Soto Muka rengöring?

[Skogsstjärnan]

Det är väl trevligt att vi hjälps åt att bringa klarhet.
Inverterad förbränning, gasol/campinggas och skillnad i blandningsförhållanden propan, butan och isobutan. Hur de olika köken uppför sig etc.

Jag skulle vilja höra Torbjörns syn på packningar och plast som används med bensin (ren/alkylat) i dessa sammanhang. Eftersom Magnus synpunkt är rätt bestämd, det är högst obra och en stor risk att exempelvis Primuskök som borde vara konstruerad med höga krav inte klarar kraven på driftsäkerhet.
Det blir lätt hänt märkliga dribblingar i ett forum som denna och jag är osäker på om alla dessa påståenden som ibland flyger runt har bäring på beprövad erfarenhet och kunskap.

 

[Rödsprit]

[QUOTE = "Scab"]
Köp ett Nova.

Dessutom har Optimus varit tvungna att kompromissa med munstycket för att Polaris ska kunna bränna gas. Så Polaris har mycket sämre effekt än Nova på tunga bränslen (tändvätska, Nato flygbränsle och diesel)...de bränslen man vill kunna bränna i händelse av kris och krig.
[/ QUOTE]

Hi, new member here but long time reader. Excuse my engelska, I'm Finnish and I somewhat understand svenska, but I have to write in English. This above post and the rest of this conversation prompted me to register here because this is the first time, apart from one obscure blog post, that someone claimed that the jet (munstycket) is different in Polaris than Nova.

I'm quite sure the jet is the same. Why? I have two old Made in Sweden Novas, two new Katadyn Novas, two Polaris AND five extra jets from five different age repair sets. All jets are 0.32mm, every last one. Apart from differences between individual jets (and there are), they are the same and have always been. I have checked them because some stoves burned kerosene better than others.

There are differences between old and new Novas. Old Nova burner bell is slightly smaller in diameter. New Nova and Polaris have exactly the same burner bell (and jet), I have measured them also. The only difference between them are the fins in burner bell. Actually you can make Polaris from Nova by shortening the fins and changing the fuel hose.

I think observed differences between new Nova and Polaris and their kerosene combustion is between individual burners than models. None of my old Novas burn kerosene as well as Polaris.

Now, I'm not here to start a fight or argue, I'm very happy to be proven wrong. If you could just point me to where it says Polaris has different jet than Nova. After all, Katadyn has only one repair set for Nova / Nova + and Polaris.

*edited because of Google translate..., I'll try better next time*

 

[Polar300]

Det stämmer med min erfarenhet. Det är större skillnad i beteende mellan köksindivider än det generellt är mellan jämnåriga Nova och Polaris - på samma bränsle alltså. Skillnaden sitter främst i slangen - vilket antagligen är skälet till att Katadyn inte säljer slangen som lös reservdel (vilket Primus gör med sin slang) - och i utformningen av brännarkoppens väggar.
/Odd

 

[Svartfot]

Hi, new member here but long time reader. Excuse my engelska, I'm Finnish and I somewhat understand svenska, but I have to write in English. This above post and the rest of this conversation prompted me to register here because this is the first time, apart from one obscure blog post, that someone claimed that the jet (munstycket) is different in Polaris than Nova.

I'm quite sure the jet is the same. All jets are 0.32mm, every last one. Apart from differences between individual jets (and there are), they are the same and have always been. I have checked them because some stoves burned kerosene better than others.

1. 
   I love this. 😁 It seems I got completely smoked by a Finn. Your answer is very convincing.
   
   However, this leaves me truly puzzled for the following reasons:
2. 
   
3. 1) In the limited number of comparative tests I have seen between Nova and Polaris, Nova has come out on top when burning Kerosene.
4. 
   
5. 2) In youtube videos where Polaris is burning Kerosene it often seem to be feeding richer than my two Novas.
6. 
   
7. 3) According to Katadyn data Nova and Polaris have significant difference in specification (BTU, burntime, boiltime). BTU of 2850 vs 4200 is not a negligible difference.
8. 
   
9. 4) For burners with dedicated LPG nozzles that nozzle is significantly bigger than what is needed for other fuel. For example Primus Omnifuel gas (0.45mm), gasoline (0.37mm), and kerosene (0.28mm). This indicates that the logic would be to increase nozzle size to accommodate LPG.
   
   5) When I have contacted Katadyn they have responded to other questions but refused to answer questions about the nozzle.
10. 
    Alone each point was not enough for me to assume that the nozzle was different, but when viewed together I really didn't see any other logical explanation? I fail to see how a difference in fins and hose can achieve this if nozzle, pump pressure (25 pumps as per instruction manual), and everything else is identical?
    
