Four years of a wait for THIS fuel tank and vapouriser assembly to get reunited with a stove. The perfect candidate came along, a low price on a complete but rough Primus 77 of 1934 vintage, so an early one given the twenty-one subsequent years the ‘77’ was in production. What kept the price modest was a caved-in end to its fuel tank ... ... a component I happened to have spare! While swapping control wheels, correct metal one for the plastic one on my spare, I realised the plastic one wasn’t ‘wrong’ for that control spindle/pricker rod. You’ll see that the threaded portion is longer on the one intended for the plastic wheel ... ... to accommodate the thicker mounting boss of the plastic wheel. A 1937 catalogue in the Stove Reference Library lists a Primus 61 range - intended solely for indoor use and lacking the Model 77 camping stove’s pack-away components, lid and windshields. It has the plastic and not the metal knob. ‘77’ from the same catalogue for comparison. Much cosmetic work to do and a missing foot/stowage clamp to fabricate from 5mm diameter steel rod, but everything works, including the pre-heater. The trivet is holed by rust in one spot - a silbrazed repair awaits. Worth the wait. John
Great work resulting in a lovely flame pattern. Look forward to seeing the completed fettle. Best Regards, Kerophile.
I think I've got one of those 77s somewhere. Looking at your beautiful flame shots make me want to track it down and fire it up. Nicely done. Ben
I've always liked the design of those 77's. Yours runs great, are you going to paint the case or keep it as is? Jerry
Well, Jerry, the trivet will need painting after I’ve zapped it with the blowtorch for the repairs so it would make sense to strip and paint the case too. You certainly have Ben, THIS ‘35 year model, which is period-correct to my ‘34 to justify utilising your excellent decal close-ups to add the finishing touch with water-slides when I’ve re-painted the case. John
I hope you go well with it, @presscall. I have a couple of 77s in the cue in the shed. I like the cut of their jib. Cheers Tony
Yes, John. My lantern queue (note my thoughtless mistake above!) is moving faster than my stove queue at the moment. Tony @presscall
I'd forgotten that I posted photos of my 77 in the reference gallery. Hell, I'd even forgotten I had it until I saw yours. Looks like it's in pretty good shape. Now all I have to do find it. Ben
Nice job John. I have to jump on mine and get it done. New favorites keep pushing it back and back and back...you know how it goes??? lol This might...I say might motivate me. Alex
Bit of progress on the holed trivet. The problem. Shaped brass sheet patch. Testing for fit, front ... ... and back. Hard solder (silbraze) applied.
More progress, clean-up of stove parts and getting acquainted with the various components. Showing the lever arrangement for engaging/disengaging the pre-heater feed tube. The spanner (wrench) supplied to conveniently adjust the graphite packing nut. Secondary burner throttle range, closed ... ... and fully open. Brass components, manifold. Under a layer of paint, what remains of the decals on the inside of the lid.
Paint-stripped the case, the original finish, dark green, and (thankfully) the decals proving impervious to the paint stipper chemical I used. I’ll flat the residue diwn and test a patch on the underside to see how it takes the paint I have in mind, then mask off the decals and fabricate a replacement for the missing ‘foot’.
John, You just shared your successful result. in ref. gallery. I post to thank you for yet another example of excellent detailed posts. I comment also re how very unique this stove is among Primus offerings of the time. One main functional difference being vapor is delivered to mixing chamber inside burner head (although, it seems no additional mixing is required). No inner cap needed. -VS- all other Primus silent burners the final mixing occurs at the burner head, inner cap needed. source of images. That big wide burner being kind of a one-off for Primus, used only on the 77 and none other like it i can recall. I'm curious, > given the test of time, and it's unique, is this model design considered a success, a winner? > there was mention, and true, it borrows design features from US/CA suitcases, a BIG difference being: all that beautiful Primus brass!! [[ edit and kero vs petrol ]] Do you have an opinion John... In moderate outdoor temps, might the 77's brass works (thermal conductivity) deliver improved self-pressurizing (less pumping needed)... better than US suitcases? not a noticeably difference? or not sure? EDIT: duh, I forgot for the moment US= petrol, your safer 77 = kero, right. I suppose that makes a comparison apples to oranges . Still, it is a different vaporization process (for Primus kero) and I am curious how well it self-pressurizes? -------------------------- 1930s Primus 77's: 16 3/8 x 9 1/4 x 4 3/8" at 9 lbs is considerably smaller and lighter than typical US green suitcase. The 77 specs compares very closely to successful smallest US suitcase 1922 AGM No.3: 14 1/2 x 8 3/8 x 3 1/2 at 9 lbs. Thanks again tag @presscall
No, the Primus 77 too is a gasoline stove Mark. My opinion on the Primus? It’s a well thought-out design, without borrowing particularly on Coleman, AGM or PW technology. Primus’s alternative to Coleman’s locking check valve for instance is its pump rod threaded just below the knob to screw into the pump tube cap, pushing a conical tip to the pump rod into the air inlet hole of the non-return valve. Yes, no Coleman instant-light feature, but an effective pre-heater facility just as quick to pre-heat as the Coleman’s air-bleed pre-heat. John
