School me on Brazing torches

[Grant Gunderson]

I got one of those little benzomatic units with mapp gas and oxygen. For small things it’s kinda ok, but seems a bit under powered and I’m always having issues with it having a consistent flame especially when the tiny tanks get below 50%.

So thinking of investing in an Oxy-Acetylene set up. Are the smaller tank sizes decent for most small to medium size projects? Thinking of maybe doing a bike frame at some point and space is at a premium. Should I be looking at victor for the gauges / torch? Or are the other brands decent too?

 

[The Cobbler]

I have a set of torches , I forget the name but they were used, name brand. bought them many years ago.
I use a "B" acetylene tank and a small oxygen tank , customer owned . it's fine for heating & brazing but the oxygen tank is too small to do any cutting. but the plasma & angle grinder look after that for me.
I bought an adapter that threaded in tot he acetylene regulator that fits the B tank. I didn't want to use an adapter as it adds so much bulk to the regulator.
if I remember I'll get a picture tomorrow and post it here . it's nothing fancy , but it works for me

 

[Firebrick43]

If doing fine thin work a dual stage regulator is going to be better. A single stage you will be constantly messing with it at low pressures especially towards the end of the tank.

My favorite is airco/concoa. Smith/miller makes some nice regs as well. Victor was a decent company for larger stuff but they have gone to hell over the last 10 years since being bought out.

As for the torch doing fine work I would highly suggest a meco midget or a smith airline torch. The midget can be bought new, all the aircraft torches such as the smith airline are going to have to be purchased used on ebay or similar. Fortunately that the torch itself has little to go wrong if it looks good and hasn't been physically abused.

The regulators can have diaphrams go bad if they are old but in perfect shape. Regs can be rebuilt and is worth it if you already own it but if you have to buy a used one and then rebuild it to boot?

 

[Steve_P]

I have an OA set with small tanks that are on a cart. The tank naming and numbering conventions give me a headache, but the acetylene is about 18" tall, and the O2 is about 24" tall. I definitely wouldn't go any smaller than these. I bought my setup 30+ years ago, so I don't remember the details other than I initially had at least one tank that was smaller and it lasted for what seemed like 5 minutes of use. So, I either brought one or both back and exchanged them for larger, what I have now. For hobby type use, don't go smaller IMO unless you drive by your welding store every day and don't mind filling up in a middle of a project.

My torch set and regulators came from HF. Yes, I know.... They are all fine, but I'd obviously go with a name brand today.

 

[rooster59]

Really like smith. 2stage for the O2 is nice.

 

[slowtwitch73]

I've done quite a few frames and other fillet stuff.

My regs and handle are old victor that I had rebuilt. Not sure about the new stuff. OA is pretty straight forward... not like TIG where a reg can really screw you.

By far the biggest thing as far as investment is kevlar hoses.. way easier on the arms/hands and easier to get the tip where you want it.

I use a #2 tip. Probably leaning towards the large end for bikes, but don't get caught into thinking jewelry size is going to work for you... there's a fair bit of mass when doing bikes.. even with thin tubes. Your technique and flame adjustment should be able to regulate the heat as needed.

Tips aren't too expensive so get a few and experiment. I don't like changing them out .. I found #2 can do a bb cluster and a small guide on a thin tube.

 

[Grant Gunderson]

I've done quite a few frames and other fillet stuff.

My regs and handle are old victor that I had rebuilt. Not sure about the new stuff. OA is pretty straight forward... not like TIG where a reg can really screw you.

By far the biggest thing as far as investment is kevlar hoses.. way easier on the arms/hands and easier to get the tip where you want it.

I use a #2 tip. Probably leaning towards the large end for bikes, but don't get caught into thinking jewelry size is going to work for you... there's a fair bit of mass when doing bikes.. even with thin tubes. Your technique and flame adjustment should be able to regulate the heat as needed.

Tips aren't too expensive so get a few and experiment. I don't like changing them out .. I found #2 can do a bb cluster and a small guide on a thin tube.