    Any thoughts on this?

 

[Svartfot]

Rödsprit, som ytterligare stöd för det du sa noterar jag nu att reservdelspaketet för Nova & Nova+ (som även innehåller munstycke) nämner att det även passar Polaris i den detaljerade beskrivningen. Det har jag inte sett tidigare.

(If it is problematic to understand let me know)

 

[Rödsprit]

1. 1) In the limited number of comparative tests I have seen between Nova and Polaris, Nova has come out on top when burning Kerosene.
2. 
   
3. 2) In youtube videos where Polaris is burning Kerosene it often seem to be feeding richer than my two Novas.

Yes, I've seen those videos. The difference between Nova and Polaris burner bell is clear, this might have something to do with it or not. And in videos where there isn't side to side comparison, you can't really tell anything. What is said to be kerosene or paraffin might as well be closer to lamp oil, C13-C16 hydrocarbons.

Polaris was designed to burn LPG also, where Nova is liquid fuel only. There has to be a compromise as we know. Out of the box Polaris fuel-air mixture is spot on for alkylate gasoline (but there are differences between individuals). Raising the flame plate just a little increases air for kerosene but then LPG has little problems igniting... So I think Katadyn wanted to make sure people wouldn't have problems with LPG and that's why out-of-the-box Polaris might burn richer with kerosene. Nova doesn't have to deal with LPG but it can if you just change the hose.

1. 3) According to Katadyn data Nova and Polaris have significant difference in specification (BTU, burntime, boiltime). BTU of 2850 vs 4200 is not a negligible difference.

I think this might be just very clever marketing. I haven't got any huge differences in boiling times when all things are equal. I don't know how they came up with that.

1. 4) For burners with dedicated LPG nozzles that nozzle is significantly bigger than what is needed for other fuel. For example Primus Omnifuel gas (0.45mm), gasoline (0.37mm), and kerosene (0.28mm). This indicates that the logic would be to increase nozzle size to accommodate LPG.
2. 
   

You are absolutely right. That's how Primus does it. MSR XGK-EX has one nozzle for gasoline and kerosene. It works, burns gasoline better than kerosene, so I guess you could say it's a compromise like Polaris (=Nova) nozzle. Kovea Booster+1 has one nozzle also but for gasoline and LPG, so it's the other end of the spectrum.

1. [*]
   5) When I have contacted Katadyn they have responded to other questions but refused to answer questions about the nozzle.
   [*]
   
   [*]

2. 
   
3. Maybe by admitting the nozzle is the same they feared people see through their marketing and realise that only real difference is the hose and maybe some optimization to burner bell. I don't know. Latest Katadyn stove patents are only for burner bell assembly. I didn't find anything for nozzles.
4. 
   

5. [*]
   Alone each point was not enough for me to assume that the nozzle was different, but when viewed together I really didn't see any other logical explanation? I fail to see how a difference in fins and hose can achieve this if nozzle, pump pressure (25 pumps as per instruction manual), and everything else is identical?
   
   Any thoughts on this?

I think I have given some possible explanations above. The burners are different, but I haven't found any evidence that the nozzle is different, which was my main point. And I have had to adjust the flame plate on all my Novas and Polaris to achieve better kerosene combustion.

 

[Svartfot]

Yes, I've seen those videos. The difference between Nova and Polaris burner bell is clear, this might have something to do with it or not. And in videos where there isn't side to side comparison, you can't really tell anything. What is said to be kerosene or paraffin might as well be closer to lamp oil, C13-C16 hydrocarbons.

Polaris was designed to burn LPG also, where Nova is liquid fuel only. There has to be a compromise as we know. Out of the box Polaris fuel-air mixture is spot on for alkylate gasoline (but there are differences between individuals). Raising the flame plate just a little increases air for kerosene but then LPG has little problems igniting... So I think Katadyn wanted to make sure people wouldn't have problems with LPG and that's why out-of-the-box Polaris might burn richer with kerosene. Nova doesn't have to deal with LPG but it can if you just change the hose.

I think this might be just very clever marketing. I haven't got any huge differences in boiling times when all things are equal. I don't know how they came up with that.

Good points.

When I bought my first Nova I assumed it would function as the Polaris. (Cynical as I am, I suspected that the difference between Polaris and Nova would be smaller than Katadyn was painting in the marketing.) So I got myself a 5L bottle of Aspen alkylate 4 stroke, assuming it would be the preferred fuel as you describe for Polaris. I found that the flame indeed was blue, but boil time was unimpressive.

