Fired up my Svea 105, seems last time it ran great. Swapped out the caps today after running it a couple times the last two days, runs great now after it ran weak and yellowish flames. Only thing I did, replaced the Svea 1239 outer cap for a SH&H cap which was identical and the inner cap. The replacement inner cap was in good shape, but the old one shows material flaking off, but that material is not loose. Funny, my other Svea 1239 cap has a different inner cap, one with three sets of three holes around the top. Not sure which is the correct setup. The inner cap pictured is a Svea cap. Looks like 817 or 1817 on it. Will a rough surface make that much difference? Duane
That is a very rough surface. It is enough to interfere with the gas flow. The clearance between inner and outer caps is quite thin. Any buildup will give uneven burning. It looks as if someone coated the cap to keep it from rusting. Fix is easy. Power brush cap smooth, coat only with light oil. I power brush inside of outer cap also. Inner cap with nine holes, is to be matched with burner that has holes in the mixing tube. That is to help extinguish under burn. If not matched, no function, no harm.
Well said @dspearsy2k. It's cropped up before on CCS that even without surface scaling and pitting such as that combinations of inner and outer caps can work well or fail miserably to produce good (regular blue flamelets) combustion. Frustrating at times, but presumably it's down to inner profiles as you say and mismatched caps create the 'wrong' configuration of combustion passages. John
I got curious, so tried to find the common denominator if any. Turns out the Svea outer cap is not a team player. Thought it worked great last time per my notes on the tag. Only difference I could see is the Svea cap has a barely noticeable higher, peaked dome. I tried to touch up the Svea inner cap pictured, but the material is too hard to hand sand. Would have to use my Dremel. A few years ago, I thought this was the issue with my 45A, but I believe it was the alcohol, not the good stuff. I bought new caps anyway. I guess the Svea outer cap with the inner that has the three sets of three holes is a good combo on my Svea 1915 burner. Thank you for the help. Duane
I have experienced similar flaking on inner caps and have found the material hard to remove. Mainly on older caps but also on some not so old. What causes it I do not know. Poor quality steel and heat?? The best way I have found to remove the scale was to sharply tap(sends a shock through) the scale area on the cap with a small steel hammer bit by bit while holding in the hand, until the bond is broken and the scale drops off. Like knocking slag off a weld. Takes awhile though and not always a total success. John
@hikerduane I had one that looked about the same when I restored a Primus 5 from 1933. I used a rotating circular brush to remove and polish the surface. After this the flames where perfect than it was when I tested it the first time. Michael
@hikerduane Can that other inner with the 3x3 holes on top be an Optimus to go with the Optimus burners having the four holes in the lower upper part of the center spigot/tube? This is the underburn prevention setup. Those 3x3 caps can also flake, by the way. 847 is a parts no for a Sievert Svea inner cap. I would say this type of flaking is pretty common. Your case is a bad one, and I would also say it will influence the performance. My experience with this is mostly from 111s, and on those a nice smooth inner is vital to good performance. This flaking also collects dirt and cause all kinds of problems with underburn from this dirt glowing. Stoves can run wonderfully with crappy inners, but I think this narrows the interval the stove has for this wonderful operation; it will be more likely to operate poorly from another cause. I guess this is a sort of explanation for the “personalities” these things have. I do not know exactly why the steel flakes like this, but it must be something with the steel quality and production, and the extreme heat the inners endure. However – there are a lot of caps exposed to the same heat without flaking. I also have outers and dampers with this issue, including my one remaining 4200. Caps and flame- plates and -rings have a hard life, as they literally takes the heat for the burner. One can “burn off” several but the burner itself is still in good shape – now days it would be change the whole burner or most likely throw away the entire stove and buy a new one. I am not sure if this way of minimizing the number and cost of the parts needed to keep a stove going daily for decade after decade, was 100% intentional from the designers, but it is a brilliant construction. All the best, e
Good morning, You're right, the caps put up with lots of heat. Funny, even new stuff will not run properly it seems. My 199 does not have perfect blue flames or my 11 Explorer, but a couple other silents have a beautiful blue flame. Duane
I have the exact same experience with the later Optimus products – including the 10 Ranger. I looked at four 111Ts yesterday evening. Three of them had flaky inners. The fourth with the no flaky cap, have alky setup and little use, so not quite representative. I have a few fixed leg R stoves with a bit of age on them; would have been interesting to take a more systematic look at possible flaking on them – hmmm …. This hobby – there seem to be an endless number of interesting things to look into. All the best, e
My 10 Ranger runs great, last fired up in Oct., I think. Now that you mention it, will have to go out and try it. Just back from snow camping. Duane
