Thanks Kristijan, I know how you mean about jumping in with both feet with no experience. Ive been guilty of that all my life- but thats how I learn- by innovation- not by copying. I don’t want to do what has been done when I can see what the results are already. You are right that a heavy steel wall burn pot will hold a lot of heat- but I know that refactory mix does the same. Thank you for taking the time to offer these comments.
The fuel is an easy fix, Ill remove it and crush and grade it. Ive just started making a rotary trommel- It will get used lots for other jobs too. Mushroom substrate preparation - compost prep. I have a lot going on here.
The fan pressure is dismal! The draught exiting the flare pipe is not enough to flutter a cigarette paper.
Is anyone here running double fans ? I could go parallel or in series.I wonder which would have more effect? the simplest way would be to insert an inline bilge blower straight after the squirrel cage blower in line and immediately entering the flare tube?
Idealy you want a nice mix of fine and corse particles, you want the voids between larger peaces to be filled with finer stuff if that makes sence.
I understand your thod process perfectly as l was the same. Not so much anymore, l learnt it suits me better to skip things up and stand on the sholders of people before me.
You can also just use an compressor to blow air in the intake. You can get huge airflows that way (venturi effect). A temporairy test solution
Yes - that was my first thought- but was nervous about causing a ‘woof’ - my partner is watching from behind the curtains. I must remain to appear competent haha. Tomorrow I will do this- then the booster blower if it improves. Ive played lots with forced air oil burners- https://youtu.be/A-KYIjcucrY
Stuie,
I’m very much with Kristijan. Learn from others mistakes. Life is too short to make them all yourself. We could try building our projects out of rocks and trees, but I’d rather not. Well, I guess trees are not so bad. Still a lot of work though.
Squirrel cage blowers aren’t really the best for a gasifier IMO, something like an inline bilge blower or a shopvac would be better at least for testing. Bilge blowers are what most of the truck and car guys use.
LOL. My pipe gasifier did that for me. I looked at @k_vanlooken’s Some school Thailand thread and made my old Briggs geni run the very first time. I had no blower of any kind. I just used the suction from the engine. That old time mixture screw allowed me to wean it off liquid fuel as the gas started to come in. I came away feeling that I couldn’t miss. But I realized later that one MUST have at least 24 inches of char above the nozzle for it to work. As @KristijanL says 1/8-3/4 inch char works best, but I started with 1/2- 1-1/2 and it worked. I only got ~20 minutes run time at first, but as I screened out fines and added fresh char to the used, smaller pieces run times got a little longer.
Rindert
P.S. I had I cyclone filter on there at first but got rid of it later. Not needed.
Morning Rindert- Its howling with wind and lashing rain here so I won’t be out there. Im pleased with the cooling effect of the cyclone, It’s stripping out the condensation well.- Granted- If I had not stored my char outside in the rain then I would have less moisture. My region is known for its high rainfall and constant 70% moisture. Now that I am a ‘Pyrologist’ 
I have to up my game. Ill build a roof, a trommel and Ill copy Matt’s char retort design that uses the flare to heat itself. Then I’ll have decent fuel.
Next- get a decent fan on board. As I was building it I was dubious that the 3 amp fan could pull though all that pipework- I discovered ages ago that when you slightly restrict the inlet of a squirrel cage fan - you absolutely kill the output. Thats why I questioned earlier why negative pressure is used. This weeks farmers market income will get misappropriated and spent on a big 4" inline fan
Thanks to everyone’s help Im understanding more and more.
Save time go to big W or Kmart and buy a mattress inflator pump , or make a injector with your compressor , charcoal lights so easy and makes gas pretty damn fast so i would look at changing other area’s first , remember charcoal its self is the best insulator so the fastest way to to get some life into your machine would have to start with reducing the size of your charcoal .
The next issue is the 500 ml of condensate , was your charcoal damp ? did you leave it uncovered out side in wet or misty conditions ? I live half way up a mountain and i get low cloud in my garden most mornings everything is wet to the touch ,but my charcoal is in its drums stays dry and very little condensation , i also stopped using a cyclone i think sheep’s wool is one of the best ways at trapping the fine dust , The fan does not need to be as large as a bilge blower for charcoal in my opinion , but maybe your build is so different from the norm .