Further testing showed that both my Novas consistently performed better with with BBQ lighting fluid (C10-C13/ EC 918-481-9 ) and lamp oil (within C13-C16). Basically all different fuel in the range C10 to C20 burned flawlessly.

I also concluded that Kemetyl lighting fluid (T-yellow) was producing soot and residue on the burner that I didn't see from other "heavy" fuels. After reviewing the safety data sheet I attribute this to the C8-C26 (fisher-tropsch).

I have seen similar results with "furnace" fuel that contain heavy naphtha. So I have decided to stay in the C10 to C20 range and avoid "naphtha" completely.

It gives my a wide range of easily available fuels that make the stove run basically maintenance free. These (medium) heavy fuels also seem to lubricate the system sufficiently. Connecting the stove to fuel bottle has always been a hustle free experience to me independent of the weather. An issue I have seen raised numerous times among other Nova users.

Interesting finding about the flame plate. I have read about this in some other forum. However, I didn't pay too much attention to it because the flame plate claws are so soft that the plate seem to move around rather generously during normal hike handling.

Have the fuel filter been consistently the same in all of your stoves?

My first stove worked flawlessly and had a brass filter. Same as show in the replacement kit.

However, my second stove felt very restricted and required excessive pumping. Some troubleshooting reveled a very restrictive white "mouse tampon" that I replaced with some fluff from a cotton swab. After that it all worked flawless.

I have seen a number of complaints in forums related to Nova about poor performance, fuel blockage from using lamp oil/paraffin, pulsating. Problems that I suspect might be related to this specific fuel filter.

I hope Katadyn didn't introduce this mouse tampon on Nova to create the marketed performance difference between Nova and Polaris.

 

[Rödsprit]

Good points.

When I bought my first Nova I assumed it would function as the Polaris. (Cynical as I am, I suspected that the difference between Polaris and Nova would be smaller than Katadyn was painting in the marketing.) So I got myself a 5L bottle of Aspen alkylate 4 stroke, assuming it would be the preferred fuel as you describe for Polaris. I found that the flame indeed was blue, but boil time was unimpressive.

Well the energy content is bigger in kerosene as you said. If the nozzle stays the same and the fuel burns completely you get more BTUs / kJs from any stove using kerosene.

Have the fuel filter been consistently the same in all of your stoves?

Either completely without or with brass filter.

I have seen a number of complaints in forums related to Nova about poor performance, fuel blockage from using lamp oil/paraffin, pulsating. Problems that I suspect might be related to this specific fuel filter.

I hope Katadyn didn't introduce this mouse tampon on Nova to create the marketed performance difference between Nova and Polaris.

I think they stopped using that white filter in Nova years ago, older Novas had that filter.

I also think these user reports or experiences concerning different fuels, pulsing, poor performance etc. in both Nova or Polaris stoves are because of:

• small manufacturing differences in burner bell, or
• small differences in nozzles, or
• user error

Polaris PolarDawg2 silent cap is in my opinion better than what is available for Nova. That might be the biggest difference apart from the fuel hose.

 

[Polar300]

... Polaris PolarDawg2 silent cap is in my opinion better than what is available
for the Nova. That might be the biggest difference apart from the fuel hose.

Fact is Gary Adams [ Bernie Dawg ] himself states that the PolarDawg2 is by far
the most advanced silent cap he has ever designed. And he's done many a silent
cap design over the years...
/Odd

 

[Svartfot]

Polaris PolarDawg2 silent cap is in my opinion better than what is available for Nova. That might be the biggest difference apart from the fuel hose.

I am unfortunately not a big friend of Dawg silent caps for the following reasons:
1) The extra weight further increase preheating requirement.
2) I use the stove primarily in winter and the snow make the original sound more meditative than annoying. ;-)
3) The cap is another thing to lose in waist deep snow.
4) I don't know how it impact performance. However, all "tweaks" I have tried over time have left the Nova worse or indifferent at best. So I stopped messing around and started to fully enjoy it as it is.

 

[Rödsprit]

all "tweaks" I have tried over time have left the Nova worse or indifferent at best. So I stopped messing around and started to fully enjoy it as it is.

I agree, Nova is best left as it is, it's excellent burner out of the box. On the other hand, my experience is that Polaris really benefits from silent cap.

 

[Polar300]

... On the other hand, my experience is that Polaris really benefits from the silent cap.

It sure does! Ah, all those dB that disappears... 🎧 ... And it burns much better too - imho.
YMMV of course.
/Odd