acetylene vs propane

[bambuko]

...I've been looking for adaptors without luck so far...
William.

Have you tried these guys?

HL060023 is two stage FabMaster Elite Reg 2 Gauge Propane 2 Bar (0-30 psi).
Advantage of this one (assuming it is available?) is that it would come with UK fittings.

...I notice that the Harris reg recommended by Will Neide is available in various ranges including 0-15 psi...
William.

Harris regulator is a single stage...
Neither you nor Bill mention the size of propane bottle you are using and I am sure Doug is right that "...twice the size of an American BBQ tank..." (whatever it is?) is probably easier on the regulator than tiny 3.9kg bottle.

[Doug Fattic]

Here is both my American and Ukrainian propane set up for comparison. I see that the new Ukrainian regulator I bought just before I left the last time does have a pressure gauge. I bought the most expensive one I could find in the market which of course in American dollars was still very cheap. I always try to find out what threading is on the brazing/welding equipment in Ukraine but nobody can ever tell me. I would love to see a chart of what is used in various countries.

I had to have my Victor acetylene regulator rebuilt one time and I asked that they make it possible for use with propane and I’m not sure what they actually did. As I understand it both the size of the diaphragm and its 2 stages contribute to its steady output.

[jclay]

I think it would be worth it to buy a "turn key" regulator instead of trying to convert one. I honestly don't know what makes one propane specific, BUT I have had no issues with this regulator on my propane tank. My previous regulator, don't recall brand or style, would fluctuate like crazy and drive me nuts. Bad diaphragm? The Harris regulator is solid and steady. You can definitely watch tank pressures change depending on large fluctuations in room temp (day to day changes), but the outlet pressure and flame remain constant regardless of tank pressure. I suppose the tank pressure gauge is unnecessary, but it's "nice to have."

The fluxuation you describe is more likely due to out of spec friction between the stem damper bushing and orrifice valve stem. If the regulator was new then hysteresis from slightly excessive friction (stepwise over damping) is a common cause; the bushing is tight and the brass valve stem hasn't been polished by use; jerky movement. If the diaphagm is on the smaller end of the spectrum then that just exacerbates the problem. If it was an old regulator then I'd wonder if the damper bushing was worn to the point of under damping the movement of the valve stem. I suppose an old rubber diaphragm could cause the same symptoms but more commonly they cause a slow creep of the flame adjustment.

I think it's worth noting that perfect flame adjustment isn't required for good lug brazing. You might want it or like it, but it isn't necessary. Two stage regulators exist to compensate for substantial supply pressure fluxuations that are more usual to high flowrate, high duty cycle use in industry but even there I have seldom seen them in plant facilities I've worked in. A compact format single stage regulator (diaphragm OD typically under 2") will fluxuate more than a medium format unit (a little over 2" OD) which falls short of the substantially more stable large format unit (3" OD). All will work for brazing.

Unless your 2-stage regulator has a 3" OD secondary diaphragm then it won't combat oscillation as well as a large format single stage. It will creep less if your cylinders change pressure appreciably during your brazing cycle.

Large format regulators waste more gas on primary side bleed down than medium or small format units. That's particularly noticeable with oxygen cylinders.

Everyone has their own preferences and perspectives. For me, the medium diaphagm (elastomeric) single stage regulators offer a fine combination of low cost, good stability and a bleed-down loss that's on the low side. The large format single stage regulators with 3" stainless steel diaphragms are tops for stability and longevity in my book though.

[bambuko]

Thanks for the photos Doug,
Blue Rhino bottle has 15 pounds of propane (according to their webpage).
I am using 3.9kg bottle (around 9 pounds)

[Will Neide]

If it was an old regulator then I'd wonder if the damper bushing was worn to the point of under damping the movement of the valve stem. I suppose an old rubber diaphragm could cause the same symptoms but more commonly they cause a slow creep of the flame adjustment.

The large format single stage regulators with 3" stainless steel diaphragms are tops for stability and longevity in my book though.

Yep, it was a 2nd hand regulator and suspect you might be right about the old diaphragm.

When I bought my new one, I was very much concerned about longevity and considered it an invest, as I do with much of my tooling. Pay to play?

[Tman]

Just tried my new setup (same as Doug pictures above in post 262) assembled and can not get the propane to light. Looks like I need to replace my cheapo hand-me-down tips with actual propane specific tips.

[Doug Fattic]

Trent, try 2 things before giving up on your present set up. 1st turn the propane pressure down very low - like maybe 2 psi if possible. That also means you can not be blasting the oxygen at the same time. It is difficult to light a propane flame under higher pressures. 2nd let the concentrator run for several minutes before lighting. One of the most common problems with a concentrator is that as they age they do not put out enough pure oxygen and the not-pure-enough-oxygen-air keeps the propane from lighting. The problem might also be that it needs a new filter.

