need welding tricks.... keeping things cool
 

I have a BUNCH of shafts that need to be welded (using tig) on the end
to secure an arm that is swaged onto the shaft. The weld will be
about .375 long, bonding the arm to the shaft. Directly behind the
arm, with about .250 clearance is a nylon bushing.... I don't want to
melt the bushing when welding. I have to weld a bunch of these... in
the hundreds. MIG welding puts too much of a bubble there, and the
tig looks OH soooo much nicer.

I need an easy setup to weld this without putting heat into the nylon
bushing.

I rigged up a small air nozzle to blow on the backside of the arm to
keep things cool.... I cannot seal the airflow from getting around to
the front because the design of the arm has a few screw holes in it, I
think the air flow from the nozzle is disrupting my welding gas.

So I was thinking about how I could eliminate the air flow, and I had
an idea this morning about submerging the shaft in water, with the
weld area above the water line. Now I would not be attempting this
without asking the group here about the impending dangers.... foremost
on my mind would be electric shock.... so please, if you have positive
and helpful remarks / suggestions I am all ears.

need welding tricks.... keeping things cool
 

wrote: (clip) impending dangers.... foremost on my
mind would be electric shock....(clip)
^^^^^^^^^^^^^^^^^^
The water, the workpiece , your bench and the ground cable will all be at
the same potential. Go for it--the water will certainly keep things cool.
If you do a lot of these in quick succession, the water may start to get
hot. I'm sure you can deal with that. Ice cubes? ;-)

need welding tricks.... keeping things cool
 

an idea this morning about submerging the shaft in water, with the
weld area above the water line. Now I would not be attempting this
without asking the group here about the impending dangers.... foremost
on my mind would be electric shock.... so please, if you have positive
and helpful remarks / suggestions I am all ears.

I've done this often with great success.

Karl

need welding tricks.... keeping things cool
 

On Tue, 11 Sep 2007 08:58:24 -0700, wrote:
I have a BUNCH of shafts that need to be welded (using tig) on the end
to secure an arm that is swaged onto the shaft. The weld will be
about .375 long, bonding the arm to the shaft. Directly behind the
arm, with about .250 clearance is a nylon bushing.... I don't want to
melt the bushing when welding. I have to weld a bunch of these... in
the hundreds. MIG welding puts too much of a bubble there, and the
tig looks OH soooo much nicer.

I do not think that there is any way to avoid damaging the bushing
that is .250 away from the weld.

i

I need an easy setup to weld this without putting heat into the nylon
bushing.

I rigged up a small air nozzle to blow on the backside of the arm to
keep things cool.... I cannot seal the airflow from getting around to
the front because the design of the arm has a few screw holes in it, I
think the air flow from the nozzle is disrupting my welding gas.

So I was thinking about how I could eliminate the air flow, and I had
an idea this morning about submerging the shaft in water, with the
weld area above the water line. Now I would not be attempting this
without asking the group here about the impending dangers.... foremost
on my mind would be electric shock.... so please, if you have positive
and helpful remarks / suggestions I am all ears.

need welding tricks.... keeping things cool
 

wrote in message I have a BUNCH of shafts that need to
be welded (using tig) on the end
to secure an arm that is swaged onto the shaft. The weld
will be
about .375 long, bonding the arm to the shaft. Directly
behind the
arm, with about .250 clearance is a nylon bushing.... I
don't want to
melt the bushing when welding. I have to weld a bunch of
these... in
the hundreds. MIG welding puts too much of a bubble
there, and the
tig looks OH soooo much nicer.

I need an easy setup to weld this without putting heat
into the nylon
bushing.


Another thought. Set up vise grip pliers with copper jaws to
act as a
heat sink. The jaws could even be water cooled since you
have
100's to do. The copper should be a close fit, perhaps even
use
silicone heat sink compound to help conduction.
Phil



--
Posted via a free Usenet account from http://www.teranews.com

need welding tricks.... keeping things cool
 

"Phil Kangas" wrote: (clip) Set up vise grip pliers (clip)
^^^^^^^^^^^^^^^^^^
Try to find a pair of Ice-grips. Meant as a joke, but actually, that might
work. Pre-cast properly shaped blocks of ice that could be held between the
weld and the nylon with a rubber band.

need welding tricks.... keeping things cool
 

Get some air-conditioning, copper, capillary tubing and circulate water
through it after wrapping the Nylon bushing and shaft with it.


wrote in message
oups.com...
I have a BUNCH of shafts that need to be welded (using tig) on the end
to secure an arm that is swaged onto the shaft. The weld will be
about .375 long, bonding the arm to the shaft. Directly behind the
arm, with about .250 clearance is a nylon bushing.... I don't want to
melt the bushing when welding. I have to weld a bunch of these... in
the hundreds. MIG welding puts too much of a bubble there, and the
tig looks OH soooo much nicer.

