Subject: RADIATOR DENTS

From: [email-masked] (Ron Thompson)
Date: Tue, 22 Feb 1994 15:08:20 GMT

HI, 

I AM LOOKING FOR ADVISE ON REMOVING DENTS FROM THE RADIATOR OF A 1926
KOHLER GENERATOR ENGINE. IS THIS THE SORT OF THING THAT MIGHT BE TAKEN
OUT BY PRESSURIZING WITH WATER AND GENTLY TAPPING WITH A RUBBER HAMMER ?
OR IS THIS A UNSOLDER AND WORK FROM THE INSIDE JOB ? NEITHER PROSPECT 
SOUNDS LIKE FUN. I DO NOT LIKE THE THOUGHT OF TAKING IT TO A SHOP AND 
LEAVING IT. IT IS HARD TO FIND A REPLACEMENT FOR SUCH THINGS .

THANKS, Ron

Ron Thompson                      |     Internet:  [email-masked]
Psychology Dept.                  |     Voice:     904-644-5563
Florida State University          |     FAX:       904-644-7739
Tallahassee,  FL 32306-1051

---

From: [email-masked] (David Jenkins)
Date: 22 Feb 1994 16:08:17 GMT

In article <[email-masked]>, [email-masked] (Ron
Thompson) writes:
|> HI, 
|> 
|> I AM LOOKING FOR ADVISE ON REMOVING DENTS FROM THE RADIATOR OF A
|> 1926
|> KOHLER GENERATOR ENGINE. IS THIS THE SORT OF THING THAT MIGHT BE
|> TAKEN
|> OUT BY PRESSURIZING WITH WATER AND GENTLY TAPPING WITH A RUBBER
|> HAMMER ?
|> OR IS THIS A UNSOLDER AND WORK FROM THE INSIDE JOB ? NEITHER PROSPECT
|> |> SOUNDS LIKE FUN. I DO NOT LIKE THE THOUGHT OF TAKING IT TO A SHOP
|> AND 
|> LEAVING IT. IT IS HARD TO FIND A REPLACEMENT FOR SUCH THINGS .
|> 
|> THANKS, Ron

At a guess, I'd say it was an "unsolder and work from the inside" sort
of job.  This IS a guess, without seeing it, but I have a good
imagination! :-)

Un-denting tubes is something that is done by gunsmiths, usually on
the barrels of shotguns (and no, I don't know if it weakens it).  If
you can get the tube out, think about replacing it with new tube.  If,
as is often the case with old radiators, it is made of brass, don't
forget to anneal it before attempting to push it out again.

Trying to pressurise it will probably be dangerous at the sort of psi
you will need to have any effect.  You only have soft-soldered joints
(correct?) and they may give way.  You could try pumping it full of
water, venting ALL the air, so if it does crack or spring a leak then
you will just get a small spray of water rather than a catastrophic
failure... you're pushing your luck with such an old thing, though.

Thinking about it as I type this, you will probably have fun
unsoldering it - by the time you've got the bit of solder melted
enough to undo it, everything else will fall apart as well!

If it was mine, I'd find a friendly old mechanic who knows what he's
doing and doesn't mind you watching what he's doing... but this is a
rare animal.

-- 

David Jenkins

* I'd rather be steaming... *

---

From: [email-masked] (James Foster x2912)
Date: Tue, 22 Feb 1994 17:22:43 GMT

In article <[email-masked]>, [email-masked] (David Jenkins) writes:
|> In article <[email-masked]>, [email-masked] (Ron
|> Thompson) writes:
|> |> HI, 
|> |> 
|> |> I AM LOOKING FOR ADVISE ON REMOVING DENTS FROM THE RADIATOR OF A
|> |> 1926
|> |> KOHLER GENERATOR ENGINE. IS THIS THE SORT OF THING THAT MIGHT BE
|> |> TAKEN
|> |> OUT BY PRESSURIZING WITH WATER AND GENTLY TAPPING WITH A RUBBER
|> |> HAMMER ?
|> |> OR IS THIS A UNSOLDER AND WORK FROM THE INSIDE JOB ? NEITHER PROSPECT
|> |> |> SOUNDS LIKE FUN. I DO NOT LIKE THE THOUGHT OF TAKING IT TO A SHOP
|> |> AND 
|> |> LEAVING IT. IT IS HARD TO FIND A REPLACEMENT FOR SUCH THINGS .
|> |> 
|> |> THANKS, Ron
|> 
|> 
|> At a guess, I'd say it was an "unsolder and work from the inside" sort
|> of job.  This IS a guess, without seeing it, but I have a good
|> imagination! :-)
|> 
|> Un-denting tubes is something that is done by gunsmiths, usually on
|> the barrels of shotguns (and no, I don't know if it weakens it). 

And it's done even more by musical instrument repairmen, usually on
brass horns owned by junior high students B^) but my wife did once
get to work on Clarence Clemons tenor sax B^).  In general the brass
will not be weakened, but this is highly dependent on the sharpness of
the bends.  My guess in this case is that we are talking about relatively
shallow dents with no real sharp edges.  These should not be weakened
at all by being pushed out.

|> If
|> you can get the tube out, think about replacing it with new tube.  If,
|> as is often the case with old radiators, it is made of brass, don't
|> forget to anneal it before attempting to push it out again.

Unless the dents are severe you will not have to anneal.  While brass does
work harden, it is not that extreme.  

|> 
|> Trying to pressurise it will probably be dangerous at the sort of psi
|> you will need to have any effect.  You only have soft-soldered joints
|> (correct?) and they may give way.  You could try pumping it full of
|> water, venting ALL the air, so if it does crack or spring a leak then
|> you will just get a small spray of water rather than a catastrophic
|> failure... you're pushing your luck with such an old thing, though.

Probably true.

|> 
|> Thinking about it as I type this, you will probably have fun
|> unsoldering it - by the time you've got the bit of solder melted
|> enough to undo it, everything else will fall apart as well!

Probably also true.  Kids, NEVER let your dad solder a post back onto
your saxaphone, no matter how much he says he can do it.  It's very 
embarassing to have to bring your horn into the shop with a separate
shoebox full of parts that sprang off  B^).

|> 
|> If it was mine, I'd find a friendly old mechanic who knows what he's
|> doing and doesn't mind you watching what he's doing... but this is a
|> rare animal.

A specialist is probably the best bet.  Another trick you can try if you
are in DIY mode is to use a dent puller on the dents.  No, don't use
a slide hammer and drive a screw into the middle of the dent.  Get 
some brass rod and braze one piece onto another to make a tee handle.
Flare the end somewhat and file it flat.  Soft solder this to the 
center of the dent.  Pull on the handle to pull the dent out.  This 
will probably not work well if the gauge of the metal is very thick.
One of two things will happen.  Either you will pull the dent out to
the degree you want, or the solder joint will pull loose after the 
dent has been relieved somewhat.  In the first case just unsolder the
rod, wipe off most of the solder and buff off the rest.  In the second
case, do it again.  Just passing on a trick that worked pretty well when
we couldn't get either direct or indirect access to a dent and it wasn't
worth the cost of disassembling the instrument.  You are not likely to get
a perfect surface with this, but you can usually get pretty close.