Fuel amount for a Jon-e Gi pocket warmer

I was looking for a larger pocket warmer. I bought a Jon-e GI. It is much larger than any of my other units. My filler bottle for my S-Boston suggests 15cc of fuel to fill it. Anyone have a suggestion for the amount of fuel to add to the Jon-e GI?
Thanks
Jim

That's a good question, so I've done up a video tutorial that should address this. So some seat of the pants measurements and simple math should enable a more precise answer. You can use two methods. 1: You can calculate volume by measuring the dimension of each and comparing them as one being a percentage of the other. 2: Or you can use displacement. Displacement may be the preferred method when you have a round handwarmer.

More details at this video:


Timeline:
00:00 Question posted in the forum
01:00 Displacement, or measuring?
01:50 measuring the S-Boston
02:00 measuring the Jon-e
02:10 measurement results, use a linear equation to figure out the answer
02:30 discussing how to measure other types of handwarmers: seat of the pants, or do some math?
03:15 how to use the displacement method.
05:00 getting water from Bryant Creek

According to my original paperwork from Jon'e the GI version will take 3 ounces to fill, however I tend to underfill by 1/2 oz. just to be on the safe side. I would not want to contaminate the platinum cat. I would post a copy of that information but have problems uploading pictures.

Thanks. 3 oz is almost 90ml, that seems like an awful lot, I'm guessing it's good you are underfilling.

Thanks for the replies. And thanks for the video. I was curious to try the displacement method. I first wrapped my hand warmer in shrink wrap stretch plastic. It was not waterproof. Best to use the zip lock bag method as illustrated in the video.

I might have edited it out in the video, but the results I had indicated 50 ml was the best amount to fill. But since then I note that Xteacher saw in the instructions they say almost 90ml can be used. That would mean that if you used your handwarmer every day, you would not even get 2 weeks out of a litre of fuel. As a Senior Citizen on a fixed income with no friends, that's more than I can afford!

Yikes! 90 ml does seem like a large amount of fuel. I recently added about 45ml and was able to maintain heat for almost 24 hours. I seldom need more that 12 hours of consistent heat. I will stat with 45 ml and add or reduce to the amount as needed. I also am a senior citizen and have time to think of these important matters. Thanks for sharing.

Jim

If you use VM&P naphtha which is what Jon'e Handwarmer Fuel is at least that's what it says on the Jon'e can, you can buy the fuel for around $10 a gallon. As a retired old Fart, even I can afford that!!
***How can I upload a picture of the original Jon'e instructions? Please advise!

Indeed any Naptha will work, and it goes under numerous names, EG: white gas, aviation fuel, etc. I read somewhere last week in a forum where some Muppet said that methyl alcohol worked great. I think he must have been drinking it rather than putting it in his handwarmer, then hallucinating.

It's common with these Forums that they do not host images on their own server due to the cost of server storage. So that means placing them on a cloud drive and putting an embed link into your post. I've been using Amazon S3 for my cloud backup and website hosting for over a decade as it is dirt cheap (you only pay for what you use). But I think you can use almost any cloud storage, many of which are free.

The problem with being retired (which has only been the past 2 weeks), is it is no longer easy for me to cruise through all the local campgrounds while working and collect all the free camping fuel the wasteful campers leave behind.

Does anyone know the dimensions of the proper spring(s) to retrofit the Jon-e GI? I have catalyst material and only need a spring or two which I'm hoping to source from Lowe's.