Thank you for letting me join. I recently purchased a Primus 1020 manufactured in 1933. On inspection, I noticed a fibre washer located on the upward threaded part of the tank where it attaches to the frame. Question is does anyone know the material used in this washer?

I cannot see that type of washer on the spreadsheet found on fogas.se

Maybe they show a newer version there.

20190824: If the temperature doesn't exceed 400 degrees then one of the four sheets from the Clas Ohlson set would do it http://m.clasohlson.com/se/Packningssor ... r308419000

Regards Matti

Originally that washer was made of asbestos. If you're making anew one, just use any (heat resistant) fibre material. I use something called Klingersil, but that is only because that is what I had. This material also works well for the washer under the top cap nut.

An ordinary rubber o-ring also works great as a seal for the tank lid.