MTFCA Forum

Planning ahead, I would like to be able to use my Gas Headlamps at OCF parade or at a evening Cruise-in display. I am on the fence on whether I would like to use a small 10cf tank of Acetylene, -or Carbide (-see link below) in my Carbide Generator tank. How much difference in light (Lumens??) output will I see with one type of fuel over the other?

I realize that the Carbide is a little more difficult to clean-up after the evening is over, and the tank & regulator have initial purchase costs involved, ...but anything else that would sway me towards one over the other??

TIA!!


https://www.amazon.com/dp/B078X347X8/?c ... dp_it&th=1

Hi Brent, I've used both the stock acetylene generator and a Prest - O - Lite Acet. tank and like the POL tank much better. Using the stock generator I only got about 20 minutes of good light and then it gradually declined to just a glow. I liked the challenge of getting the generator to work properly but decided to try the POL tank for comparison. A friend worked at the local welding supply house and we went into their full tank storage area and I selected & bought a full tank with the correct offset valve. I found that the POL tank will give the same strong flame for as long as you want it, like 2 hours at the OCF. Further, when you close the POL valve the lights go out almost immediately and there is no clean up necessary. I've been using that same tank for over 10 years now and see no indication that the tank is becoming empty. The brightness of the flame between the two sources of acet. shows the flame to be about equal until the acet. source from the generator runs out. I had to search hard to find the correct POL regulator and I'm very happy with the whole POL setup.

Keith

BRENT in 10-uh-C wrote: ↑

Wed Jun 25, 2025 12:34 pm

How much difference in light (Lumens??) output will I see with one type of fuel over the other?

Brent,

It's exactly the same fuel/gas. Prest-O-Lite is just a name brand. It's all just acetylene gas.

At the weld gas store I used to use, they had a huge tank that they filled with calcium carbide, then introduced water, then pumped it into acetylene cylinders.

Brent,
I LOVE burning my acetylene lamps with my Prest-O-Lite B tank!
As noted above, the stock acetylene generator is messy and needs to be cleaned out after each use.

Brightness depends of what size of burners you have. Burners are marked: 1/2 , 5/8, 3/4, etc. The number indicates cubic feet of burned gas per hour. Ford used 3/4 burners.
An MC tanks can only be used for a brief static display!

The problem with using an MC tank is it will not provide adequate acetylene supply for the lamps to be used continuously. You can only use it for brief demonstration purposes.

I have to put on my safety guy hat here:

"To minimize the withdrawal of liquid solvent, acetylene should be withdrawn from the cylinder at a rate not to exceed one-tenth (1/10) of the capacity of the cylinder per hour during intermittent use. For full withdrawal of the contents of the cylinder on a continuous basis, the flow rate should be no more than one-fifteenth (1/15) of the capacity of the cylinder per hour.

If you don't adhere to withdrawal rates, acetone (contained in the acetylene cylinder to stabilize the acetylene gas) will be drawn off with the gaseous acetylene. This acetone reduction from the cylinder makes the cylinder unstable and poses an explosive hazard. The acetone withdrawn with the acetylene gas passes through the regulator and on through the entire system. If this happens...the acetone deteriorates any rubber or plastic parts of the system. Typically, the regulator will fail and shut down the system before the cylinder becomes unstable."

An MC tank holds 10 cubic feet of acetylene. Standard burners used are 3/4 (that means they burn 3/4 of a cubic foot of acetylene per hour.) Since there are two of them, the flow is 1-1/2 cubic feet of gas per hour. So you are already way outside of the safety standard. If you use burners marked 1/2, you can get down to the safe operation range for intermittent use. However, 1/2 cuft burners only give off about 18 candlepower. Whereas 3/4 burners give off about 29 candlepower.

The B tank holds 40 cuft of acetylene. The E tank holds 30 cubic feet. Either a B tank or an E tank are ideal for continuous use.
: ^ )

Keith

To elaborate on what Keith posted, efer to the upper left of ad below.

Our local museum operates the gas lights on the cars during the Christmas holiday. They use MC tanks with welding regulators inside a running board tool box. The lights are not illuminated brightly enough for highway driving and it’s more to provide a steady glow. The tanks are inclined on wedge blocks to avoid losing the acetone liquid. Several of the cars run out of acetylene on the second night necessitating tank swaps.

For my son’s car, my local welding supply maintains a small supply of original POL tanks with script and offset valves. We were able to buy one of his tanks outright. While my son uses carbide, he doesn’t look forward to cleaning the pot.

I also see that Amazon has several brass regulators specifically for MC and B tanks. They are small with a gage that estimates what’s left in the tank. They are not as obvious as a standard welding regulator.

Thanks Keith, et/all!!

So define "intermittent" please. Again, this is a parade that lasts approximately 1½-2 hours.

FWIW, I don't have a Running Board to mount a Prest-o-lite tank onto, so I'm not sure a B or E tank would be an option.

The Prest-O-Lite "B" tanks are what I have been using for about ten years. I suggest setting
up your headlamps/burners with an acetylene tank even if you use carbide later. You don't
want to break a Mangin reflector with a leaking burner or base.

I wasn't able to find a POL regulator that Keith has so I use a small Uniweld Regulator with
a Radnor valve at the headlamp. All of this from Airgas near me. The tank is a POL "B" that
may be laid on its side because of the offset valve.

