# Fire Piston



## davedirt

Well got one for christmas........Buffalow horn model.


----------



## T.P.

Pics.....

You tried it yet??


----------



## davedirt

Yes I did and it amazes everyone........


----------



## Slingblade

You using char cloth or tinder fungus with it?


----------



## RBM

I have several of these metal fire pistons. This one is a four inch model.






The plans came from the now dead site burghscouts.com. If you want the .pdf file for the plans, send me a pm and I will try to e-mail the file to you as an attachment. The file is too large to attach here or I would do it. It is not hard to build with common tools and all the parts are available at the local hardware store. No lathes or special equipment. Probably costs around $10.


----------



## fishinfart

Hey guys - What the heck is a fire piston?


----------



## dawg2

fishinfart said:


> Hey guys - What the heck is a fire piston?



http://www.wildersol.com/

I have a couple from these guys above.  Very cool.


----------



## RBM

I have a Model T built from the plans on the site below. I am working on a short or mini Model T at four inches that is actually finished but in the epoxy curing stage (full strength in 24 hours) before I can test it. The metal fire piston above works great but the coal is small and must be transferred to light a larger piece of char inside a tinder bundle in order to generate enough heat to light the bundle. These things are fun and great around the house or for camping in controlled conditions but as I have said before I would not stake my life on one in emergencies or in the woods in uncontrolled conditions where compression (loss of) and tinder (lack of, and/or not dry enough) problems will spell doom for it. Bottom line, buy a disposable pocket butane lighter for a little over a dollar for emergencies or if going to the woods.

Update. The mini Model T at four inches does work. Lit a good sized coal with it that should be large enough for transfer to a tinder bundle. May post a pic if I can sometime.

Model "T" Fire Piston


----------



## RBM

Here are the photos of the four inch Mini Model T. A couple of notes. I would not recommend keeping the lube in the handle storage compartment. It can turn into a big mess in hot weather. I put spare O-rings or gasket material in one handle compartment and tinder in the other. I just keep a tube of ChapStick for O-ring or gasket lube. I seal the wooden plunger with epoxy so there will be no water absorption or wood swelling that might possibly be a problem. It is a much smaller piston (four inches) than the original (nine inches) and with a tinder cup (no deeper than 1/8 inch deep) it produces a larger coal (and easier to access) than a small 1/4 inch drill hole at 3/8 inch deep.


----------



## RBM

Here is the latest update for a bump.


----------



## RBM

I am working on a 3.5 inch aluminum piston now and that has been a real challenge to make even with tube and rod blanks. Aluminum deforms and scars badly due to its softness. It is lightweight but probably not the best material to work with for this.

I have been trying to get some polycarbonate tube and rod blanks and that is also proving to be a challenge. Just getting polycarbonate from a site (company) that will take mail orders. The polycarbonate is not transparent but translucent and it does allow distorted viewing of the ignition and that is what they are used for, demos. Polycarbonate is the strongest and most heat resistant of plastics but after a coal is lit, it would be best to immediately drop the coal out rather than blowing on it as with other materials because the plastic will melt. Not from the ignition but once the coal is burning. Acrylic and plexiglass are plastics that have not proven to be as reliable as polycarbonate. They may work (see the catastrophic failures in the link below) temporarily but not long term unless they are in pristine condition. At least this is my understanding from what I have read. Here is a good article on it.

Some Thoughts on Fire Pistons

Take care using some materials as catastrophic failure can be very dangerous when materials are under extreme pressure.

This link has plans for a large size polycarbonate fire piston from MAKE Magazine.

The Fire Piston


----------



## RBM

The 3.5 inch aluminum fire piston with the cross-bore tinder cup works. I built it on a 3/8"OD rod and a 3/8"IDX1/2"OD tube. ID is inside diameter and OD is outside diameter. Aluminum is dirty to work with but the piston works. I don't have pics of it but it has no handle. I just use the tube to push down with while the plunger is upright on a hard flat surface. It does feel kind of strange (I think its the material that makes it feel slow) when firing it although there is compression and the plunger rebounds in the tube from the air pressure. I would not want to make another from aluminum. Let's just say there were many problems and a whole lot of work. 

