Modern tank for acetylene lights

[bdtutton]

Earlier this year I tried to switch my 1914 Touring car back to acetylene lights and ran into some issues. While it is possible to find a Prest-o-lite tank I can not find anyone to fill it. I checked with the local industrial gas suppliers and they said they no longer fill tanks, only exchange tanks and the Prest-o-lite style tank is not one they handle. There is one place that i may be able to get one filled, but it is at least an hour drive away.
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So...here is my question. Has anyone tried to mount a small standard acetylene tank under the car to run the lights? It would have to be something standard that was easy to swap at the local industrial gas supplier.
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As of now I have a 12v battery under the rear seat and halogen bulbs where the burners were. It actually works well, but I am trying to keep the car as original as possible. Any ideas would be appreciated.

[Dan McEachern]

Most industrial gas suppliers have "B" bottles available. They also have "MC" bottles which are much smaller. An MC bottle will fit under your back seat.

2022-12-27_21-28-39.jpg (18.04 KiB) Viewed 4886 times

[Allan]

One problem with modern bottles is they need to be installed on the vertical due to the way they are set up internally. That is fine in the back of my van. We even use a modern regulator to control the gas flow. Putting a modern bottle under the back seat may not be possible.

Best of lick in your endeavours.

My son left myT Cococlate van outside a banquet venue on one of our National Tours, with the regulator turned way down so there was a really low flame. A number of participants told hime of this when they arrived. His reply? They were in parking mode. Kids!!!!

Allan from down under.

[Wayne Sheldon]

It is VERY important for acetylene tanks to sit in their proper direction!!!! It is "possible" for a tank sitting the wrong way to create a potentially explosive situation! Years ago, I saw the industry's safety film! It is not something to be ignored.
Era Prestolite tanks had offset valves in one end. They were intended to lay flat, and it is CRITICALLY important that they be mounted with the offset valve on the high side!
Modern tanks, with the valve centered in one end, MUST be standing or leaning with the one end much higher than the bottom end. General rule is that IF an acetylene tank is laid on its side (for storage or transporting), it MUST stand properly on its end for at least half an hour to allow the gasses and liquid solutions inside to reposition properly.

So, the big problem of modern tanks for our antique automobiles is that they no longer supply tanks that can be used laying on their sides! And there is no good place in most of our antique automobiles where a modern tank can be stood up!

Laws vary greatly from one state to the next. Some states still allow the old Prestolite tanks to be refilled. Many state do not allow it. California does not allow refilling of tanks more than some number of years old. Over the years, I have known of a few small shops that could and would refill them for antique automobile use. Maybe you can find someone? Maybe someone in your area knows of one? I don't know if the last place I knew of is still willing or not?

[TMiller6]

Our local museum uses MC tanks mounted inside a running board tool box on two blocks. The blocks sit on an angle and the tank uses a modern regulator for the gas. There is sufficient room inside the box to keep the valve high.

[Loftfield]

AirGas has "B" tanks available. These have the same valve offset as the Presto-Lite tanks so can be mounted horizontally, making sure, of course, that the valve is on the high side when mounted. Sizes are available that will fit the Presto-Lite brackets, put some Presto-Lite decals on and only the AACA 400 point people will notice. When I tried to get my Presto-Lite tank "certified" I was told that if the tank failed then it would be condemned and I wouldn't get it back. I use the modern "B" tank for the very odd ignition of the headlamps and keep the Presto-Lite for show's, no real trouble to change out.

[TWrenn]

What Tom above said is true, however it's all but impossible to find "B" tanks anywhere. As I recall, my local gas supplier said there was only 2 places in the country to get them. I've tried for years to get one and can't. On the other hand, as Wayne said, you can at least get a small tank, I had the "MC", which stands for motorcycle as I understand it, and I had it behind the seat on Pete, my 1912 Commercial R/PU, I had it tilted at about 20 degrees and it worked fine. Trouble is, it's only good for 3 hours of running time. Better than nothing I guess!

[Russ T Fender]

I have my bottle mounted under the floor of my '10. I built a bracket that keeps it at an angle so the valve is at the location it would be if it was offset. Been that way for more than 20 years. Only problem is that the older I get the harder it is to open and close the valve but it's really no worse than checking the oil.

