Draw plate cleaning

Hi all,

We have problem at the shop with our carbide draw plate. The wire
comes out under sized I think due to build of metal on the die
surface. I going to have one the guys clean it in the ultra
sonic and steam it, but I don’t think this totally solve the
problem. I think the build up is similar to that on a metal lathe
tool bit (cold welding) of metal onto forming surface. Has
anyone got any neat solutions to this problem of cleaning this
out?
Jim @Zimmerman

 I think the build up is similar to that on a metal lathe tool
bit (cold welding) of metal onto forming surface.  Has anyone
got any neat solutions to this problem of cleaning this out? 

Funny, I was just thinking about cleaning up some ragged holes in
a steel drawplate this afternoon. What I’m going to try (don’t
know if it’ll work ) is this. Soak a round toothpick in oil
(olive oil, cause that’s handy), wipe it of f. Roll the toothpick
in powdered diamond (360 grit, may use other grits als o, I’m a
facetor so that’s available). Chuck the toothpick in the
flexshaft & polish out the hole. If the toothpick doesn’t work
because it’s too soft, I’ll try copper wire=2E Probably start
with #14 & taper it. Apply the oil & diamond & have at it. You
may be able to mix a little diamond with oil in a teaspoon, then
add a small amt of this mixture to a dry tapered wire already in
the hole to be cleaned. Don’t now if it’ll work, but it looks
good on paper (bg).

Dave

        We have problem at the shop with our carbide draw
plate. The wire comes out under sized I think due to build of
metal on the die surface.   Has anyone got any neat solutions
to this problem of  cleaning this out? 

G’day Jim; If there is metal build-up it depends on the metal
as to your approach. If silver or sterling you could try warm
conc. nitric acid - it shouldn’t necessarily go for the tungsten
carbide, and a bit of grease will stop any etching of the steel
in which the carbide dies are embedded. Though conc nitric only
reacts with the iron surface which it immediately ‘pacifies’ to
inhibit further reaction. However, having said that, tungsten
carbide used to be made by pressing the carbide powder with
cobalt metal powder and heating to high temperature (sintering);
the acid might just go for the cobalt! If it is gold then you
could try aqua regia, but you’d have to protect the steel in that
case. Cheers, –

        /\
       / /    John Burgess, 
      / /
     / //\    @John_Burgess2
    / / \ \
   / (___) \
  (_________)

Hi David & John,

John, thanks for the Ideas on the chemistry side but I think I’m
going to use David’s idea with a twist. I find the reagent a
bit scary even I think it would work just fine. I will use the
tooth pick but instead the courser diamond grit and olive oil. I
use the spray on 50000 diamond grit use on ceramic laps for
graver and stone polishing. Thank you both. Jim
@Zimmerman

Hi Jim,

  I use the spray on 50000 diamond grit use on ceramic laps
for graver and stone polishing.

That’ll probably do it. After I sent the msg, I thought 360
might be a little aggresive for any precious metal build up. 50K
should leave you with a very smooth finish. Let us know how it
works out.

Thanks,

Dave

A dumb question from a “newbie”: could you clean out your
drawplate holes by drawing a metal (like brass) which would be
significantly harder than silver and gold but softer than the
steel plate?

Lee

Another possibility:

Is the gunk held in the holes by the lubricant I use on the
wire? Beeswax in my case. I’ve got to deal with cleaning my
plates too and have been wondering if soaking them in a solvent
might help.

Colleen

Hi Peter,

Interesting letter. Most of your points are true and well taken
by myself. The hole that are major concern are the .75mm to 1.mm
and we hand pull these. We only use the a machine on larger
diameters and have no problem with build up on these holes. The
holes that are giving a problem are not producing a poorer
product, they are just undersized. I have a feeling that the
metal or scale in the hole is being burnished bright as wire
passes through. I have managed to clean the plate. Again nice
letter.

Jim @Zimmerman

Hi Lee,

Our draw plates are used for all sorts of metal gold (all karats
and colours) Platinum, Silver, and even iron binding wire for
making C channel wire. Some of what we use is close to brass
but we still had the problem with build up. Drawing wire will
not drag out the stuff on the side of the die.

I did wind up cleaning the draw plate in the sonic and then
steaming it out. This cured 90% of the problem and then using
the toothpick and the 50k dia. polish did the rest. I did break
off the tip of the toothpick twice but it was easy to poke it out
with a broken burr that I sharpened.

Jim
@Zimmerman