Quote Originally Posted by Lawrie Amatruda View Post
As far as I know most antique, ball, butt , barrel reservoir guns and air canes have the exhaust valves in the reservoirs, these are compressed air guns, which are pre Giffard guns and are easily converted to Co2 use by using a modern valve material, as I have done with all the ones I own, the part that should not be there shown in Aimless's picture is the part that seems to be entwined in the middle of the exhaust valve spring, which looks like it has been put there to support a broken exhaust valve spring, as mentioned by Mr Fletcher they are very simple valve mechanisms, and when resealed will last many years of use before requiring a reseal if at all, I use 95 shore hardness polyurethane in all of the ones I own.

Regards, Lawrie.

My point was that it would not be possible to attach a modern tank in anyway to replace the original Giffard tank because of the exhaust valve being in the tank: an exhaust valve is something no modern air gun tank has. My original vision was attaching a modern paintball tank to a Giffard. However, can't do that without building a special adaptor with exhaust valve.

You are indeed correct that all the old ball/butt, etc reservoir guns had the exhaust valve inside the tank. Off the top of my head, I think the Giffard is the last of that breed. Can't think of another gas or pcp gun again being made this way. Sort of emphasizes how the Giffard, although a CO2 gun, technically, was still an old style 19th century air gun.