I'm researching Optimus fuel pump specifics. I'm seeing the threads about pump cup conversions for the 111, going from rubber o-ring to leather cup. I was also reading somewhere that if you plan to run a stove on alcohol, the leather cups are not ideal due to the alcohol drying out the leather cup. So 2 questions: Is there any truth that alcohol will ruin a leather cup? If everything is sealed/working right, alcohol should not get to the pump cup, so seems to me you have a bigger issue than alcohol getting on your leather. Wondering if this is why this stove uses an o-ring design. Assuming that you stay with the o-ring setup, what is the best lube to use these days? Apologies if the lube answer is posted somewhere. I searched but my terms may not be correct. Thanks!
That’s surely the case. The contrary assertion from whatever source you located is illogical. The only time fuel in a pressure appliance reaches a pump cup washer is when a non-return valve seal breaks down and the leather only requires re-oiling subsequently to remain perfectly serviceable. Silicone grease is recommended for lubrication of an O-ring.
While I'm an old school leather proponent, o-rings DO have advantages. You can carry numerous spares in VERY little space. They are fast and easy to change. You can get silicone grease in the little tear open packs at most auto supply or plumbing stores. And they don't take up much space either. I'm still a leather man, but I also like to keep them original. I can argue for and against both. Flip a coin.
Damaged o-rings are usually toast; damaged leather pump cups can often be restored, at least temporarily (as, on a trip). O-rings are especially easy to damage in cold conditions. ....Arch
Agreed- replacing leather with o-rings was a retrograde step, the same as replacing cork pump valve seals (NRV pips) with manmade compound. Both done for economic/supply issues no doubt. Leather pump cups have an extraordinarily long service life. They will only give trouble if allowed to dry out i.e. lack of maintenance. A lot of problems occur these days when stoves are brought back into use after a long time and the cup has rotted or otherwise deteriorated. Oil may temporarily make it supple again but the damage is done and reliability is gone. If the stove isn't abandoned for yonks that won't be a problem.
I've had a couple of times when nearby campers couldn't get their stove going, and I was able to revive their leather pump cups and therefore their ability to cook. If they'd had o-ring pumps, they would have been out of luck. ....Arch
They'd have been out of luck if they didn't have spare o-rings. And, with leather, they'd STILL have been out of luck if YOU weren't there to play the rescue ranger role. Haha! Hopefully, they learned to take care of it themselves in the future. Good on you for getting them running again.
Thanks for the recognition. Hikin' Jim @hikin_jim (who doesn't show up on this forum very often anymore) and I were on a backpacking trip a few years ago and ran across a couple guys struggling to cook breakfast. They asked if we knew anything about stoves, and Jim said something on the order of, "This is really your lucky day!" We got them up and going in short order. When I backpack, I don't carry spare parts for anything I'm not using, but I sometimes have a few O-rings and such when car camping. The thing I've done most often, though, is to lubricate dry leather pump cups. People who don't normally camp will have dad's (or grandpa's) old Coleman and never thought to try it out at home first. (This is not something that happens often; maybe every 3-4 years.) ....Arch
I am using a 111T on alcohol regularly everyday since 3 years. This is another one who was in bad shape when I got it but it is ok because I knew I will opened it all to make sure everything were right plus I wanted a 111T on alcohol. so it needed to be super clean inside too. After I receive a new alcohol jet and a rebuild kit for the pump plus a leather support because the original was cracked and changed the NRV. And make 3 alcohol restrictor from Doc Mark example model, I was ready to fire up the new paint stove. Of course I have lubricate for 24 hrs the new leather with a high temperature oil that we used in refrigeration when we want a unit to work longer the time a new parts arrive on a rush. Here I have to say that I am writing all that story to show that my stove was ready to go and I still don't understand why it happened. -NO the stove has no leak whatsoever but the leather pump dry quickly which doesn't happen with others stove. ?????? To finally fix the problem after many try I did mix oil and white grease and now it is ok. So the reason that happened is maybe the kind of alcohol , which I used Methyl Hydrate, or others reasons that I like to know but it happens. Crazy!!!!!! Here what I mix to fixed the problem. I did the mix once only in the last 2 1/2 years and everything is good now. I just realized that I should do that with the others to have peace of mind. Lololo JP
