Category Archives: Ask BernieDawg

NRV Head Dimensions

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Hi BD
I want to fix my old stove and I need to get the NRV out of the pump tube to replace the old rotten pip. I tried to buy one of those NRV wrenches from S. Korea and, then, from the UK, but those sellers don’t seem to be able to ship overseas due to COVID-19. Can you tell me the dimensions of the NRV head, please?
TIA, Old Stove Guy
Hi, Old Stove Guy
Sure. You bet. Here are some photos. All measurements in millimeters. This is a genuine Sweden-stamped and Swedish-made NRV. The dimensions are proper for the vast majority of NRVs in stoves out there. Be aware there are a few stove companies that vary from this style. Optimus, Primus, Radius, Svea/Sievert and Enders all use this style of NRV.
P2070106.jpgP2070108_2.jpg
Length
P2070110_2.jpg
Width
P2070112_2.jpgP2070113_2.jpg
Depth
P2070114_2.jpg
Head diameter (just for interest)
Iif you are a home hobby sort, it’s probably easiest to take a steel bolt just under the inside diameter of your pump tube, cut off the threads with a hacksaw, and then cut a slot just slightly undersized in the end of the cut-off bolt with the hacksaw. Clean the cut to exact dimensions with a file. The end will look like the end of this more polished out-of-production NRV wrench made by now-retired and out-of-sight tool maker Stu Burgess in England: (In other words, you can’t get these any more.)
P2070115_2.jpgP2070117_2.jpg
If you are more of a machinist, maybe have a vertical mill, you can use a 4mm end mill with two passes in your mill and make a closed end wrench like this:
P2070118_2.jpgP2070120_2.jpg
The closed-end wrench just above is an original Optimus wrench for marine stoves. The advantage of the closed end wrench is that it won’t do this in use:
P2070125_2.jpg
I tried to make this one up from a bolt recently to fit into a specialty off-brand stove whose NRV head is down inside a pocket in the end of the pump tube. That’s a rare stove and you don’t have that concern.
The failed example I show directly above is made from a too small diameter bolt. So, try to keep your bolt as large in diameter as you can to avoid the sides bending out like this. More material gives better support.
Lastly… here are some unsolicited pointers:
  1.  – the best way I’ve found to remove NRVs is to put the wrench upright in a vise, put the stove over the wrench, then use strong downward force on the tank to keep the wrench head on the NRV head so it doesn’t skip off the end of the wrench. I demonstrate the technique in this section of one of my YouTube videos: https://youtu.be/2LKsxIYCTko?t=226
  2.  – tighten the NRV just slightly/gently before trying to untighten. This may help to break the brass-to-brass bond if there is no NRV head washer present
  3.  – if you chose to use penetrants… it will do no good at all to put the penetrating oils down the pump tube. The NRV is air and liquid tight sealed inside that pump tube. Instead, use a small brush and reach inside the tank through the fuel filler to apply penetrant to the outsides of the pump tube where it will run down the tube and get into the exposed threads of the NRV that are hanging out at the end of the threaded pump tube end block. That is where you want penetrating oils to assist.
Hope that helps. Good luck!
BD

Heat & Air Clean Regulated Burners?

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Hi BD
Is it possible to “heat and air clean” the carbon and other crud from a regulated burner using compressed air and a torch?
Thanks!
Burner Guy

Hi Burner Guy
Thanks for your question! Yes! Absolutely, you can clean regulated burners using the manufacturer approved heat and air cleaning method. Like all burners, you’ll want to disassemble the burner, removing the jet, the spindle and the spindle nut.
But, you’ll need to close off the spindle opening.
So how to block the opening at the spindle? What I did was take a spare spindle nut and silver braze a cap on the open end. I just used a slip of brass sheet over the open end and machined it round after the brazing. But, you could leave it rough and all and it would still do the job. 

Once threaded into the spindle housing, the modified spindle nut will direct the air through all parts of the burner and out the jet.

Hope this helps!

(PS – Before anyone asks… yes, this is a very odd burner and is somewhat rare. It was close to hand from a long-term stove project I’m working on. So, yeah, it looks a little different from your everyday standard regulated but the idea is still the same.)
BD

Stove Part Supplier Links

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Here’s a list of stove part suppliers that I’ve used or know about. As I think on it, I may add more, so check back frequently. This list is current as of June 2020. These suppliers tend to come and go in many cases. If I’ve listed your outfit and you don’t want to be listed just let me know in an email. If you find a dead link or if you know of a link I should add, please let me know by emailing: bd@berniedawg.com and I’ll try to add, update or remove it as required as soon as possible. Thanks!