This is the best supplier for polycarbonate I have found so far and they do take mail orders. Polycarbonate is not real expensive but.....a processing fee (orders<$50) and shipping makes it way too much. If anybody runs across a reasonable dealer, please let me know. Thanks.

Interstate Plastics

Never mind. Its a bit pricey at $27.16 but Wally World can order it.

American Lighting LLC 8' Colored Polycarbonate Tube

Or Wayfair where Wally World gets it from.

American Lighting LLC 8' Colored Polycarbonate Tube

For those fortunate enough to have lathes, mills, and drill presses, traditional wood pistons can be made from such high density woods as Coco Bolo, Osage Orange, Iron Wood, and the like. Or animal horn like Water Buffalo horn. The very earliest pistons used Bamboo. Or pistons can be machined from many different materials. As mentioned above, pistons can be ordered from dealers. Its just too much fun and challenging actually making them myself rather than buying them. I do have a bought traditional Coco Bolo string gasket piston but I need to return it sometime because it has failed to fire for me.


----------



## RBM

RBM said:
			
		

> For those fortunate enough to have lathes, mills, and drill presses, traditional wood pistons can be made from such high density woods as Coco Bolo, Osage Orange, Iron Wood, and the like. Or animal horn like Water Buffalo horn. The very earliest pistons used Bamboo. Or pistons can be machined from many different materials. As mentioned above, pistons can be ordered from dealers. Its just too much fun and challenging actually making them myself rather than buying them. I do have a bought traditional Coco Bolo string gasket piston but I need to return it sometime because it has failed to fire for me.



I think my bought traditional Coco Bolo piston has an uneven and/or enlarged bore or tube causing the problem. They can be made by hand as below but the amount of time and work in the videos below speaks for itself.

A native Making an Aboriginal Fire piston
Part 1
http://www.youtube.com/watch?v=5NKq4ChNOew&feature=channel_page

Part 2
http://www.youtube.com/watch?v=yK2yqcKdUZc&feature=channel


----------



## RBM

I now have two 3.5 inch working polycarbonate fire pistons. I just plugged one end of the poly tube with .5 inch wood dowel plug, epoxied of course. The plunger is a wooden dowel at a tad (1/16 inch) under 3 inches with a wooden handle (cut from a wooden broom handle). I epoxied the wooden plunger (wiping excess off) to seal the wood most importantly to make the wood air-tight but it also waterproofs it. They have a cross-bore and O-ring. Really neat to actually see the ignition. Even better because I can see what is going on with the O-ring and the tinder at the bottom of the tube seeing the air compression. The clear tube allows me to fit the plunger better. They weigh practically nothing.

Will post pics when I can get some taken, transferred, and uploaded.


----------



## westcobbdog

I like the pvc rig you made RBM, that is awesome. Got to try that.


----------



## RBM

westcobbdog said:
			
		

> I like the pvc rig you made RBM, that is awesome. Got to try that.



That one is a four inch model I just call it a Mini Model T. Just follow the Model T link instructions for everything, but instead of making it the original nine inches, do a four inch. It is important that you use all CPVC parts, not PVC.

When I am giving inches for the length of the pistons, I am referring to the tube length. This does not include any handles. So it is not overall length I am referring to. The plunger is usually about 1/16 inch shorter than the bottom of the tube at the end cap or the plug. However, both the tube and the plunger of the aluminum piston below is 3.5 inches exactly. Because aluminum is metal rather than wood I don't worry about damage to the plunger end striking the bottom of the tube if compression is ever lost. You can clearly see the 1/16 inch gap between the wood plug and the wood plunger end of the poly piston below. A piece of thread is placed under the O-ring allowing the plunger to be carried in the tube for storage because it allows air under the O-ring breaking compression.

Here are the photos of both the 3.5 inch aluminum piston and the 3.5 inch polycarbonate piston.


----------



## lcopeland22

saw on here a while back where someone used a mini mag light.


