I have one of those bottles as a back up, all I do when I need it to be refilled is take it into my local sealey dealer (like MK said find your nearest on the sealey website). It costs about £10. The dealer sends the bottle back to sealey and you recieve a new one full of gas in a day or too.
My local fire extinguisher supplier will fill a pub type cylinder with CO2 for £7.
This has about a million times the capacity as one of those little cylinders too.
Harry it might be worth you taking an industrial bottle from BOC or AP out on a short term rental. Do what you got to do and sling it back at them. Worth looking into if you have a reasonable amount to do. There is the bonus that CO2/Argon mixes weld so much nicer.
so whent to get my cylinder of co2 this morning and the spares shop had got it all wrong . i had asked for a 1 kg refill they got a small throw away cylinder .
i had asked for co2 they got argon . could they get it more wrong ?
so the person behind the counter had a look on his computer and then he told me that sealey don't do a 1 kg refill and all they do is a throw away . my reply to this was to go to the back of my car and get my 1 kg cylinder with the words sealey and refillable on the side and placed it on his conter . ooo came his reply will have a look on my computer againe here it is £28 . at this point my blood had began to boil and evaporate so i walked out the door .
I then remembered that a car spares shop that i go to sell's sealey tools so i went to this shop to see if he could help . i walked in the door and said can you get me some co2 and his reply was do you wont a throw away or a refill . .
And it only cost me £8