View Full Version : Primus Omnifuel

2006-04-24, 02:51
Don't know if this is of interest to anyone, but I've purchased a Primus Omnifuel for use on our hike on Greenland this summer.
Since we normally use the Trangia windscreen/pot stand as platform for our stoves (LBP and alcohol) I decided to try and build the Omnifuel into the Trangia.
I had seen a solution, where the Trangia base were simply cut to allow the pot stand of the Omnifuel to stand below the base. This I didn't want to do since I then would have to carry the full weight of the Trangia and the Omnifuel.
I purchased a Trangia adapter for Optimus/Brunton Nova and I found that I could mount the Omnifuel burnerhead in the adapter with very little tooling. But it almost cost me half a finger anyway.
It took a bit of grinding to let the omnifuel fit snugly into the Trangia base.

Yesterday I did a test using the 0.28mm jet and Kerosene for fuel. Since I never have burned Kerosene as stove fuel I managed to fool around a bit and almost burned off my eyelashes http://i53.photobucket.com/albums/g50/kleth/Hiking/burned.gif when producing a m flame. But at last I got the burner started and it burned hot and clean with an almost invisible blue flame and almost no smell http://i53.photobucket.com/albums/g50/kleth/Hiking/mummy.gif.
But it's certainly not very quiet :fisheye:

If anyone is interested I can post a few pics of the adaptation.http://i53.photobucket.com/albums/g50/kleth/Hiking/flame.gif

2006-04-24, 06:52
I'd be interested in seeing it. I often have a hard time picturing things from a discription.

2006-04-24, 09:59
Pictures would be great. Your earlier suggestion in another thread here was a great one, to use my Optimus Nova stove in conjunction with my trangia. Curious how your design turned out...

2006-04-24, 11:39
Pictures would be great. Your earlier suggestion in another thread here was a great one, to use my Optimus Nova stove in conjunction with my trangia. Curious how your design turned out... Not much of my design :biggrin: But a ready made product tooled a bit to fit my needs. The Nova can be mounted directly, if the Trangia has the fuel-hose hole and the a hole for the regulator (big hole). Then all it requires is an Trangia adapter. See pic for Nova mount http://www.wildwasser-laden.de/images/tra-multifuel_brenner_1.gif

I'll snap a few piccies of my Omnifuel.

2006-04-25, 01:58
The Primus Omnifuel (http://www.primus.se/primus/Products/product_sheet.asp?ItemId=34156) is not the handiest of stoves and I'm fond of our Trangia cooking set so naturally I wanted to mount my Omnifuel in the Trangia.

The Nova burnerhead is mounted using its bottom screw and can be mounted directly in the adapter. The Omnifuel is assembled the same way so I acquired the Trangia adapter for Optimus/Brunton Nova
The Omnifuel has other proportions, so I had to bend a flange (red arrows, blue is the spring bracket) on the adapter to allow the Omnifuel' regulator to fit through the regulator hole (Probably didn't have to, but I like things to be easy to dismantle)
I also wanted to lower the burnerhead a bit, to allow enough air to the combustion, so I drilled the adapter' bottom hole using a 9,5mm drill (It's stainless and spring steel, so it's not fun to drill using hobby tools).
The expanded hole allowed the mounting stud to pass through the hole, lowering the burner head 4mm. The head could now be screwed firmly into position within the adapter, using its own bottom screw and a washer.
http://i53.photobucket.com/albums/g50/kleth/Hiking/image004_small.jpg http://i53.photobucket.com/albums/g50/kleth/Hiking/image010_small.jpg
The result is good, you can see the sides of the spring bracket (End of red arrow) on this picture, they secures the adapter within the Trangia base by holding the adapter down.
The Omnifuel regulator prevented a snug fit in the Trangia base, so I had to cut the regulator hole a bit larger.
Also I don't want to be able to switch burner and pack the Trangia without the use of tools, so I cut a new hole for the fuel-hose. The existing fuel hose hole in the Trangia base is not large enough for the Omnifuel' hose.
http://i53.photobucket.com/albums/g50/kleth/Hiking/image007_small.jpg http://i53.photobucket.com/albums/g50/kleth/Hiking/image008_small.jpg
The final result is easy to mount, since it just clicks in place and it works brilliantly. I'm working on measuring the fuel consumption rate, so I can see if the additional space costs too much efficiency.
<update date=2006.05.15>
I've done 3 burns on kerosene now. In average I've used 18g of kerosene to bring 1kg of water into rolling boil (26g+14g+14g). Air temperatures have been between 10-20C.
By watching the water closely (lifting lid frequently) I've found that, if I set system to bleed when steam-bubbels form on the pot bottom, I can bring entire batch to rolling boil on the fuel in the hose and thereby saving some fuel. Also in average I've used 5g of methylated 96% ethanol for preheat.
<update date=2006.06.28>
I did my first burn on coleman fuel. It works really well and is very easy to get started. It used 16g of coleman fuel to bring one kg of water (at 10C and air at 20C) in a kettle into rolling boil. I belive that the fuel consumption can be reduced to 13-14g if boiled in a trangia pot w.lid and when I learn to bleed the bottle at the right moment to reduce fuel usage after the water boils.

2006-04-25, 02:16
Very cool job. I would live to modify mine, but need spare time right now to do so...very busy this month...

I will include a pic when I get to mine. Thanks.

2006-08-06, 03:29
On this year trip we (2 persons) used 1L of white gas and 190g LBP, this included 3 hot meals a day, baking, coffie, cocoa, other hot drinks, water for washing (clothes, person and dishes, pots ect.)
And the last day we had to burn the excess fuel (both LBP and white gas) . . . .

Also I found that the Omnifuel is capable of burning liquid LBP but not without running blazing hot.