The Svea 123R I bought on ebay was missing the heat shield disk in the windscreen. As a work around, I'm testing the idea of using a carbon felt disk to serve the same function. Here's a YouTube video of my test run. Photo below.
another clever stovie,did you put you hand on the tank to see is it was really hot after running for a bit.i see the carbon fiber works as a priming pad.
is it a problem now? A fair question, i thought: is it better w/o anything than with the felt? I don't know and seriously wonder? If, say on hottest of days, with as big a pot on as u may want use on top, will it burn a fount full of fuel w/o overheating? if it works, it works, done. i'm a newbie but I think i see 2 potential problems w/experiment. > my impression is the "shield" as you say is also a barrier / heat reflector, it reflects / helps contain the radiant heat up nearer the burner level. > cooling: Invision the plate in-place, full roar. The many vents just above fount level allow open-air and heat-rise draft sucks cool air over top of fount up thru center. It's ALL exposed to radiant heat,with that setup, is the mid-area of fount not cooled as much as it would be with the orig plate? tossin it out there
DG - I did not find the fount to be unusually warm when running with the carbon felt but it was a very cold day and there was no pot on top so testing is still needed. OMC - Agree that w/o the brass heat shield to act as a reflector, some energy that would otherwise get to the pot is lost. Whether the amount is significant or not, I don't know. I think your second point may be more significant though. The airflow is now less controlled so maybe there will be less cooling air flowing over the fount and then up through the burner. Has anyone done test to determine what's the operating range for the temp of the fount? I know with canister stoves Roger Caffin has deduced that if you can touch the canister w/o saying "ouch" it's safe. PS - One could say I'm felting instead of fettling.
What I've done with my 123s is to cut out a small disc of carbon felt to fit into the depression in the middle of the tank (where you normally put your alcohol preheat). This provides much more efficient preheat, particularly in the cold where the alcohol will catch fire immediately.
Hi Knotty, Exeter Yak, the king of Svea/Optimus 123s did many pressure and temperature measurements on operating stoves. For example with a 123 stove he wrote: The top tank temperature probe was positioned on the high area of the tank, near the riser/vapo setup. It was probably receiving a lot of infrared from the burner above, and my max temp reading once the stove was running at maximum output was 245 degrees F. I think I will place that probe in future tests at the top of tank/windscreen junction to hide it from burner IR. The bottom temperature probe was under an edge of the tank bottom. It should be attached to the dome under the tank 1/2 way between center and the edge I think. It maxed out at 75.3 degrees F. I ran the stove for about 15 minutes total, adding the pot of water at about the 1/2 way point. The maximum tank pressure reached about 22.5 PSI. I will be changing from the 160 PSI gage to a 45 PSI type to get better resolution and hopefully more accuracy. Upon shutdown, the tank pressure increased to 25 PSI, then lowered as the stove cooled itself in open air. So far, so good I think. Next will be some monitored test runs with data taken for charting. From this post: https://classiccampstoves.com/threads/11516 More than you ever wanted to know. Best Regards, Kerophile.
Andy - I've gone and done just that. The wicking action of the felt in the priming depression makes the fuel easier to light in very cold weather. kerophile - Thanks so much for providing info and a pointer to Exeter Yak's research.
FYI. I went and made a replacement brass heat shield for this windscreen. Details in this message thread.
