Refillable gas bottle problem in cold conditons

[Guest petej]

Apologies for this long winded post, but I feel its an important issue for owners and potential owners of refillable cylinders. There has been much talk recently of the problems filling refillables at gas stations, I thought I ought to bring it to your attention of another problem encountered whilst on holiday this year (Jan) In southern Germany. Camping for long periods where the temperature was dropping as low as -10c we started to notice when refilling that we were getting less and less gas in each time, usually about 10ltrs goes into a 6kg bottle (85%) but this was gradually reducing until at the end of the holiday (4 weeks), we were only able to get about 7 - 8 ltrs in. We returned from holiday thinking it might be a problem with the regulator freezing or possibly condensation freezing in the pipes somewhere. I am an active member of motorhomefacts.com and noticed a post from someone with the same problem, they had contacted Gaslow and were sent an email reply (copied to me) that they (gaslow) had only just become aware of the problem and had come to the conclusion that it must be a problem with the gas mix on the continent. It turns out that over there it is common practice to use a butane/propane mix for garage forecourt supplies. Gaslow were looking into the situation…. For the full details, read these 2 links on motorhomefacts.com.... http://www.motorhomefacts.com/postlite4117-lpg.html http://www.motorhomefacts.com/postlite4303-update.html Further to this, I asked gaslow for a verbal update on the situation. Richard Glazebrook, the MD of gaslow was abroad at the time and unavailable, but I was assured a reply on his return. On 7 feb 05 I received a phone call as promised from Richard with an update:- After many enquiries to the relevant authorities for lpg on the continent he can confirm that it is standard practice for a mix of propane/butane on garage forecourts abroad. This problem is apparently either a way of using up surplus butane or possibly a cost cutting measure as butane is cheaper than propane. This is not a problem in the UK as the majority of the fuel here is propane with minimal butane added (if any). Normal road vehicles using lpg tanks do not suffer any problems as they operate a 'liquid take off' arrangement causing no problems with the mix in the cold. lpg bottles use a 'vapour take off' and this is the problem as butane doesn't vaporize at low temperatures so it can't get out of the bottle in these conditions. There are 2 possible solutions being evaluated by gaslow at the moment; 1. He has sourced (from Japan I think) a disposable heating wrap that operates on a chemical reaction process (similar to those emergency light sticks you crack open to operate) and will heat the cylinder sufficiently for up to 12 hrs at low cost (somewhere around the £2 mark). The idea being, the propane runs out (with an amount of butane left in the bottle), you then enable the heated wrap and burn off the excess butane before refilling the bottle. This solution would possibly be of interest if power consumption was an issue as it consumes no 12volt or mains power. 2. He is also looking into the feasibility of a low power 12volt wrap but this would be more expensive and there would more reliance on power than the previous option, probably no good if you wildcamp in these conditions or simply don't have access to mains electric or have insufficient battery power. It is stressed that this should only be an issue for motorhomers spending extended periods in sub zero conditions. Normal winter holidays shouldn't present a problem as it's after repeated refilling and the resulting gradual reduction in bottle capacity that causes the problem. He has also quite rightly strongly advised that you do not attempt to remove the cylinder, turn it upside down and discharge the excess butane into the atmosphere, very dangerous I think you'll agree! (you'd probably end up with your hands welded to the bottle!). I also mentioned the problem of my gauge in these conditions showing red all the time even when the bottle is full and he has confirmed this is the butane causing the inaccurate reading as the gauge works by pressure. I can confirm that my gauge, once back to normal temps now works ok, so that seems a fair conclusion. Hopefully i've got all that info correct (its me age you know). I would certainly have thought more carefully about the purchase of refillables if i had known this before purchase, but as i said, probably only a big problem if you do a lot of extended winter camping and hopefully a solution is coming soon. Richard has promised to reply within 6 weeks after further research and I have every reason to believe him. It seems to me that this is a company that doesn't shirk it's responsibilities and is actively searching for a solution to a problem beyond their control and genuinely cares about its customers (others will say they've got no choice, or sales will drop). Usual disclaimers, nothing to do with the company, just impressed with their attitude and after sales service. This problem will obviously affect all other brands of refillable bottles when used on the continent in winter. Watch this space for an update in the future….. Pete.

[Guest Clive]

Commercial LPG is a mixture of Propane and Butane. In the UK it’s about 95% Propane. On the continent it alternates between 40% Propane in the summer and 60% Propane in the winter. Butane has a higher calorific value so cars run a little better on Butane than propane - if the driver notices. The "MIX" is under direct control of the oil companies and is not published at the point of sale.

[Guest Derek Uzzell]

I once read in a French magazine that the propane/butane ratio in France in exchangeable "propane" bottles was 90:10, in Morocco 50:50, but in Germany 100:0 (ie. it's all propane.) However, I recall that Truma used to offer anti-frost heaters for gas-bottle connectors, which perhaps suggests otherwise. As butane has a higher calorific efficiency than propane, this may be another reason for having as much of it as practical in autogas. How about heating the gas-locker's structure to cause the butane component in the LPG to vaporise? If a motorhome has a powerful enough blown-air system (that will probably be in use in cold weather) it might be possible to extend the air-trunking to warm the sides or rear of the locker.

[Guest clive]

" If a motorhome has a powerful enough blown-air system (that will probably be in use in cold weather) it might be possible to extend the air-trunking to warm the sides or rear of the locker." (Or even to blow into it from above C. ) I like that one Derek, it sounds a lot better than chemical or 12 volt powered heaters. But how about my new 55 litre bulk tank I have just fitted? My intention is to always leave the UK with a full tank of mostly Propane. As we usually only use about 7kg of Propane on a 3 week summer jaunt in France I guess our increased capacity will last us a tad longer.

[Guest Derek Uzzell]

Clive: Yes, I considered suggesting leading the ducting into, or through, the gas-locker's interior, but I knew the idea would horrorstrike the safety-conscious amongst us. I also thought about running the 'van's hot-water system through it, which is probably better from a safety viewpoint. You are going to need to uprate your Scout's VIN-plate if you keep on tarting it up like this. Remember Howard Hughes' dictum "Simplificate - and add lightness". On our next motorhome I'm planning to use a 10 litre refillable bottle + a 3.9kg (7.8 litre?) Calor propane cylinder as back-up. Why cart around lots of gas if you can easily replace it?

[Guest Clive]

Actually I have only added weight over and above what I would normally carry as 3 X 6Kg bottles if the new gas tank is right on its 80% mark. Metalwork weight is almost unchanged. But re-fils are a third of the cost. Its all fully documented and 52 pictures taken during the process. Special VIN plate? I have one in my hand.