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Flame thrower tinkering

Blacksheep10

Well-known member
Joined
May 19, 2020
Member Number
91
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447
I’ve had 2 threads recently asking for a source of a few parts. My first question was about 18v to a 12v efi inline pump. Tuesday evening I janked together an old spare e2000, a mig tip, an 18v drill base and a gas can with electrical tape and hose clamps. Worked amazingly well for a 3 hour build. It just wasn’t safe. At all.
Ordered a bunch of crap on Amazon Wednesday and for most of it Friday evening. After pouring concrete all morning and drinking beer watching it get hard in the afternoon, I got to the version 2.0 flamethrower this evening. My second thread was about where to get a specific isobutane torch. You guys found that torch, but it didn’t fit a budget build. I also wanted an electronic ignition that only hit when you’re on the trigger. We experimented Thursday with a 20-12v buck transformer and a high voltage pulse generator. It sounds like a taser and throws a hell of an arc. Fired the old flamethrower with it and it worked. We also burnt up the pulse generator that night with too large a gap and too much input voltage. Ordered another and also another buck transformer to go down to 6v.
My buddy gave me a few old air packs. Luckily top (bottom in scba config) valve is 8mb. I had a 8mb-6mj fitting laying around and it ran right in. Some 6an lines and fittings and the inlet to the pump was connected to the backpack of fuel. On the output side of the pump, I wanted a check ball. The old pump would siphon and leak all over when left sitting down. To have room I bought the m14 din fitting, “fashioned” a coupling nut and put the spring and ball inside. The other end of the lug nut...I mean coupling nut I put an oil drain plug and drilled/tapped the center to 1/4-28. It fits a mig tip. Started with .035.
I’m about $150 all in. I could trim some stuff down and change a few things and make it cheaper. I’m also looking at how to refine the chassis design. To be more attractive. This was just to see if all the parts ply nicely together. Hopefully soon I’ll clean up the execution but it felt good to have it kick ass right out of the gate.

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What I need now is a spring loaded cover/protector on the momentary button /trigger. On the normal butane pilot ones you accidentally hit the go switch and it squirts some fuel out. This one being self igniting, you set it on the button and it’s fucking go time.

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The part in your hand is sub 10lbs. The tank is pretty damn heavy. I do have several vids, can we host those here? I need to set up an account somewhere?
 
hell yea, i need to rig up a good brush burner myself.
with the original one, I had it done quickly with crap I had laying around. If you just want to control burn it’s fast and simple. I have a good vid of us trimming thorns off a locust tree with it.

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The part in your hand is sub 10lbs. The tank is pretty damn heavy.

why don't you use one of those plastic 6 gallon boat gas tanks?
be easy enough to stuff an in-tank pump into one through the filler hole
couple bolts with holes tapped in their heads for the wires, presto
 
If I wanted more pressurized hose I’d do a co2 setup. I have lots of backpack scba setups. I wanted a fuel pump style with tip sealed close. I’ve had an erroneously loose fuel fitting spray and cause a fire in a race, rather not while it’s on my back. Or my sons back.

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Electronic ignition needs more work. Burned up another taser module. Pulled an audible and went back to the shop and mounted my map torch. I still want an isobutane torch that isn’t $60 and unavailable. Light and long lasting. We also rode 110’s and onewheels all day, so even if the flamethrower wasn’t 100%, the trees and creek were still fun.

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If I wanted more pressurized hose I’d do a co2 setup. I have lots of backpack scba setups. I wanted a fuel pump style with tip sealed close. I’ve had an erroneously loose fuel fitting spray and cause a fire in a race, rather not while it’s on my back. Or my sons back.
I can dig it
I've thought about a propane-pressurized one
propane because then I can use it for the igniter torch, too. Just one of the little throwaway piezo ignition plumbers torches
 
[486 said:
;n232456]
I can dig it
I've thought about a propane-pressurized one
propane because then I can use it for the igniter torch, too. Just one of the little throwaway piezo ignition plumbers torches
I can see that, propane is what, 150 psi without looking it up. Either way that still a flammable gas left open if the igniter is off. Heavier than air and can soak in clothes. Diesel with enough gas to make it flare has worked well thus far. Not “flammable” per se but lots of btu’s under the right conditions (above flash point). I’ll keep going on this path and refining. The tig’d lug nut check valve adapter chokes flow just enough that this iteration doesn’t have the distance. It also flares more even with a similar mixture. Will play with tip size etc.
 
