Greetings, I have some basic questions about two tank lids that I have. I have attached a picture of the two lids. One of them is like what came with an Optimus 111 Hiker stove, and the other came with an Optimus 8R (the older vintage with the embossed writing on the lid). 4 Questions: 1. Is it ok to substitute either of these lids for use with either the 111 or the 8R ? 2. Is there anything such as maintenance that I should do to check what seems to be a valve of some kind at the top of each of these lids? Any dis-assembly, cleaning, checking, reconditioning? 3. Any other Lid-lore that any of you out there might share, or any other links to info that might be relevant, helpful, or interesting? 4. Best place to buy a replacement nitrile washer for the 8R lid (I am in the US)? I only need two. Thanks !
Yeah, but swapping the newer style cap to an older collectible stove probably reduces the stoves value to collectors. Yup. d6SEE1ToCSQ[/media]]Link The penta-screw cap is younger than the slotted cap. The penta style came later and seems to have been a Sievert design that was adopted by Optimus when Optimus bought Svea/Sievert. Some people claim that the penta-screw style is "adjustable". I disagree. The penta-screw style is designed to fire correctly when in the middle of it's range with the threads just showing out of the cap. But, if screwed all the way down, it will still open when pressures are below the burst point of the tank. This style was adopted because it is easier to manufacture rather than to introduce some sort of adjustability. My opinion based on repairing many of these caps and also testing release pressures with a shop-made jig for the purpose. In the US? A&H. Check eBay for seller "bella10102". The Viton seals from The Fettle Box are better, but Ross is in the UK. See the side banner link to the right.
The operating range for Viton is about -4F to +400F; Nitrile is about -20F to +230F. These ranges can vary slightly by manufacturer.
True but a large amount of nitrile on the market doesnt have the amount of nitrile in it to handle our fuels constantly. Viton is artificially manufactured and cannot be made not to spec unless its not viton at all. Good quality nitrile is as good but how do we tell good from bad until it fails miles from home or a good source of replacement washers
Uhhh... I always thought stovies preferred Viton over nitrile because Viton is more chemically resistant to seal-degrading fuels like naphtha (Coleman fuel), kerosene, alcohol, gasoline and diesel. Greater temperature range? Ok. If you say so. More reason to like Viton, I suppose. Though my nitrile o-ring supplier says the nitrile orings have a service range of -30F to 200F. Matters not to me. The fuel resistance is why I buy Viton. I don't find my fuel caps getting up to 230F, anyway. I hope no one else does either.
its the low end of the scale that might matter to some. Here in NZ there are very few places that ever get to -4F though and I cant see people wanting to cook in those places.
Sources: http://www.fluidseals.com.au/o-ring_application_guide.html http://www.dkirubber.com/materials.asp http://www.sealanddesign.com/category/Rubber-Compounds-O-Rings/462.html http://orings.com/tech_compound.php Quite possible; it depends on the formula utilized by manufacturer.
Okie-doke. You've proven you can definitely Google! But, is it important? Viton, for my money is used because it resists degradation from volatile fuels and that's the point of the application. Maybe Ross could chime in on why he promotes it's use at The Fettle Box when he gets a chance. His ad copy seems to suggest for longevity.
It is in the cold you least want a stove to not work. So if Viton only works to -20°C, it is a very bad idea to use it as washer in a stove. It is much better to replace the washer every year, than have one that do not work when you need the stove at most.
MSR, Optimus and Primus don't seem to agree with that low-temperture concern since they appear to use Viton o-rings in their backpacking stoves.
These materials are fine, but after all, they weren't used by Optimus when they made the original 111's were they? So, really, how much of an advantage are they over low cost 'plain old' rubber washers? I'm guessing very little, especially if you replace them every now and again
There are old posts discussing the use of nitrile vs viton. Ross decided on viton after trial and error. I suppose one can learn what he learned all over again. Ken in NC
Sunny, Plain old low cost rubber isn't fuel resistant and will start degrading immediately. I tried it once when impatient. I placed an order with Ross then went to the hardware store to get a plain rubber washer to use in the meantime until the vitons arrived. That experiment was totally unsuccessful. As soon as fuel touched it the rubber just warped and bubbled up.
I bought a bulk pack of nitrile washers a while ago. Only one I used on a msr bottle failed in under 6 months. Good nitrile would of lasted and possibly cost the same.
G,,day , I use Scepter Mil Spec Gerry cans for fuel storage and 4WD use . the Milspec cans use Viton gaskets exclusively , I reckon they have a good reason for it . the civilian cans use something else , I presume some type of nitrile , it is nowhere near as durable and long lasting as the Viton. the caps on these cans screw on so the gasket cops a fair punishment from torsion when really tightening the cap , no failures at all . think the same setup as a stove filler cap , but over 2 inches in diameter . cheers kerry
We utilize Viton® in our new washer kit for Svea 123 fuel caps. It is a good material for such applications. http://store.quietstove.com/quietstove-srv-washer-fuel-cap-rebuild-kit-with-srv-tool.html All the best, Craig P.S. 50% discount on the above item for CCS members. PM for more info.
Heh-heh! Well, since you are quoting me directly Craig, I'd thought I should mention that I'm highly unlikely to buy your kit, thanks anyway. For a multitude of reasons. Not the least of which is that Ross at The Fettle Box provides a superior product and is actually a stove collector with knowledge and background who knows what he is doing and deserves my money. If I needed a kit and didn't wish to manufacture it myself, Ross at The Fettle Box would be my go-to guy. Also, it has been drawn to my attention by several (former) customers of yours that the rounded lobes of the penta security bit you sell can rather easily slip out of the penta of the penta screw in penta-equipped SRV caps. I have done additional testing of these bits and found that this is indeed a danger. After initially trying these bits here in my shop and mentioning that they seemed like a good alternative for the budget conscious, I'm now recommending that people not use these tools as they can rather easily damage the penta-screw fixture of the caps beyond repair. None of these comments are intended to damage your business, but, rather, to alert uninformed stove users that there are better alternatives that will keep their stoves running properly. Cheers!
