Did anyone ever figure out the thread on a Butane bottle?

[Flapdisk]

Hi Guys, I haven't got any Propane bottles but I have got three Butane bottles empty, I would like to make air receivers out of them and I have read everything I can find but can't find a clear statement as to the thread size on the top of the bottle.

Mine has the clip on reg, but the bit in the bottle does unscrew, I took one off today and have the bottle soaking, It looks about 3/8 but tapered Can I drill it and re tap it to 1/2" BSP?

 

[rtbcomp]

All mine were between 3/8 and 1/2 BSPT, ie a non-standard size.

The way I dealt with it was to remove the valve, drill it out and solder a piece of 15mm copper pipe in it to take 15mm compression fittings. This assembly was then refitted to the bottle.

Don't attempt to drill the valve in the bottle, there are some steel components inside which may cause sparks.

 

[Cobbler]

I use old gas bottle as an additional receiver & air pig. The hole in the top of that bottle is 3/4 BSP. The one I use is about 40 years old though.

 

[The_Yellow_Ardvark]

I use old gas bottle as an additional receiver & air pig. The hole in the top of that bottle is 3/4 BSP. The one I use is about 40 years old though.

The newer ones are metric.
Some even have an adapter to convert one to the other.

It is a case of, if you can get one out, measure it.

If not make a converter system of your own.

 

[Flapdisk]

Thanks guys, the hole in mine is definitely smaller than 3/4 as a half inch fitting is larger than the hole, a 3/8 is close but the thread in the hole seems coarser than the fitting.

 

[Mee]

Many are 5/8th BSP.

 

[Flapdisk]

Hi Mee, yes it seems they come with many different sizes, I can see the sense in what rtbcomp is saying above, about making use of the spigot the reg clips to and I maw well do that, but on one of them first I am going to try re drilling and tapping to 1/2", there is plenty of meat around the hole on mine, they welded a thick ring in the top so providing it all cuts clean and the metal is good it should work. It's soaking full of water and washing up liquid at the moment and I have had to order a 19mm drill bit, I will post pictures of how it went over the next week or so.

 

[The_Yellow_Ardvark]

@Flapdisk
Before you go mad with a drill.
Grind off the paint to about 50mm Dia. round the hole. If you are lucky you may find a sweated insert.

That will tell you how big you can drill and tap a hole for your new fixing.

36 grit will soon remove it.

With reference to the course 3/8 it could be a M11 course thread if it is a modern cylinder.

 

[Flapdisk]

Thanks for the tip Ardvark, will do mate, I will check that out tomorrow.

 

[Flapdisk]

Just been out and took some pictures, It looks clear to me because it's a raised insert that there is enough meat for a re thread. I did a few with a rule in metric and imperial to see if any of you experts can tell from the major dimension what the size is? I know little about threads.
In case you ask, I did it in the middle of the ruler as it was easier to balance it while I took the pictures :-)

 

[dannyp]

as a bodger my prefered method is to get a male / male hydralic union of the desired size, stuff it in the hole ( opening the hole up a bit if needed ) and weld round it

i have no worris with doing that or about it being good for the pressure as ive welded hydralic fittings together meany times and never had an issue with the pressures involved with hydralics and thats upto 40x more pressure

 

[Flapdisk]

Thanks guys a couple of good tips there.

 

[outofthefire]

Why dont you just drill through the valve there should be enough brass left to take a thread.

 

[Flapdisk]

I may well do mate, I haven't decided which method to do yet, I have a couple of these bottles I'm messing with.

Question for all.. How much would you pay for an empty 47k propane? I put an add on the local facebook for sale site and a couple of people have said they have got bottles but when I ask how much they want, they say oh! I don't know what they are worth, so they want me to sell it and buy it :-(

 

[outofthefire]

I may well do mate, I haven't decided which method to do yet, I have a couple of these bottles I'm messing with.

Question for all.. How much would you pay for an empty 47k propane? I put an add on the local facebook for sale site and a couple of people have said they have got bottles but when I ask how much they want, they say oh! I don't know what they are worth, so they want me to sell it and buy it :-(

Nothing, bottles find me usually, I work next to an air products dealer and I got an old 47kg from them for nothing.

 

[eSCHEn]

I paid about twenty quid for a pair of supposedly empty 47Kg propanes last year.

I think they're both about half full judging by the heft but haven't weighed them to be sure.

 

[Mee]

Mates premises are opposite a metal recyclers and they dump them outside their entrance, pity you aren't nearer to me as you could have as many as you like for free.

 

[Seadog]

But where are you Mee?

 

[Mee]

Here.

 

[Flapdisk]

Lucky gits :-) Ok well I just paid a tenner for one, I guess that's ok