Wood-gas stove for the BPL Trapper Mug, Part 3

Today, instead of cleaning all day like I should have been doing... I decided to go test some hypothesizes I had on my wood burning stove. The main hypothesis I had was that it was starving for oxygen as the stove burned for longer periods of time. The reason for this thought was that initially the stove would burn fine, than after five minutes or so it would slowly die down and smolder. In the earlier stages say 5 to 10 minutes you could add some thin tinder and blow a little on the coals and it would flare back up. The longer that the stove burned for the harder it would become to "relight" the stove. This equated out to the complication of never getting my water to a boil. I also noticed that every so often the updraft would flare flames between the lid and the burn box. So I epoxied the 2 parts together hoping that it would permanently seal the 2 parts together.

Yesterday, I placed 4 small holes semi-equidistant from each other, approximately half way up the burn box. I also took a look at the outer can and decided to slightly boost the available air intake by removing the sections between the holes to make 4 semi-equidistant large intake holes with a regular sized hole in between each large hole.(think of it as forming a + sign of large holes, one large hole at the point of each plus sign.) The burn was a lot better after these modifications, but as the fire burned longer it would still become difficult to revive the flame if the fire died down to a smolder. After the burn I JB Welded the lid and the burn box together to help seal and eliminate the leak between the parts.

Today, I cut 2 grooves in between each of the 4 mid height burn holes at the base of the burn box. Hoping that this would help increase the flow of air to the base of the fire and ultimately increase the ability to revive the fire after I threw too much wood in the burn box, or after it just smoldered down to coals. After a trial run it proved to greatly help the fire rehabilitation after it died down. The fire barely took a breeze from my breath and the fire would self revive and flare back up. The fire was a lot more consistent and became a lot easier to keep a good flame going strong. Initially in order to keep the flame going I would have to be using paper thin sticks only. With the lower and midway holes I was able to start using pencil thick sticks to fuel the stove, which reduced the frequency of which I had to feed the stove, but it still needs a constant tending due to the small burn box. The JB weld was a waste though, since the fire exceeds the temperature rating of the JB weld and it started to bubble and eventually failed.

Don't mind my the dyslexia, I initially did not plan on making a video out of this... So I was supervising the cats, tending a fire, videoing and trying to think while talking with no preparation...


The mid height burn holes and the first slots for the lower vent holes.

Here you can see the elongated holes in the base of the stove, I have sticks abound broken and ready for starting the stove.

The stove loaded and you can see the fire starter on top of the wood stack and the little bridge above. Which will be ignited by the fire starter and drop down and ignite the rest of the wood. The twin wall design stoves operate with an updraft in the outer wall creating convection currents sucking the air into the outer wall, through the holes to fuel the fire. After much research and lots of trial runs this method has been the most effective at quickly starting and preheating the inner wall to start the convection currents on these small stoves.
Prepared for the burn.
Here is the final lower venting setup. If I were to make another one I would drill the vent holes in before I removed the can's base, since there is not enough structure to push against in order to drill the holes without the base of the can I just used the cut off wheel on my dremel to turn the slots into triangles.


After the video test run, I enlarged the holes near the base of the burn can and ran a burn without the pot. With the larger holes I was able to start using pinky width sticks after the fire was good and hot. Granted you still need to be mixing in a lot of small wiry sticks and pencil sized sticks with the larger sticks to keep the flame burning hot. Using the larger sticks though helped lower the amount of constant feeding that was required in the earlier prototypes, but it still needs constant tending and watching. I'm pretty happy with where this model has gone and I'm very glad that I kept with it and didn't give up. The only thing left to tinker with is the height of the pot stand and take the final weight measurements. The next major step is an actual field test along the trail at a cozy campsite after I'm tired from walking... Only then will I be able to tell if I want to keep this as a potential stove for fair weather to moderate weather trips where wood will be plentiful. We'll see how the field testing goes...

The present weight of the stove without a windscreen or pot support is 2.6 oz. So figure the final weight will be between 3.0 to 3.5 oz with a windscreen and pot support.

