Hi, There has been some correspondence about these elusive creatures so I took some images today. The body of the damper has an outer diameter of about 43 mm. The domed cap has an inner diameter which I measure at about 42.7 mm. The material of the domed cap is brass of about 1mm thick. The total height of the dome is about 7.5 mm. The domed cap has the appearance of the back of an old-fashioned pocket watch. It would be almost impossible to make the body of the damper in a home workshop but it might be possible to turn a domed cap from the solid. Hope this helps. Regards, Kerophile.
You are right. I don't see how the outer cap can be made without a mold. BEWARE, the inner cap will melt if you get the stove too hot. If you locate any caps inner or outer. I'm in the market too. Thanks, Andrew Large
Hi Andrew, I think it unlikely that we will turn up any of these creatures. The one in the post dates from the early 1960s and I guess was one of the last made, in the time of the Primus Trading Company. I don't understand what you mean by the burner getting very hot. If the damper is operating correctly it only "sees" the paraffin vapour/air mixture and combustion and the flame occurs from the perforations in the burner assembly. It is only if you get under-burn that the silent cap will get very hot, very quickly, and probably melt, But that is a potential problem with all silent burners. Regards, Kerophile.
Hi Kerophile The subject of the silent dampers for 96s and 100s is fairly complex. I think that the early Primus ones started with the bottom part having the perforations as part of the assembly and a separate top plate. I hope this is going to work as I have recently being having trouble with Photobucket and images The left item is a standard silent outer cap for scale. The next one is the two parts of an Primus silent damper which I believe to be early. Early Primus silent burners had the vertical perforated plate as part of the burner with a separate domed plate on top. This was simplified to the current design with a separate inner and outer cap separate from the burner. I have no evidence to support this but I suspect that the silent dampers were probably simplified to the outer cap having the perforations and the inner cap being simply a steel dome with a flanged hole punched in the middle. It is possible that these parts were crimped together. The two right dampers are rare. They are Primus 4200 silent dampers for 96 stoves showing the appearance from above and below. The two componenbts are crimped together and made out of Primus metal. They date from the 1930s. You will notice that the damper was patented at that time however I have no idea what was the reason for the patent. It may simply be that the parts were crimped together which prevented the loss of half of the damper. Whilst they are termed a silent damper the sound that they make is half way between a silent and a roarer burner even though the flame pattern is a pure silent patten. It makes a nice flame to cook on. There are some burner heads that these do not fit. Incidently I do not have any spare ones so do not bother to ask. This shows the Primus damper assembled The two items on the left are the components of an Optimus silent damper. The two on the right are standard silent inner and outer caps for comparison. I think that the damper components come from the 1950s because the outer cap is marked Optimus Sweden. I think that the marking changed to Optimus Optimus in the early 1960s. In 1962 the marking changed to Optimus Primus because Optimus started making both brands of stoves in that year These are the two assembled dampers. It is probable that Radius and Svea had their own design of dampers however I have never come across either so cannot be definite. There is a similarity between all silent dampers. They either have smaller holes or less holes than a standard silent outer cap. The reason is that the jet on 100s is only 0.23 mm diameter instead of 0.32 mm diameter so the fuel coming out is less than on a standard silent stove and produces less flame and obviously less heat. A 96 produces the same heat as 100 even though the 100 is a much bigger stove. It is possible that you have the components of a silent burner in amongst your old parts. The Optimus outer caps have only three rows of holes instead of the normal four on a silent outer cap. The early Primus ones have smaller diameter holes than a normal silent outer cap Regards Bryan
Hello, Thanks Kerophile and Kaw550red for the information and photos on the various silent caps. All the photos are so nice I think I can smell metal. Regards, Doug
Hi George and Bryan Absolutely stunning photographs! It is a shame that these burners are not easily available. I have many stoves, but I have none with the burners you show. Maybe sometime such a burner will turn up.
You know,these burner plates remind me very much like the bearing dust caps for trailer axles! drill a few (well, a lot) of holes and presto! What is the width of the steel cap? Any takers?
Hi Steve, well spotted! Unfortunately it is not the cap-type burners we are short of. We can get those for $6-10 each from Base Camp. It is the earlier style, a complex fabrication, like the one shown in my post which are as rare as rocking-horse droppings! Regards, George.
Ah,well... Though it looks possible to make the outer ring by removing the top from a standard cap, then dropping in a inner cap, then replacing the trimmed piece. Lot of effort, tho. I assume this is a 'looker', not a 'user'? Fully restored, then a shelf queen?
