Troubleshooting pocket rocket to burn paint off a barrel

I can’t seem to get a good down draft from my pocket rocket.

The 6” intake stove pipe is an inch from the bottom of the barrel.

The 6” chimney is 2 inches from the bottom of the barrel.

Idea 1: remove the spark arrestor.  No change.

Idea 2: raise the chimney to be a foot from the bottom of the barrel. No change.

Idea 3: add another 2 ft section of stove pipe to the chimney.  This helped a bit but still not a strong draft. Competing chimney effect.  Photo attached at this step.

Idea 4: add another 2ft section of stove pipe to the chimney. This made it worse.

Idea 5: remove one 2ft section of stove pipe and raise the chimney so that there’s a 1.5-2ft gap between the bottom of the chimney pipe and the bottom of the barrel. Helped a bit.

Idea 6: chimney pipe is too leaky from open screw holes. Plug them or use new stove pipe?

Should I try smaller pieces of wood?
Should I have primed the chimney?
Should I have used an 8” intake/exhaust?
My arms are getting tired of manually trying to change the draft.

After 4 hrs, is there now too much ash buildup? Should I shut it down, clean her up, and try again?

I aim to get a good ‘rocket’ sound and no competing chimney.

What does the other end look like? As in, what are your burn tunnel and heat riser made from, and what are the dimensions? You seem to be doing all the right things on the outlet side so let's suss out the input. [EDIT: I missed the bit about "pocket rocket" and of course there's no burn tunnel or heat riser. D'oh!]

This is another thing I've used stale petrol for in the past. Inevitably I end up getting out the wire wheel.

What seemed to work best was raising the gap at the bottom of the intake by 4 inches and pushing air into the feed using a shop vac. I didn’t have to use a shop vac but it helped bring the temps up from 500/600 to 800/1000.

As you can see from the photo, I was only able to get paint off the bottom 2/3s.

Looks good so far!
I'd try spraying oil onto the outside of the barrel,  filling it with wood and burning it with the lid off.
Add forced air as needed.

Try using a wire brush whizzer in a 4” grinder, takes 40 mins to strip a whole barrel clean.

I believe the chimney isn't suppose to extend into the barrel.

The hot air will be pulled up the chimney so it won't heat the top section of the barrel.

Exactly.

However in my case, even though I have my chimney in the proper position, I’m not getting more than a third at the bottom burning off. The main problem is that the paper dries out really fast and then catches fire before the paint can burn.

Probably the other issue is that the top of the chimney I have has a really narrow piece for fitting it into another section of chimney, if I can figure out a way to remove that then the whole thing will draw better, but I’m not sure I can remove it. Even without that, though, it seems like it’s getting hot enough. It’s just not staying wet long enough for the paper to do its job also, I’m not sure if I should’ve put more clay into the mix for soaking the paper, it looks like I’m just getting water but Hard to tell in the dark now. Maybe I need to slosh the clay water around where to stir up the

Alex Ronan wrote:I believe the chimney isn't suppose to extend into the barrel.

The hot air will be pulled up the chimney so it won't heat the top section of the barrel.

Wrap it in rockwool is another solution from donkey boards. Hm.

Also add waste oil to the fire.  I tried that one first but it’s still not hot enough to do the top part of the barrel without some kind of insulation. I guess I’ll try the rock wool

I found that blowing air into the intake using a shop-vac was unenjoyable yet effective at getting the barrel to burn hot enough (~800degF) to burn 80-90% of the barrel. I recommend hosing yourself down and definitely wearing a respirator.

Note that I left the lid on loose and midway I'd turn the lid so that there weren't cold spots on the barrel.

I stopped wrapping the barrels with paper.

Don't forget a spark arrestor!!

I was able to burn a barrel for 20-30 minutes, let it cool down as I prepped the next barrel, move the lid over and burn the next barrel. I was burning barrels at roughly 1.5hrs per barrel. Results will vary based on fuel source, cardboard packing, etc.

A twisted rope style wire wizzer on the end of a 4” grinder will strip a barrel in less that an hour without pouring pollution into the air.

Fox James wrote:A twisted rope style wire wizzer on the end of a 4” grinder will strip a barrel in less that an hour without pouring pollution into the air.

I've tried all of these options, the one in the middle is what I find works best after a burn but I haven't found that it works well before a burn. Also note that the metal likes to pelt my legs and go into the soles of my shoes.

Is this what you're referring to or something else?

I have also struggled with a lot of options. Without burning it took more than a wire disk. More like sanding it down.
After burning the wire brush worked for me.
Either option is a big mess. I wish there was a better way.

Benjamin Dinkel wrote:I wish there was a better way.

same.

Mineral wool wrapped around  seemed to do the trick, though it released a lot of toxic stuff into the air.  Next time I’m going to do the paper clay layer first and then put the mineral wool over that.

They’re not super specific in the book about how thick of paper should be, but I think I should’ve put several layers of paper, one layer just seemed to dry out super fast and then burn.

Hmmm, dont know what the problem is with a 4” grinder and a wire whizzer, I must of cleaned a dozen or more.
I still managed  to pollute the air though!….

Wow, Fox -- that was a great video!! I'm going to have to rewatch it several times! I think you might have a mighty good point there. I'll have to give that approach another try.

I have used that same brush. But my barrels where the blue type. I think they’re not painted but coated and really tough. It brushed parts off but a part of the “paint” melts to the metal.
Guess I’ll have to try to find different barrels.

What do you do with the ashy paper after? Is it still toxic? Burn again in rocket ? Erica and Ernie, help!

What you probably don’t want to do is forget about it till after the next windy day. Lesson learned.

Hey Joshua, I would dispose of the burnt paper along with any of the ash and coal produced in the process. I’m quite sure neither is safe to use for anything else.
Same goes for the dust created when sanding the residue off.
I was actually thinking of trying to find someone with an industrial sander. That would take care of all the dust and all the particles that I don’t want in my lungs and in my garden.