Found her true Rhythm, Life after The Cabinet of Curiosities

Hi all, here's is one of my early Primus No.1 cookers that i recently put back into use after a quick fabrication of a new leather Plunger on the bench grinder. Cheers

 

How’s that done?

John

 

Beats me but @AussieBurners has it up and running like a champ.

Ben

 

Welcome to CCS @AussieBurners

That's a nice flame

 

Welcome to CCS.

 

Hi John. I use a thick leather hide, 3mm-3.6 / Drill your center hole on a drill press or just a hand drill or you can punch it, then i cut a rough circle larger than i need to fit into plunger tube around the drilled hole, making a rough washer, then i use a tight fitting drill bit in the drilled hole, usually the same drill i drilled the hole with ...position the leather on the flat shank part of the drill position the made leather washer between your thumb nails both sides while holding the drill bit (You can use a steel rod anything that fits in the drilled hole) then you proceed to spin the washer against the bench grinders face carefully adding needed pressure with thumbnails, the washer is spun into a perfect circle with the drilled hole perfectly centered by being spun. Spin the washer until you get the perfect fit, use some oil on washer to soak as you go, taper the washer edge if desired with the angle you hit the grinder face, when bolting the now spun washer onto plunger rod you can alter the fit with nut pressure that pushes the leather out, you can then fine tune the fit and spin the leather if necessary while it's on the plunger rod.

Thanks for the welcome guys. Cheers

 

@AussieBurners
Ingenious and thanks for the explanation. It reminds me of a similar process I used to create a dished profile on a nitrile disc to make a Radius safety release valve washer using two Dremels, one fixed and the other hand held.








Turns out I was labouring under a misconception that the Radius SRV had that profile from new, when it only acquired that shape when it’d been in use for a good while!

 

Yes I have used a Dremel many times for fabrication and a mini lathe, I find making leather plunger washers works far better than buying a dried-out shrunk cup that you find in a kit, that may just fall apart being a thin cup, you can tailor/ tweak the fit making them with a premium tanned leather plus they certainly don't need to be cupped so making them is very easy, you can also stack them if you desire a cup width

 

Optimus No.1 I'm salvaging, IT came with some terribly repaired legs the soldering was near an Inch wide and rough as guts, that's what i Am addressing currently.













Here it as i found it.






Tomorrow we will clean the legs up, solder the legs back on and make a new leather plunger seal.

 

I certainly agree that old stock and original leather cups are usually useless, they might soften up enough to function after oiling but can't be relied upon in serious use. I always try tearing old ones apart, only a few percent survive, and the failures would have soon broken down in use and fragments of leather have the potential to prevent the pump valve seating, putting the stove out of action if you're out and about even if you carry a spare leather and tool to fit it.

Not sure about the longevity of a flat leather disc though- I imagine there is a reason the cup shape was used on all the countless tens of millions of stoves, lamps and blowlamps sold over a century or so.

 

I will let you know how long the leather lasts, It's a good 3.6mm solid thickness of tanned leather and i can fab one in under 10 minutes from a belt leather

 

So, this is your 1st attempt at this method?

 

If it works for you then why not, but it seems quite time and tool intensive for something which might not hold up as the sealing/wearing area is much smaller than a cup. The original pattern cups are much simpler to make, and can be as easy as:

Cut a vaguely round 30mm disc (by all means punch, or scissor round a template but perfection not needed)
Massage in (or under running) water for a few seconds to saturate
Shove into end of pump tube with the largest socket which will fit (or anything else hard, round and the right diameter)
Leave to dry overnight
Trim off excess with scissors, punch hole as nearly concentric as you can (although it's not utterly critical), oil and fit
Total time input a few minutes.

Or going full luxury as you have a drill press, a piece of ally or plastic riddled with 17mm holes makes an excellent and easier to use former than the pump tube itself, and can be used to make half a dozen or more in a few minutes.

 

Plenty ways to skin a cat, it's nothing but a tight-fitting seal needed that push's air, all is working well regardless of how we get there, 8 liters of Kero so far and not a hint of any air escaping past the seal. I will try other methods I have a dozen more stoves on the way in the post I'm sure some may require a different approach if they have a different plunger rod set up that requires i fabricate another fix out of materials at hand.

 

Splendid sausages!

 

Thanks