Thanks! That exactly the kind of information I was looking for.

 

[slowtwitch73]

If you really get into it an inline fluxer is the bees knees.

Figure out your shop venting.. the fumes aren't pleasant. Nice thing is it can be done outdoors... no shield gas to worry about.

No such thing as too clean... it's a huge pita to get a joint up to temp, start brazing, then have the flux **** the bed for whatever reason... too much heat or contamination... then you have to let the joint cool, remove flux/burn (pita), re clean.. which if you have a partially done joint can be a challenge, etc etc.

Waaay easier to take the time/care from the start.

Paul Brodie on Youtube has some excellent vids.

 

[rlitman]

Literally ANY sized real oxygen cylinder will be better than that Bernzomatic toy. The Bernzomatic cylinder starts out at around 300 PSI, so it's no wonder it's only 1.1 CF capacity (a number they try to hide). A 20CF cylinder is the smallest real high pressure cylinder you'll find used with O/A, costs hardly more to fill than the disposable Bernzomatic ones, and you get twenty times the usable flame time per fill.

That being said, I'd suggest looking at 60CF cylinders. They take up the same floor footprint as a 20CF, are about the same price to fill, and seem to be the sweet spot in one-hand pick-upable portability. 60CF can be used for a cut here and there, and while cutting will empty it fast, you can do a lot of brazing out of 60CF of oxygen.

 

[Steve_P]

Literally ANY sized real oxygen cylinder will be better than that Bernzomatic toy. The Bernzomatic cylinder starts out at around 300 PSI, so it's no wonder it's only 1.1 CF capacity (a number they try to hide). A 20CF cylinder is the smallest real high pressure cylinder you'll find used with O/A, costs hardly more to fill than the disposable Bernzomatic ones, and you get twenty times the usable flame time per fill.

That being said, I'd suggest looking at 60CF cylinders. They take up the same floor footprint as a 20CF, are about the same price to fill, and seem to be the sweet spot in one-hand pick-upable portability. 60CF can be used for a cut here and there, and while cutting will empty it fast, you can do a lot of brazing out of 60CF of oxygen.

I'm not familiar with the Bernzomatic "toy", but if it's 300 PSI, then, yeah, that's a joke and you'll never get any work done with that. I guess it's intended for plumbers? A real O2 tank is 2000 PSI when full, so....

I looked earlier and my acetylene tank is 40 ft^3; I definitely wouldn't go smaller than this. When I go to get my tanks refilled, I'll probably move up to the next sizes as it's a bit of a PITA for me to get to my "LWS", and I'm no longer a poor college student who can't afford a bigger tank. What I have now is fine for me, but if a 60ft^3 will fit on my cart, and it sounds like it will, then I'll do that as it will extend my refill time.

 

[bb29510]

victors are good, no matter what model you get, they are good, no matter what anybody else says, they are good

 

[TdK71]

Got my setup on FB Marketplace for $400 a few years back, another $125 to test and fill the tanks, and I have all the flamewrench I need to accomplish any task.

 

[rlitman]

I'm not familiar with the Bernzomatic "toy", but if it's 300 PSI, then, yeah, that's a joke and you'll never get any work done with that. I guess it's intended for plumbers? A real O2 tank is 2000 PSI when full, so....

I looked earlier and my acetylene tank is 40 ft^3; I definitely wouldn't go smaller than this. When I go to get my tanks refilled, I'll probably move up to the next sizes as it's a bit of a PITA for me to get to my "LWS", and I'm no longer a poor college student who can't afford a bigger tank. What I have now is fine for me, but if a 60ft^3 will fit on my cart, and it sounds like it will, then I'll do that as it will extend my refill time.

