Here is a question for the Sensei’s.
Hypothetical situation.
It’s the Zombie apocalypse. The defecation has been fed into the thermantidote. Cat’s and Dogs living together, total hysteria.
And the magical red goo that I use to mask my welding mistakes with is no where to be found.
What is a good alternative? Extra bonus points for … non store bought … solutions.
Folks been pyrolyzing for a long time.
How did they seal up in the past?
Thank you.
Tar makes a good sealant, I would guess a piece of tight woven rope soaked in warmed liquid tar may suffice as a hot gasket?
This is actually a good read and good info to learn. I didnt know they put tar in candy?? What??!!!
Welding mistakes leaks in steels just clean well and braze over it. Brass rod. And flux powder.
Clamp together/bolt together joints layered spun fiberglass or mineral wool fibers compressed works well.
Cast iron plates have been joint sealed up for a long time with fine stove cement. Actual cement has varied over time with available materials. Originally no asbestos fiber filler. Then LOTS of asbestos fiber filler. Now no more asbestos.
S.U.
Good to know I’m not the only one that thinks about these things Mark. I suspect many others do but prefer not to look like weirdos. When I started to play around with the bucket simple fires I wanted to make sure a person could build them with just what they could find laying around. Any kind of silicone has a fairly short shelf life. I really like refractory cements like SteveU posted, and a smart builder would stock pile some, along with ceramic blanket, but I also use clay that I dig out of the ground and purify to get rid of the organic matter. Just more work. Some of the best steel ever made was made by Viking sword smiths, starting with raw iron ore in clay furnaces. Even with wood gas makers it is a matter of design compensation.
Now tell me how you are going to get wood glue when the gorilla is no longer on the shelf.
I think Sodium Silicate, otherwise known as “Water Glass” that cures to a high temperature solid has been used. It is used as a binder in foundry sand mold cores. It can be cured with CO2 gas. I am still learning about this. It is a primary ingredient in many home-brew refractory recipes. There are YT videos on how to make it. Maybe a hazardous, but do-able process. You can also purchase it ready-made. I think some of the so-called Ceramic Blanket Stiffener / Rigidizer products may be Sodium Silicate. 
Good old clay from the earth has been used from the beginning of man and gasification prosses. Mixed The clay with tars and pitch and different types of organic fibers like hemp and strong fibers type plants. If it starts to leak pack more on top until the retort prossing is complete for making charcoal. This is still being used today with kilns and ovens for gasification needs.
Bob
Yes. The high temperature red RTV is really just a very recent tool. in the past not so much needed as using instead different forms of asbestos fibers. Worked wonderfully. No more that.
The red h.t. RTV is really just a make-do. A substitute.
Ha! “The Virus” and it’s stop-in-place supply chain freezing made it clear often time you will only have what is already, locally there. Use it up. And done and gone. With then none.
Welding gases.
Welding consumables.
New replacement engine spark plugs.
Learn to clean, file and re-gap. Never as good as new. But good’nuff.
High quality engine lubrication oils.
Learn to filter, de-water, chelate out nasties and re-use. Nope. Not as good as new, use-it, then throw it away. But good’nuff.
Think about it. You can DIY make electrical power much easier than purifying and concentrating out welding gases.
O.K. after years resisting I can MIG now.
Still . . . couple of fellows here on the DOW: J.O., JanA? Tone? or Woodsrunner? say they only stick weld their gasifer builds ups. SS build ups.
Think. Think. Think. Do not lock yourself into only one way. Make good’nuff your motto.
Let the Elites, and the Seekers, chase tail, their purities. Never settling. Insulted by a good’nuff attitude.
S.U.
I have been thinking on this as well Steve, watching truck and forklift parts drying up waiting months at a time to get rigs back on the road out making money. Building everything within the confines of the shop here at work relying on shop supplies. My at home welding equipment not near on par with work goods, if this job were to expire, dry up or better came along, how to further woodgas projects from home. Cant rely on the power grid. Debating a gas powered welder like a big Lincoln ranger Miller Bobcat. Multi use machine, home generating power, mig tig stick multiprocessing. Gasoline power, could be woodgassed? Red high heat silicone is only one thing in a massive project that could go missing, many other things to think about if parts supplies were to start disappearing… has anyone ever woodgassed or char gassed a welder? no way my backup solar power could run a welder, my biggest generator will barely run my 110v Lincoln 100 doing 18g sheet metal. Not sufficient in any way for heavy welding like burn tubes and top plates…
Norman I was amazed ~2009 how well a 17KW Genrac V-twin generator converted to woodgas. Sure could HD weld with that.
