Soldering/Welding Techniques

jpanhalt

Joined Jan 18, 2008
7,918
That is exactly the torch I used for up to 1/4" ss thin-wall tubing (hypodermic needle). Acetylene comes in an "MC" tank. I was told that originally it was used for motorcycle lights. At least it is easy to remember. You will want a larger oxygen cylinder, probably. I made my cart out of 1/2" threaded steel pipe and use steel worm gear bands to hold them in place..
 

drc_567

Joined Dec 29, 2008
714
... Just from looking at the example pictures, part of the problem may be that the metal to metal contact from the vice face is acting as a heat sink, preventing the solder assembly from reaching and maintaining the minimum soldering temperature. If the assembly could be gripped at a further distance from the parts to be soldered, and with less surface in contact, a larger torch may be unnecessary. ...
 

Thread Starter

cmartinez

Joined Jan 17, 2007
6,469
... Just from looking at the example pictures, part of the problem may be that the metal to metal contact from the vice face is acting as a heat sink, preventing the solder assembly from reaching and maintaining the minimum soldering temperature. If the assembly could be gripped at a further distance from the parts to be soldered, and with less surface in contact, a larger torch may be unnecessary. ...
Excellent point ... I'll see what I can do with what I have.
 

drc_567

Joined Dec 29, 2008
714
If you have a pair of the Vice-grip pliers that have a wire-cutting feature, with angled gripping edges next to the main grips, just adjust the wire grips so that they have light pressure on the workpiece.
 

SLK001

Joined Nov 29, 2011
1,511
Clamping things to be silver soldered in a huge vise like that is almost guaranteed to fail. The vise is just too big of a heat sink and pulls the heat away almost as fast as it is put in.
 

SamR

Joined Mar 19, 2019
1,176
You will need to find a welding supply shop. The torch and gauges are the easy part. The tanks not so easy for the home DIY guy. Probably cheaper in the long run to job it out to a welding/machine shop.
 

Thread Starter

cmartinez

Joined Jan 17, 2007
6,469
The tanks not so easy for the home DIY guy.
yeah, so I'm finding out already...

Probably cheaper in the long run to job it out to a welding/machine shop.
I'm aware of that. In fact, I already have a trusty supplier that can easily handle this sort of job. But this is going to be a recurring job, hopefully, so the investment in both time an money is well worth the while.
 

SamR

Joined Mar 19, 2019
1,176
Good Ole Wally World https://www.walmart.com/ip/Gas-Welding-ft-Radnor-Acetylene-With-Victor-CGA-200-Cutting-Outfit-MC-Style-Carrier-Cylinders-Light-Duty-Oxygen-Tote-Brazing-Cylinder-cu-Not-Included/23480239
Full kit without gas. Must be filled at welding supply shop or rather exchanged for full tanks or sent out for filling.

But you need to visit your welding supply shop first. Here in the states, the tanks are inspection date stamped and gas suppliers are finicky about taking "Odd" tanks in trade for full cylinders.
 

Thread Starter

cmartinez

Joined Jan 17, 2007
6,469
Good Ole Wally World https://www.walmart.com/ip/Gas-Welding-ft-Radnor-Acetylene-With-Victor-CGA-200-Cutting-Outfit-MC-Style-Carrier-Cylinders-Light-Duty-Oxygen-Tote-Brazing-Cylinder-cu-Not-Included/23480239
Full kit without gas. Must be filled at welding supply shop or rather exchanged for full tanks or sent out for filling.

But you need to visit your welding supply shop first. Here in the states, the tanks are inspection date stamped and gas suppliers are finicky about taking "Odd" tanks in trade for full cylinders.
Same thing down here, more or less. I'm looking now for disposable mini-tanks.
 

BR-549

Joined Sep 22, 2013
4,936
The best advice I ever got for silver solder......buy plastic gloves.....emery every mating part.....never touch work with bare skin......now flux immediately, heat, flux and solder.

Clean, rough, non contaminated surface.
 

jpanhalt

Joined Jan 18, 2008
7,918
You will need to find a welding supply shop. The torch and gauges are the easy part. The tanks not so easy for the home DIY guy. Probably cheaper in the long run to job it out to a welding/machine shop.
That varies based on location in the US. In one town, I had the choice of demurrage (basically a daily rental) or buying the tank. Buying was much cheaper for me. I now "own" my tanks, which doesn't mean I always get the same tank back. In my current town, you can also just leave a deposit that doesn't increase with time. Cost of refills may vary with whether the tank is rented or owned. Also, all tanks need to be pressure tested at some interval. Since I don't usually get the same tank back, I have never had to pay for that pressure testing. When I exchanged my MC tank for a larger acetylene tank needed for heating and cutting, I got the current full cost credited to the new tank.

In my experience, welding shops are interested in selling the gas, and over time, that's what you pay for assuming you want to keep an outfit ready. The tank charges are only to deter theft.

I have 4 tanks: acetylene, oxygen, argon (for wine and TiG), and argon/CO2 for MIG, As for gauges, while a single stage will work, I recommend two-stage regulators for oxy-acetylene stuff. You will get a much more stable flame.
 

jpanhalt

Joined Jan 18, 2008
7,918
Same thing down here, more or less. I'm looking now for disposable mini-tanks.
I think you will regret that. Once you get into it, you will find other uses.

Edit: A 2-stage regulator is probably less important for acetylene than for oxygen. Acetylene is not pure acetylene. It is dissolved in acetone for stability and the pressure change with use is less.
 
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SLK001

Joined Nov 29, 2011
1,511
How do you mean? That I'll somehow use the tanks separately for a different purpose?
No, he means that once you start gas welding or brazing or soldering, you will find other things that you can weld, braze or solder. The recurring cost of disposable tanks will start to add up quickly.
 

shortbus

Joined Sep 30, 2009
6,987
Just some thoughts from what has been posted since my earlier post.

Never saw StaySilv flux that color. What I have always used at all of the places I worked over the years was white. It dries out over time but just a drop of water on the top of the flux surface will give you enough to work. With the white flux it goes from white to melted "clear" when the proper temp is close, that is when you apply the solder. But even though it is called commonly "silver soldering" it is really silver brazing. There is another type that is really silver solder, it's called StaySilv 15, a little lower temp and used for HVAC work. Then there is another one that is lower temp yet and a real nonlead silver bearing solder (8% silver) called Stay Bright#8, it is just as strong as the silver brazing.

Those jewelers torches work with a regular set of full size tanks and regulators. They attach to the end of the existing hose, where the normal torch would fit. Got a set of them but they aren't as nice to use on anything very big, the HAZ(heat affected zone) grows because it takes so long for the small flame to heat up.

That Torch set from the UK is also available here in the states by Bernzmatic. It uses a throw away oxygen tank and MAPP2 gas. For what your doing(small) a MAPP gas torch should work I have this one and have used it on some HVAC work using the Stay Brite#8, 3/4" copper tube. https://www.bernzomatic.com/Products/Hand-Torches/Instant-On-Off/TS8000

As far as silver soldering stainless I dispute the need to sand or any other prep other than wiping any dirt off of the joint. I have done much of it over the years and never once done any sanding or other prep on new stainless. Made countless(multiple thousands) thermocouple "wells" as part of my work serving my apprenticeship, using the white flux and StaySilv wire.
 
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