Pocket rocket air flow issue

Hi all,
I built a small pocket rocket to take to a couple of camping events I do a year.
It is a 25L oil drum like this (Oil drum picture) and some ~ 3 inch diameter flex exhaust (Exhaust picture), I put a couple cm thick layer of clay perlite, but now re-thinking this. The pipe stops about an inch or two off the bottom. I find that is is very hard to maintain a good burn. I have been able to maintain the cherry red at the inlet for maybe 20 mins. The small sticks (maybe an inch thick) tend to burn quickly and fall to the bottom meaning that the airflow although not stopped is restricted and the 'rocket' stops. Also if I try to progress to 2 inch sticks it seems to burn too slowly and starts to smoke again. Any help would be appreciated.

Many thanks

John

John Dyer : I would consider your work so far an experimental model and plan on moving on to a slightly bigger pocket rocket and regular Black wood stove pipe.

While on this page (rocket stoves ) I went to the Permies Toolbox at the top of the page a selected Search, on the next page I typed pocket rocket
in the search engine , and have selected a couple of threads with pictures to help others follow your build !

Links below :

https://permies.com/t/29586/rocket-stoves/gallon-pocket-rocket-barrel-heater

https://permies.com/t/21830/rocket-stoves/Pocket-Rocket

Note that some of these treads have links !

Pocket rockets are problematical in that they work SO Well they quickly Oxidize/rust, and the challenge is to spend as little money as possible with each new re-build !

Dry wood ash or sand or pumice or a layer of clay perlite on the bottom will help save both the bottom of your barrel and keep you from setting afire the blacktop drive
or the ground at your favorite camp site . Other Insulation on the outside of the pocket rocket will only quicken its rusting out /failure.

Generally for use outside, 3 or 4 steel fence posts spaced 6-8 inches out from your drum and wrapped in chicken wire should prevent accidental contact and still allow
you to feed your Pocket Rocket !

While Pocket Rockets seem to be only off or ON you can slow them down ether by underfeeding once the rocket is hot or by over loading the feed tube with wood and
restricting the amount of air Your pocket rocket can draw.

Always burn the driest wood you can- allowing for the insulating material on the bottom of your drum a 2'' air gap should be big enough with 4''-5'' pipe !

Think like Fire ! Flow like a Gas ! Don't be a Marshmallow ! For the good of the Craft ! Big AL

One more link :

https://permies.com/t/43625/introductions/Universal

Enjoy the camping ! A. L.

Allen, thanks for all the advice. It was really experimental as I chose the flexi pipe for the exhaust as it would allow me to bend it over and fit in the back of my car. After following the links it would seem that air flow is truly more of an issue than I thought. I'll dismantle the current one and enlarge the CSA to make it work properly.

Cheers for the help

John Dyer : With care you should be able to use a pocket rocket for a camping season, some re-building is usually possible, The Pocket Rocket is much
loved by Zombie Hunters 'Prep'ers and Ice Fisher persons and those on picket lines !

Put in a 55 gal plastic bag or wrapped up in an old tarp and loaded into the car they can then be stuffed full of other camping gear to cut down on wasted
space.

Keept in your garage handy for power failures, a more lasting and useful arrangement would be to make a cage 6'' - 8'' outside your pocket rocket with
a latice form of openly stacked bricks or blocks !

And a final link, not as portable :

https://permies.com/t/25974/rocket-stoves/tea-stump-stove-plans

Clear Skys ! Big AL