Hi Bryan, you should have been a theologian! I looked at four Pr.96 stoves today,the first 1954, one 1961, and two dated 1962. All four have non-captive air-screws. I would say that it is perhaps sensible to examine whether your thesis that the majority of Primus 96 stoves, post 1935 were fitted with captive air-screws, is still tenable. If it looks like a duck and it walks like a duck...it probably is a duck. Best Regards, George.
Hi Bryan, here is a link to a 1958 Pr.96, fitted with a non-captive air-release: https://classiccampstoves.com/threads/10879 Regards, George.
Hi George We are obviously not going to agree so it is better to finish this correspondence. Irrespective of how many stoves you produce with the early loose airscrew tank lids you have not produced any evidence that those tank lids were made between 1935 and 1962 and the documentary evidence that I have studied and my researches into the stoves make me believe that those early tank lids were made no later than the mid 1930s. There were six documents which included 3 Primus catalogues, two Condrup catalogues and a Primus Parts List dated between the1930s and 1962. All of those documents show captive airscrew tank lids. Also the stoves produced in the middle to late 1930s all use the captive airscrew tank lid and that includes 51s and 54s as well as 96s. Used stoves have parts replaced when the old ones fail and many of the spares stockists had very old parts that had not been sold. Stoves can be unused because a part has been borrowed from them to make another stove work and then the missing part can be replaced with a wrong part. Primus moved their factory in 1955 which involved transferring their machinery and all parts to the new factory. It is feasible that the move exposed unused superseded tank lids which were then used on stoves produced after that period. The date codes were secret and buyers wanted a usable stove and would be very unlikely to notice that the tank lid had been made many years before the tank. They bought a model not a model of a specific age. Spare stove parts were made in huge numbers and it is feasible that a batch could have been lost in the factories which were really huge. I have not seen any PTC period Optimus or Primus 96s with those early tank lids but I have seen a lot with the captive airscrew Incidentally cross bred ducks quack as well as pure bred ducks My input to this matter is now finished. Regards Bryan
Hi Bryan I respect your wish that we should end correspondence on this matter..... but not I hope on others. The basic problem is that we cannot produce the evidence to prove or disprove your thesis, which appears to be Catalogues are correct, and stoves can be modified at any stage after they leave the factory. If you wish to base your stove dating on Catalogues alone, you are going to condemn an awful lot of stoves to being mongrels. We can all point out errors in Catalogues, particularly in the use of out-dated printing blocks for illustrating new versions of stove models. Best Regards, and my continuing respect. George.
Hi Bryan, I have just thought of a possible dating test: All metals produced since the first atmospheric nuclar bombs were detonated, contain trace amounts of radio-active fission products. If you have access to very sensitive nuclear detection/counting apparatus it is possible to date metals to pre or post 1945. It would be interesting to see if any non-captive air-screw/filler caps were produced from post 1945 brass. Just a thought-experiment. Regards, George.