If those things don't work, take your setup back to where you bought your concentrator. He has a bunch that you can try and see if one of them will work.

[Tman]

I will try that Doug. I was closer to 5psi. Are you lighting at 2psi and THEN adding in the oxygen slowly? I also was not letting the machine run very long. Thanks again.

[Doug Fattic]

I have the oxygen knob on the torch handle turned on just enough so the concentrator doesn't beep the warning that the oxygen isn't flowing. So it is barely turned on. The concentrator is set somewhere between 2 and 3 lpm. Then I turn the propane knob on the torch handle only a 1/16th or so. Not much anyway. Too much and the escaping gas flow will keep the flame from lighting. It is like trying to start a camp fire in a strong wind. Once the flame lights than you can adjust the torch knobs to get a neutral flame with the right amount of volume.

Once i got the hang of it the settings weren't so important. For example I could light the flame with more or less lpm coming out of the concentrator. And I would just leave the oxygen knob left on when I turned off the propane so I don't have to set the gas volume each time I light the flame.

[Tman]

OK, I am starting with the propane on WAYYYY to high then!

[waterlaz]

I always try to find out what threading is on the brazing/welding equipment in Ukraine but nobody can ever tell me.

I can tell you that =)

At the output of propane and oxygen valves there is either a G 3/4 thread or a W 21.8x1/14" thread (usually marked as СП 21,8 х 1/14 in cyrillic).
The G 3/4 is usually used for bigger tanks. Smaller tanks use this wierd W 21.8x1/14" thread.
It is 21.8mm in diameter 14 threads per inch and 55 degrees.

Everything starting from the output of your regulator and up to the torch is metric. The two common threads are M16x1.5 and M12x1.5

The threads for propane and acetylene are left-hand threads obviosly.

PS the valve on your propane tank in Ukraine probably has a W 21.8x1/14" thread. The valve on the oxygen tank that I've seen might have a G3/4.

[waterlaz]

No, the OP had it right:
....

So, basically, yes! =)
What you get is a big clumsy thermometer that can somewhat be used to estimate the amount of propane left but since the temperature depends on the gas flow rate, the ambient temperature and the time you've been brazing it is probably more efficent to put the damn thing on some scales

[Doug Fattic]

I can tell you that =)

At the output of propane and oxygen valves there is either a G 3/4 thread or a W 21.8x1/14" thread (usually marked as СП 21,8 х 1/14 in cyrillic).
The G 3/4 is usually used for bigger tanks. Smaller tanks use this wierd W 21.8x1/14" thread.
It is 21.8mm in diameter 14 threads per inch and 55 degrees.

Everything starting from the output of your regulator and up to the torch is metric. The two common threads are M16x1.5 and M12x1.5

The threads for propane and acetylene are left-hand threads obviosly.

PS the valve on your propane tank in Ukraine probably has a W 21.8x1/14" thread. The valve on the oxygen tank that I've seen might have a G3/4.

Thanks Evgeniy! I should have realized you could figure out the threading. When I have asked suppliers or manufacturers at American welding shows they have no idea nor do they know where to find out. Hopefully you will be able to ride out to our shop on the college campus at Bucha in a couple of weeks while I am there. I invited the guy from Kharkov to visit us for a day too. I'm still thinking about the possibility of getting an oxygen concentrator for the shop so we don't have to lug that huge Oxygen bottle back and forth when we need a refill now that you did the research on where they can be bought. However that money has to come out of my personal funds and I've got to be getting more fixtures from Cherkassky too. Does the end of your concentrator have an American B fitting or is it metric?

[waterlaz]

Thanks Evgeniy! I should have realized you could figure out the threading. When I have asked suppliers or manufacturers at American welding shows they have no idea nor do they know where to find out. Hopefully you will be able to ride out to our shop on the college campus at Bucha in a couple of weeks while I am there. I invited the guy from Kharkov to visit us for a day too. I'm still thinking about the possibility of getting an oxygen concentrator for the shop so we don't have to lug that huge Oxygen bottle back and forth when we need a refill now that you did the research on where they can be bought. However that money has to come out of my personal funds and I've got to be getting more fixtures from Cherkassky too. Does the end of your concentrator have an American B fitting or is it metric?

Yeah, the prices for filling up oxygen are so low in Ukraine (especially when using 40l tanks) that buying an oxygen concentrator seems like a veeeery longtime investment.
I probably wouldn't buy one myself if I had a car. I figured that it takes a lot of my time to visit the filling station every time my tiny 7l tank is empty.
And of course I sleep better knowing I do not store pressurized oxygen. I feel that people at the filling station were closing the valve too tight and were damaging the threads in the valve.
After each refill it took all my force (I'm not very strong but still) to close the valve. After some time it got better until the next refill.