[PeterN]

I made a bracket similar to Keith’s in the thread linked below. Mine is attached to the frame and one of the running board cross braces. The regulator sits just below the gas tank. I have to crawl under the cad to turn the bottle on but I usually only light them once a year at Old Car Festival so it’s not too bad.

https://www.mtfca.com/discus/messages/7 ... 1487304464

[Drkbp]

Bryan,
You can still find Prest-O-Lite "B" tanks with the off-set valve. These you
may lay on their side as Wayne says with the valve "up" on the running board.
They do not have the "pressure valve gauge" in the bottom which precludes them
from being filled today. There is a plug where the old "Prest-O-Lite Tank Pressure
Valve" was.

I have found these "more modern" Prest-O-Lite Tanks mixed in with the regular center
valve "B" tanks at both my AirGas and Praxair supply houses. You have to look carefully
to see them when they are mixed with the regular "B" tanks.

Below is a batch of "B" tanks that were at my local AirGas Welding Supply. There were two
Prest-O-Lite off-set valve tanks mixed in. Two arrows. I like the "coarse" knob style
valve because I don't have to fiddle with a "key" to turn off the bottle and it closes faster.
I use a small regulator. Those who "crack" the valve will probably like the old style valve.

The acetylene tanks in my area of Texas are filled about sixty miles from me and I discussed
these tanks with the manager a number of years ago. They replace the old style valves when they
fail with the coarse style with the knurled knob. He said the Prest-O-Lite tanks with the pressure
gauge fail almost every time in the bottom where the gauge is. As long as the POL tests, he fills it.

I keep one on the car and another as a spare to exchange when I find another one.

[Farmer J]

I bought a MC tank and regulator, but can’t get the flow reduced enough with the regulator. Anyone have a recommendation on what regulator I should use

[bdtutton]

Has anyone thought about this from a different angle? Are there any other gasses that could be used like acetylene that would be easier to work with?

[Dashpot24]

Hi
I am new to this forum, and ignorant of the acetylene light setup, but will post nonetheless.
I do not know where you are in SW Michigan, but there must be a supplier such as Airgas or Praxair down by Michigan City.
The industrial suppliers probably do bulk exchange because some compressed gases are by-products of refinement processes.
I am not familiar with the acetylene light setup, but can't you use a disposable tank such as a Bernzomatic 14 oz type? They are propane or MAPP, and since acetylene is really a gas mixture, I wonder if that would work.'
The issue with CG cylinders in general is that tanks need re certification every 5 years or so. I think it is an OSHA requirement. So, if you have an older tank, it may be necessary or good practice to have it re certified. Usually, industrial suppliers have a site or contractor who does this for them too.
Anyway, this might help you understand the difficulty of getting the tank filled.

Cheers!

David

[Drkbp]

Jerry,
I use a small Uniweld Regulator on a Prest-O-Lite "B" tank.
I'm sure the welding supply can set it up on a Motor Cycle tank.
I set it to about 4 to 5-psi. Then the small Radnor acetylene valve
(located between the radiator side panel and each headlamp)
allows you to set the flame right where you want it on each headlamp burner.
There is only a short piece of acetylene hose between the Radnor and burner base.
Once you set the flame, turn the headlamps "on/off" by opening or
shutting off the acetylene tank. Makes it real easy to light up without
having to set everything again.

Keith made the best photograph of a lit headlamp, see below!
That is what you are looking for....

Just set the Motorcycle Tank valve "up" to keep the acetone out of your
small regulator. They were made to lay horizontal across the handlebars of motorcycles.
Most supply house folks don't know why they are called MC tanks or B(us) tanks.

[TWrenn]

I bought a MC tank and regulator, but can’t get the flow reduced enough with the regulator. Anyone have a recommendation on what regulator I should use

Jerry,
Back when I had my '12, I couldn't get it down enuf either. I just figured out how much to open the valve with that little handle with the square hole in it and left it there, then just opened and closed the main knurled valve on the tank
This worked well.

[Russ T Fender]

I've never had a regulator in line. I just crack the tank open a smidge and once the lamps are lit I adjust it accordingly. Just don't open it too much to start. Never had a problem.