USA:
EU
UK:
Australia:
South Korea:
Taiwan:

Which Cap for a “Multifuel”?

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Hi BernieDawg
I  have  a  short  question  about  the  bernie dawg silencer caps. Does the Omnifuel Cap fit to the Multifuel Burner?
Best regards,
Stove Guy
Hi Stove Guy
Thanks for your questions.
I’m not sure from your question which “Multifuel burner” you are meaning. Primus has made several different stoves they have called the “Multifuel”.  And, Trangia has sold two different types of “Multifuel”-named burners. All this makes things confusing if you don’t go by model numbers or full product names.
Sooo… I’ll cover them all. Sometimes “short questions” need long answers. Sorry about that. This is a bit complicated, so please read through this carefully.
Omnifuel 3289
The OmniDawg cap is for the Primus Omnifuel 3289 stove.

Omnifuel 3289

Trangia X2 Multifuel 750001 Burner made for Trangia by Primus – current production
The Trangia X2 Multifuel 750001 burner is made for Trangia by Primus, but it is made in a way so that it is not as powerful a burner as the Omnifuel. It looks like an Omnifuel, but it’s less powerful because of the reduced power jet supplied with the X2 for use with the preferred fuels (isobutane canisters and white gas). This is also a very expensive burner for what it is. You can usually find used or even new Omnifuel stoves for less than the cost of the greatly overpriced X2. You’ll also retain the precision control and simmering using an Omnifuel due to its spindle control (absent on the X2).

For the reduced power Trangia X2 Multifuel burner, the PolarDawg silent damper cap works best using isobutane canisters and white gas due to the smaller jet supplied for those fuels. The DragonTamer is a pretty good second choice for these fuels. Trangia makes it pretty clear in their product manual that isobutane canisters and white gas are the fuels of choice for this burner. If you intend to use kerosene with this burner (I discourage this fuel for this burner), then the supplied same-size-as-the-Omnifuel (0.28mm) jet that comes with the X2 will need to be used. This turns the burner back into a simmer-disabled Omnifuel burner, so you should use the OmniDawg cap if you decide you absolutely must use kerosene.
Some clever stove users have changed out the jets on their Trangia X2 Multifuel burners so that the X2 runs the same jets as the Omnifuel. For example, using a 0.37mm jet will let you run the X2 burner with white gas at the same power as the Omnifuel. Using a 0.45mm jet will let you run the burner with isobutane at the same power as the Omnifuel. If you intend to do that, it may cause melting of your Trangia windscreen surrounds if you are not careful and attentive. But, using the more powerful jets makes the X2 more like the Omnifuel, and a OmniDawg cap would be the right one to use. If you use a 0.25mm jet with kerosene (not recommended), thereby reducing the output of the burner, you can use the PolarDawg or the DragonTamer. Confusing isn’t it?
Caution! I do not recommend the use of a re-jetted X2 with an OmniDawg cap with the Trangia 27 sets as the small size of the surrounds puts the surrounds too close to the flame. Trangia 25 sets are okay… if you are careful.
Trangia Multifuel Burner 780001 made for Trangia by Optimus – discontinued product
The original Multifuel 780001 burner sold by Trangia was made for them by Optimus and is a stripped-down Nova burner. There are “fins” inside the burner bell of this burner.
The proper silent cap for this burner is the Dawg-A-Nova cap.
Primus 328894 and 328896 Multifuel
The newer 3288 (correctly termed the 328894 or the newer 328896) Multifuel is a reduced feature (no stove-side control spindle) Omnifuel-based stove. Sort of a Omnifuel “lite” stove.

Multifuel 328894 or 328896

For a bit more money you can get a real Omnifuel and the additional cost is well worth it for the control spindle. Because the Omnifuel is also much more popular, you can even commonly find new Omnifuels at discount for prices well below the retail cost of the 328894 or 328896 Multifuel. The 328894 or 328896 Multifuel comes with a reduced size jet set compared to the Omnifuel. While the Omnifuel has 0.45mm, 0.37mm and 0.28mm jets for isobutane, white gas, and kerosene, respectively, the Multifuel comes with 0.37mm, 0.32mm and 0.28mm jets for those fuels. This is why the Omnifuel produces 3000 watts of power while the Multifuel only produces 2700 watts of power. If you plan on mostly kerosene use, get the OmniDawg for this stove. If you plan on white gas or isobutane and intend to use the correct jets for the Multifuel, then you need a slightly less powerful cap like the DragonTamer or the PolarDawg to match up with the lower output of the Multifuel.
You can also “cheat” a bit if you are planning on using white gas by using the 0.37mm jet that came with the Multifuel for white gas. This will increase the white gas flame output and let you use the OmniDawg cap just like with an Omnifuel stove.
Sorry that this is a bit confusing. Primus is marketing a strange beast with the Multifuel. Your best bet is to bypass the odd Multifuel stove and go directly to the full-featured, award-winning, and more powerful Omnifuel.
Primus Himalaya Varifuel 3278 and Multifuel 3288 – discontinued product
These are two long discontinued stoves from Primus that I am often asked about. Both stoves feature small diameter burner bells and smaller jets than the Omnifuel.

