Instructables
This is an easy way to make a fire piston. A fire piston is a method of creating a fire by compressing air, causing heat, and igniting some tinder! More info on the fire piston.

DISCLAIMER:

I AM NOT RESPONSIBLE FOR ANY ACCIDENTS CAUSED OR RELATED TO THIS INSTRUCTABLE.
 
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Step 4: Assembling the chamber

To assemble the chamber, grab your J-B Weld, hex cap, and steel pipe nipple. Mix up just enough J-B Weld to fill the hex cap up about half way. Also, put some in the steel pipe nipple. Screw the steel pipe nipple onto the hex cap. Take your dowel and pack/tap the J-B Weld down in the chamber. After you have packed/tapped the J-B Weld down, set the chamber upright in a safe place for the night so it can dry.
Morpheus2 months ago

This is awesome! I made one and it worked first time! The only changes I made were using a much longer bolt with a short thread. I cut the threaded end off, and didn't have to worry about filling the threads. I followed all the rest of the instructions as listed (I did use a silicone o-ring). A great 'ible, even two years on...

fetech1 year ago
Have you thought of using an appropriate sized eye bolt instead of a carriage bolt?
awesome
salomon1996 (author)  fetech1 year ago
I guess I would prefer the Carriage Bolt. You could sure try an eye bolt, but wouldn't the eye be in the way? Interesting to try though.
My thought was that one could get a better retraction pull by using the eye of the bolt. Just mental attempt at a better mouse trap.
salomon1996 (author)  fetech1 year ago
True, maybe one could just somehow make it more comfortable to push downward.
mikaleda2 years ago
you could use a lower grade bolt and it would be easier to drill it doesn't need to be a super hard bolt
salomon1996 (author)  mikaleda1 year ago
True.
godoggie2 years ago
One thing to keep in mind is that the petroleum jelly will eat away at the O-ring with time. Since this is simple to take apart, it would not be hard to replace, so it's ok. Good 'ible!
salomon1996 (author)  godoggie2 years ago
Thanks much! :D
did not work. AT ALL.
Why did you need to use J-B weld for this? Why can't you just screw on the cap, or maybe use a bit of gorilla glue/pipe dope to get it completely airtight?
salomon1996 (author)  masterbuilder2 years ago
Gorilla glue or pipe dope would most likely also work, J-B Weld was just what I used.
Thanks for posting; it worked out great. I filled the thread on the bolt with epoxy it made it easier to cut nice round grooves with my dremel and make it drag less on the down stroke. Also added an extra O-ring and polished the bore of the cylinder.
I found that by holding the top of the carriage bolt to the ground with two fingers and holding on to the cylinder part I can get a 90% success rate with most tinder materials. holding it in this fashion it is just alot easier to get a fast down stroke, hold for a second, and quickly remove the cylinder to expose the ember. This also keeps the ember from falling out if it's small and allows you to slowly blow it into an intense ember without having to move the piston around. So if you're working with crummy tinder you'll have a greater chance of blowing on it before it goes out.
salomon1996 (author)  1337gallagher2 years ago
Your welcome! Glad it worked and good ideas with the epoxy and extra O-ring and the technic for holding it! Could you post some photos of the O-rings? I'm curious about that one! :D
B2BSurvivor2 years ago
AWESOME! I have been looking for a simple plan to make an inexpensive fire piston. Yours is great, and well laid out. Excellent "instructable" !
salomon1996 (author)  B2BSurvivor2 years ago
Thank you much! :D
streetrod52 years ago
Good Instructable! - I'll try this, but I'm going to clamp the bolt into my vice, or clamp it flat to my steel table before drilling the end hole. It would also work to tack weld the bolt to the steel table (and grind it smooth later), but I think just using a C-clamp lying on the floor, I would put myself in the ER. Do you think plumbers' silicone grease would work on the O-ring?
salomon1996 (author)  streetrod52 years ago
LoL! :P

I tried some copier fuser roller silicone oil and it works GREAT! :D It's really thick and slick. I'm not sure if there is a lot of difference between plumbers' silicone grease and this stuff, but they are both silicone, so it should work, I would think. :)
malsonc2 years ago
Great Instructable! I have a couple of questions however. You are using a 3/8" bolt, but you say to grind the threads down to 7/16" - am I missing something? It seems like you would need a 1/2" bolt to have enough material to reduce it to 7/16".

The other question concerns the composition of your O-ring. If it is a common rubber O-ring, then petroleum jelly will cause it to breakdown prematurely. If it is a silicon rubber O-ring then you are OK. If it IS a common rubber O-ring I would suggest a silicon grease instead of the Vaseline.

I'm definitely going to try this when I can get back into my shop. I know I have all the parts there - it will just be a matter of finding them since the move.

Thanks again!
salomon1996 (author)  malsonc2 years ago
Thanks for pointing that out! I will try to figure that out... :P

That is some good information!

Your welcome! :D
jamilks2 years ago
Salomon, aloha~

Thanks for the fine Instructable! I'll have to try this one out....it helps that I have access to a lathe but you make it very do-able with common tools!
Question: is the purpose of the epoxy just to seal the cap to the pipe or is it to provide a solid base for the stroke?
salomon1996 (author)  jamilks2 years ago
Your welcome! :D

It is mostly for keeping it air tight.
good, I would think just buying a threaded end cap would be easier. I was trying to think of how a threaded end cap would NOT work here. I guess there's really no reason to use the epoxy unless the hardware store is otherwise out of stock.

I would venture a guess that the more expensive "seamless" type of steel pipe (contrast "welded") would be less likely to have the ridge down the inside that needs to be removed. That looked like a lot of work from over here.
salomon1996 (author)  kill-a-watt2 years ago
Ya, if you can find a seamless one, go for it! :P It would save you time and work! :D
Phil B2 years ago
Thank you. I appreciate it that you used very common items easy to find. I would like to try this sometime. I could see making one for the preschool at our church. Using it to start a fire would make an interesting demonstration for the kids. I would like to try this.
salomon1996 (author)  Phil B2 years ago
Your Welcome! :D I hope that if you do make it and use it for a demonstration that it will go well! :D God Bless!