Intro: A Lightweight Backbacking Pot Using Sugru, and a 24 Oz Can
It's not a new idea to use a 24oz can as an ultra-lightweight backpacking pot. This instruction shows how to modify a can using Sugru to make it more effective and useful!
If you're new to Sugru, it's a material that is moldable and cures to a hard silicone just by exposure to air (moisture). It is heat/cold resistant and sticks to stuff really well. One caveat - the package says that some people may have skin sensitivity to the uncured sugru. I didn't have any problems, but who knows?
This hack focuses on making the pot more functional when it's hot. A bare aluminum can that you just boiled something in is too hot to hold. It's also uncomfortable to put your lips to a burning hot can, if you care to drink your soup or tea from the pot. Also, we can make it a little easier to handle the pot lid.
For those interested, the total pot+lid weight is estimated to be 1.36 oz, or ~39 grams. As a comparison, the Snow Peak Titanium Trek 700 (24 oz volume) pot with lid weighs 4.25 oz.
Step 1: Materials
1 large aluminum can (24oz is a pretty good size for a pot)
2 .17oz (5g) satchets of Sugru (they come in packs of 6 or 12)
Smooth-edge can opener
Scissors (for opening the sugru).
That's it! Pretty simple, right?
Step 2: Modify the Can to Be a Small Pot
Take a smooth edge can opener, and cut the top of the can off. This is a special kind of can opener - it won't work well to use a regular one. You can see mine in the picture.
The top will serve as a lid while the pot is heating up - so keep it, and try to keep it nice. I made the mistake of drinking the contents of the can first :) Now there's a big hole in the top. Oh well - it still works pretty well. I would recommend taking the top off first, then drinking the contents.
At any rate - the can opener leaves the lip at the top very clean, and also leaves the top such that it rests nicely in the lid.
Step 3: Hack It With Sugru!
This is where all the fun comes
It's time to hack it with Sugru. As an overview, the my goals are:
1. A way to protect my lips from the hot aluminum when I'm drinking out of it.
2. A way to hold the pot when it's too hot to hold the bare aluminum.
3. A way to handle the lid.
The first thing I attempted was the lip-protector.
Note: I learned after the project was done that the sugru website says "sugru isn’t suitable for use in direct or prolonged contact with food." An official response to whether or not this is okay was:
"sugru isn't food grade so we can't advise that it be used in anything that comes in direct contact with food / your mouth... I'm not sure about this though as I guess it's only in contact with the outside of your lip. I guess you have to make your own judgement on it depending on how it is practically in use..."
An alternative is to use a silicone wristband around the top. It will add 5g to the total weight, and it is generally food-safe. The other alternative - skip the lip protector, It's not crucial to the project, and you'll save 5g, or put that extra sugru into thicker grip spots!
The lip-protection took one of the .17 oz packs of sugru. I learned a few things attempting this. If you choose to use sugru for this, here's how I did it:
1. Roll the sugru into a snake, and wrapping it around the can. That was pretty effective, but then I struggled to get it to spread evenly.
2. Spread the sugru around. The trick to spreading it is to smear the sugru, rather than trying to just mush it around. Smearing worked really well to get it most of the way. I learned a little late that all you need is water + soap to keep it from sticking to something (like your fingers).
3. So once you get it smeared evenly, smooth it out by whetting your finger with soap and water, and work it until it is satisfactory. I could have made it a lot prettier. But I was happy with it.
Step 4: Pot Holders
Second, create hand holds/pot holders for when the pot is really hot. This took most of a second pack of sugru.
1. Assess where to put the sugru to make the pot easy to hold when it's hot. My fingers fit really well on opposite sides of the can.
2. Make a mark for where to put a thumb spot on one side, and a finger spot on the other side.
3. Split the sugru into two large chunks, and set a small chunk to the side for the lid handle.
4. Work the sugru to create a circle for the thumb spot, and an oval for the fingers.
5. Press the two pieces of sugru onto the spots you've marked for the finger and thumb.
6. Mold the sugru to fit your fingers, and thumb. This part makes a pretty big difference. Custom molding it to your own fingers makes it much more effective! I decided to put ridges on them so that you don't have to hold the pot entirely by squeezing the sides (the ridges let you rest some of the weight on your fingers. )
7. Smear the edges down to the can so that nothing will catch the thumb and finger spots when it's in your pack.
8. Smooth it out to your liking, or texture it to your liking, to make it easier to hold the can.
Step 5: Lid Handle
Third goal: a lid-handle.
1. Take the tab off of the can top.
2. Grab the left over sugru from the last step.
3. Press your small piece of sugru onto the small circle that was holding the tab.
4. Mold to your preferred shape. I ended up making it pretty thin, which is fine. I think next time I will try a different shape because it's a bit flimsy and I'm worried something will catch on it in my pack and tear it off. But it works great so far!
That's the last step. Onto the next page for results and observations.
Step 6: Results and Observations
After it cured for 24 hours, I boiled some water in the pot on my backpacking stove. I figured this was about as hot as it needed to get to test the Sugru's heat resistance. The package says it's heat resistant to 160 Celsius, which is 320 Fahrenheit. That is well above the boiling temperature.
1. Lid-holder: this performed perfectly. It was large enough to grip, and pull the top off, but didn't heat up too hot to hold even when the pot was at a full boil. Next time I might make it even smaller. I'm slightly concerned that it will get roughed-up in a backpack.
2. Lip-protection layer of Sugru: Effective. I was able to use the can to drink out of, without discomfort to my lips, when the water was still hot enough to burn my tongue (oops!). I could definitely eat or drink out of this pot without burning my lips.
3. The pot holder spots: Effective. They were cool enough to touch way before the aluminum was, and well before the water was cool enough to drink. When the pot was at a full boil, I could touch them long enough to pull the can off the stove. It's not a perfect heat insulator, but it is effective enough. I consider that successful. The one design flaw I would improve on next time is to add a top-ridge to the finger spot.
The heat resistance of the Sugru turned out to be about as good as you get from a silicone hot mit. I've used a silicone mit to take cans out of boiling water (for canning), and it gets pretty hot after you've had it in the boiling water for a bit. The same is true for the Sugru. I don't think you can avoid it.
Overall: The addition of sugru only added .34 oz to the already ultralight pot (1.02 oz). The weight addition is definitely worth the added comfort that the Sugru brings.
A heineken can is 1.02 oz, or 29 grams. Adding the .34 oz brings the total up to 1.36 oz, or ~39 grams for your pot.
So there it is. An aluminum can and some sugru makes a nice backpacking pot!