Ok DanE,
Thanks for the details on the fittings, very useful. I will look for the threaded fitting here so I'll be fine overthere. Indeed as you describe finding the canisters can be hard and starting at Walmart for a supply is handy. Ok we'll be fine, thanks for the advice. GrA
In my experience even Walmart can be spotty when it comes to availability of isobutane canisters. They do not stock the same items in all parts of the country. I have been to quite a few walmarts that did not carry them. In 2007 on the TA I looked for them for a very long stretch of the ride. From after Pueblo to the Virginia line I didn't see anywhere that had them, except one place in Illinois that was closed when we went by.
I think availability of canisters is better now than it was then, but I'd still advise carrying a spare or arranging to have them mailed to you via USPS general delivery when needed. If you do mail them you need to label the box:
"ORM-D, consumer commodity, surface mail only"
There are limits on the size and number of containers allowed in a package. I think it is safe to mail 3 or fewer of the smaller canisters.
There does not seem to be widespread agreement on what is or is not okay, even among postal employees, but I have never had a problem mailing a couple 4 ounce canisters. This usps document seems to verify that isobutane camp fuel is ok if you follow ORM-D labeling:
https://about.usps.com/posters/pos138.pdf