[KWTownsend]

The problem with using an acetylene MC tank for Model T headlamps is it will not provide adequate acetylene supply for the lamps to be safely used continuously. You can only use an MC tank 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.

I did a night drive with the acetylene lamps using the MC tank pictured on the previously attached post. When I got home I could smell an obvious bad odor. Later, I realized the problem was as outlined above. I then was able to gather up the parts I needed for the current set up, using a B tank.

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. A B tank will provide enough gas (at a safe flow rate) to illuminate a pair of acetylene lamps for more than 26 hours of night time driving pleasure.

: ^ )

Keith

[KeithG]

Whatever you do, don't use Mapp gas for your acetlyene lamps! I did that once and found the Mapp gas burns much hotter than acetlyene and it cracked one of the original reflectors in my lights. Big bummer!!!
Since then I use a B tank that I bought filled from Airgas. It has the correct offset early original valve that used the small square wrench to open. I also searched for several years at Hershey for the original Prest-o-lite regulator and now have the complete P-O-L setup on my '14 Touring and it works great! I only use it at the OCF and have done it for about 6 or 7 years now and still on the original tank fill.

Keith Gumbinger (Yes, I'm the other Keith)

[Susanne]

Just to clarify something (that scared the bejeezus out of me) I read above...

Acetylene is NOT a "mix of gasses", but an actual pure chemical compound (C2H2) so using a mix (such as MAPP) is not going to work. As someone mentioned you will break stuff, cause a fire hazard, etc. Also the mini bottles of actual acetylene are really small - MAYBE an hour of acetylene. Also the reason Acetylene was (and is) used is when combined with the right % of air it throws off it's characteristic white light... Propane or Butane (or most other hydrocarbon gasses) do not do that...

Also the reason MC tanks work for motorcycles is they run one 1/2 (or 5/8) foot burner (in the headlight) and one mini burner (might be about 1/4 foot, it's almost like a miners lamp burner) in the taillight... Most folk that have multiple lights (like on a sidecar rig) run B tanks so they have enough gas to see for more than a short jaunt to the store... OR they run a carbide generator... If you have a source for Calcium Carbide, IMO a generator (with its issues) is a better way to go.

My 2¢... for what it's worth! (probably about 2¢)

[KWTownsend]

Bryan,
If your local gas folk won't fill and return your offset B tank, I'd suggest to ask them to notify you when one comes in. Maybe they will, maybe they won't, but it wouldn't hurt to ask.

I have a B tank on my car that has a brass "collar" near the neck that has a Prest-O-Lite logo on it. I took it to my local gas dealer to be filled, and specified that I wanted that particular tank back. They called when it came back in filled. I was devastated when I picked it up and saw the brass logo was gone! I check the numbers and it was the same tank. The guys at the shop knew nothing about the brass logo.

:^ (

[TWrenn]

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

Keith when I used my MC tank I wouldn't run an hour or so at a time with no problems. Just saying!

[Dan Hatch]

Seems I remember there was a orifice made in the fitting that screwed on to the tank that set the flow to the lights? Have not seen one in years. Dan

[Drkbp]

Thank you Keith T for the draw-down cautions and experience with the MC tank.
Also, DO NOT enclose these fuel tanks in tool boxes, non-working carbide generators,
under touring car seats, or any other enclosed or poorly ventilated areas!

Keith T's last post at 10:00 a.m. is spot on.
I went by Airgas this morning and he only had eight regular center valve "B" tanks.
He said he had several Prest-O-Lite's last week or so but if I would leave my number,
he would pull one when Western International Gas makes their next delivery of "B" tanks
with a Prest-O-Lite in it. He also offered to chase one down for me using the picture
I posted above in this thread of the Prest-O-Lite tank. Western International Gas is an
acetylene filler and supplies all over the U.S. and currently are filling them.

While at Airgas, I checked today's cost on acetylene tanks, refill charge and both include tax.
1. Prest-O-Lite "B" tank (including gas)........$202, ......Refill your POL....$46
2. MC tank (including gas).......................$124, ......Refill your MC.....$32

Carbide is fun but expensive today.
You can refill your POL "B" tank 3-1/2 times for the cost of the
amount of carbide to produce 40-cubic feet of acetylene gas (10 pounds).