Building my own spirit burner.

I have failed to find a suitable spirit burner anywhere for sale so I am going to build my own out of two plumbers 32mm copper end caps. I will use the model plumbing fittings I have purchased from PM Research for the filler cap and brass pipe work. Once suitable holes have been drilled in the end caps for the filler plug and burner pipe, I will silver solder the two halves together.

My question is this : how hot does a spirit burner get ? Do I have to silver solder (650 degrees C melting point) the pipe work too or could I just soft solder it using some 243 degree Celsius solder I have in the solder box ?

Hi Brian,

Presumably you do not anticipate handling it with asbestos gloves!

Soft solder it.

Keith

Hard to comment not knowing the design you intend to use. You say you will silver solder the caps together, if you use soft solder elsewhere and the unit actually gets too hot the results could be a bit messy, to say the least! I would suggest silver solder throughout.

assuming its along the lines of your other one I'd probably silver solder the burner and the pipe that joins it together, silver solder the two pipe caps together and then use soft solder for the rest of the pipe joints and filler, etc. That way you don't have to worry about the caps comming apart while soldering the pipe/filler to it and should the burner ever get that hot the solder inside the bottom of the firebox won't melt.

J

This morning I did all the drilling and tapping. Nothing is soldered yet but you can see what it should look like. To the left in the second photo there is a large brass end cap. When the other fittings arrive from the US then I will use two of these large brass end caps soldered together to build a bigger burner with two wicks.

The copper burner will take 20mls of methylated spirits and the brass burner will take 40mls but should burn at twice the rate. Yes, I know the metho should run out before the water runs dry in the boiler but these burners are for a bigger boiler I am building.

Does anybody in the UK sell those pipe fittings ? The US postage is getting very expensive even for small items.

Edited By Brian John on 02/01/2015 03:50:23

maccmodels.co.uk (advertised in MEW) sells small pipe fittings

Forrest Classics are PM Research dealers so they keep some of their fittings. I also posted a link to EJ Winter in teh insulation thread they keep some of teh fittings and being in Oz the postage should be reasonable.

You will need to have the open end of teh burner at the top level of the liquid in the tank if it is not to drain out so that will want extending if you are going to take advantage of the larger tank capacity. A larger dia at the burner end will also help give more heat due to teh larger flame.

J

Yes, I can see now that this design will not work as it is too high. The column of fluid will push it out of the burner end. I tried filling it with water and that is just what happens.

You could solder a flat disc onto one of the brass threaded caps, would give you the same 20mls capacity but half the height. Or if you can get some larger dia tube just cut a ring and solder on top & bottom plates

Brian

I know some of the guys on the Freesteam forum are into constructing burners maybe worth a visit . http://freesteammamod.myfreeforum.org/index.php

H

Is there any particular reason you're making this out of copper/brass apart from aesthetics? As far as this newbie knows a spirit burner is just a fuel reservoir with a wick and possibly a wick height adjustment. Any design must depend on how hot is gets inside your burner enclosure and if memory serves you had the boiler up on high stands with good ventilation underneath so the eat is unlikely to go down to the fuel reservoir if you built something simple with the flame on top. As a kiddie i made some just using a low tobacco tin with a rope wick out of a tube out of the lid - unscrew to fill.

If you have enough space for the fuel reservoir under your stand then it'd be nice to get some temperature measure under there. These sorts of things are cheap enough http://www.maplin.co.uk/p/infrared-thermometer-with-laser-targeting-n92fx although their accuracy depends on the colour and reflectance of a surface. If the temp is a low as I'd expect then your material choices get wider.. ally, glass, old cans etc

You need a vertical tube for a wick tube that is a fraction higher than the fuel level in the tank.

Ideally the horizontal tube would be steel or stainless to reduce heat conduction, if you get too much heat transferred to the tank, don't be surprised if you get a jet of flame from the breather hole. Your horizontal tube is about right, it will need a wick that goes from a length coiled in the bottom of the tank, along to under the vertical wick.

For my hot air engines, I usually refuel with an eye dropper, 5 to 10 drops per run, but you can get a plastic syringe from the chemist for feeding medicine to the baby etc, not sure whether they are 5 cc, or 10 cc.

Ian S C

Ingenious use of copper end cap but I'm struggling to get a sense of scale. What dia are the caps?
If not too committed to the design I suggest you look up "chicken feed" systems as used by 16mm and G1 locos or the wide flat tanks used in the small Mamod engines.

Actually a dipping tube from the top where you have the pin hole will sort the level out chicken feed style.

Remember that meths has a much lower surface tension than water so will behave differently.

Edited By Bazyle on 02/01/2015 11:57:59

I made a complete mess of soldering the pipe work. I used 243 degree soft solder and Bakers as the flux. It just would not ''flash'' and run around the join. I know I got it hot enough as some of the brass melted !

What temperature solder should I be using for this sort of pipe work ? Could I use electrical solder ?

Edited By Brian John on 05/01/2015 06:35:44

.

Bazyle ... For info. ^^^

I agree; very ingenious, and has the potential to look very appropriate.

MichaelG.

If you melted the bras syou had it way to hot. Just play the flame over the parts you need them a little over 243degrees.

Yes electrical solder will do but you really want flux on the work before you start heating which flux cored won't do.

LACO soldering flux paste is a non-corrosive alternative to Fry's/Bakers and seems to work well for all lead/tin solders, including electrical cored solder and proper tinman's solder (which works better than the electrical stuff)..

Neil

I am going to have another go at soft soldering the spirit burners but I was wondering how hot these spirit burners get during operation. I am referring to the hottest parts which hold the wick and also the tubing connecting it to the reservoir.

1. Could some of those new copper glues (rated to 315 degrees Celsius) be used instead of solder ? I also have Loctite 567 thread sealant which is rated to 204 degrees Celsius.

**LINK**

2. When soft soldering, can these mini blow torches be used ?

http://www.ebay.com.au/itm/141542018232?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

Edited By Brian John on 08/02/2015 04:53:36

I use those lighter blow torches for soldering heavy duty copper wire into 5mm bullet connectors but I doubt they'ld cope with the thermal mass of your copper end caps.

The copper end caps are already soldered using silver brazing solder. I only have to do the pipe work and the wick ''funnel'' now.