Couple of years later I bought a new 12kW Miller Trailblazer in gasoline EFI V-twin. I only ever ran it on gasoline. My intention was to woodgas it. I had 100% confidence it would have worked. This changing place we lived at (with everything public road visible and hearable), I became convinced on an away week; or weekend, it would 4-6 guys walk-away, and be gone. This is happening now to too many of our neighbors.
The fellow I sold it to is a well know woodgaser, charcoal gasifier. He lives 100% off-grid. I am sure he did.
And he later sold it to finance his consumer plastics into diesel engines drop-in fuels project. He then went with a diesel generator instead. He dropped from a relatively quiet, but frenzy 3600rpm to a popping louder, but mellower, 1800rpm.
Trick is to grossly oversize to have the lower make-power on woodgas to be able to still stay voltage and frequency stable.
DO NOT MINIMIZE to save buy-it money. Do not waste time then trying to make a smaller KW system make same power as it did on gasoline or propane.
Them alligators . . . you were just supposed to be welding man.
S.U.
That’s one reason why I bought the biggest generator that Harbor Freight had, the 9kw unit. I expect 6kw on charcoal but maybe even that’s optimistic. I don’t have any heavy kw dependent equipment, my new flux core welder is fairly low power, 2300 watts if I’m to assume it uses the entire 20 amps of 115v it asks for, probably more efficient in 220v mode. I’ll probably have two of these generators come next year one for the house and one for the shop.
youtube search: woodgas welder.
If you are talking about this generator
It will only be good for around 2500 watt sustaining on any wood gas. 3000 to 3500 if you are making optimal gas.
HF over rates some of the units. This one for sure its no more powerful than the 8750 I think they just put a larger carb on the 9000 watt unit or they over clock them. But on woodgas it makes little to no difference between these two units. Been running these generators for years now and they are excellent for woodgas for what they cost cant go wrong on them. But dont have too high expectations. If you 2500 watts sustaining you are doing good 
When you have the option, always run equipment on 220 Cody. I have no idea how the plug on the little inverter welder I’ve been using makes the swap but I always ran my shop saws and equipment on 220
Thanks Matt, it is great you have first hand experience and letting us all know the truth of what you can expect.
Bob
Yeah its supposed to be in the 60’s this Saturday. So this will be a great day to run some wood gas thru an engine!. The victim this time will be my new 8750 Inverter generator running from a 2022 M-2 Mule gasifier. It will be interesting to see if there is a different between it and the older versions.
Side note I am in contact with the manufacturer of these generators and maybe import my own with colors to match. Plus my versions may have the parallel connections and kits available. Im working on getting more details on that as the units they show have this connection in the pics. I am also trying to find out if the DC output can be bypassed and go direct to battery for direct battery charging. I believe the output is 48 to 60 volts DC. Ill be testing mine this weekend. But these are the same generators HF gets.
Yeah if I’m going to lose that much power I should relegate it to battery charging. I run 12v systems though, I’m priced out of the 48v and others higher than 12. Even then though, I’m kinda miffed that the 12v output is the accursed cigarette lighter socket.
Well this is about a 50% loss. Like I said they are over rated. On gasoline those generators are realistically only good for 6 kW running 6.5 kW at best. Not the 7250 or what ever that is claimed. So 3 kW is all that really should be expected and then to add in some cushion for fluctuations; 2500 is the more realistic expectation. You can get 3 to 3.5 kW fairly easily, however in my experience this isnt reliable. Sometimes you can sometimes you cant.
What about with some mild performance mods like shaving the head, etc. I know it then sets you out of the convenience of gasoline unless you get it just right to run on premium only.
Also since it always runs wide open then maybe a cheater cam, unless the cams are already ground for maximum output at top end.
If you plan to run the inverter batt system thats all you need to get more. As long as your average charging is below your average output; you can then of coarse sustain much higher output. For instance my charger is only 800 watts going from my generator to the battery bank. However I can run up to 5kW output as long as there is enough power stored. Really thats the best way to go about it. Nothing wrong with 12 volts. Put your charger right next the batteries and run AC to the charger. Keep the charger, battery’s and inverter as close together as possible and keep your power leads short and you wont have an issue.
Modifying the engines Id have to agree with Steve its not worth it by the time you spend time and effort into beefing up these small engines you are better off just going to a larger one.