I need an easy setup to weld this without putting heat into the nylon
bushing.

I rigged up a small air nozzle to blow on the backside of the arm to
keep things cool.... I cannot seal the airflow from getting around to
the front because the design of the arm has a few screw holes in it, I
think the air flow from the nozzle is disrupting my welding gas.

So I was thinking about how I could eliminate the air flow, and I had
an idea this morning about submerging the shaft in water, with the
weld area above the water line. Now I would not be attempting this
without asking the group here about the impending dangers.... foremost
on my mind would be electric shock.... so please, if you have positive
and helpful remarks / suggestions I am all ears.

need welding tricks.... keeping things cool
 

wrote in message
oups.com...
So I was thinking about how I could eliminate the air flow, and I had
an idea this morning about submerging the shaft in water, with the
weld area above the water line. Now I would not be attempting this
without asking the group here about the impending dangers.... foremost
on my mind would be electric shock.... so please, if you have positive
and helpful remarks / suggestions I am all ears.


Hundreds of them? Dunk them. The only other solution I can think of would
be to use a
pressurized water mist, but that's probably messier than a dunk tank and
might not
pull the heat away fast enough. Possibly some type of wetting agent and/or
a circulating
pump may be necessary. I'm assuming that both pieces to be welded are a
mild steel?

need welding tricks.... keeping things cool
 

On Tue, 11 Sep 2007 12:52:56 -0500, Ignoramus26973
wrote:

On Tue, 11 Sep 2007 08:58:24 -0700, wrote:
I have a BUNCH of shafts that need to be welded (using tig) on the end
to secure an arm that is swaged onto the shaft. The weld will be
about .375 long, bonding the arm to the shaft. Directly behind the
arm, with about .250 clearance is a nylon bushing.... I don't want to
melt the bushing when welding. I have to weld a bunch of these... in
the hundreds. MIG welding puts too much of a bubble there, and the
tig looks OH soooo much nicer.

I do not think that there is any way to avoid damaging the bushing
that is .250 away from the weld.

i

Oh heck yes. Heat conduction in steel is not that fast. Immersing
the bushing works for sure, weld 'n dunk also works if you're quick
enough. I've TIG-welded to within 1/4" of paint without discoloring
or blistering it. It is important to block the heat-sensitive part
from radiant heat from the arc.

need welding tricks.... keeping things cool
 

On Tue, 11 Sep 2007 08:58:24 -0700, wrote:

I have a BUNCH of shafts that need to be welded (using tig) on the end
to secure an arm that is swaged onto the shaft. The weld will be
about .375 long, bonding the arm to the shaft. Directly behind the
arm, with about .250 clearance is a nylon bushing.... I don't want to
melt the bushing when welding. I have to weld a bunch of these... in
the hundreds. MIG welding puts too much of a bubble there, and the
tig looks OH soooo much nicer.

I need an easy setup to weld this without putting heat into the nylon
bushing.

Nu-Calgon Thermo-Trap heat sink paste - available at welding and
refrigeration supply houses. Goes on like toothpaste, and sticks and
cools the item it's coating (like a refrigeration ball valve or
reversing valve) while you braze the valve in a half inch away.

http://ftp.nucalgon.com/ftp/prodlit/3-61.pdf (800K)

For a production line situation like this, couldn't you install the
nylon bushings AFTER the welding process? And if they come installed
in the part pull them out, do the work, then press them back in.

A bit more work to R&R but no material costs for the heat sink paste
compound (or whatever method you settle on), and zero chance of
melting the nylon because it's 5 feet away...

-- Bruce --

need welding tricks.... keeping things cool
 

UPDATE on this... I welded up a water tight pipe to hold the shaft
that I have to weld on in place, and filled up the pipe with water
right to the brim and welded 10 of these shafts, and the water kept
the bushing from melting. I had to switch the water out after 4
shafts, as it was pretty hot. This is EXACTLY what I needed to help
me out. THANKS!

need welding tricks.... keeping things cool
 

On Sep 11, 5:52 pm, Ignoramus26973

Directly behind the
arm, with about .250 clearance is a nylon bushing.... I

I do not think that there is any way to avoid damaging the bushing
that is .250 away from the weld.

i
I think he means the weld is on the other side of the arm plus another
1/4 inch to the bushing.

Dan




I rigged up a small air nozzle to blow on the backside of the arm to
keep things cool.... I cannot seal the airflow from getting around to
the front because the design of the arm has a few screw holes in it, I
think the air flow from the nozzle is disrupting my welding gas.