Warning! Playing with fire and tools can be dangerous! This post is for informational purposes only. Using any of these methods, or using a fire, a stove or tools can cause health hazards, injury or death!!! Use this information at your own risk.

Wood-gas Stove for the BPL Trapper mug Part 2

The other week I got a few more minutes to play with the stove designs in an attempt to get them to work a little more efficiently. I'll be getting less time over the next few months since Fall quarter of college starts on the 28th of September.

I took Prototype 1 and shortened the outer can by 1" to get the bottom of the burn box a little closer to the base of the stove and to see how it performs with getting the hot coals closer to the actual fire. Since they fall through the grate as they become ash. I also revised the mesh on the bottom of the burn box as I had previously intended. I used a 1/2" wire fence mesh from Home Depot, which was also used to make the pot support. I was tempted to get the 1/4" mesh... but I went with the standard 1/2" mesh for weight and the fact that is what it appears most stove builders use for pot stands as well. After cutting the bottom of the outer can, without my hydraulic press was fairly hard to get the base of the can to press neatly onto the can. I dented the outer can and partially crushed it... I straightened it back out with a pair of pliers and turned the lid inside out and worked it back onto the bottom of the out can. With some help of the pliers I managed to get everything to fit fairly snug back together.

The next model revision (prototype 2.0) I made was to use the same standard sized peach/soup can and use a Campbell Tomato Soup can for the inner fire box. Figuring it would allow me to use the full depth of the peaches can, by giving me an extra 1/2" of length and a 1/2" wider for the fire box. I took a different approach to the holes on this stove. Instead of marking to drill every 1" and using a 1/2" drill bit, which was than augured out to be ~ a 3/4" hole as I used on the original can... I marked ever half inch and drilled a 3/8" hole which I augured out to ~ a 1/2" hole. I figured I'd try more holes at a smaller size... I used a similar procedure as part 1 to make the burn box and installed the wire mesh and put the stove together.

The 1" cut mark for the the first prototype.
The start of prototype 2.0
The soup can nested into the peach can.
The old burn box next to the new burn box.
The cheesy wire grate before replacement in ver. 1.0, and the wire grate in ver. 2.0
The stoves side by side.
Testing... The new design smoldered a lot and I could barely get it to even get a couple minutes of good burn time... Which has been a fairly consistent problem with both designs, yet it was definitely amplified with this model. Some of it might be my choice of wood, but I think these stoves are slightly suffocating due to the small amount of ventilation and their small burn box size. Which gets full and I can see where O2 movement could be a problem. I need to play with the oxygen delivery systems on the inner can first, I think I'll add a couple holes lower on the burn box to help fuel the fire mid can. Prototype 1.1 burned a lot better, but I still had trouble getting a consistent burn, granted it was a little better.

Trapper mug, stove 1.1, stove 2.0
Stove 2.0 with the new pot stand.

The next plan is to do a little more research, and play with the O2 delivery (add a few holes to the inner can at a little lower level, and maybe some mods to the outer can holes as well). I might also cut down the tomato can to fit into the shorter can as well. I'm not going to give up quite yet, but I might reroute my design to a larger stove if I can't figure out a way to get this stove to burn better. There might just not be enough distance between the walls on the second stove... But only tinkering and testing will tell... Nothing like smelling like a camp fire at the end of the day!

Warning! Playing with fire and tools can be dangerous! This post is for informational purposes only. Using any of these methods, or using a fire, a stove or tools can cause health hazards, injury or death!!! Use this information at your own risk.

Wood-gas Stove for the BPL Trapper Mug, Prototype 1 (mini-me1)

So I've been eyeballing wood-gas stoves for awhile and even came across some great plans on BPL MYOG forums for a 5.5oz wood-gas stove. The problems for me was it was on the heavy side, materials weren't going to be cheap, and it suggested I buy some special tool from Harbor Freight. Granted the special tool would of made my job of tinkering easier and cleaner, but I didn't have the money or time to buy the extra expenditures. The other problem is that it wouldn't nest in my Trapper mug or a Tibetan Tiatanium 700ml mug, which is what I'm contemplating getting for longer trips. Therefore it would take up even more space in my preferred little pack. The thought of going on a long trip and not having to carry any fuel really intrigued me. I could start gathering sticks along the trail on the way into camp or wherever I was going to be cooking.