I have a NOS Victor but carbide is expensive today. The one pound can of carbide yields
only 4-cubic feet of acetylene; two hours. The POL "B" tank has 40-cubic feet of acetylene
which is good for about 24 hours of use. I light them when I light the kerosenes in twilight
as they are so visible at distance.

The acetylene gas lamps are air cooled. I don't light them until I am ready to drive and shut
them off if still for longer than 5-minutes or so. Another reason to use POL, easy relight and
the bonnets don't get hot.

Drkbp wrote: ↑

Thu Jun 26, 2025 10:09 am

The Prest-O-Lite "B" tanks are what I have been using for about ten years. I suggest setting
up your headlamps/burners with an acetylene tank even if you use carbide later. You don't
want to break a Mangin reflector with a leaking burner or base.

I wasn't able to find a POL regulator that Keith has so I use a small Uniweld Regulator with
a Radnor valve at the headlamp. All of this from Airgas near me. The tank is a POL "B" that
may be laid on its side because of the offset valve.

I have a NOS Victor but carbide is expensive today. The one pound can of carbide yields
only 4-cubic feet of acetylene; two hours. The POL "B" tank has 40-cubic feet of acetylene
which is good for about 24 hours of use. I light them when I light the kerosenes in twilight
as they are so visible at distance.

The acetylene gas lamps are air cooled. I don't light them until I am ready to drive and shut
them off if still for longer than 5-minutes or so. Another reason to use POL, easy relight and
the bonnets don't get hot.

Thank you, ...but again, I don't think I am going to have room for that large of a PoL tank.

Brent,
What car will you want to burn acetylene headlamps?
I would not run an mc tank for more than 15-20 min.

Before I became more informed, I used an mc tank and regulator and went for a long drive, maybe 45 min. When I shut off the tank, i could distinctly smell the acetone.

With the B tank, there is no need for a regulator. I run it less than an 1/8 tutn open, barely crack it.

I made a special adapter plate to mount the Prest-o-Lite brackets on and use the original acetylene generator mounting bolt holes. I wasn't going to drill holes in my original 1911 running boards!

On my 1912 van I have D sized welding cylinder standing behind the seat, complete with regulator. The flow is infinitely adjustable. On a national tour my son parked the car outside the dinner venue with the gas turned down low so the lamps were dim.

Guests kept telling him he"d left the lights burning, but were somewhat flummoxed when advised they were on parking mode!

Allan from down under.

KWTownsend wrote: ↑

Thu Jun 26, 2025 9:21 pm

Brent,
What car will you want to burn acetylene headlamps?
I would not run an mc tank for more than 15-20 min.

Before I became more informed, I used an mc tank and regulator and went for a long drive, maybe 45 min. When I shut off the tank, i could distinctly smell the acetone.

With the B tank, there is no need for a regulator. I run it less than an 1/8 tutn open, barely crack it.

I made a special adapter plate to mount the Prest-o-Lite brackets on and use the original acetylene generator mounting bolt holes. I wasn't going to drill holes in my original 1911 running boards!

An early 2 cylinder Maxwell

I talked to every welding supply house I could find in the area and they all stated that even if I found a POL cylinder, they could not refill it. They all said that refills are no longer done locally because their cylinders are exchanged and filled at a central facility. I took my burners out and replaced with halogen bulbs. In the fall I often have to drive my 1914 home from work after dark and the drive is about 30 minutes and my halogen bulbs do a pretty good job, but I would really like to try running with gas burners. Any ideas about POL tanks and getting them refilled?

Not sure if it will work but know it works with some propane, I intend to try in the future. Take a new full tank, construct a connector male on both ends with no regulator. Connect both tanks together and invert the full tank above the old empty. If you can cool the empty (ice wet rag ect) and warm the full (set in sun) it may go faster. Typically a very slow process.

Bryan,
Best way I've found to find a filled Prest-O-Lite tank is to ask the supply house to let me look
at their B-tank rack of filled cylinders. Below is a photo of acetylene B-tanks at an Airgas
near me where I exchanged a POL tank for another POL tank I posted above. There were two
(arrows) POL tanks in the rack of standard center-valve B-tanks and I took the one in the back/left
corner with the "coarse" valve since I use the small regulator. The other POL is a "fine valve"
(no knob) which works good if you just want to "crack" the valve like Keith prefers.

Most supply house folks I've worked with are not aware of what the off-set valves were for;
valve-up on a running board to keep the acetone in the cylinder.
Also, they WILL NOT refill old POL tanks with the pressure gauge in the bottom of the tank
and NO ATTEMPT SHOULD EVER BE MADE to transfer acetylene gas between tanks.

Propane should not be used in Model T acetylene gas headlamps.

Brent, i don't have a brass car, now, but decades ago, had a 13. Finding a small acetylene tank to put inside a gutted carbide generator, might be tough, if not impossible. Since you don't have the Prest-o-lite tank and brackets, and since this setup is not going to be permanent, maybe you could get the smallest tank you can find that would provide an adequate amount of acetylene and fabricate some temporary brackets to mount it to the frame or running board supports under the splash aprons.

I've seen the B tanks hung from the rear cross member of the frame, if that's any help whatsoever. (Not on Model T's, of course)