I am rebuilding a 1972 Trail Mite and want to remove the big propane tank on the front. The only thing the propane tank runs is two burners. I want the option of being able to heat some coffee on it but we will never use it for much more. We have been camping in our 79 Fiber Stream for 3+ years now and have never used the burners so I think I am safe in saying we won't use these. This is what I would like to do. I want to put a box on the front hitch area of the trailer and have the propane tube run into the box. When, if ever, I want to use the burners I would like to be able to just screw one of those small throw away propane tanks you can buy anywhere into it in the front box. The same principle as a small portable barbeque. Any ideas as to how I can do this, Thanks Ken

Ken
You might consider one of the smaller propane tanks. They make them in 5 lb and 10 lb sizes. their smaller and won't take up too much space and are a good source of emergency juice, to tide you over, when the home BBQ quits just as company arrives.

Hi: The problem with the "thro away" tanks is they are "HAZ...MAT" and the Parks have to pay dearly to dispose of them...almost more than they cost to buy!!! You can buy a smaller size refillable tank than a 20lb er...Think of the poor fellow running the crusher when he encounters a 1/2 filled tank too late Alf S. North shore of Lake Erie

I too have waffled about yanking all the propane out of my trailer Ken. Only because, like you, I don't use it. I'm always hooked up when camping. I've never used the propane furnace, refer on propane and the stove maybe 3 times. Then I started paying attention to circumstances members have had during horrible winter weather this past year...in particular. More than one, moved into their trailer when they lost power for days on end in their stick built homes....and were able to "live" comfortably. Since the world's weather seems to be getting weirder every year, I'm going to do what James suggested....go to a much smaller tank. That way, if I AM out camping and the campground loses power...I can still have my coffee...and if my home loses power in the winter, I can stay warm in the trailer. I can then always hook up one of the five 20 lb tanks I have hanging around for my barbecue

Whatever decision you make, will be the best one for you.

Check the ordnances B4 you do it.

If U put the tank in a box - U may create a possible explosive hazard if the bottom of the box is sealed tight.

Propane is heaver than air and will flow down to the bottom of the box and if the bottom is open under the tank, the gas will flow out.

I may consider going to a smaller tanks too.. I only have the stove to use.. with no furance the ones I got are really to big. I can turn mine in at the RV place and the propane company will depose of them. I also use full hookup, so really doubt if I need these big tanks....

Ken, how is that little guy coming along?

I am sure you have made it much more happy in your care than it was at the musicians house! Poor little thing, looked all ignored and neglected..

I would recommend this option too... But I realize that the cost of these tanks is quite high. The Lite House trailers came with smaller bottles...

Propotionately they are high. 1/4 of the volume of a 20#, but twice the cost. I can get a 5# here in Portland for around $35. But, how often are you going to BUY one? As far as I'm concerned, that's a one time deal. Now the disposables

I use a smaller propane tank on my Compact Jr. I needed more room on the tongue so I could mount the spare tire. I bought my 5 lb. tank at Camping World for $50 then found that Northern Tool sells a 4 lb. for $36. It has worked great and will go several seasons before needing a refill.

Tom Trostel

http://albums.photo.epson.com/j/ViewPhoto?...&p=73194432

I converted the two 20 lb tanks on the front to a single 10 lb and set the battery box beside it. Be prepared to pay more for the smaller tank than a 20 lb. I you plan on enclosing the tank in a box be sure to provide plenty of ventilation, both top and bottom. I'd keep any electricals away. My biggest problem was figuring out a method of tying down the tank to the frame.

If you want to use a disposable bottle Northern Tool carries an adapter that might simplify the connection. I carry one for emergencies. ber sure to get the one that allows connection from a disposable tank to the POL hose or Quick Connect, not the refill adapter.

I also have a 5 lb tank and and a propane camping stove for cooking outdoors.

Here's the link to
Nothern Tool

Thank you Dan M. It is ordered and will be shipped out on Tuesday. Ken

Christi, try finding a free ad paper (or local internet ad site) to run an ad and sell your existing tanks to help pay for your conversion.

you could always do what i did and solve two problems in one.
yep after purging i cut in half and made the bbq pit out of it and got a microwave for my coffie and popcorn.

Click to view attachment

I replaced my 20# tank with a 10# from Home Depot and use a Steak Saver to connect a 1# cannister as a backup (BTW, Steak Savers have changed slightly to accomodate the newer connection thread arrangements on the newer tanks).

