Warming propane bottles?

[promotive]

Has anyone ever warmed their propane tank to keep it from freezing? I thought about using a pad heater like we use on a race car oil tank or maybe a battery blanket. Any ideas or comments?

[Dragons lair]

Mike, Little cool this morning? Need a little heat in the shop. Got a spare readdy if you want to try it.
Ken

[Mills]

That may work, when I get to the point of freezing, i usually set the tank in my slack tub. Since moving to a 100 lber I do not experience this problem at all. Yet.

[Pault17]

I currently use and rotate little BBQ bottles until I get my 100-lber hooked up. I usually shine a 100-watt flood light on my tank while in use. haven't had any problems as yet.

Mike, I was up your way a few weeks back and the views are absolutely beautiful

[orgtwister]

i don't have a propane forge but on the crucible furnace is propane and we would put it in a tank of water to stop the frezzing but the best is to upgrade to a bigger tank and here i'm told that if you get the hundred pound tanks delivered its cheaper then filling the barbaque tanks

[Ice Czar]

best is to upgrade to a bigger tank

the ideal solution

heating any fuel gas in a pressurized tank is problematic, it requires some threshold where its shut off to maintain safety, far better to couple it with a larger thermal mass (like the slack tub mentioned) to forestall joule-thompson cooling

what may work for one member may not work for another
variables include the relative humidity and ambient temperature in the shop (the frost point of the ambient air) the size of the tank, and its consumption rate.

some solutions like very low powered heating (the light mentioned) are unlikely to exceed a heating threshold (or get left on by accident)

the tanks should have a pressure relief valve in the event of overheating, but where a venting event takes place (size of secondary containment, ventilation, ignition sources) is another consideration.

Can you heat a fuel tank safely? yes with a little common sense and due diligence.
Is it the best idiot proof solution? Not really. It requires attention and judgment as the shop temperature changes and the consumption rate changes.

Id opt for the ability to intermittently couple the tank to a larger thermal mass (at an appropriate starting temperature) to prevent icing.

;) Edited December 3, 2008 by Ice Czar

[metalmangeler]

I use a large outside tank here, propane will not vaporize below -40 F. so if you are using enough in a small tank to get below that temp or if that is the outside temp then there are problems. The propane place which delivers to us recomends a magnetic heater that is normally used to warm engines so they will start on cold mornings. This tank is about 185 gallon if I remember correctly I don't have problems with this system here, the tank is always outside, the only safe place for propane, the last few years I don't remember the temps getting below -35 F, so I would expect it to work in NC.
With small tanks inside I have used a tub of water it works pretty well.

[Woody]

What is commonly called "propane" seldom is pure propane. It is LPG, Liquified Petroleum Gas, which is mixture of varing amounts of propane and butane. So the temprature at which they boil to gas varies with the average weather conditions at the location. The farther south you go the warmer the ambient conditions, the more butane that can be added to the mixture. Also the warmer the temperature, the higher the pressure that will develop in the tank.

This might seem long winded and not relevant to the question but based on the above, what might be sufficent warming in one location to produce the desired flow of gas in another location might be enough warming to raise the pressure in the tank high enough to activate the pressure relief valve or if the pressure relief valve is missing or inoperable, cause the tank to rupture. Further, unless you purchased your propane tanks new, you have no idea of what they were subjected to previously.

It has already been recommended several times to place small tanks in a tub of water, that is very good advice, cold tap water will do nicely.

[promotive]

I have a 100lb bottle, but I am using it on our gas logs for the winter. I had thought about a tub of water to set the tank in, I will try that. I guess using the torch to heat the bottle is out!

[Woodeye]

Right - good idea not to use the torch. Does it get cold enough in Asheville to really have a problem with LP? My house is heated with LP here in Wisconsin as are many others and we all have these huge tanks outside with no problem. I have never really had any problems with the smaller tanks in my forge for that matter either. Perhaps you don't really need to worry about it.

[Mulciber]

I have a 100lb bottle, but I am using it on our gas logs for the winter. I had thought about a tub of water to set the tank in, I will try that. I guess using the torch to heat the bottle is out![/QUOTE]

That's right up there with Russian Roulette. I've done some stupid things but I would never recommend them to you. Get a 500 watt shop light from the store. They're about 7 bucks. Remember to turn it off when you're done.

Best of all would be to get another 100lb tank They're around 80 bucks at Home Depot. Here in Denver it's like 20% cheaper to fill and use a big tank than to keep refilling the bbq tank.

Edited December 3, 2008 by Mulciber

[ThomasPowers]

If you are in the market for a larger bottle I'd ask at the local propane place if they knew of a used one for sale---you want to start building up a relationship with them.

A good relationsip is worth money in the bank! I just dropped off my portable tanks over lunch and they will fill and hold them for me until I can stop back by and *then* charge me for the gas.

