Thread: how does it work - brass blowtorch

G'day Clinton

To light this you need to get a small bit of rag (tee shirt or old jocks) and soak it in kero
Put this on top of bottle in the little depression around where the nozzle is going into bottle
Pressurize till you get fuel spraying out and light rag
This will then Vapourize the fuel and stay alight, this process will take a few minutes
Once you get a flame going you can then just keep the pressure up and to shut down you just open the relief valve

These old girls work a treat, I have a few laying around which I restored
Every time I light one I have to clean it up as the lighting process gets it covered in soot and burnt rags
As long as you clean it up after each use the soot and gunk won't build up to much
These days I just use the oxy torch

Cheers DJ

I always use metho instead of kero, eliminates the black soot and burns with a hotter flame.

If you pump up the pressure till it sprays out the front and then loosen off the release wing nut till it stops then light the rag Let it get hot and you will get then message it is vapourizing then pump up more pressure and it should burst into the hot flame you need.

You need to have a pricker handy they are usually a piece of tinplate with a fine wire about 10mm clamped in the end by bending over the metal. This is to clear the fine hole to get a good ejection of the vapour. Some blowtorches are easier than others to start and keep going.

By the way did anyone see the Collectors show last week with the guy who had a collecting of hundreds of blowlamps in all shapes and sizes.

Ok, thanks.

I can pump up the pressure, but liquid comes out only on the first few pumps. Then it stops coming out - a blockage perhaps?
I can pump it up till I can not force the pump down any more - I reckon this is taking the pressure a bit far anyway.

I take it that by heating the nozzel I'll pre-heat the fuel - so that pressurised vapour comes out, not liquid??

yeah, vaporisation of the kero is the idea.
I have a similar one Seviet (primus) from a hand me down. I was stuck one day with half the dash out of the car and a heater "radiator" (for inside the car) snapped at the solder ... no oxy in site ... sunday evening ... I just had to get it going ... steep learning curve but got there ... I now have a blow torch and a can of map gas for "next time"
I can understand your facination . Good fun project but for $20 a blue can of gas and a blow torch attachment is a hell of a lot quicker and more convenient.

Pretty much what everyone has said and I agree that metho is a better starter. If you want to make it easy and not get the torch dirty... You'll notice the indentation around the top of the tank(where the outlet gland is), just fill that with metho put the blowlamp on a level surface, and light the metho. it gets the heat where you want it to start the kero vapouising properly, and as soon as you get a bit of sizziling close the valve and pump it up! Only use the pricker if the flow of kero slows or stops... These jiggers are not oxy... but they are still very useful tools.
Cheers, Steve.

Ok, thanks.

So, now I think I know a little more:
1. that its meant to be vapour that comes out of the nozzel, not liquid.
2. this is done after the liquid coming up the nozzel gets pre-heted.


How am I going?

Does the blowtorch stop putting out liquid when the bottle is pumped up fully, mine puts out liquid for the first few pumps only.

So, do the rag preheat trick, then I pump it a little more and when it starts burning madly, I pump like crazy and build upthe pressure... turn it off by releasing the pressure with the needle valve.... hope the pressurised kero gas does not ignite when my hand is in the way

Is this sounding about right?

Edit: just saw the other posts.
I think its just a great little tool.... simple and robust engineering/scientific principle. Ijust want to make it work and then wave it around. Then I'll work out if I'll ever actually use it. Not bad for $15.

Clint, I hink you have a blockage. Suggest you empty all the kero, strain then refill. Remove jet and clean, ensure the nozzle is clear with pricker.

Like the other guys say, get your fire in the pre-heat collar ready to go (not lit yet), pump until you see kero dribble out the nozzle, stop pumping immediately. When the kero stops squirting, light the fire and wait.

You may get a couple of little flame throwers, but pretty soon, as the kero is pre heated and the heat causes the pressure to build up, you will get ignited gases coming from the jet.

Give this a minute or so then start to pump up. The flame will grow strong.

Kero blow torches are much better than LPG etc, I beleive they burn much hotter.

Good luck.

I'm with Bodgy, I reckon they are hotter that a standard LPG torch.
Clinton, all correct but as I mentioned earlier you don't really need a rag, just fill the groove with metho and light it....It's much cleaner.

Grryphon's right - no rag, fill the depression with metho and light. No need to pump first, just get the vapourising loop hot, wait until the metho is almost burnt out , then pump, the kero gets into the very hot loop, vapourises and comes out of the jet to be lit by the last of the metho flame. The kero then gets vapourised by the blowlamp flame which by now should be making a healthy roar. As it heats up, increase the pump pressure. The flame should be a light blue and visible for about 10 - 15 cm. If it goes out, no need to remetho it as long as you're quick, you can relight with a match (keeping fingers well out of the way of the outlet mouth) while the vapour coil is still hot.
If the pump doesn't give a continuous stream of kero when it's cold, then you've got bits of cr@p in the tank which is blocking the jet. Pull the jet off and blow out the feed tube then rinse the tank thoroughly, use the pricker GENTLY, you don't want to enlarge the hole, fill with clean kero and try again.
A little bit of oil on the leather pump washer will keep it sealed and make pumping easier.
We used these all the time for burning off paint, heating soldering irons, bending steel strip and copper pipe, plumbing with Yorkshire fittings, in short anywhere you need a lot of heat in a hurry or where you would use a Primus propane torch now, but much cheaper to run. Not hot enough to weld and not controllable enough to braze but will get steel up to red heat easily for bending.
Cheers
Graeme

Oh yeah, one other thing. I've found where ever you're burning metho mix 4:1 with water to get a cleaner burning flame ... ie less soot.

Cool doohickeys aren't they?

And you are right, they 'should' burn hotter than an LPG torch, and if buring the same amount of fuel per hour, will pack a much heavier punch.

And the one you have is a much smaller version of my furnace jobby.


I pressurize this thing before lighting it up, but because the tank is attached to the burner on yours, it's not a good idea to have it up to pressure before it's hot. The heat from preheat will add some pressure to the tank as it is, and you only need to add enough to get it running right.

Hmm, think I might make up a smaller version of the monster for little stuff. Sick of using the gas burner and not having enough oomph.

And a small pic of what the flame 'should look like', albeit on a smaller scale. Mostly blue, maybe heading into purple. Purple is practically perfect, but it's also throwing out lots of UV radiation, so glasses are a must.

thanks to all who have helped me out.

I'll give it a go at lunch time I reckon... depending what 'emergencies' (i.e. someone who can't plan their week decides to make their problem my problem ) suddenly arise.

These things don't seem to sell real often on ePay, lots of listings ending with no bids.... Mine was $15 including postage from S.A.
A cheap way to learn something new, and to have a new to(y)ol to muck about with. Can't wait to make it roar

Post us a photo Clint - without burning your shed down of course.:eek:

I just found the original instruction sheet.
Cheers
Graeme