The project started with scouting out the cupboard for any combination of cans that might actually nest into the mug and would be able to be fit into each other to create the stove. I didn't really have a weight that I was shooting for with this project, but I wanted it to be light and functional. Since I haven't really played with wood-gas stoves I also didn't want to be out a lot of money if I didn't really like the idea.

I found a Hunt's Tomato Paste can and an Alberstson's Peaches can. They seemed to be about the right dimensions to work and the large can would nest into the Trapper mug. Did I know if the tomato paste container was really large enough for a burn box... nope... but that is what tinkering is all about, finding out what works and what doesn't. You have to try it to find out for sure.

The final weight is 2.5 oz. without the pot support. I haven't made one that is staying yet, so it could affect the actual final weight.

Cost:
A couple dollars worth of cans and some of your time if you already have tools lying around the house.

Materials Required:
2 nestable cans
A plan
A cutting tool (dremel or something that you can use)
Possibly some JB weld
A drill or some form of metal punch
A side cutting safety can opener

The Hunt's Tomato Paste can on top of the Albertson's Sliced Peach can. Here I traced out the small can onto the lid of the large can to mark the hole for cutting.
Here I cut off a lid off of each can. The lid that was removed from the large can do not discard! It was the one that the smaller can was traced onto and it will be reused.
I set the lid that was removed from the large can back onto the can and used a cutting wheel on a dremel to cut just inside of the line that was previously drawn onto the lid.
The center was then removed from the lid. Since we cut to the inside of the line we allowed room to trim the lid to form fit to the small can. You can discard the center piece that was cut out.
I than trimmed the left over portion of the lid ring from the small can's open side.
Using a small grinding adapter on a dremel I slowly smoothed out the cut from the large can's lid until it was just at the inside of the line I drew. Don't remove too much material, because you want a tight fit with the little can.
When you get the cut smoothed out to the line, start test fitting sliding the small can into the hole. At the first sign that it will fit very snugly slide the 2 pieces together. Remove the parts and drill the holes as stated below for the small can, than you can cut off the other lid remaining on the small can. At this point if you made the hole tight enough you don't really need to epoxy the 2 parts together. If you didn't take your time to make the hole tight you can use some JB weld or any other chemical that you feel safe with to bond the 2 parts together. I used JB weld even though mine was a very tight fit, but I got hasty and lit it way before the JB Weld was dry and it cracked, dried up and did not bond. I won't be re-bonding it because I made it such a tight fit.
I left out the cutting of the holes because that is what I will be playing with until I get this guy to burn well. Basically I found the largest size drill bit that I had, measured out 1" intervals along the top side of the small can just low enough to be just below the top of the small can. I used a punch to mark the holes and to keep the drill from wobbling. I started with a small bit and slowly stepped up the size until I finally reached the largest size. I did the same with the large can but moved the holes up from the bottom of the can so that 3/4 of each hole was above the base of the inner can. After the holes are drilled remove and discard the other lid on the small can. Than remove the bottom lid of the large can and keep it. The large can's lid will be used as a base to protect the ground from the fire and will make the stove self contained during the burn. Which will help reduce the chance of catching anything else on fire along the way.

First ignition.
A makeshift pot support, which will not be used in further testing. I need to get a wire mesh pot support that allows the air to flow a little. The closed off design helped stifle the flame at times.
The stove nested into the BPL Trapper mug.
All the parts disassembled after the hour burn. I didn't take a close up of the wire mesh that was put on the base of the small can to hold the wood inside the burn box. The reason for that is that it was a very makeshift assortment of metal fencing rods and it will not be in the final design. I'll be using the same wire mesh that the pot support will be made out of for the bottom of the small can.

