Earlier this week I was walking past my local camping/fishing shop and on the street outside was a battered green biscuit tin with something intriguing inside. A closer look revealed a Primus No 5, fairly tarnished but otherwise good, with a note reading "£10. Needs attention. Bits inside." The 'bits' turned out to be the silent burner caps; lucky they had them as I had never seen a silent burner before and wouldn't have discovered until later that they were missing. The chap in the shop seemed almost reluctant to sell it to me, emphasising that it would need a rebuild before it could be used! I can't strictly describe this stove as my first fettle, as I have in the past fettled a couple of paraffin blow lamps and my dad's old Optimus 8R (currently in need of new paint after a slight fireball incident the last time I took it camping ). It is however the first time I've fettled a paraffin stove, and I learned quite a few things along the way. The first thing I did when I got home was to put some fuel in and cautiously fire it up outside: There was a slight breeze so I had a bit of trouble priming it until I improvised a wind shield, and I quickly found that the tank wouldn't hold pressure. I was able to boil a kettle on it but only by pumping almost continuously. The shiny spot on the tank is where I'd experimented with cleaning it with Scotchbrite, but other than that it's pretty much 'as received'. A bit of Googling later and I found this website, and the "fettlers masterclass" articles. I ordered a set of burner washers from kerophile, and on eBay I picked up some citric acid, nitrile rubber sheet, and a bottle of Rustin's metal lacquer. Next I knocked up a couple of tools to remove the nipple and the NRV: Getting the NRV out was no problem, but unscrewing the two halves of the valve proved more difficult, and I accidentally damaged the thin brass tube in the process. I soldered the split end of the tube back together, then I replaced the knackered spring with something similar that I cannibalised from a ballpoint pen. This, I hoped, would cure the leak. When the nitrile rubber sheet and the burner washers arrived I cut out a new filler cap seal (by drawing round the old one and cutting it out with sharp scissors), reassembled the stove, and gave it another try. This time it held pressure a lot better but the NRV was still leaking to the extent that I had to pump it back up every thirty seconds or so. At this point I decided to order a new valve from Base Camp. Along with a few other spares and postage the order came to double what I'd paid for the stove! The citric acid arrived next, so I went down to Wilkinsons to buy wallpaper paste to make up a batch of GSR. After staring in confusion at the many different sorts of paste in the shop, I settled for the cheapest one! One problem I ran into while cleaning the brass was that there were many areas of the stove where patches of the original lacquer still adhered. The brass under the lacquer was tarnished and the acid was unable to lift it, so to get a uniform shine I had to use a combination of Nitromors and various abrasives to get rid of the old lacquer before re-applying the acid. I had a go at cleaning out the inside of the burner by repeatedly heating it with a hot air gun (I didn't have a working blow torch to hand) and quenching it in water. Hardly any carbon came out, but from peering into the bottom of it with a torch and blowing through it, I suspect it was already pretty much spotless inside when I bought it. The pump leather seemed fine so I simply lubricated it with some 3 in 1 oil. The cooking ring I cleaned up by stripping off the old brass paint, wire brushing as much of the rust off as possible, treating it with Jenolite rust killer, then spraying it with two thin coats of "barbecue paint" (cheap high temperature matt black stuff). I looked into getting hold of some high temperature gold paint to match the original but it would have been expensive and I suspect it would quickly get scratched and sooted up in use anyway (I'm intending to use the stove for camping). After polishing the brass parts of the stove until I could see my face in it , I washed the polish off with soapy water and brushed on a coat of Rustin's metal lacquer to maintain the shine (only from the riser tube down - I figure it would just burn off if I put it on the spirit cup and burner). By this time my new NRV had not arrived from Base Camp and I was impatient to get the stove finished, so I whipped the old NRV out to have another look. The problem was clearly that the rubber bit in it had gone hard. I didn't have a suitably sized piece of nitrile rubber to hand, but I did have the thin sheet I bought to make a replacement filler cap seal. "What have I got to lose?" I thought, and set about bodging the seal by cutting out a little disc of new rubber, slicing an equivalent thickness off the face of the old seal, and reassembling the valve. The valve now seals perfectly, but you have to push the pump piston quite hard to get the air to pass through it. I might try shortening the spring slightly if it gets on my nerves. This morning I cleared a space in the garage, set up my video camera, and recorded a video of myself brewing a cuppa! In the video you may notice a bit of smoke curling up around the kettle. That was from the new high temperature paint on the cooking ring 'baking off' - it stopped smoking after I had run it for another 20 minutes. It seems to be burning very well now and not losing pressure. It took eight and a half minutes to boil a full 1 litre kettle of water. Incidentally I'd like to find a more 'period' looking kettle for it... My next task will be to knock up a wind shield. Next weekend I will be camping for two nights at the Morris Minor Owners' Club National Rally and I intend to take this stove with me. Last year I took the Optimus 8R and managed to get some use out of it despite several well-intentioned fellow campers offering me the use of their modern gas stoves when they saw me struggling to prime it out in the open. That was the weekend when we had such heavy gales that half the gazebos in the show field blew away overnight!
