results. Drill a bolt, say with a HSS bit, will work harden the part due to the heat AND friction, its the high friciton, high heat that work hardens the hole that you are trying to drill. Carbide should easily cut thru this unless you have a chunk of drill bit broken into the part you are trying to drill.

You also have to consider when drilling you are centralizing the heat and it cools quickly, thats another reason its work hardening, becaues its a local temper.

All and all you should always go slow and use proper lubrication