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Leaky torches


#1

We have a little problem that some of you might know the answer to.
We use primarily Hoke torches. For years we used propane and oxygen.
About 3 years ago I moved to a bigger shop and we switched to
natural gas with a Gas-tec booster (that is working out great by the
way). I called 3-4 suppliers to ask whether we needed to replace our
propane/02 Hokes with natural gas/02 Hokes? They either didn’t know
or said it didn’t matter. We needed 2-3 new torches and those were
nat. gas/02, but the rest are the old propane versions (and they all
seemed to work equally well). What has happened is that we have had
2 of the propane Hokes begin to leak. We can smell gas when
everything is off. We stick the torch tips in water and you can see
little bubbles. We replaced the torches.

The question is, are these leaking because the valves have worn out
or because they were made for propane and we are using them for nat.
gas? Another question, can we repair the leakers?

Mark


#2
we switched to natural gas with a Gas-tec booster (that is working
out great by the way). 

Thanks for the kind words about your G-TEC Torch Booster!

It should not make any difference to your torch whether you are
using natural gas, propane or acetylene for that matter. Common
jewelry torches use any of these gases with the only difference being
the tip size you can use and the flexible hose connecting to the gas
source (Type R can only be used with acetylene; Type T can be used
with all gases). The leak problem doesn’t come from switching from
propane to natural gas.

You didn’t say where the leak is coming from…did you tighten the
nuts on the gas and O2 valves?

Ed Howard
G-TEC Natural Gas Systems
gas-tec.com


#3
You didn't say where the leak is coming from...did you tighten the
nuts on the gas and O2 valves? 

The leak was coming out of the torch tip when both the gas and O2
valves were shut tight. We could smell gas, so we put the torch tip
in a beaker of water and could see bubbles coming from the tip. So
we figured the valve wasn’t seating properly. We tightened them but
it was still leaking. We took them apart and put them back together,
but still leaking. We need to keep working so I just replaced the
torches. I would like to have them repaired rather than adding them
to our pile of useless tools.

Mark


#4

Hi Mark,

We tightened them but it was still leaking. We took them apart and
put them back together, but still leaking. We need to keep working
so I just replaced the torches. I would like to have them repaired
rather than adding them to our pile of useless tools. 

I’d take the torch to a local shop that sells welding gases &
supplies. They usually can repair torches. If they don’t feel
comfortable working on small torches, they will probably be able to
refer you to someone that does.

Dave


#5
We need to keep working so I just replaced the torches. I would
like to have them repaired 

“O” rings… Most torch valves seal with O rings. Take one off, go
to the hardware store and get a dozen identical (must be) O rings
and change them. If yours doesn’t use them, which is unlikely, then
there’s no telling what’s up with it.

http://www.donivanandmaggiora.com


#6

The torches have rubber seals in the valve stems and also on the tips
(o rings). Most likely you just need a new packing rubber on the
valve stem. If the valve seats are the problem (scored by over
tightening or tightening down on dirt that scores the sealing
surfaces), they may be junk. I agree about taking them to a welding
shop and see what they say or call the manufacturer and talk with
them.

John Dach


#7

I had one jeweller that wanted to use Hoke torches. I didn’t really
have a problem with that since I learn on them. The thing is about
Hoke is they work with a brass needle valve that has a metal on metal
seat. If the machining is out even a little when they’re made then
they leak. Once in every three happens to aligned so it doesn’t leak.

I tried re-grinding the needle taper. Then the seat taper. It never
really ever worked out. They have to match exactly in the center.
There is no telling where that is. After about four torches, the
jeweller finally retired from the bench and problems got solved. I no
longer consider letting Hokes on the bench.

Meco have the same capacity but work more reliable. They also have
better valves.

Jim
Jim Zimmerman
Alpine Custom Jewellers & Repair
http://www.handengravingcanada.com


#8

Hi Jim,

I had one jeweler that wanted to use Hoke torches. I didn't really
have a problem with that since I learn on them. The thing is about
Hoke is they work with a brass needle valve that has a metal on
metal seat. If the machining is out even a little when they're
made then they leak. 

I think you nailed this problem right on the head Jim. These are
Hoke torches (which I really like) but they do have brass needle
valves that seat brass on brass. We took two of them apart and the
two valves were slightly different from each other which I thought
was weird. In defense to the much maligned Hoke torch, we do have 10
of them in the shop and these are all that have leaked, and I have
always used them (30 years) and this is the first problem I’ve had.
But listening to my own defense isn’t very convincing I guess when
20% of our torches are leaking! I’m still going to try to get them
fixed, Dave"s suggestion made sense and I also plan on trying to
contact the manufacturer to see if they will stand behind their
product.

Mark


#9

Hi Mark,

I know what ya mean about having got used to them. I love the way
the feels in your hand. The one I learned on was great. It two year
of
constant use to get it there, but the valves were smooth as silk. I
thought I had great tecknique in my second year on the bench till the
Italion came in.

We had this guy come in to get us caught up with work. He had worked
in a italion factory where he had learned. Oh my gosh, he use the
biggest tip we had and the flame was a foot long. He held the rings
in his fingers while he solder them. He had scar tissue build up on
the tips and it would burn as he solder away. He was just incredible
fast.

I did learn a few things from him but never really tried to copy the
way he did thing to closely. There have been a few thing that I’ve
change over the years that are different from when I learned. My own
shop doesn’t have the faint gas smell to it like the old shops used
to. I painted the wall white, to reflect more light. The old shops
were always gray with soot.

I swear half of the jewellers were deaf because of the Handler dust
control system and the sonic. Those I 've isolated because I do like
to still hear. There are many things that were simple accepted
because
no had taken the time to figuire out a better way.

I love the way a hoke feels but there are better torches. Hoke
should do some R&D and figuire out a better valve.

Talk to ya later,
Jim

Jim Zimmerman
Alpine Custom Jewellers & Repair
http://www.handengravingcanada.com


#10

Hi Jim,

It’s funny that you mentioned a guy from Europe (Italy) who soldered
while holding rings in his fingers. I was trained by a guy who was
trained in Germany and I remember him doing the same thing. It was
sort of a, are you man enough to do this, kind of thing. He was a
great goldsmith, still is. And for me one of the great joys of being
a goldsmith is playing with fire for a living (in a controlled and
careful way of course) so it was a fun exercise.

The only benefit I ever gained from holding it while I soldered it
was the idea that you can get a sizing seam soldered before the heat
travels around to the top of the gold ring. A great thing when you
have a pearl or some other heat sensitive stone in the ring. These
days I think it’s better to pull the pearl if you can. I’m now older
and wiser so I try not to play games with other peoples’
merchandise.

By the way, I guess a helpful tip for those new to gold work is that
when you are soldering a sizing seam in ring that has a stone you
don’t want to overheat. Position the ring in spring tweezers upside
down (with the seam up). Coat with boric acid and alcohol, burn off
the alcohol. Place your solder that was dipped in flux on the seam
and heat from the inside of the ring. Here’s the tip, as the solder
balls up and begins to flow the boric acid turns from a white powder
to a glaze. You can watch the heat traveling down the shank toward
the top of the ring as the glaze spreads. You need to get it soldered
before the glaze gets to the top (which is at the bottom). Then
quench the solder seam before it does. This works with gold rings
that aren’t too heavy, won’t ever work with silver.It’s a simple tip
and better than holding it in your fingers.

Mark