BernieDawg dropped by on this topic I posted in the fettling forum Military No.12 burner woes Reading that the spindle in the afflicted burner had a missing pinion tooth, he kindly popped a replacement spindle in the post to me, but something with that distinctive paw-print too Yes, a BD 'Top Dawg' cap for the No.12, and an incredible piece of work it is Gary asked me to try out the cap - a sort of test-drive - and report back on how I thought it did the job. Absolutely, said I! Now, the No.12 burner is a rough old thing in some ways and initially I found that casting imperfections around the inner circumference of the mixing chamber ... ... made the the BD cap spigot on the base a slightly tight fit. No problem, I dressed the aperture with a round file, taking off the casting high-spots Perfect fit! Alongside my roarer burner plate, (still shedding oxide flakes you'll notice) the BD cap was Silk Purse, my roarer plate Sow's Ear Ok, the experiment began. Priming Full power Getting down to a simmer, going lower ... ... perfect simmer, and with those businesslike windscreens on the No.12 it stayed that way on a day with a stiff-ish breeze Tea test! Those flames erupting below the burner are as a result of the roarer burner locating lug slots in the burner shroud I've another No.12 which came without a burner so I grafted on a silent burner from an Optimus 111T ... Though it can be removed and replaced with the Optimus roarer variant, the beauty of BD's cap (apart from the sheer beauty of the cap itself) is that like the 100 silent 'damper' cap that inspired Gary's early experiments ... Silent 'damper' cap ... it turns a roarer into a silent burner in an instant - and back again when the mood takes Initial impressions? Simply superb. The cap functions perfectly, is impeccably made and allows the No.12 to perform as powerfully and controllably as in its roarer guise, but does so at a whisper! More testing yet ... ... TO BE CONTINUED John
After a few test firings, I took a closer look at the cap, now a classy 'blued steel' finish Gary will confirm, but looking at the burner holes, there's an apparent graduation in hole diameter between rows. If I'm right, Gary has a reason for that ... Gary? The BD minicap I have is a heck of a versatile component, going on Primus 71, Radius 46, Primus 96, Optimus 8R ... I could see the potential for the No.12 cap having alternative (stoves) applications, starting with an old favourite that I featured here Chrome Primus No.10 in French enamelled stand Here's that stove Still thinking about it, but having read a recent post about the amount of hours Gary spends creating BD caps, I thought I'd sample some of the labour. Taking the BD cap to a buffing wheel, after half an hour (!!!) the best I could manage was from this ... ... to this Ok, maybe I've got the wrong grade of buffing soap, or diameter of mop, or mandrel RPM ("a bad workman blames his tools" they say) but I take my cap off to Gary (pun intended) for astonishing dedication to his craft! Right, back to the stove/cap experiment. This is the Primus No.10 burner getting down to basics That burner mixing chamber aperture is awfully close to the spigot on the base of the BD cap, which fitted ... ... perfectly And it fired up perfectly too. Powerful maximum ... ... steady, reliable simmer There was no underburn either, the cap handling the power of the No.10 jet effortlessly ... ... and bringing a couple of litres of water to the boil in quick time I'm sure there are other applications possible too. The BD cap on a Primus Omnifuel worked well combustion-wise, but was just a bit too tall for the height of the pot rest - I've an idea for spacers to go on the pot rest though Brilliant, Gary, just brilliant and many thanks for the 'test drive'! John
Ah you beat me to it John. Great review and pictures fellow tester and stovie. I am another very lucky tester of TD2&3. TD2 is a very good working prototype and TD3 is the older sister to your TD4. I must apologize to Gary for not getting to this sooner but work... ah you know. No excuse. About the holes. This is what Gary said in an email to me. Anyways, I wanted to quickly add some of my pictures. The puppydawg is one small cap next to the Topdawg Top row Primus new 4010, Puppydawg PD4, Midicap MD21, Minicap BD22. Bottom row Topdawg TD3, Primus 4200 and Primus 4010 for P100. Stove eclipse Cheers, Jeff
holy smokes, look at those caps! that's what i call 'putting on the Dawg!' great review and lineup of pics - simply beautimous!
Sorry for butchering your pictures John But wanted to point out the flames coming under the burner bell. The flames are coming out of the 4 tabs that hold down the burner plate. This doesn't seem to affect the burner at all. And may act like the burner on a Tilley CS56. I first noticed this after a few minutes of a test burn. At first I thought it was a hole in the burner. Thoughts of Bill's burner problems came to mind. Jeff
Field test of the BD 'Top Dawg' cap next. The No.12 stove obviously isn't ideal for backpacking, but if it's the only item in the pack and separate arrangements are made to carry the other brewing necessities ... then out it goes Just the sound of the waterfall and not the competing sound of a roarer burner! Last time I was there, over Christmas, this was the scene John
Thanks for the feedback/report John and Jeff! Your burn looks to be about what I was getting. Just a tiny trace of yellow that I can't seem to get to go away. Sorry about the fitment and your need to adjust your burner. It fit great on my #12, but I reckon that there is some variation between burners. 320 holes means that these are probably not viable for production, but it was fun to build some. Thanks to Jeff for getting me going on the idea and also for being so patient whilst I flopped about for a loooooong time figuring it out. Excellent pictures once again! Cheers, Gary PS - If you really do want to bring that cap back to a shine, John, work the oxidation discolouring out with 400 and 600 grit carbide paper, followed by 0000 steel wool. Then go to the buffer for the high shine. I use black emory compound on one wheel, then switch to red rouge on another wheel. It's faster to use the papers first rather than trying to do it all on the buffer. The wax of the compounds may build up in the holes of the cap, but do a rinse in Coleman fuel/naptha and that wax will pretty much melt away.
Hi Gary, I really like your BD special for a British No.12 stove. I reckon the flame pattern is almost perfect. If there is a hint of red at the highest power it is due to a slightly fuel-rich mixture. The fairly deep skirt of the burner somewhat restricts the air supply to the burner head....at least compared to a conventional No.5 type burner with a whole ring of air holes surrounding the vaporistaion chamber. It is actually the 4 holes associated with the locating lugs for the flame plate which provide essentially all the external air supply to the BD cap when used on the No.12 burner. Great work as always. Best Regards, George.
That is a interesting and great point George. The air flow in this burner is a little off due to the lack of the air holes the Primus 5 burner has. Would drilling holes in the burner bell make it better?
Greetings, Guys, John, what a brilliant setup for your #12!! Gary has really gone another light-year step ahead in his development of this wonderful Top Dawg cap!! Even though I realize that it probably won't be offered for general sale, I truly appreciate the development and work that it took to create such a fine silent cap, and you have done it true justice with your post here!! Well done, all around, Mates!!! HUZZAH!! Truly brilliant! Take care, and God Bless! Every Good Wish, Doc P.S. Jeff, LOVED the Dawg Family Photo, too!! Well done, and tons of canine fun!!
Thank you Doc, I have two more caps coming making 8 caps from Gary plus the rebuilt 4200. Do you think I am hoarding them? Jeff
Most interesting. For no particular reason, other than I think they look neat, I'd like to have one of these stoves but the shipping costs would break the bank this year. lance
Incredible cap! thanks for sharing John. Have you noticed any difference in the fuel consumption or heat output. ( I know its a blast furnace either way if you want it to be, with a huge fuel capacity)
I'd guess fuel consumption is the same as with the 'roarer' cap John, determined by the jet orifice size and the tank pressure. Heat output is another matter, determined by the efficiency of combustion. Bernie Dawg's caps are surely efficient, and that's borne out in the respectable boiling times I've noticed, at least comparable with the roarer's equivalent effort. John