Welcome to the forum & thanks for a great first post! Lets have more pics of it with those old Moggies next weekend!
Nice one mate, cut a front panel out of the biscuit tin and use the stove inside the tin (the tin makes a great wind shield), this was common practise years ago
Thanks all! linux_author: Nice but not quite what I had in mind. There's one on eBay at the moment that I have my eye on. rik_uk3: I've been considering doing exactly that. Not yet figured out the best way to reattach the panel when I want to close it up though.
Hi Alex, Good commentary of your fettle. Your Primus 5 is one of the later ones, probably made in the 1960s at the time of the Primus Trading Company. I suspect that the biro spring in your NRV is too long/strong and that is why the valve is reluctant to open when you are pumping. Here is a link to a very similar vintage Pr.5 in its custom-made box: https://classiccampstoves.com/threads/10487 Best Regards, Kerophile.
Hi Alex, Here is a link to some photos of the Pr.5 in the box: https://classiccampstoves.com/threads/5467 Best Regards, Kerophile,
Thanks Kerophile. My biscuit tin looks very similar to that one, except it's quite tatty and has been very roughly brush-painted in a dark green colour, so I'm not too bothered about butchering it to add a hatch in one side. My stove doesn't have a date code anywhere on it either. It does look exactly like the one you gave as a retirement gift.
Hi Alex, once you get your new NRV fitted don't be afraid to pump up the stove well! This link will show you the sort of flame pattern you should aim for on full power: https://classiccampstoves.com/threads/8876 Primus claimed that you could bring 2-pints of cold water to the boil in 4.5 to 5 mins. on either their No.1 or No.5 stoves, and I have no reason to doubt them. Good Luck with the biscuit box mods. It will make your stove much more usable out-doors. Best Regards, Kerophile.
Alex I have a biscuit tin windshield on which the former owner ( and maker ) had folded over the edges after cutting out the front panel. If possible this is worth doing as the bare edges will murder your fingers when pumping it up etc.
I fiddled with the valve and got it working a bit better, then I fired the stove up, gave it about 15 pumps (the flame did look slightly bigger than yesterday), and stuck on a kettle containing 2 pints of cold water. It took 9 minutes 8 seconds to boil. How can you tell how much pressure you can safely put in? I don't want to damage the tank.
That depends on how much fuel is in the tank, as you can't compress fuel, only the air above it. So more fuel means less pumping initially. Remember that there is a limit to the rate at which the burner can vapourise the fuel, so continual pumping will not produce a bigger frame, there is a limit. I wouldn't get hung up on boiling times, they are not the measure of how good a stove is; the better measure is how controllable the flame is and what range of outputs it can achieve to assist you in cooking. If it hasn't been run for a while I would leave it running outside to use a full tank of fuel which will help clean out the burner tubes.
WOW I have a number 5 too, I drive a 1960 Austin A40 as my everyday car and I'm only over in Rossendale!!! We will have to meet up sometime! Having said that, your number 5 looks a LOT nicer than mine (mine needs a lot more cleaning before it gets to that!!) Very nice job indeed you've done there!! EDIT: I wish I saw that stove outside that shop as well - whichever it was!!
Hi Calum, that would be cool. I have two Minors and I drive one or the other every day. The shop is in Nelson town centre near my office.
Excellent! what colours are they? I've heard there is a red A40 in the Nelson area - you haven't seen it or know who owns it do you? EDIT: forgot to say, good tool making! I keep meaning to make myself an NRV tool but usually I can find a 1/4" drive socket or similar that fits the bill!!
A royal blue 1963 traveller (currently off the road for cosmetic work and a suspension rebuild), and a 1970 2-door saloon in various shades of green and iron oxide brown, with tasteful patches of duct-tape silver. As well as driving them every day I like to take them on road trips. I've done Land's End to Orkney (via John O' Groats) in both of them, I've circumnavigated Ireland in the traveller, and most recently I drove around the Scottish highlands and islands in the saloon. No, I'm afraid not. There are a couple of other Minors in Nelson that I see occasionally but it's becoming increasingly rare to see classic cars being used on the road. Every year there are fewer of them about. I don't think we saw one other Minor on the whole Scottish trip. :frown: Thanks. It only took about half an hour once I'd found a suitable bolt to make it from.
I got my 'new'* camping kettle from eBay today. It's slightly bigger and has a wider base than the one I was using previously. Amazingly this appears to have cut a couple of minutes off the time to boil 2 pints of water (now down to 7 mins)! My test methodology wasn't very rigourous however it seems clear to me that the wider base was able to catch a lot more of the heat coming off the burner. Perhaps the boil times Primus quoted in their sales literature (assuming they were genuine) were using a special high-efficiency boiler that was able to capture nearly all all of the burner output? * Bought in 1967 from M&S to use on a honeymoon camping trip to Cornwall and stored in the loft ever since!