Far left is the inner burning box, in the middle is the large outer can, on the right is the trapper mug and the base of the wood burning stove.
As stated previously this is prototype #1, I still need to play with the holes on the outer can to try and get a more efficient burn. I will be changing the makeshift pot support and the wire at the bottom of the burn can. I also noticed that the type of wood also made a large difference on how it burns. The small twigs don't seem to matter when burning through the bark, but the slightly larger sticks need to be stripped of bark. Another idea that I will be investigating is finding an aquarium tube and using it to help blow air into the fire when it starts to smolder or die down so that I'm not huffing in the smoke fumes. After a couple more burns and some more dialing in I'll post another thread on the revisions and further thoughts on the mini-me wood burning stove.

Warning! Playing with fire and tools can be dangerous! This post is for informational purposes only. Using any of these methods, or using a fire, a stove or tools can cause health hazards, injury or death!!! Use this information at your own risk.

MYOG Rain Wrap

Well, I've been eyeballing the ULA Rain Wrap for awhile, but figured I'd embark on making my own since I found a scrap piece of sharkskin gray silnylon that was nearly the exact dimensions I needed. I only needed to trim off a couple inches to square off an edge. On backpacking gear test I found enough information to back engineer the wrap to my specifications.

The great thing about this piece of gear is that it is a multi-function piece of gear. It can be used for a ground cloth for all my gear that won't fit inside my bivy, and as a piece of very breathable rain gear for moderate to hot temperatures. The problem lies with if and when I get around to doing really long distance hiking like the PCT it is too see through to use as a modesty wrap for doing laundry at a laundry mat. I'll have to make another one in a darker color.

Materials Required:
31"x64" piece of silnylon
about 60" of 1/4" elastic (will be trimmed shorter but is easier to install if it's longer)
3/4" velcro
a grommet
micro cord lock.

Dimensions for your own reverse design can be had at the above link and find the first review of the ULA Rain Wrap. Here's some pictures of my rendition of the Rain Wrap.

The rain wrap/kilt laying out open in ground sheet mode. It can be used to set gear on under a tarp, or to sit on mid day while having lunch...


The wrong side or inside of the wrap/kilts built in stuff sack.


Standing in front of a fan with the optional velcro attachment not in use.


Standing with the optional lower velcro closure closed. The double layer up front is supposed to be good for allowing you to use the wrap as a modesty wrap when you are doing laundry at a laundry mat on a long hike. Albeit in sharkskin gray the Silnylon is kind of thin, and before I get the chance to do any super long hikes I'll make one in a darker color.


Stuffed into the internal stuff sack.


Compressed in the Internal stuff sack.

Golite Ultra20 Quick Adjust Strap Modification

Quick adjust and removable elastic cinch straps.



Lets face it, The Ultra20 quilt has a lot of potential for the quilt user on a budget, but the strap adjustments really suck. How I would love to have the money to burn and buy a Nunatak Arc Alpinist quilt, but at 1/2 to 1/3 the cost the Ultra20 is unbeatable in it's class. For the cold sleeper it may not take you down to 20 degrees; but for the warm sleeper who knows how to add insulation layers in colder weather it will take them down to 20 degrees. I have only had mine down to around 36 degrees with only boxers on, and I was sweating to death at several points. A lot of the heat retention is also determined by the insulating pad that you choose, since a lot of your heat is also lost to the ground.

The biggest downfall to the Ultra20 quilt is the inability to easily adjust the straps to reduce or increase the amount of ventilation through out the night. In this post I will go over a quick adjustment system that will allow you to easily cinch or loosen the straps to your sleeping pad as the night goes on. In another post I will go over some techniques I have learned to vent the quilt and stay warm.

Initial Weight of the Straps
0.65 oz
The New Weight of the Straps:
0.25 oz

Materials Required:
2 yds a 3/32" elastic cord
2 micro cordlocks.

Directions:
1) First if you have slept with the straps on your quilt before and already have them adjusted to where they fit on your sleeping pad on cold nights... Just remove them, but set them aside clipped. You can use this as an approximate length for your new straps.