[promotive]

Right - good idea not to use the torch. Does it get cold enough in Asheville to really have a problem with LP? My house is heated with LP here in Wisconsin as are many others and we all have these huge tanks outside with no problem. I have never really had any problems with the smaller tanks in my forge for that matter either. Perhaps you don't really need to worry about it.

:confused:It was 15 degrees here yesterday morning! Just be cause you don't have a problem, does not mean my tanks are not freezing up! The torch comment was a JOKE! Some people do have common sense!

[ChrisB]

I had a tank freezing problem when it was 80

[promotive]

I have a 100lb bottle, but I am using it on our gas logs for the winter.

See above, I just wanted a solution for the small bottles.

[Woody]

If your tank is freezing up when the ambient temperature is well above the boiling point of propane, it is because of the conditions addressed in Ice Czar's post on page one of this thread. Toss the tank in a tub of water and it will solve the problem

[Bentiron1946]

LPG flowing through the regulator is similar to Freon flowing through an expansion valve so in a way you are creating a refrigeration unit. In my misspent youth we used to go into the back country and in order to have a cold beer at the end of the hike we would take a can of Freon, a large empty cup and a can of beer. You place the beer (still in the can) in the cup, then you open the valve on the can of Freon and drink cold beer. Well that is what you are doing with the LPG. Yes you can run water on it or put it in the slack tub but even with the big bottle you can get cold enough to slow or stop the flow. I know because I have done it here in Phoenix in the middle of the summer with it being 110F with a high volume of flow of gas doing bronze casting. It is hard to get a 100# bottle in a slack tub and it a royal pain the have the hose running on it (water+molten bronze=disaster). The folks at the propane dealer suggested the large tanks suitable for whole house use to solve the freeze up problem. Household applances are running at much lower pressure then the typical atmospheric forge and don't cause the freeze problem.

[Brian C.]

Set the tank in an old fashioned galvanized wash tub, fill half way with warm water. I made a steel strap that connects to the handles of the tub, through the handles of the tank, to keep it from floating.

[Ice Czar]

In my misspent youth we used to go into the back country and in order to have a cold beer at the end of the hike we would take a can of Freon, a large empty cup and a can of beer.

Elegant, but lacks that little bit of overkill required for world wide fame :p

[promotive]

Brian, I am going to try out your design. Thanks

[ironrosefarms]

Ice, that link is simply amazing... and I don't drink beer...

[CRAFTBENDER]

Google Pelsue bottle warmer #9651. It is a silicon rubber belt 375 watt and is made for that purpose.

[CRAFTBENDER]

I looked up the price. $395, wow! Cheaper to get the bigger bottle or even use a manifold on two smaller bottles.

[saintjohnbarleycorn]

The torch idea has been used with very explosive results. People would use the torch, heat one part of the the thin metal, weaken it, raise the temp of the tank and yahoo! Its in all the hvac books as a real no no. Even though you were joking, just in case some one was speed reading and didn't get the joke.

[Steve Sells]

I shut down a job 2 winters ago. becuase of stupidity.

We were working in ceiling area on the electrical in the ceiling, and I noticed one of the salamanders that was providing heat, was aimed at the 100# tank of propane, at a distance of about 5 foot. So I come down off my scissor lift and moved it away, shortly after the GC comes over and rolls it back in front of the 18inch diameter salamander torpedo heater. I tell him that's dangerous, he complains that its is HIS equipment, and I need to mind my own business, if I was not so stupid I would know its there to keep it from freezing ! I p[ointed out we are not working next to a pair of 100# bombs, either move it , or I move our crews.

Lucky MY crew was union, as such al the members of my crews knew the laws and OSHA regulations, and we have safety clause.

I was acting foreman, since the man running the electrical part of the job was at a meeting, so I pulled the plug on our temp electric service (which also shut down the power to both the dangerous heaters) and told my crew we are on paid break until this safety issue is resolved.

The GC demanded power, I told him to read our contract, after that we can talk out front, until then we are shut down, and so is our electrical system due to his violations.

Soon my foreman and the GC boss both came back from the meetings, walked up to our break area to see what was wrong. After I explained both sets of eyes buldged out, and the salamanders were soon being removed from job site as there was NO venting for their exhaust gasses anyway. after that, we turned the power back on, and the GC that risked all our lives... he was removed from that job site.

My foremen pointed out to the lead contractor that not only did I have that authority as the acting electrical foremen to leave any area that is dangerous, but as a local EMT I could have just called the local fire Marshall and had his company FINED big $$, but choose discretion and walked away rather than argue with the clueless. This GC that was a problem, turns out he was a HVAC guy, seems clear why he is not anymore.

We did see that GC one more time, the day after, there was a safety meeting called. Mandatory attendance for All workers. It was fast and short, the old CG spoke, read the laws about salamanders and explosion hazards, then apologized for being stupid and not obeying safety issues the day before, then left the building after introducing his replacement..