Both stoves, the Varifuel 3278 and the Multifuel 3288 work well with the Minicap, either with or without legs. I recommend the Minicap with Legs if you are only planning on using the Minicap with one of these Primus stoves. If you would like the flexibility to use your Minicap on other small self-pressurizing stoves like the Optumus 80, Radius 42, or Svea 123/123R, then I recommend the Minicap without Legs.

Sorry for any confusion this may cause. Primus and Trangia haven’t been kind to us in naming so many stoves as a “Multifuel”. I hope my post will enable you to select the right cap for your stove.
Happy Camping!
BD

Stuck NRVs??

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Hi BernieDawg
I have this great old Primus 100 stove that I’m trying to fettle. I’ve got the NRV loosened up, but it seems to be stuck in the bottom of the pump tube and won’t drop out of the tube. It’s hung up somehow. It wiggles around and is loose down there at the bottom of the pump tube. I wonder if there’s some gunk in the tank that’s hanging it up?
What can I do to get it free?
Sincerely,
Stuck and perplexed
____________________________

Hi Stuck

Well… I think this might make a good blog topic actually, because I get this question and this issue fairly frequently. And, don’t feel bad – it’s common and it happens to me, too. Here’s how I handle it.
1. best thing is to buy a tool which can solve 75% of these sort of stuck NRV issues. What you want is an “ear forceps” aka an “alligator forceps”. They come out of Pakistan (for reasons I don’t understand) for pretty cheap. They are stainless steel. And they help you with other tank related stuff, say reaching into a tank to retrieve something, or at the end of the pump tube in case a rotted leather pump cup gets stuck down there. Check pricing on eBay, but here’s a screen shot of a pair I picked at random just so you can see what I’m talking about:
The larger one is about 6.5″ long and is a great size for pump tube and stove tank work. But, you can get them a lot longer, too. It was selling as a Buy-It-Now with free shipping for only $6.50.
2. next thing is to take your little flashlight and peer into the tank. Is it all black and gooey in there? If it is, then your idea about gooey stuff being on the end of the NRV barrel is probably right. Here’s how to fix that and clean your tank, too. Get a gallon of acetone at Home Depot, Lowes, or wherever. Fill the tank with it. Let it soak (plug the openings with some paper toweling to control evaporation). If you want to get really industrious, you can add some BB’s to the tank and shake it around. Pour out the acetone into a metal or glass container through a coffee filter for reuse – you can reuse it on many tanks. Shake out the BB’s, or use a magnetic pen tool to remove them. Rinse the tank with just a splash of acetone and you should be good to go. Acetone dissolves the black gooey crud (dried kerosene). It will dissolve the gooey crud on the end of the NRV barrel and then it should pop right out. This should take care of another 20% of the problems.
3. two other issues can cause the NRV to hang up in about 4% of cases.
a. there can be a little burr of brass where the vent hole in the side of the NRV barrel was punched in the barrel. You can use your alligator forceps gripping the NRV head with an unscrewing motion (like you are unthreading the NRV) to “unscrew” the burr past the opening in the pump tube end plate. Do it with the pump tube opening facing toward the floor to allow gravity to assist you. Use a little 400 grit wet dry sandpaper or a small file to remove the burr once you’ve got it out so it doesn’t give you problems again.
b. the other problem comes about from using lead NRV head washers. The lead will expand outward when the NRV head is tightened down, sometimes into the opening for the NRV head threads. This can hang up the NRV. Alligator forceps should help you to get it out, again with that unscrewing motion. Consider to switching to HDPE (#2 plastic) NRV head washers. You can punch them from the lids of food containers, so they are cheap to make and they almost never cause these hang-up problems. They last forever, too.
4. Lastly… for that final 1% of stubborn NRVs… if you have compressed air… set the air output to about 40 psi. Hold a rag in your hand over the pump tube opening to catch the NRV. Install the vent screw and apply a little compressed air into the burner mount opening with your thumb over the filler opening. Pop! Out shoots the NRV into the rag in your hand. These can shoot across the shop if you don’t use a rag to catch it and be difficult to fine otherwise.
Hope that helps!
Happy camping!
BD

Primus 100 Silent Cap?