2) Stretch out the closed factory straps (doubled over) to find an approximate length for the new straps. Add about 6 inches of length to the elastic cord over the length of the old straps and cut. (if you have not used your straps before measure out approximately 30" and cut the cord.)


3) Make a loop on one end of the cord. This will allow you to remove the straps for warmer trips when the cords are unnecessary.


4) Install a micro cord lock onto the line opposite of the side that you just made the loop. Make a double or triple nonslip knot (just like the knot that you use to start tying your shoe except 20 it 2 to 3 times on top of the knot) at the end of the cord on the toggle end. Make sure the knot will not pass through the cordlock.


5)Which ever side of the quilt that you want to be able to adjust the straps on, tie a 4" piece of elastic cord using the same type of nonslip knot used in step 4. Make sure there is just enough room to stuff the toggle through the cord loop you have created. If it is too tight you will not be able to remove or install the straps and it is too loose the straps won't work well.
The picture shows the cord and cord lock through the loop from step 5. If done correctly there is still enough stretch to the loop the Toggle can be removed.


6) On the opposite side of the knot and loop that you made in step 5 feed the cord through the factory stitched loop. Now take the toggle end and feed it through the loop you made on the cord.


Pull it on through to tighten it to the quilt loop.


7 )Feed the Toggle through the adjacent sides cord loop.


8)Trim all excess cord from the knots you tied and singe the ends so that the cord does not fray.



9) Repeat steps 1 through 8 for the other strap.

Now the quilt girth can be adjusted by a pull and toggle adjustment on a stationary cord. Where as on the original design the adjuster floats wherever under you and is a serious pain to find when you are half asleep and getting a cold draft.

MYOG 5yds to SUL Tarp and Alacart Bivy Build

On the ever increasing desire to lighten my pack, I decided to embark on building a new tarp and bivy with all the options included for trips where I don't need to carry a 2 person tarptent. I almost made the tarp out of cuben fiber, but I decided that I need to start simple with cuben since supposedly sewing it excessively weakens the strong fabric. So I'll try a cuben shelter at a later date.

The Tarp:
For the tarp I decided on Spinntex .08oz a yd fabric. It's silicon impregnated like 1.1oz Silnylon except that it is silicon impregnated polyester. Supposedly it is a little louder, a little lighter and doesn't sag as much in wet and cold conditions. The plans came from the BPL 5yds to SUL project. The tarp came out to be 7.9oz with 48' of Aircore Nano guylines and quick adjusters, plus 2 oz of stakes... 9.9oz as carried. So at .8 oz for the guyline kit, the tarp by itself is roughly 7.1oz. The stuff sack weighs .15oz. This project gave me a ton of practice with felled seams and made me become fairly good at sewing felled seams...

Spinnaker stuff sack.


Tarp layed out for the beak attachment.


Playing around with trying to get a good taught pitch.




The hangline clips and hang line for wet gear.





Things to complement the tarp build:
I'll probably make a very lightweight and small bug bivy that will attach to the clothesline clips. It should allow more breathablity in hot weather and the ability to go lighter in good weather or below the tree line in buggy conditions.

The Bivy:
Well I wanted all the options but I didn't want to pay much over $70... MLD has some similar bivies in the $200 range... I wanted a side zip for easy entry, bug netting for skeeter season... It started out with an RS180 bivy pattern, I shortened the hood by 8", and widened the pattern by 3 inches in the shoulders and hips area to increase room for the neoair. I eliminated the velcro closure and stiff bill with an overlapping flap in favor of a full closure zipper with side zip and zippered skeeter netting. I also added tie out points for the bathtub floor at all 4 corners, so when the weather hits the fan I have the option of guying out the bivy to the tarp stakes to create a storm proof floor.



With a sleeping bag and Neoair inside the bivy.



In buggy season mode.


Side zip open for entering and exiting the bivy in bug mode.


Side zip open for entering and exiting in rainy conditions.


closed up for normal rain conditions.



The Combo, Tarp and Bivy in use in Spider Meadows.