View Full Version : canister wt. scale
squeezebox
02-08-2014, 09:31
Here's my idea for a canister wt. scale to tell how much gas is in the canister.
Get a ft. long piece of say 1/4 in elastic, seemed a good width in my mini test with a full 8 oz canister 3/16 flat or 1/8 cord might be options too. Walmart has a fair selection. rubber bands could be a good choice too, but not as durable.
Tie a small loop in each end of the elastic.
Hook one end to your stove head , slips off the canister, and the other end to a small carabiner , hang it somewhere. with full canister. Maybe while bear bagging.
Get a thin stick or UL plastic ruler, measure say from knot to knot, make a mark on your ruler, when the canister is empty measure again , make another mark. That distance is your full to empty scale.
Thinner elastic will stretch more but will bottom out.
Might need different elastic for 4 oz and 8 oz canisters.
wt. of set up? My guess way less than 0.5 oz.
If it sounds good!! squeeze it !!
I think the concept would work, but my question is why?
Not why would it work, but why would you need to do it? I think you are over thinking this. You start your hike with a new canister, hike till you go into town and then buy another canister. Use the old one till it's gone and switch canisters, next time you are in town buy another canister, wash rinse repeat.
It does not take long to figure out how long a canister will last once you start hiking. If for some reason you do run out, you will not starve before you hit the next town, any food you can eat hot, you can eat cold.
If it is weight you are worried about, when you stop to refill your water, drink an extra cup of water at the spring and carry a cup less on your back to offset the weight of the canister. A small canister weighs about the same as a cup of water.
Another method of determining how full your canister is. Look very carefully at it first thing in the morning, water will condense on the outside of the canister and show you how much fuel you have inside. Try it.
Slo-go'en
02-08-2014, 13:59
You could make a balance, which might be more acurate. Use a wood dowel a foot long, tie a string on each end and in the middle. Hang it from the middle string. Hang your fuel cansiter to one end (use a small stuff sack) and a cup to the other. Fill the cup with water until you get a balance - the dowel is horizontal. If you have markings on the cup, you can tell how much water it took to balance and hence the weight of the canister.
Or you could shake the canister and when you stop feeling fuel slosh around inside, it's getting near empty.
4eyedbuzzard
02-08-2014, 14:24
Rubber band stretchiness (coefficient of elasticity for us geeks) will change with temperature, age, etc. Probably not the most accurate option. Floating it in water in the cooking pot would be a more repeatable option and require no extra stuff - as the fuel is expended the canister will rise higher above the water line. You'd have to experiment with "float line" vs remaining fuel to come up with the relationship of fuel vs buoyancy. Keeping the canister upright in the pot and making sure there is no air trapped underneath the concave canister is important - yeah, I confess, I actually tried this to see if it would work and it does, but floating it valve down in a large diameter pot isn't very stable and it isn't very stable once the fuel gets lower either. The Jetboil pot does quite well with this floating method as it is close in size to the canister diameter, keeping it upright.
Yeah, you're overthinking this. It's easy enough in other ways to get a decently accurate idea how much fuel is left in a canister and how many more boils you'll get. With practice just by holding the can in your hand you'll get a good idea how much fuel(boils) is left in the canister. Adjust as needed(boil water over a fire, eat cold(not going to kill you), etc. I really don't make iso canister fuel content into as big an issue as I once did. If you feel you must know these things ASAP do as Moldy or 4eb says or buy the Brunton stickers that attache to the canisters to see how much fuel is left. These stickers are basically self sticking thermometers that do what Moldy spoke about. I think a feww other comaqpnies make these stickers now. A packet of a bunch is like $2. If you want to see what they look like check out the link to Zelph's site and scroll down to Gauging Fuel. I warn you though when entering Zelph's site you have entered the lion's den of Stovie obsessionists. :)
http://www.ehow.com/how_8362862_do-much-propane-left-canister.html
http://zenstoves.net/Canister.htm#GaugingFuel
RedBeerd
02-08-2014, 17:29
http://seattlebackpackersmagazine.com/how-much-gas-do-i-have-left/
Another way to measure and requires bringing nothing. If you've got a pot that will fit a canister you're good.
Always having an extra when you know you're getting close is ideal, IMO. Nothing to worry about except cooking!
squeezebox
02-08-2014, 17:37
Yes , I admit to having a problem with over thinking, take my tent stakes from me and tie me down, Please !!
You're in good company Gulliver. :D Drag me from the cliff edge when I do it too. I hope that Trans Ozark Tr gets completed. I could dig thruhiking fro St Louis MO to Lake Fort Smith Akansas.
MuddyWaters
02-08-2014, 21:31
Or...you could put a little water in a pot, and float in in water. MSR cannisters are marked to show you how full they are by doing this.
Wt = 0
I do not have the answer all I know is my jetboil, on my 2nd trip would not light below freezing, when I got home at 70 degrees it lit fine. I know many said you must sleep with your fuel, but the sleeping bag may get crowded, water, sawyer squeeze, fuel can, damp cloths and will there b room for me! They had fuel in them it was just to cold to come out.
Starchild
02-08-2014, 22:07
There is a water floatation method which works well, buy a MSR canister to learn how to use that method as it is on the canister itself. In time the shake test should work for most.
... I think you are over thinking this. You start your hike with a new canister, hike till you go into town and then buy another canister. Use the old one till it's gone and switch canisters, next time you are in town buy another canister, wash rinse repeat...
I agree that the OP is over thinking this, but I do not feel is it needed to carry 2 of them. With the smallest canister's ability to boil over 10 liters of water and the next size up 22L there is little need to carry more them one unless you need lots of hot water in excess of that. Hiker boxes swing both ways, a place to give and a place to receive, less weight to carry and less $ to be spent.
There is a water floatation method which works well, buy a MSR canister to learn how to use that method as it is on the canister itself. In time the shake test should work for most.
I agree that the OP is over thinking this, but I do not feel is it needed to carry 2 of them. With the smallest canister's ability to boil over 10 liters of water and the next size up 22L there is little need to carry more them one unless you need lots of hot water in excess of that. Hiker boxes swing both ways, a place to give and a place to receive, less weight to carry and less $ to be spent.
My reason for not dropping the used canisters in hiker boxes is because I want to make sue the canisters are disposed of properly.
Once I know the canisters are completely empty I pop a hole in them, that way I can safely throw them in the trash.
Most hikers just drop them in the nearest trash can, even if its not complete empty. I just can't do that.
I know that means carrying a few extra ounces, but I think its the right thing to do. It also means you never run out of fuel.
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