I can see that, propane is what, 150 psi without looking it up.

eh, extremely variable pressure, based on temp
not using the propane as fuel for anything but the torch, I'd be spraying diesel, possibly mixed with used oil
 
I've always thought about making a really small flamethrower as in something easily held in your hand and worn on your wrist. Would be a great Subway self-defense item. Oh I should give you my wallet? Eat flames. I have a bunch of components that I have accumulated. Was thinking of using a blood pressure cuff for its air compressor and several CO2 cartridges as pressure reservoirs.
 
I'm still on the phone with the Ham radio guy and we determined that the buzz coil has to be the most robust setup with the most off the shelf parts.
He is going out to the shop to attempt to recreate it just with the relay alone and will report back.

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I've always thought about making a really small flamethrower as in something easily held in your hand and worn on your wrist. Would be a great Subway self-defense item.
Would be a great bear defense item! I can't see any animal ignoring fire...

I want a 12ga foregrip with a pressurized flammable pepper solution forced through a boat horn orifice with an igniter. Anything that can get past 000 buck, 110db horn, pepperspray, and fire deserves lunch. :laughing:
 
Oh, and in before some nerd decides this needs an Arduino bluetoothed to their phone.
 
I'm still on the phone with the Ham radio guy and we determined that the buzz coil has to be the most robust setup with the most off the shelf parts.
He is going out to the shop to attempt to recreate it just with the relay alone and will report back.

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He just sent me a video of it chooching, buzzs like a mofo. That seems like ignition is sorted then. Cheapest ign coil and a 30a relay for spark.
 
Oh, and in before some nerd decides this needs an Arduino bluetoothed to their phone.
Too late, already suggested it in the other thread, I don't think its needed though.
time delay for fuel pump could be done with a NTC thermistor maybe to limit inrush current momentarily.

 
Since I made this thread Ive added a prefilter so its all AN from tank to pump. Also a flush trigger button, the one in the pic above would get bumped and you were burning shit. I've also redone the check ball housing on the lathe and it work great. The whole thing is easy to use and works well, it would be easier if the bakpack were lighter.
 
I missed this the first go round. I have been dreaming up something similar for a long time. I really can't imagine where I could use one around here, anywhere that is remote enough to not get seen is also a tinderbox. Might be able to use it on a boat on the Sacramento river.:lmao:

We once made a water nozzle out of an old V8 pushrod and it had an incredibly smooth stream with no dribbling out to a very long range, always thought one would make a good flamethrower nozzle.
 
I'm still on the phone with the Ham radio guy and we determined that the buzz coil has to be the most robust setup with the most off the shelf parts.
He is going out to the shop to attempt to recreate it just with the relay alone and will report back.

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Get a Model T coil. 6 volts and available off the shelf.
 
Get a Model T coil. 6 volts and available off the shelf.
I'm curious, is there any advantage to a old school "canister" style coil versus say an LS coil?

As for 6 volts, I was thinking of running everything off of 12 volts with a voltage reducer to drop from 18 volts to 12ish volts.

Slightly less likely to fry coils, fuel pumps and relays that way and everything is on the same voltage.

Or are you saying to run a 6 volt coil on 12 volts so you get a hotter spark than out of a 12 volt coil on 12 volts?

Aaron Z
 
I'm curious, is there any advantage to a old school "canister" style coil versus say an LS coil?

As for 6 volts, I was thinking of running everything off of 12 volts with a voltage reducer to drop from 18 volts to 12ish volts.

Slightly less likely to fry coils, fuel pumps and relays that way and everything is on the same voltage.

Or are you saying to run a 6 volt coil on 12 volts so you get a hotter spark than out of a 12 volt coil on 12 volts?

Aaron Z
A canister type coil if fine. They are just autotransformers - a common ground so only 3 connections instead of 4.

A Model T coil will run off 12 volts. It's just a buzzbox so your parts count will go down.
 
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