Thread: What I did this weekend.. part 2
This is sort of a CNC related project... all will become clear eventually... some of this I did last couple of weekends... the last bit I did today...
First take a propane cylinder... empty of course... got three for nothing on FreeCycle...
check its empty, then remove the valve and fill with water... leave for a week or so...
about 350mm up put a length of masking tape round the cylinder and mark a line using a pencil taped to a bit of broomstick in true DIY fashion!
Attack it with an angle grinder and cutting disc... a 115mm B&Q 500W one will burn and die before you've finished, so Screwfix came to the rescue with a 230mm 2000W one on special offer for £30 delivered next day... goes through 4mm steel plate like a hot knife through the proverbial butter...
In the bottom 65mm from the centre, cut a 22mm hole (tricky without a suitable hole cutter and being a budget project I wasnt going to buy one... so drill 5 holes and finish with a rotary file... its going to be out of sight so the finish isnt critical nor is the diameter!)
In the side, just above where the base finishes, cut a 38mm hole. The hole needs to be tangential to an imaginary 150mm tube in the middle of the cylinder, so I set it up on the mill table with the centre of the hole offset so that the outer edge would be tangential. This is a bit more critical so use a hole cutter. Fortunately I had a couple of them, the B&Q one lasted 1minute and is only good enough for cutting blancmange, the Bosch one fared a little better and finished the job but is pretty useless now :cry:
Finally remove the centre section of the top to about 80mm diameter. I did this by clamping the top upside down on the mill table, drilling round the weld that holds the valve boss, then cleaning it up with a boring head.
Total cost so far ... NIL... and only a small amount of swearing :lol:
Next couple of weeks.... what to do with the following...
Looks like a furnace.
I cut one up a while ago and made this.
It's a barrow for holding large armatures and rotors.
Problem I have is space, when they unload these and they are on a sack trolly they are two wide to go thru doors and past machines, some of these puppies can weight 3/4 of a tonne.
Soooooo get them to lie front to back, cut this propane bottle up with a small angle grinder and those 1mm thick cutting disks, if you have never used them before, once you do you will never use the normal ones.John S -
Yep thats exactly what I used.... bought a pack of 5... made short work of the bottle and a few lengths of angle iron.... mind you you need a powerful angle grinder for these bottles, they are 3 - 4mm steel (at least mine is)... the 500W B&Q grinder died spectacularly in a plume of blue flame that shot out at least a foot!!!
13-09-2010 #4all will become clear eventually.
To get a pefect line round the bottle for cutting its head off I used me belt that keeps me trousers up...whipped it round,buckled it and straightened it up level,then felt tip pen around the belt edge.
Whats with filling it with water,Irving?
On a safty note to who may follow this for melting Aluminium?....
Do not attack it with a grinder unless you know it free from gas,even if the gas is burned up do not still attack it as the pressure is still there in the bottle.
To safely cut its head off....
Burn off the gas in a mobile calor gas fire and wait for the flame to go out,disconnect the bottle and also disconnect the hose from the fires connecting valve take the bottle outside and connect the valve to the bottle, switch the valve to the open position as you would if it were connected to the fire,leave for a few hours or overnight to disperse any pressure in the bottle then safely you can remove the brass valve from the bottle with a spanner and commence cutting. SEE WARNING BELOW
Irving,have you made a flame thrower head yet?this is really important for maximium heat.
Last edited by irving2008; 13-09-2010 at 11:36 AM.
13-09-2010 #5Whats with filling it with water,Irving?
Leaving the top open over-night (or even weeks), as you suggest, will not vent the gas properly and could even lead to a very dangerous explosive gas/air mix in the bottle.
Well there won't be once the valve has been removed and depressurised. :lol:
What about the gas left in that's at atmospheric pressure ?
Unless you vacuum a cylinder or use something to displace it then the original product can still stay in there.John S -
I've done it the way I explained above...burnt off the gas,reconnected valve off the fire and left it overnight in the open position to depressuise,the hardest part was shifting the bottles valve,stuck solid it was with the bonding putty they use to seal it good style.
Still here,John...no ones house had a valve passing through their window.
13-09-2010 #9Well there won't be once the valve has been removed and depressurised.
IT COULD KILL YOU (or some other who's stupid enough to take your advice)
To cut open a gas-bottle (or any fuel tank etc.) safely, do it Irving's way - fill it with water - leave it for a few days to ensure there's no gas trapped in the seams and crevices (and to help remove some of the stink!)
Last edited by Lee Roberts; 13-09-2010 at 02:58 PM. Reason: Obscenity
I agree with Bill & JohnS - even after a week standing out in the garden the water smelt of propane and there was an oily scum on the surface...
Even venting it will not remove the remaining gas as once it has reached atmospheric pressure there is little interchange of gas with the outside world. The danger then is when it reaches stoichiometric ratio (about 20:1 oxygen to propane) it becomes highly explosive. The water prevents any possibility of this happening. I should have added that I put some washing up liquid in it too to break the surface tension and ensure the water got into any gas filled crevices and gave the whole thing a good shake.
Last edited by irving2008; 13-09-2010 at 11:35 AM.
RFQ: Need partBy Buckis in forum Projects, Jobs & RequestsReplies: 0Last Post: 21-02-2014, 12:21 AM
By luke11cnc in forum Machine DiscussionReplies: 0Last Post: 27-02-2012, 06:08 PM
By Gary in forum Marketplace DiscussionReplies: 10Last Post: 19-02-2012, 11:42 AM
By Gary in forum Manufacturer NewsReplies: 6Last Post: 21-08-2011, 10:29 PM
By irving2008 in forum Metalwork DiscussionReplies: 2Last Post: 12-09-2010, 08:25 PM