For reference:


The red cylinder is nothing more than a 14oz disposable propane cylinder, with a left-hand thread, pressurized with oxygen. This isn't a plumber's tool, and that certainly isn't a high pressure cylinder. It's a hardware store toy. I know, because I was suckered into owning one too. It does make a decent flame, but you'd better work fast, because that oxygen cylinder empties in minutes. For comparison, I'd say the tip is comparable to a Victor 00 welding tip, which will use up to about 3SCFH of acetylene according to the chart. Oxygen consumption is 4x that stoichiometrically, so 12SCFH with a 1.1CF cylinder gives you 5.5 minutes of flame per bottle - ideally. But with the pressure inside the cylinder dropping so rapidly over that short period, I would waste half that time merely keeping the flame adjusted, fighting the crappy regulator.

40cf is a weird size. Too big to carry in a tote with everything (the tote kits come with 20cf cylinders), yet small enough that you're refilling it a lot. But I guess if size is a constraint, it will still fit in a large cabinet.

 

[Hohn]

Very interested in this myself.
I was keenly interested in the Smith Little Torch for a long time, but running it on full size regs and cylinders. I think it might do nicely for the kind of work I had imagined.

 

[rlitman]

Very interested in this myself.
I was keenly interested in the Smith Little Torch for a long time, but running it on full size regs and cylinders. I think it might do nicely for the kind of work I had imagined.

I have one. It's VERY "little". Good luck even lighting the #1 or #2 tips. Their ruby orifices are SO small that half the time your sparks just miss the gas coming out, and the two smallest tips are only capable of burning acetylene or hydrogen (I'm not even sure if propane will fit through them). The smallest two tips are good for a jeweler (using magnification) soldering prongs onto a stone setting. The #5 tip is comparable to my Victor 00, but it's such a small handle that you get uncomfortably close to the larger flames it is capable of putting out.

One day I'll find a good use for mine. In the meantime, it's keeping a drawer happy. It does work nicely on full sized cylinders. I'm sure it would burn for days on mine.

 

[Steve_P]

For reference:

The red cylinder is nothing more than a 14oz disposable propane cylinder, with a left-hand thread, pressurized with oxygen. This isn't a plumber's tool, and that certainly isn't a high pressure cylinder. It's a hardware store toy. I know, because I was suckered into owning one too. It does make a decent flame, but you'd better work fast, because that oxygen cylinder empties in minutes. For comparison, I'd say the tip is comparable to a Victor 00 welding tip, which will use up to about 3SCFH of acetylene according to the chart. Oxygen consumption is 4x that stoichiometrically, so 12SCFH with a 1.1CF cylinder gives you 5.5 minutes of flame per bottle - ideally. But with the pressure inside the cylinder dropping so rapidly over that short period, I would waste half that time merely keeping the flame adjusted, fighting the crappy regulator.

40cf is a weird size. Too big to carry in a tote with everything (the tote kits come with 20cf cylinders), yet small enough that you're refilling it a lot. But I guess if size is a constraint, it will still fit in a large cabinet.

Ok, yeah, that's definitely a toy. Maybe it'd be useful for making jewelry? I'm sure that would get expensive real fast with disposable cylinders that just last a few minutes.

We had some 2-3" copper tubing where I worked, and the plumbers used the carry totes with the tiny high-pressure cylinders, which I guess are 20 ft^3 from what you said.

I'm not constrained by cylinder height, I have a "proper" cart that I purchased from the LWS, so I'll definitely size up on my cylinders when I swap them out. I'm about due, and I use them so infrequently that I noticed yesterday that one of the tanks has expired. It's been at least 3 years since I've swapped tanks!

 

[rlitman]

...I'm not constrained by cylinder height, I have a "proper" cart that I purchased from the LWS, so I'll definitely size up on my cylinders when I swap them out...

If they let you. I started with 60CF, and have a few of those. They're still easily transported with one hand lifting the valve.
80CF cylinders are nominally around the same diameter, so they'll fit the same cart, but they get valve protection caps, and really need two hands to move about.

 

[lilredex]

Forget those Bernz torches......nothing but frustration.

My set up is Victors med. duty with a "B" tank (40 Cu. Ft.) and an 80 Cu. Ft. O2, about the right ratio. Had mine more than forty-five years and still going.