I use my LP for range top and 6KBtu LP heater; folks with a refrigerator and/or RV heater would likely need more.

BTW, the 10# tank comes in two configurations, with one being thinner but the same height as a 20# and the other being shorter but the same width as a 20# -- The tall one fits the 20# brackets on my Scamp quite well but might be more likely to come loose in a violent crash than the shorter one.

I never liked the idea of tossing those little green tanks in the recycle either so I went to Coscto and bought a case of them then went to Harbor freight and bought a propane bottle refiller http://www.harborfreight.com/cpi/ctaf/disp...temnumber=45989. It fills them up maybe 75% to 80% of new and there is no trash for the landfill. I refill them when I have my main tank of for refilling and use them as needed.

Steve

I use the small RV-style cylinders only as an emergency backup reserve, because I do not like either the cost or the waste. I do use the taller and thinner ones for a propane torch; each one lasts me for years.

I have read numerous references to refilling the single-use propane cylinders, and each time I have to ask: if it is safe to refill these, why will the business which refills the bulk tanks not refill these? Why are they invariably described as "single-use" or "disposable"? Why can they not be legally transported in at least some circumstances?

From The Heater Shop, about their adapter:

How do we know when the bottle no longer "survives"?
Checking for leaks with soapy water to see if the valve is obviously failed seems insufficient to me.

Both the Harbor Freight Propane Bottle Refill Kit Product Manual and the instructions on the Heater Shop site suggest filling for one minute; it appears to me that there is no way to know if the cylinder is dangerously overfilled. This sounds irresponsible to me - perhaps I have missed something.
How do you know when the bottle has been filled to no more than 80% of its liquid capacity?

I don't pretend to have the answers, but I hope anyone who refills them does.

Several years back I purchased a small cylinder propane lantern. The store where I bought it made the strong suggestion to NOT disconnect the cylinder until it was empty. The problem was leakage. Now either the valves have gotten better...or.... Either way, I've used the lantern and as per their suggestion have not disconnected the cylinder until empty. At any rate, I certainly wouldn't store a disconnected or refilled cylinder in any sleeping area or even INSIDE a tug.

My 2 1/2 cents.

The valves haven't changed over the years as far as I can see -- They are most likely to leak when they are disconnected, because that's when the valve sticks open either because of malfunction or debris in the seal.

I sometimes get leaking cannisters from folks packing up after the weekend and I just disconnect my 10# tank and put the cannister on-line with the Steak Saver -- They quit leaking when reconnected.

I refill the short squatty ones for lantern use... As for overfilling them, since one is pulling off of a 5 gallon tank that is only filled to 80%, overfilling the little bottle is not possible. (it's not like using a pump like used at service stations, etc. Now then it would be possible to overload the little bottles) I have weighed the refillable cylinders before and after refilling using the adaptor and have found that on a cool day only get about 75-80% fill (12 to 14 oz). Now on a warm Summer day, 85+ degrees, I get close to 16 oz. Of course, I only use clean empty cylinders, and discard the ones that show any distress. I check them after refilling for leakage. By doing this, I have never had one leak off on me. I think that one is safe in doing this as long as all suspect cylinders are discarded. JMHO Larry

I purchased one of these from Harbor Freight. To be honest, I have been reluctant to use the thing because of the comments in this thread which have been brewing in my mind for a couple of months now. I still believe that there might be an external outsite use for re-charged cylendars if used carefully. I would not use them in the camper though.

This makes no sense to me. The vapour and liquid in a propane bottle are in equilibrium, and that remains true regardless of the amount of vapour. It doesn't take extra pressure to completely fill, and I can't see how the the fill level of the source tank has any relevance; if everything is at the same temperature, I expect that the liquid will eventually fill up the lowest parts (the tank being filled).

Looking at it another way... how would the propane "know" to stop flowing at 80% full, or any other specific level?


I agree that weighing is the answer, but weighing only occasionally would not be goo enough for me, because the warm-day experience indicates that they can be overfilled. By the way, if the cylinder is supposed to hold 16 oz, then that's the right amount of weight to gain. From the original supplier, with 16 oz of propane in them, the appropriate free space is still left. The 80% maximum fill for safety is 80% of being solidly filled with liquid, not 80% of 16 oz. It sounds like these cylinders are usually getting filled to a very conservative level.

