Stainless or mild steal?

Hello again,

I did my first long run on the gasified yesterday after a little redesign based on the wood gasifier bible. My original design was actually built to run almost a 2 litre engine! I’ve scaled it down and I’m going for around 600cc now which should be fine for what I need it for.

I ran it for around 6 hours and it went great, the cooling system in place was slowly built when I was running the bigger system so the gas was ice cold before it hit my filter and I got an amazing blue flame straight though the day.

Only one issue (which happened about 5 minutes before the end of my run!!). I have a 10mm mild steel bar running through the top of the gasifier and loosely attached to the grate, this works as a grate shaker and also an agitator to stop bridging. The bar it’s self melted in half! The question I have is am I better replacing this with stainless, going for mild again or something else?

The gasifier bible I guess would recommend stainless but I’ve seen a few differences of option on here and want to ensure I make the best replacement.

Thanks, much appreciated.



That is a good question. In my opinion you better dont stick anything trough the bed for this reason. The good thing is you developed enough heat to meld the steel.
On the other hand, Tone has some good results with his gasifier. His secret is cooling of the pipe …. Correct me please if I am wrong. Still a student, no master.


Stainless and gasifiers dont like each other much…

Joep, the reason why Tone has sucsess is he has the nozzle in a reducing athmosphere. Its not the heat that does damage, usualy, its the oxigen. Just like with a cutting torch.

I agree thugh, better to not stick anything in there.


Thanks, that is why I am still a student. And a slow one :grinning:


I agree with what has been said.
Stainless steel will not buy you much time used with a rod down thru it all as you are doing.

Go back to the Gasifiers Builders Bible and see imho the best grate activator styles will be up from the center bottom. Other use and have used this VesaM, early GEK visions, ect. It does gas seal primarily because of the downward weight on just a simple flange surface buried down in ash.
Low down in-from-the-side grate mechanisms will always require some type of movable compression sealing. These wear. And then later leak air. This air sucked in burns up your made gasses.

Upper system hopper hanging ups anti-bridging again in mho is best done with peripheral upwards heating from angled up air nozzles. And other means as that Builders Book shows with it’s Pyrolysis Accelerator gas heating ring.
Some use outside mechanical viberators. Takes a command motor, eccentric weight, and a power supply. With the vibration sooner or later the metals fatigue, cracking and breaking. Hard learned experiences there.

SS/acid-proof metals in a woodgasifier is for long term useable Life corrosions resistance. Not heart of the beast heat magic. There has been crucible-foundry use patent super expensive magic metals developed for that. Not DIY affordable.
Heat magic in the core is self -forming ash insulation or as Tone is doing air flow cooling.

Ha! Ha! Make your down rod a hollow tube transferring heat by all of the system needed air; it would survive. Australian Kurt Johannson and others did this.
But then an air nozzles heat from the center out machine. The “fix” makes for other problems to cope with then.

Good deal on your good gas sucess now.
Another rule-of-thumb is if you are core hot enough to damaged exposed metals you have arrived to hot enough now.
Steve unruh


Stainless has a lower melting point and it will oxidize just as fast as mild steel.


Thanks everyone,

Long term I’m planning on veering away from this, it was something I saw a while back (at the beginning of my build) and thought it seemed practical (instead of a side mounted shaker).

I’m running the gasifier I have built at the moment so I just wanted a temporary fix, adding a new side or bottom mounted grate shaker seems like a lot of work for temporary use giving the unit is sealed.

The new gasifier housing and components should arrive next week and I can start the new build (with out the rod thought the hearth!)

Is titanium or carbon fibre any good, just for short term use, 3/4 weeks?




Hmm. I cannot say on the titanium for use in a gasifer.

But I do have some very severe conditions titanium use experiences.
I have acid skin that corrosed most metal except some SS’s; pure chromium; good gold; or titanium. I actually will rot off plastic wristwatch bands.
Previously I once has a pair of titanium made-in Italy eyeglasses frames so good I had them re-lensed three times in 12 years. My new this week eye glass frames are ALL titanium made-in-Japan. Nose pads, earpieces and all. Hurruh! No more green grown metals and cracked turned white plastics.

And I’ve has an almost all titanium pistol deep carry sweated and soaked for years that held up as well as the previous all SS pistols.
All-most all titanium because the manufacturer did use an SS barrel liner. So, I expect their testing proved a gas cutting erosion problem in chambers fire and turbulence throats with titanium.


Hi Ashley , 6 hours is fantastic , was that 6 hours of flare or generator/engine ? any photo’s or video ?
All the best Dave


Thanks, Titanium is supposed to with stand up to 3000C. I’ve ordered a new bar so I’ll give it a go and see.

Dave, yes, I have a few videos… but I still haven’t made my YouTube account (crazy as I’m on it everyday!!) I did get one picture and I’ll get the YouTube account set up soon. The run was all flare I’ve ordered the generator but I’m just waiting for the delivery date to be confirmed.

Matt, would you recommend making the entire new system from mild steel? The book recommends certain parts being in stainless but if it has a lower melting point I can’t see the benefit.



The picture was taken right at the end of the run and still seems to be very clean


Flare looks great to me Ashley , hope your generator arrives soon .



Stainless steels are corrosion resistant and to some extent will do better than carbon steels In an oxidizing high temperature environment

Inconel 625 barb fittings if you can find some

Often you can get an American pipe to thread on a BSP coupling. Use nickel based anti seize or you will never the bugger to unscrew


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Unfortunaly, titanium is the worst for this. Extremely inert in room temperature conditions but completely useless above 600c. Becomes extremely reactive, can even catch on fire. Also its melting point is at 3000ish F, not C. Thats 1700ish C.

Best candidate is high carbon steel, kinda like what Tone uses (pneumatic rock drill bits). But still it will not last long.


Nice clean looking flare, your getting good at the wood gas engineering, I think after hearing SS not any higher temp rating than mild steel, I would just make the hopper and outer hearh housing out of SS, and just keep the rest mild steel replacables. ON my WK truck heat exchanger i might use SS om that outer, if i insulate with fiber blanket from the inturnal heat, Good luck with the generator, and learning the 75% operator & 25% gasifier.I got a 20 HP engine i might try gasifying for generator, if i can gererate enough heat too cook out the tars, HOPEFULLY,