----------



## RBM

To all you fellas out there making your own homemade pistons, if you take your time with it covering each step in the process then you should have fewer or no mistakes and a better piston. Pistons have to be air-tight. No air leaks. I have had tiny leaks due to my own faulty sealing that while I had air compression it was not enough to light tinder. So I had to redo it. The good news is that loss of air compression only happen in two places, at the bottom of the tube if it has an end cap or plug and at the O-ring or gasket (pay close attention to the O-ring/gasket groove). Not hard to track the air leak down either with water or by the sound of escaping air. Once material is removed it cannot be put back so remove a little at time checking for tight fit constantly.

Most woods that are not dense enough have to be sealed with epoxy, super glue, or some air-tight glue. The porousness of most woods allows air to escape. Keep that in mind when using wood dowels for plungers and plugs.

If I can build these things with tube and rod blanks and with common tools and epoxy, so can anybody. You will run into problems at some point, just reason it out following the given instructions and keep at it. These common tube and rod materials are not expensive so starting over if need be is not a catastrophe. Good luck to you and show us your finished homemade piston photos.

I do want to talk about fire piston tinder. Here are a few links on it.

http://www.primalconnection.com/3c3FTindersForYourFirePiston.html

http://minifirepistons.com/tinder.htm

Take a look at all of the links on this link page.

http://wildwoodsurvival.com/survival/fire/tinder/index.html

The reality of a lot of the natural unprocessed tinders for pistons is that they are so difficult to light that they can be impractical. I can fire a piston over and over and never get a lit coal. Char (a processed material) either cloth or spongy punk wood is what I use the most out of necessity. I live in an area where there is often high humidity that takes its toll on finding natural tinder that is dry "enough" to use. I continue to test natural tinders in the piston though and so should you to find what works best in your area.

From my own natural tinder experience, I have tried many. Unprocessed elderberry pith lit in the piston but burned up too fast to use for a smoldering coal. Elderberry is also toxic so I would avoid using it. I have used yucca pith, dryer lint, cotton, dog fennel pith, palmetto fiber, cattail fluff, bushy bluestem fluff, thistle fluff, willow fluff, punkwood, punktree paperbark (or Melaleuca), and even dried rabbit dung (droppings) among many others. None worked. The plant fluff or down burned up and did not smolder just like the elderberry pith even when packed. I thought the idea of using dried rabbit dung (essentially tightly packed dried plant material) would have been a good one since dung smolders when lit but I wonder if I could get it dry "enough." Yes its disgusting but dung works as a good fire extender smoldering just like a tightly packed cattail head.

One other that is not listed that has possibilities is dead and dry leaf petioles, that is the stem of a leaf. It needs to be spongy like punkwood. Some of the natural tinders that are listed above as ones that are suppose to work can have moisture in them when collected (so they don't work right away) but may be usable after drying them out. Some must be in the "right" stage of decomposition.

Clean and dry plunger tinder cups making sure no lube or water is in the cup before loading tinder. Make sure your fingers are dry when handling tinder. Do not get any lube or water on tinder. Damp or lubricated tinder will not light.


----------



## RBM

Here is another homemade piston I found just searching. Plans use metric measurements though rather than English measurements.

How to Make a Simple Fire Piston
Out of Hardward Store Material


----------



## RBM

I also have a working 3.5 inch string gasket polycarbonate end bore piston like the one on the primitiveways link above. The dimensions are similar in size just in English units. For the wood plunger, 3/16 inch from the end bore (end bore tinder cup is also 3/16 deep) is the first deeper groove, and the length of the shallow string groove is 7/16 to the last deeper groove. That's it. I use about a five strand cotton string. Your results for string thickness will vary by how deep your gasket groove is. String gaskets must be tight to get the compression, both in the wrapping with the wraps tight against each other, and the gasket itself must be a very tight and even fit in the tube. Lube will help seal the string and allow the plunger to move in the tube (reduce friction).

