I’ve just changed from a synthetic bag to a leather bag. What’s all this I hear about treating leather bags?
What do I have to do?
What product is recommended?
How often?
Do I have to remove the drone stock?
What make of bag is it. If it is an L&M bag, you won’t need to season it… in fact, I am pretty certain you will not need to season many of the leather bags for UPs, as they won’t be sopping up any spit. 
I learned of a great treatment procedure from a bellows-maker on this board. Personally, I would say if it doesn’t leak, leave well enough alone as the maker probably treated it properly first (mine had been treated improperly).
the method I’ve been taught is
plug all holes but one
melt 1oz pure beeswax in 4 oz neatsfoot oil
pour the mixture into the bag and inflate
plug the last remaining hole (the one you used to inflate it)
turn the bag so that it coats the whole inside paying special attention to the seams
massage the mixture into the leather from the outside
repeatedly squeeze the inflated plugged bag until there is no more leakage
this coats the inside of the bag and the squeezing forces it into the pores. this worked great for me with one caveat - the oily mixture came through to the outside of the bag due to the porousness of the bag and the fact that I used all five ounces when three probably would have done it. as a result I had to make a plastic sleeve for the bag and a nice bag cover to pretty it up so I wouldn’t get grease on my clothes.
Forewarned is forearmed! 
All leather bags at some point in their life will probably need seasoning.The very nature of leather being fibrous,means that the stretching and pulling etc over time will probably necesitate this.I do mine on average once every 5 or 6 years on the D set which gets used most and never yet on the B set(10years) or C (3 years)which was preseasoned by the maker,unamed, but frae the same country as the new pope.Why change frae synthetic to leather? 
its normally the other way around.
Uilliam
I have a MacHarg bag that has not been treated in over 20 years. Another bag which was treated 15 years ago with lard and beeswax and is just fine, no mess, as with neetsfoot oil.
Ted
Uilliam wrote:
Why change frae synthetic to leather? boggle its normally the other way around.
I’m with you! A leather bag is a lot more work on my arthritic shoulder. Vinyl has springiness and practically plays all by itself. I’m very pleased with my marine grade vinyl bag sealed with 3M Fast cure sealant (a la David Daye).
Rick
I think it only made a mess because I used too much. the same recipe was used on my bellows and it never came through even though both were of the same leather…
Well, there are arguments for changing from vinyl to leather:
-
leather can be sealed again and again; I wanna see the vinyl-bag that lasts longer than ten years
-
(untreated) leather is glueable like wood (with wooden blocks and clamps [?holders?]) and does not require stitching. The late Matt Kiernan made these glued leather bags and they were that strong that you could (as somebody once has written here on C&F) „that you could stand on the inflated bags“
I am a bit biased towards vinyl though cause I really hate plastic. In some cases, however, it is better than leather. Key-pads from closed-cell-foam for example are by far superior to leather pads. I normally throw plastic items (brushes, bottles) „as far as I can“ (they are No. 1 esthetics-killers and the making of plastic causes pollution) but on the other hand some plastic-items are extremely helpful (CDs, PCs…). Even birds sometimes involve little pieces of (uncoloured) plastic-foil into their nests.
Best,
Hans
I have made synthetic bags that ye can sit on..They are easy to make ,should last as long as leather,don’t need seasoning and no animals get killed in the process.(Its only a bag of air after all)
Slán Go Foill
Uilliam
Perhaps Chris Bayley can re post the warnings he has been so good to post previously :roll: :roll: :roll:
Warning …(siren sound)…Take cover… latex on the radar 
What about butyl rubber.It’s cheap,and comes in great big rolls for pond
linings.Mitchell’s Materials says it’s unique in it’s low permeability to air.
I had one from Eugene Lambe with a vulcanised seam for quite a few
years,and if I have one criticism,it did tend to split around the tied in
mainstock connection due to continual flexing.However ,it was soon
fixed with a puncture repair kit, but after replacing the tied in cup for a
tank connector fitting(a plumbing fitting),I had no problems at all.
I now have a leather bag,but it’s in no way superior to a rubber bag,so
why make life hard for yourself.With a fancy bag cover,no one need
ever know!
What about butyl rubber.It’s cheap,and comes in great big rolls for pond
linings.Mitchell’s Materials says it’s unique in it’s low permeability to air.
I had one from Eugene Lambe with a vulcanised seam for quite a few
years,and if I have one criticism,it did tend to split around the tied in
mainstock connection due to continual flexing.However ,it was soon
fixed with a puncture repair kit, but after replacing the tied in cup for a
tank connector fitting(a plumbing fitting),I had no problems at all.
I now have a leather bag,but it’s in no way superior to a rubber bag,so
why make life hard for yourself.With a fancy bag cover,no one need
ever know!