[pct-l] SVEA-123 Adventures

[Jim Marco]

Ha, ha...you guys have all the fun. 

I have my plastic drink bottles in 8, 12, 16, 20 and 24 floz varieties. With a little ingenuity it is easy to strip a piece of 10 or 12ga wire leaving a 12" length of vinal plastic tube. Cutting a small hole in a spare top with a slightly smaller drill, warming the tube in boiling water(after slicing the tube at an angle,) then feeding/forcing it through the small hole it is possible to make a tight, non leaking fuel filler cap for them.
It even sucks back excess fuel from overfilling... And, it reaches beyond the burner so you can prime it with the correct squeeze. 

Priming does NOT heat the tank. Well, indirectly...it does. It is supposed to heat the valve/expansion chamber between the burner head and the stove. Any WG that enters this (through the wick in the tank) will flash to gas at higher pressures than the incoming gas and out the jet. Then the process repeats. Like priming any other WG stove. The pressure goes out the jet AND back to the tank pushing more fuel up the wick. The pressure heats the tank, with conduction keeping the expansion chamber hot. Some conduction of heat into the tank is inevitable, of course, but that is only incidental.  

If the flame is roaring, then you are wasting heat. I usually leave it about half way to full on for about 30 secs. Then turn it down to what most think of as a simmer. It does a slow put-put, but it throws much more usable heat. It takes about 7 minutes to boil 2 cups of water. I have run it like this for about 4 hours without refilling it and without overheating it. With some slight dimpling of the cover/flame deflector, you can reduce the roar to a mild hiss...but this is sort of like tuning up an old car....

A "squarish" pot works best. About 5-1/2" dia with a rippled bottom and about 5" high. A Kmart grease pot can be ridged with a couple sticks...inside and out, by annealing, then working the metal gently with a hammer...a series of concentric rings can be hammered into the bottom. It will raise efficiency about 15-20%. It also softens the aluminum making it far less vulnerable to cracking, though it will dent easier.

The old safety caps should be replaced with the newer spring loaded models (pre-1970.) A design flaw with the newer caps, they can fill with dirt or become rusted, easily. I recommend putting a drop of olive oil in the hole on the cap to prevent rusting of the spring. If you manage to pop the valve, tapping it several times on a rock will usually clear the trail grit and put it back in service, again. There is no need if you have a SVEA 123r or later. You do not need to get a new cap.

They also make a "midi" pump for it that lets you pump the tank to pressure, and prime the stove, without pouring WG on it. Simply open the valve after pumping 4 times sharply, till you can see fuel on the stem. Turn it off and light it. Just as the flame burns down (about 30sec or so) turn it on, again. This also works well at 10-15000 feet in altitude at -10-20F. It does not rely on self pressurization to force fuel into the expansion chamber.  

IFF you over heat it and let it burn all the WG out, it can ruin the cotton wick. A few strands of cotton mop makes a better than new wick. Getting the old one out can be a problem. Simply remove all the pieces and burn it out on the stove, or, with a blow torch. They also degrade after about 25 years and need replacing anyway.

Laugh all you like... I have had mine for 40 years without failing me in the woods. It always starts and runs, wet, cold or at altitude. At 17oz (stove, no cup) it is lighter than any self contained stove out there. It is the lowest starting weight I can carry for 10 days or longer (unsupported) trips at my usage. (I do two or three longish trips per year...) It is legal anywhere I go, except if there is a strict NO FLAME ban in place. 

It produces very small amounts of CO. With a couple vents open in your tent, it is possible to start it outside and bring it into your tent for cooking. Never recommended, but, sometimes necessary.

A&H Packstoves has parts(http://packstoves.net/cart/ )...call and ask if you need them.

User error? Yeah, these LET you make lots of mistakes. Not for the faint hearted hiker... But they are the most efficient stove in terms of best all around usage I have found. Small volume, compact, excellent fuel efficiency, good heat production (max is only 4700 BTU, I recommend about 700-800 BTU for operation) durable and reliable in the field. Let's see 40 years divided by about 40 dollars is about $1 per year and still going. Fuel, WG is cheaper than canisters or alcohol, about $8 per year(something less than a gallon) at today's rates for about 60 days per year. Weight is only average. As part of a 23pound system for two weeks hiking (including food) it works for me. UL? Well, I don't really consider myself as a UL hiker...more of a comfort hiker. Till I can find a SVEA like design in titanium, I'll keep using what I have. 
	My thoughts only . . .
		Jdm