Hi, I have recently been offering some heat-proof burner washers for sale to CCS members. I was subsequently asked, by PM, for some advice on fitting such washers. Above you will see burner washers fitted to a one-pint and two pint, classic stove burner. These are replacement heat-proof washers for the one-pint size burner And, these are heat-proof washers for the 2-pint size burner ( which also fits 1.75pint "discus" stoves) It was then suggested that it would perhaps be useful to make such advice more widely available by posting it on the Fettling Forum, so here goes: Burner washers can be challenging to make at home, and I had these made professionally. If you try punching them yourself you either need an expensive concentric punch set, which allows single strike production of a washer, or you do double strike, and perhaps get split washers or off-centre holes. Originally, for classic stoves, burner washers were made of asbestos-bearing compound. They were very brittle and probably injurious to health. You were advised to wet them before installation as this made them a bit more pliable...but I still lost every second one to breakage. Along with my friend, Bryan Miller, I did a lot of research to get the correct dimensions, and suitable non-asbestos, heat-resistant, gasket material....The washers I offer are the result. This is the fourth year of production, so they have been well field-tested. Base Camp also sell heat-proof washers, and I expect these are also available from suppliers in the USA. You will find that these heat-proof washers are a snug fit. I "screw" them onto the threaded portion of the burner head, until the bottom section of the thread is exposed again. A squirt of WD40 helps. I then attach the burner to the riser tube, and screw the burner on. This pushes the washer into position, evenly and with no damage. The above two photos are of a heat-proof washer in place on a one-pint burner. These are the corresponding shots of a heat-proof washer in place on a two-pint burner. If you use a second washer under the spirit cup, just follow the same installation procedure These washers are robust but only need to be tightened up sufficiently to achieve a gas-tight seal. They can then be re-used if you ever need to remove the burner head. Some buyers have asked as to whether they should replace the washers on "new" stoves that they have acquired? I replied: Once you have good washers it is easy, and cheap to replace those that came with a classic stove. On the oldest stoves these washers could be asbestos-bearing, so keep them damp when working with them to help avoid dust inhalation, and dispose of the old washers safely,in a taped-up plastic bag. I always change washers it if I am cleaning a burner, as I like to remove the burner and totally immerse it in Citric Acid. However, don't do this if there is a regulator needle inside the burner, or you will corrode the steel needle away very rapidly. I would say that best practice with classic stoves, is probably to replace the burner washers, NRV washer, and cap washers as a matter of course, when you receive the stove. The existing washers will probably be old and brittle and will give way when you least expect it, if you take the "If it ain't broke don't fix it " attitude. I should have reminded everyone of the importance of making sure all the mating surfaces are absolutely clean and free of old washer deposits, before fitting the new washers. Many people have complained, on the Website, of non-sealing washers leading to fuel or vapour leaks.Subsequently,after getting advice from CCS members, they dismantle the burner, and find that the new washer has been unable to seal due to small lumps of dirt or old washer material left on the brass surfaces. Many stove manufacturers machined a groove on the mating surfaces of burners and upstands, to encourage them to "Bite in" to the new washer. The photo above shows the burner thread and mating face of a one-pint burner. Here is the corresponding photo for a two-pint burner. The mating face of the upstand from the tank is also grooved. These are some photos of the face of the upstand on a Primus No.5 stove: These grooves need to be fully cleaned out before attempting to fit a new washer. I use a Stanley knife blade, but I quess any sharp, pointed scraper will do. You must remember to handle brass carefully as it is soft and easily scored with a carelessly-used tool. Just for interest, you should note that the filler upstand on Primus stoves is also grooved to help sealing with the rubber compound washer used on the filler cap; I hope the above information and tips are helpful. Aren't stoves fascinating? Best Regards, Kerophile.