acetylene vs propane

[Will Neide]

Nice little set-up. Were you able to torch any metal, or was the detached flame issue unresolvable?

[Erik B]

Attachment 51350

Here's my setup!

What is the reason behind using the diposable propane bottle and the extra fittings necessitated by using it?

[veryredbike]

What is the reason behind using the diposable propane bottle and the extra fittings necessitated by using it?

I wanted it to be as portable as possible. I have a workspace where I can use it, but nowhere to store a larger tank safely. So, the disposable means that I can easily lug them back and forth. I do like one bike every six months, so I'm hoping that it won't be too bad. If I go through a million, I'll grab a bbq tank and work in my driveway.

Nice little set-up. Were you able to torch any metal, or was the detached flame issue unresolvable?

I couldn't get a big hot flame, but I was able to heat up a tube to dull red all around. Just a little more adhesion at the tip and I should be gold.

[Doug Fattic]

Secondary issue: when I use enough propane to get a nice hot flame, it tends to detach from the tip. I'm using a tip rated for fuel, but it doesn't have a recess. I think I'll just go back and buy a w-j elbow and tips unless anyone feels comfy saying "oh, yeah, just jam a reamer in the end and open it up a bit"... shouldn't have tried to save money on that end in the first place.

I assume that the larger and more numerous propane mixer holes (compared to acetylene mixers) means that they are designed for a larger volume of gas at lower pressures to help keep the flame attached to the tip. I'm sure you know this but in case someone is doing an archive search to learn how to light propane, it is necessary to turn up the gasses in stages. It starts by turning on the concentrator several minutes before actually lighting the torch. The propane is barely turned on to light it with the nose of the tip almost into the striker. The fuel knob wants to be turned up just far enough so the flame is still attached once it is lit. Back it off if the flame pops off. Oxygen is now added to get roughly a neutral flame and then propane is added again. Of course oxygen again needs to be turned up to match. If too much oxygen is added the flame starts to turn a bit more blue (if it didn't blow the flame out) letting you know it has been turned up too much.

I'd be interested to know how long one of those small fuel bottles will last using say a Victor #2 tip. The cheapest place I've found to buy a Victor clone mixer/tip is from torchtools.com. The G17-1 costs $47 + S&H. An 881W is $32 and the 883-2 screw on #2 tip is $11 + S&H. Unlike many online supply houses that do not keep inventory in stock but rather order from the parent company when you order from them (which can take a couple of weeks), torchtools has these items in stock and ship right away. If one is not on a tight budget, the real Victor parts are more accurately made. What I didn't like about the 881W + 883-2 combination is that sometimes a flame can come out the back of the screw on tip when the propane is first lit. I assume that the G17-1 all-in-one tip and elbow unit (that I have never tried) would not have that problem since the tip is permanently attached to the elbow.

[shirk]

I just bought the elbow and tips needed from Torchtools. Had to place the order over the phone as their site currently has a glitch.

Doug you should call and talk to them, they spoke about a referral program. You deserve some free tools in exchange for all your awesome advice in helping us noobs get set up.

[veryredbike]

I'm sure you know..... If too much oxygen is added the flame starts to turn a bit more blue (if it didn't blow the flame out) letting you know it has been turned up too much.

I'd be interested to know how long one of those small fuel bottles will last using say a Victor #2 tip.

I only know because I read your previous posts, again, thanks for the help! That's good info about the flame turning bluer. I've been having trouble finding pictures of the differences between a neutral and reducing flame with oxypropane... my existing instincts are way off without the two-part inner flame to use as a guide. The sound is pretty different too. I'll look for that shift in color.

Played with it again tonight (before reading this) and by starting with a lower pressure setting on the propane and adjusting the flame in even more smaller steps, was able to get a flame with some oomph even with my crappy non-recessed uniweld tip. I also removed the bacteria filter from the oxycon, since I won't be sucking the air myself. Increased flow a noticeable amount.

I saw on some glass-working forums that some folks light their torch against a piece of metal... like, lay the tip at an angle against it, then get it started there. I guess it shields it so that it doesn't detach as easily as you're mucking with it? I'm not totally clear, but I'll play with it next time I have the torch out. Might be more for the kinds of surface mix torches that they use.

I just bought the elbow and tips needed from Torchtools. Had to place the order over the phone as their site currently has a glitch.
Doug you should call and talk to them, they spoke about a referral program. You deserve some free tools in exchange for all your awesome advice in helping us noobs get set up.

AMEN!

[veryredbike]

Oh, and in regards to how long one of those camp bottles will last... I'm curious too! Should be around 1/20th of a bbq tank... How long does it take you to run down a bbq tank?

Once I've spent some real time on it and have run a bottle from full to empty in a session, I'll give real-world numbers.

[Doug Fattic]

... How long does it take you to run down a bbq tank?

I don't know how long a regular propane tank lasts because my new one still says it has more than 100 PSI. This is at the end of 2 classes with 4 students making 4 frames while brazing about 2 or 3 times longer for each joint than it would take me (although I crank up the heat a lot more) and in addition numerous practice brazes and demonstrations. I think it started about 130 PSI but I didn't start to notice until the middle of last class when it was just above 120. I don't remember running out in Ukraine but I'm there for only a few weeks at a time. After I go it probably is used for cooking in somebody's kitchen again.

