@Philip Ward the rizer to tank joint is a tough one no doubt but also a repair completed by some members here (not me). i post only to mention re your The riser appears to be soldered with a large amount of solder inside the top of the tank. As @Dean described. If I take a torch to the outside that solder will drop to the bottom of the tank. If we take a different view (i often do), the solder would puddle at rizer if tank is suspended upside down when heat is applied. I'll not take credit for the idea I fully expect it has been covered on CCS. Don't go forward w/this without more input. It does not allow for prepping surfaces and for all i know might make matters worse. That's it from me, I'll follow w/interest, carry on, thanks.
@OMC that is an interesting comment. While I was scoping the inside of the tank I was considering how they would have made it in the factory. I concluded that the riser would have been crimped in place along with the filler neck and pump sleeve. Solder paste would have been applied to all joints including the tank joint. The two halves of the tank would be crimped together upside down. Then the solder paste on all joints melted upside down. Possibly in an oven. I concluded upside down soldering on the outside was beyond me so I settled on no heat and get a scraper, looking at wood working chisels as an option. Or I may just live with it if it doesn't leak.
+1 with the ...live with it if it doesn't leak. Repairs are part of an old stove's history. A LOT to be said for restorations of varying degrees but in a way it's erasing history. A related topic, this is a reason to preserve (or at least archive) NOS examples. I applaud those who seek and shelf NOS examples, to each his own. Well used suits me. ------------- a bit of a drift but re "I was considering how they would have made it in the factory. I concluded that the riser would have been crimped in place along with the filler neck and pump sleeve. Solder paste would have been applied to all joints including the tank joint. The two halves of the tank would be crimped together upside down. Then the solder paste on all joints melted upside down. Possibly in an oven." the "...crimped in place..." might also be the double strong joint. Makers brag about strength of seams/joints, rightfully so. 1930s assembly line (pics on this site) the many dozens of task-designed work stations... does not, for me, support method you suggest. I could see top half of tank, pieces added individually, with top complete, the last step being the bottom is added. All that said I do not know. I am certain if an accurate walk-thru of the process step by step of how the Primus (or Svea or Optimus or Radius) assembly lines manufactured classic 3 leggers i am sure much of it would be surprising/enlightening. If only. thanks again
History yes, that soldering was probably done by my Granddad, or by a customer in his inn for a pint of beer, possibly at the bar. If it doesn't tidy easily it is staying as is. This how I know the stove was at my Granddad's inn in the 60s. The stove lives in a Castle crisps box. Castle crisps were supplied to the inn in tin boxes:
1930s assembly line (pics on this site) the many dozens of task-designed work stations... does not, for me, support method you suggest. I could see top half of tank, pieces added individually, with top complete, the last step being the bottom is added. All that said I do not know. Yes that would work too, assemble and join the individual top joints downside. The pump tube can also be jigged correctly. Operator can visually inspect then join the tank halves.
The crisp tin (of the type also used for biscuits and other bulky dried goods) is an absolute classic- these were used as combined storage/carrying boxes and windshields for stoves from the 1930s to their demise. They were valued for extra wind protection outdoors while priming, and cooking too especially in the case of silent burners. The tin may have contributed to the riser overheating- less airflow round the tank may have tipped things over the edge if the stove was being worked hard, melting a big batch of lead for example...
@Philip Ward noticed you are also missing the reserve cap which screws on the spigot when the burner is removed and lives on the end of the pump knob when not in use. Part no 2050 from base-camp.
A bit more stove history and possibly the cause of the overheating? Original trivet and legs lost, that's ok just knock a set up: The heat flow upwards from that is not going to be good.
Yes Philip, that is certainly going to reflect a lot of heat down once anything is placed on top of it, conventional trivets have ribs or ridges to raise the vessel above trivet level, so the hot gases flow between trivet and vessel bottom. If it's possible to use this in conjunction with the crisp tin then overheating is even more likely. A bit of an oddity though- most things will sit fairly happily on the legs of the stoves without the pan/ring trivet, prehaps this was made for some other obscure purpose? Primus did market a toaster, the base of which was a steel plate similar to this creation, the heat flowing up the central hole to heat a radiant cone of wire. But this was for short runs- making toast!
The tools finally arrived and I had a new jet fitted in seconds. however the NRV is seized solid. With the tool in a vice and the stove pushed down onto it I worked the valve both ways to loosen it. I had also soaked it in oil for about 1 week. When it came to twist for a break I thought I got it but the head rounded off. I've searched the forum for seized NRVs and it appears to be a common problem but I didn't find a guide on how to deal with it. My thoughts are: Drill the head off and through the flange to the seal. Drive the NRV into the tank or retrieve with a screw extractor. Retrieve the flange and seal separately, hopefully it is not soldered in place. Is that a plan?
I thought I was going to scrap it drilling down at the bottom of the pump tube but I kept the drill central and extracted the old NRV. I can now pump and the tank and new NRV hold pressure. It looks like I will soon have a working stove :-)
I think Grandad's camp stove is complete and good for a first (in may years) firing. I still have work to do on the wind shield (not shown) and tools. Also once it has boiled a pot of tea I will decide how much I want to clean it up. More and better pictures when it is fired up (if that is the correct term?). Thank you for the help and advice, and steering me away from disaster. Couldn't have done it without your input, Phil.
The size of a flame can often appear smaller due to lighting conditions and lots of pictures are taken in darker conditions in order to best show off the flame. Otherwise, is the pressure held OK or does it need constant pumping to maintain it? That would be a symptom of pressure loss due to a faulty seal or a leak (perhaps at a soldered joint). If the pressure is good but the flame asthmatic, then that could be down to low fuel level in the tank or it might suggest some restriction in the vaporising tubes within the burner, which can get choked up with carbon over time. Does it respond to a burst of vigoros pumping? There are methods to reduce the carbon, ranging from a wire or pipe cleaner up the outer tubes, blowing them out with carb cleaner, to the heat and quench method of releasing the carbon's attachment to the tubes and then blasting it out with compressed air. It is running flame out of all the lines around the burner cap, so it doesn't look too bad to me, but what do I know? Have you tried the tea test yet? If it takes half an hour to boil sufficient for a couple of mugs then you likelyt have got a choked burner!
@Dean, no I was very surprised by how little pumping was required; I thought it would need constant pumping. Vigorous pumping just made the flame stand off the burner. I backed the pressure off a little the flame moved closer to the burner and there it stayed while I boiled a large pan of pasta for this evenings meal. It brought a large pan to the boil and cooked the pasta surprisingly quickly for a small stove.
Looking good! It appears to be working just fine- the 'flamelets' produced by a silent burner will begin a small distance from the burner cap at full power. Boiling times should be as good as a small gas ring... Great to see it working!
Light it in a darker place and you might picture what appears to be a more vigorous flame. It looks like you have done a good job there. Have you got numbers 2 and 3 lined up yet? The Opti 45, sibling of your 48 but with the roarer burner, was my first stove. I now have one from the early 1930's, with the pot belly, like your stove - later versions had a flatter tank underside further off the ground, to accommodate a slightly smaller capacity.