The trick is to test fit the string gasket on the plunger as you go. Wet the string, then wrap tightly with tight fitting wraps using your finger to push each wrap up against the other until the entire gasket groove of the plunger is filled. With the plunger, work the gasket twisting it in the string winding direction a little at a time until the whole gasket conforms to the tube and fits in the tube. If its too thick it won't fit into the tube. It is possible to get it so tight that it cannot be removed from the tube so you don't want it that tight. Then lube the gasket and it will probably take several applications so that the plunger will move in the tube. Once you fire the plunger it will be difficult to pull the plunger out due to the tight fit but a tight fit ensures the necessary compression. You can use any natural fiber string for the gasket. Cotton, Jute, bark fiber, and so on. Avoid synthetic or man-made fibers if possible as they can be coarse and score or etch the inside of a piston tube preventing the smooth operation of the plunger. The traditional string gasket can be a pain in the neck to put it mildly but it does work.

Sorry for the shaky camerawork this time.


----------



## RBM

Fooling around in Michaels craft store the other day, I put together another homemade piston. Got two permanent markers, one has an thin aluminum tube and one has a thick plastic tube. The aluminum marker has a smaller diameter than the plastic one. The idea was to put the thin and fragile aluminum tube into the plastic tube. I had to ream out the plastic tube and it is very difficult to ream out plastic with common tools. But I epoxied the aluminum tube into the plastic tube with a tight fit and without deforming the aluminum tube. The plastic tube provides strength and impact resistance for the thin aluminum tube. The aluminum tube provides a superior seal and heat resistance. The tubes already had bottoms on them so I did not have to plug or cap them. I picked up a few wood dowels and used a sanded down a 7/16 inch dowel for the plunger until I got a tight fit in the aluminum tube. The aluminum tube turned out to be about 3/8 inch diameter and 3-3/8 inches long. Anyway, I went 1/8 inch from the end bore of the plunger for the first deeper groove and 1/4 inch to the last deeper groove for the string gasket groove. I had a scrap Scrub Hickory piece around so I used that for a handle on the plunger. Sealed the entire plunger with epoxy and a curing time of about 12 hrs. It is important to wait 12 to 24 hrs. for the curing time or the wood will not be sealed.

I first tried a Yucca string gasket but did not get a good seal with it after numerous attempts of various string gasket thicknesses. Then I tried a Jute string gasket but had a hard time getting a length that would not pull apart into pieces. So I put a six strand cotton string on the plunger and finally got a good tight seal with some lip balm for lube. I have a good air cushion and plunger rebound in the tube that I look for when trying to fit the gasket for a good tight seal. I had problems with the end bore retaining the tinder (both char cloth and char punkwood). I had tinder in the bottom of the tube to clean out and the tinder kept falling out or popping out of the end bore. These are even more reasons why I do not carry a fire piston in the field beyond the tinder and compression problems. Its easy to solve these problems at home or camping but not when I need the piston to work and it doesn't in the woods. I could spend hours on trying to get the piston to work when I could already have made a firebow set and have a fire going. When everything does work right with the piston it is way too easy to light though. This homemade "craft" piston does work. I got a coal with it using char cloth after packing a lot of it in the end bore so none would come out. I have tried to light char punkwood in it but have not been able to light it. The double tube does heat up and get pretty hot down at the tube bottom from the air compression but it is strong enough, heat resistant enough, and I had no tube failure.

Oh and the cost of the piston parts I figure to be just under five dollars but a lot of work. The funny thing is I have tried to set up this piston with my own style of "DuoSeal" so this piston will take either an O-ring or a string gasket. I have yet to fire it with the O-ring that fits in the first deeper groove of the string gasket groove and that will come next. Here are some pics so far and again I had some shakiness due to trying to catch the piston with a glowing coal while blowing on it and taking the photo all at the same time. You can see the double tube of the aluminum tube in the plastic tube in the second photo.


----------



## RBM

Update on the "craft" piston. Had a major setback. When the thin aluminum tube heated up from the air compression I guess its thinness caused it to expand. The diameter of the aluminum tube expanded from the heat of the compression meaning I will have to either make another plunger or toss the tube. Add to the fact that due to the expansion of the tube and the looseness of the plunger, I cracked the plunger while firing it. So I would not recommend anyone use these materials for a homemade fire piston. This was a failure due to the inferior materials used but it was worth a try.


----------