I am no expert everyone else on this site is smarter than me i can only say what i know from running Charcoal gasifiers that run flat out making power since 2012 and a blink of the eye now running wood gasifiers .
Only change 1 thing at a time .
Dave
Thanks Dave - I appreciate the input- Yes my charcoal was in two fish bins pushed under the Land Rover to stay dry- not successful obviously!- Ive ordered a 10 amp 4" bilge blower- should be big enough to power a small hovercraft lol.
Uggh!- K Mart! I wont shop in a place that has no shop assistants but has 3 security staff on the doors!
Honestly- the air coming out the 50mm flare tube won’t even flutter a cigarette paper!
If this rain stops Ill get out there and shove the compressor hose down its throat - see what I get then
Hey Stu, how far above that center hole of the hearth are your nozzles? I had imagined you’d put the nozzle tips right at the level the terra cotta pot begins.
Just judging from the perspective of the picture, it looks like the nozzles only have a few inches above that hole. Doesn’t give the reaction much distance to reduce through inert char. I’m surprised your gas temps aren’t a lot higher.
The nozzles are 25mm below the top edge of the pot. the pot is 180mm deep
Okay so it was just my eyes playing tricks on me. Sounds good! Yeah I’d work on the fuel before changing anything else in the system for sure. Definitely invest in some drums you can seal up. Maybe if all you’ve got is solid plastic drums, chop the tops and use tarp or garbage bags to cover it up from the rain.
Top Tip!- If you cut those lids off in just the right place ( about 40mm down) then remove about 15mm of the lip left behind- they socket into the barrel and make weather proof lid
Cody l had the same thod. Picture tricked us both.
Stu, once you run the bugs out moisture will not be a problem anymore, but an advantige. Water is “fuel” for the downdraft (!) Gasifier as it reacts with glowing charcoal and gets reduced to Hydrogen. Google water gas. I actualy moisten the char on purpose with about 20% water, no dust and the reaction stays below reactor melting temps while giving hydrogen rich gas.
Had to move my char powered BCS home from a friends place today so l thod l make a video to boost your enthusiasm Stu 
I swear l wasnt drunk 
its just the damn traveling trolly steers couterintuitive and l only drove it once before. Need to rewire the brain. Almost ended in a trench twice today
.
Hi Stuie
IMHO best way to go for charcoal gasifiers: i use 12 V version
and run them on low power with a cheap controller.
You don’t need a big mass flow, Only about 40 gallon/minute for a decent flame .
stuie,
Been thinking. You used a lot of refractory. I know about that stuff from building foundry furnaces. It takes a while to dry. I have used a slow propane flame burning for ~6 hours to dry out an 80 pound furnace. After it is dry it acts better as insulation and the steam won’t be dousing the fire anymore.
Lately I’ve developed the theory that insulation is key. I’m thinking that aircrete with a thin skin of furnace cement toward the heat might be a low cost, low weight, good insulation.
Rindert
I build a lot of stuff out of this stuff. Called Siporex here, a type of aircrete. How is this called elsewere?
Wery insulative, easy to carve and it withstands wery high temps. Also dirt cheap. And light
Haha- very MadMax. anything with rear steer is mad at high speeds. especially worn out agricultural stuff I appreciate your humor and your video. And the aircrete- yes not available where I live , but in the city I have found leftovers of a product called ‘Xcallibre’ Its a 100mm thick building block that I used to make my forge from and also a wood fired pizza/bread oven. Its amazing. This stuff- https://youtu.be/Q_DABzqTCkc
There was 750ml of water in my refractory mix- I only gave it two days to dry so there would have been some moisture still there. It will be a few days till my big 10 amp blower arrives so Ill experiment with compressor and shop vac.
yes there was 750ml of water in my mix- that has to go somewhere. things will be better with the next burn. Ive used this recipe for years. when cured it is lightweight and efficient. Im sure that next fireup will be better with added air and less moisture
fascinating your bcs on charcoal!!