[veryredbike]

I don't know how long a regular propane tank lasts because my new one still says it has more than 100 PSI. This is at the end of 2 classes with 4 students making 4 frames while brazing about 2 or 3 times longer for each joint than it would take me (although I crank up the heat a lot more) and in addition numerous practice brazes and demonstrations. I think it started about 130 PSI but I didn't start to notice until the middle of last class when it was just above 120. I don't remember running out in Ukraine but I'm there for only a few weeks at a time. After I go it probably is used for cooking in somebody's kitchen again.

That sounds... substantial.

[Greensabbath]

I'm glad everything is working out with this unit, mine should come today! How did you hook up the hose/regulator to the unit? My flashback arrestors won't get here until next week otherwise I'd be firing up my unit today as well.

[Will Neide]

I don't know how long a regular propane tank lasts because my new one still says it has more than 100 PSI. This is at the end of 2 classes with 4 students making 4 frames while brazing about 2 or 3 times longer for each joint than it would take me (although I crank up the heat a lot more) and in addition numerous practice brazes and demonstrations. I think it started about 130 PSI but I didn't start to notice until the middle of last class when it was just above 120. I don't remember running out in Ukraine but I'm there for only a few weeks at a time. After I go it probably is used for cooking in somebody's kitchen again.

Darn! That's a lot of work from one tank. Guess I'll have to resort to my stockpile of camping bottles first instead of raiding my grill right away.

[mattsummers]

Propane pressure should stay pretty constant as long as any liquid remains in the tank. The vapor pressure of propane varies with ambient temperature.

http://docs.engineeringtoolbox.com/d...r_pressure.pdf

Once the liquid propane is exhausted, the pressure will drop quickly. This is why LPG is sold by weight, and not by pressure like compressed gasses like argon or helium.

That being said, I'm looking to switch to oxy/propane for brazing myself...(don't like the sooty acetylene startups in the shed)

[veryredbike]

I'm glad everything is working out with this unit, mine should come today! How did you hook up the hose/regulator to the unit? My flashback arrestors won't get here until next week otherwise I'd be firing up my unit today as well.

Please forgive errors or brevity. On a phone. On vacation.

By unit do you mean the oxycon or propane? For propane I made an adaptor: disposable attachment to 1/4 npt, elbow, valve rated for over 200psi on gas for emergency shut off, female cga 510 (I think, no full sized Internet to confirm). Used pipe dope rated for high pressure and propane, cured it to manufacturer suggested time.

For oxygen, no regulator. Used a tube used to couple medical oxygen devices and a barb to male b hose adaptor.

For folks still buying their oxycon.... I'd see if you can find something that does more than 5psi if you want to use a flashback arrestor, it won't work with 5. Remember that flow and pressure are related but different. I think the devilbliss 5lpm use 7 psi.. And it sounds like Doug got that working?

[veryredbike]

Alrighty, did a little test-brazing today. Got better at keeping the flame attached. This cheapo #2 might just be fine after all (it's oxy/fuel rated but not recessed). Also did some tests to get used to my new safety glasses, which are a bit darker than the ones I'm used to.

I'm still having trouble identifying neutral for brazing. I get to the point where the whole thing is blue, but the inner cone is a bit soft (calling this point A)... then if I add oxygen to sharpen that, it gets a little bluer and noisier (it's basically silent before)... but still quieter than what I'm used to (calling this point B). After that it gets louder and I see a more pronounced blue shift (point C). I'm guessing point A for fillet, point B for lugs, but I'm not sure if I'm shifting things over a bit and it should be B and C and I'm just being cautious about how much blue constitutes bluer ;-) Anyone run across a good video of this for propane? I haven't found a really clear one yet.

Thanks again for the thread, having my own torch to play with is pretty awesome. I've got some paid training and a class to teach coming up that'll pay for a few more practice lugs, and some e-richie tubing to go with the nice Llewellyn lugs I have sitting next to my couch in a box. Pretty excited to make a bike with this thing.

On lifespan of the little cylinders... still going strong, but I did enough practice today that I don't think it'll be a problem. Even if it goes out soon, I think I could do a main triangle with one bottle... which is fine at my slow rate of work.

[Doug Fattic]

Veryredbike, I went out to the shop tonight to light up the propane torch to see if I could provide any additional information. I carefully watched the flame change color from greenish to blueish as I added oxygen. The right blend of propane and oxygen was just at the color shift when the green became blue. Of course as I continued to add more oxygen it got even bluer. I measured the inner cone and it was 16mm at that adjustment with a Victor #2 tip. Of course in addition to the balance between the 2 gasses you have to have the right volume. That depends on the thickness of material being brazed and I go by the sound of the flame. It is a bit loader than the gentle hissing of an oxyacetylene frame.

For learning purposes, I wouldn't use too dark of a lens. If one is brazing all day long than greater precautions are necessary but one has to see what is actually happening at the joint in order to catch on what to do. For occasional use I think good sunglasses will work. Eventually you can go to a number 3 lenses when your motions become more automatic.