My concentrator has a 9/16" 18tpi thread on the output ond is currently connected in an awkward way since they don't sell anything with this thread in Ukraine :)

[Doug Fattic]

My concentrator has a 9/16" 18tpi thread on the output ond is currently connected in an awkward way since they don't sell anything with this thread in Ukraine :)

Yea, that is an American size "B". I'll bring a B size brass fitting with a barb on the other end that can be inserted into a hose and held in place with a hose clamp. What is the inside diameter of your hose? Barbs come in different sizes but the most common one fits inside a 1/4" hose - which as you know is about 6mm. The quarter inch designating the inside diameter of the hose.

It isn't the cost of refills that I am trying to avoid, it is wanting the convenience and safety of a concentrator. As you have seen the size of the tank we have in the shop is really big and heavy and takes 2 people to move it. In fact it usually takes another person to keep in stable in the van in transit. Yuriy's van and another helper are not always available when it runs out. And of course it always runs out at 4:59pm Friday afternoon so I can't work on the week end. We have taken decent safety precautions to help avoid an accident but there is a lot of potential trouble in that tank strapped to the wall. And just like you've noticed the valves never seem like they are quite right.

[waterlaz]

Yea, that is an American size "B". I'll bring a B size brass fitting with a barb on the other end that can be inserted into a hose and held in place with a hose clamp. What is the inside diameter of your hose? Barbs come in different sizes but the most common one fits inside a 1/4" hose - which as you know is about 6mm. The quarter inch designating the inside diameter of the hose.

Thank you! I have a 6mm hose.

[Doug Fattic]

Evgenie I am Ukraine and looking forward to seeing you this Friday. Dmitrij from Kharkov is also coming as you probably know by now because he was going to contact you about how to get to the shop. I got through customs with 100 pounds of Anvil fixture in 2 suitcases and my carry-on. Actually they ignored me completely because of course I look angelic. A few years ago I had to put all my luggage though an X-ray machine but now we go though a narrow hall after leaving baggage claim where the customs officials just stop the suspicious looking ones. There is another Ukrainian amateur frame builder that contacted me about our Ukrainian made fixtures but can't come this Friday because of his work in the navy. He found out about what we are doing in Ukraine by reading this website.

Actually when I put the Anvil together in the shop I discovered I had left a piece back home. Fortunately there are a couple of young teachers coming over the following week that are going to help with a summer camp held here on campus to teach English to kids that could never afford lessons. They will bring the missing piece.

I've been working with Yuri making another frame. He has been through the process in many ways over the years but this is the 2nd time we have gone through everything step by step writing notes and taking pictures of each of those steps making a fillet brazed frame. This 2nd time through allows him to refine his detailed notes from the 1st time. His teaching background makes him an excellent student. There was an American that took my frame building class that was going to come this summer to make transportation frames to refine his skills but his cancer returned so he has to have more treatments instead. Bummer. He had found bicycles during his 1st rehab and just took that to the next level.

I am thinking that the day you are here we will do a rear triangle the old British way before expensive fixtures with a true wheel, a straight edge with an adjustable pointer and a homemade T tool. It is a very accurate method just slower. I doubt anyone in Ukraine will be able to buy an Anvil anytime soon so we won't use it but just admire it while we do it the old fashioned way. The Anvil will be for Yuriy to build frames faster. See you in a couple of days. And yes I brought a brass B fitting with a barb that will fit your oxygen concentrator outlet.

[William Chitham]

I think I have solved my problem with falling propane pressure. I bought a Harris single stage reg off ebay for £17.99, tried it last night and it worked perfectly. Set to 5 psi, torch lit for about 15 miniutes, didn't have to touch the reg once so I can recommend it as a cost effective solution for anyone in the UK struggling with a cheap (eg Wescol) regulator. Just checked and the seller has 2 left.
Thanks to all for advice,
William.
Harris_Propane_Reg.jpg

[Rkanz]

I found an O2 concentrator for $100 at a thift store which sent me down the propane road. I called Victor and they told me it was safe to use my old 210 aceteylene regulator with propane. I upgraded to TM Tech hoses and a Victor j28 with a Torchtools mixer and TEN tips. Overall this was an inexpensive conversion and my first tests were successful. Thanks to Doug and everyone for all the invaluable help. I could not have done this without the information on this site.

Russ Kanz

Sorry for the upside down picture. Can't find the rotate function.

image.jpg

[rauce]

I'm using a Uniwled 71 torch, Gentec 881w mixer and Gentec 2,3 and 4 TEN tips. So far this has been great for lugs and fillet practice but I'd like to start doing forks (practice ones to cut open of course). Will I get enough heat out of the 4 TEN tip to do a crown? I've seen some builders using a rosebud for crowns.