I assume that the temperature matters because a temperature mismatch between source and destination should produce a pressure difference, which will drive flow. The filling instruction with one of the adapters calls for chilling the cylinder, presumably to speed up filling. More chilling, faster flow, more likely to overfill...?


So the only check is whether it leaks immediately after filling, suggesting that the only concern is that the valve is failing. Can the valve which doesn't leak after filling at a cool temperature then leak when the temperature rises, and the pressure with it? How do we know this hasn't been happening, just not in noticeable amounts?

Unlike water, and like gasoline, I believe LP can expand and contract with temperature, so that may be a factor.

I think the valve leaks are due to debris in the seating, so if it doesn't leak after filling, it's not likely to leak under pressure (I would expect more pressure to make a better seal).

I've attempted to refill cannisters from my 10# OPD tank but have only had marginal success (maybe 25% fill at most, without chilling).

All liquids expand and contract with temperature changes, but it is more noticeable with hydrocarbons (oil-based stuff) than water, and particularly with light stuff like propane. The relatively unique thing about propane compared to more familiar liquids is that it expands all the way to being a gas at "room temperature" and normal pressures; to get an open bucket of propane to stay liquid, it must be way below freezing, so instead it is stored under pressure.

Pete, how are you attempting this transfer? The only available place to attach the hose or adapter onto a bulk propane tank is a vapour port - it is on top, so no liquid comes out there. If you invert the bulk tank so liquid will flow out, I would expect the OPD float to go up, which is towards the foot of the tank and therefore open... but maybe OPDs don't work so well upside down? The bulk tank valves are also designed to limit vapour flow rate, and are not supposed to pass liquid out at all, so maybe the flow-limiting feature is a problem as well.

Water actually expands the most... when it turns to ice.

I have reviewed the instructions on the use of this small cyclinder fill device.

It takes advantage of gravity flow of the liquid propane from the 20 lb. tank into the smaller tank. This flow will cintinue until the liguid blocks the excape of any additional vapor from the smaller tank. Therefore, if the instructions are followed correctly, the smaller tank will never overfill as the liquid will not allow all of the vapor to escape.

I only use small tanks of propane for soldering. If I used them for cooking and heating while camping, I can see no reason why I would not use this device.

"Water actually expands the most... when it turns to ice."

Actually, it expands the most when it turns to superheated steam, I believe <grinz>. But I was referring to the liquid phase of all these materials, of course!



Here's a link to refill instructions, showing gravity flow, plus chilling the cannister creates greater relative pressure in the bulk tank, increasing the rate of flow:

Refill Adaptor

By following the instructions and diagram,the bulk tank is upside down and the cannister is on its side, so some vapor remains in the top part (above the fill valve) and overfill is unlikely.

Seems to me that with the OPD stuf aside, if the bulk tank is upside down and the cannister is fully right side up (using a connection hose to do this), eventually all the vapor from the lower tank will make its way up into the upper tank as gravity causes the liquid LP (L^2 P?) to flow down, potentially overfilling the cannister. I haven't yet taken a cannister apart to see if there is internal plumbing to prevent overfill.

The process can be forced by opening the overpressure valve on the cannister ('reverse' Shrader valve, pull to open) to let vapor out -- Even on it's side, opening the valve might allow the cannister to be overfilled.

Brian, I suspect you are correct in that the OPD provisions are hindering the process, but I was successful in getting some LP to transfer.

If you tried this with partially filled water tanks, air in the rest of the tanks, and only one hose between them, you would be very frustrated as the air flowing up the hose and water flowing down interfered with each other. If any air was trapped in the lower tank (such as by placement on the side as described by Pete), it would get compressed until the pressure of the water from the higher tank was insufficient to push any more in... but we're not talking about water or air here.

Both tanks are full of propane liquid and vapour in equilibrium - there should be no air anywhere. The vapour in the lower tank (the small cylinder being filled in this case) is propane and I see no need for it to escape... it should turn to liquid as required. Since vapour-to-liquid conversion (condensation) releases heat, it would tend to raise the temperature in the lower tank, and thus the pressure - that's probably why the pre-chilling advice. It's just the converse of the chilling effect of vapourizing propane.

I don't see any difference between the small cylinder being filled this way and a bulk tank being filled, so I don't see any limitation on overfilling, except that it will take a long time (especially if the condensation heating effect is significant) and the person doing the filling quits after a minute or so.

This has be intrigued... almost enough to try this and check... but I'm not sure it's worth buying the $20 adapter.