[veryredbike]

Thanks Doug! Great advice all around! I'll play with it more this weekend.

[MannaDesigns]

Here is my list of equipment for brazing with propane:

1. Propane tank from a local store
2. Propane regulator with 2 gauges for both line and tank pressures with CGA 510 tank fittings
3. 5 LPM Oxygen concentrator (it does not need an oxygen regulator)
a) or an oxygen tank from a local welding supply store
b) They come in 20, 40, 60, 80, 125, 150 and 251 cubic feet sizes with prices from $75 to $350
i) which requires an oxygen regulator. It is preferable to get one with the least wide oxygen pressure settings (like 0 –40 psi instead of 0 – 100)
4. Type T 3/16" hoses (the smallest) with B fittings on each end (probably 12 foot length – 25 or 50 ft. is also an option)
5. "B" size flashback arrestors to connect the 2 hoses
6. Smith Kevlar 10' hose with A and B fittings ($70+) (Smith part # 14779-4-10) (this is optional since you can run a T hose to the torch)
a) or TM technologies light hose (item # AWS-0052) ($45)
7. "A" size check valves that stop the back flow of gas but not a flame (can be optional).
8. Uniweld 71 "airline" torch handle
a) or the Gentec or Metalmaster 140T or the Victor J-28
9. Gentec 881 elbow (the equivalent to the Victor UN-J) (Victor part # 0325-0101) (this unit also needs a separate screw-on TEN tip)
a) with Gentec 883TEN-2 screw-on tip (the equivalent of the Victor 2-TEN tip – Victor part # 0311-0485)
i)one might also want a size 3 and maybe a 4 (Gentec 883TEN-3 & 883TEN-4) or (Victor 0311-0486 & 0311-0487)
a)Another elbow tip all in one option is the Uniweld 17-2 all fuel brazing tip (one might also want the 17-3 size)

Wow - what a great thread! This is my first post on this forum, but just read through this thread as I'm just getting into the frame building thing too. Realizing I should have done a bit more research on torch setup.

I ended up with a victor performer start-up kit from my local welding supplier, it was a really good price by the time you added in regs, torch, nozzle, cutting attachment, rosebud, goggles and hose, and 2 large tanks for oxy/acet. (Victor Performer Torch Kit Set with Edge Regulators 0384-2045)

However, I have noticed (during my practice work) that the torch balance tends to be right at the knobs as mentioned and as I've been researching my issues, does make control a bit more difficult (not impossible by any means). I was looking at the Ameriflame MD71TH on Amazon that was linked (Ameriflame MD71TH 6-Inch Light Duty Welding Handle for General Purpose Heating, Brazing, Welding and Other Flame Processes - Amazon.com), and I think saw that its compatible with the victor nozzles. Can someone confirm that for me? Trying to figure out what I will need to replace to go to the smaller torch size, and it would be awesome if the 0 and 00 nozzle i just ordered worked with the Amerifame Smaller torch and didn't also need to nozzle ends as well.

Also I see that my victor 100FC has built in flashback and arrest so would need to get those as well for the new torch. My kit came with a 3/16 T hose and looking at the Gentec's here: GENTEC 171W Tips Sizes 000-6 - I'm a bit unsure which size I'd need, same goes for the Check valve. It looked like they were all 9/16 or just "B" type - is 3/16 the standard?

I'll most likely continue using the 100FC torch for now, as I can't afford to go and swap it all out, but would be awesome to have it all sorted so I can start acquiring pieces. I'm still in the process of setting up a jig, mitering setups, etc and just trying to practice my technique as much as possible.

Thanks again for this info and I'm excited to read more!

[Will Neide]

I was looking at the Ameriflame MD71TH on Amazon that was linked (Ameriflame MD71TH 6-Inch Light Duty Welding Handle for General Purpose Heating, Brazing, Welding and Other Flame Processes - Amazon.com), and I think saw that its compatible with the victor nozzles. Can someone confirm that for me? Trying to figure out what I will need to replace to go to the smaller torch size, and it would be awesome if the 0 and 00 nozzle i just ordered worked with the Amerifame Smaller torch and didn't also need to nozzle ends as well.

I have the Uniweld torch (same torch?) and I have the Victor tips.

[shirk]

I finally got my torch up and running.

My regulator shipped without t-handle for adjusting pressure, after getting frustrated with not being able to find one locally I just used a bolt.

Played around some last night with lighting and adjusting the flame. Made a small tower of brass blobs. Need to get some proper brazing rod and flux now.

[Will Neide]

Just want to say that this has been a super helpful thread. I scrapped my initial plans of using a concentrator and went with good old bottled oxygen instead. No problems getting the flame where I want it and no problems putting enough heat into various metal projects. I did go with the ameriflame (uniweld?) torch and a Victor 2-W-J nozzle. Also went with TM Tech hoses attached to normal T grade hoses, with the TM Tech hoses hanging from the ceiling. It's such a light set-up!

FWIW, I finally bit the bullet and went with a respirator mask, and have to say it's really made it easy to tolerate the fumes.