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Dear BernieDawg
I found a great old Primus 100. It works well and is very nice. But, how can I make it more quiet for use in camp in the early morning ? Thank you for your help!
Noisemaker
 –
Hi Noisemaker
The Primus 100 stoves are among my favorites. A silent damper cap can make your stove quieter, and also generate a better fuel/air mix for efficient burning.
 –
 Best choice is a Primus 4010 silent damper cap. They work super awesome on the 100s.
Base-Camp in England had some of the 4010’s a while back, but they’ve sold out of them now. Watch for a possible (though unlikely) return of the 4010 at Base-Camp sometime in the future, or ask around to some of the stove forums. Perhaps someone there would sell you one of their extras.
 –
Another good choice for a Primus 100 silent damper cap is to fab up a cap adapter I call a spigot plate. I’ve made lots of these over the years. It’s a great newbie brazing project for anyone who wants to work on stoves.
 –
Basically, you take a round piece of sheet metal with a hole in the center and braze a short piece of 5/8” diameter tubing to the middle.

OLYMPUS DIGITAL CAMERA

OLYMPUS DIGITAL CAMERA

The spigot plate holds the inner cap centered, and the outer cap settles around the inner cap.

OLYMPUS DIGITAL CAMERA

OLYMPUS DIGITAL CAMERA

You can make the diameter of the sheet metal base to fit either the first or the second ledge in the lipstick burner bell and then just use a regular cap set with the stove.

OLYMPUS DIGITAL CAMERA

OLYMPUS DIGITAL CAMERA

Good luck on this project. It can be done with hand tools and an electric drill. You don’t need specialized tools.
Happy camping!
BD

Silent Cap for 111B?

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Hello BernieDawg,
I’m sure you’ve received this question before, but I’ll go ahead and ask. Do you have a silent damper for the Optimus 111 stove (hiker) with the “roarer” burner?
Thanks,
“Bugged by Noise”

Hi, “Bugged”
Thanks for your question and your interest in my silent cap products. I *have* received this question quite a few times.

The short answer to your question is no. No one anywhere to date has a silencing product to work on your 111 roarer burner. Sorry.
Now, in the past, some folks have gotten all mad and upset about this. It’s almost like they think I’m holding out on them or something. So, I hope you won’t mind too much if I try to show why I do not have any caps for the 111 style burner.
Here’s the explanation. The standard 111 or 111B burners have the traditional shaped design where the vaporization chamber is above the jet. Fuel moves into that chunk of metal above the jet (the burner “head” or vaporization chamber), the fuel is heated into a vapor up top and then the vapor moves down a tube, into the jet and spews upward as flame to heat the vapo chamber. It’s pretty neat how these work, really. These burners look like this one on a Optimus 22:
111 roarer copy
All silent caps, mine or others, are designed to work with another, and very different, type of roarer burner where the design uses a bell-shaped structure. Here’s a Dragonfly burner without it’s flame plate in place. With this burner, the jet spews vapor upward which hits a flame plate above the burner. The flame plate spreads the flame out and the flames heat the side walls of the bell. The heat from the flames is conducted back down to the base of the burner which is where the vaporization of the fuel is going on.
P4210030
What the caps do is capture the vapor stream and emit it through hundreds of tiny holes. There are then hundreds of teeny flames that bathe the rim of the bell in heat and the heat is conducted back to the base of the burner to vaporize the fuel. Lots of teeny flames are much quieter than one big monster flame.
P4210026
You can see how the flame plate sits on the bells of these two Primus 96 stoves.
P5190092
This is a burner from a Phoebus 625 which really shows the bell structure well.
P9030005P9030006
It is pretty straightforward to replace a flame plate with a silent cap on a bell-shaped burner. Just pop the flame plate off and add the cap to replace it. Here’s a MSR FireFly stove shown with a flame plate and then a silent cap.
PA230642PA230643 - Version 2
But, so far, nobody has been able to come up with a way to remove the flame ring on a standard roarer burner with that overhead vaporization chamber and add some sort of device to make it silent.
111 burning
Believe me when I say I have thought long and hard on how to make a “cap” for the traditional overhead vapo chamber roarer. I’ve tried a few experiments, too. Nothing that’ll work so far. The feller who can come up with a way to silence these burners is going to have a really popular product on their hands. 😉
The good news is that Optimus made a silent version of your 111 stove in two different flavors, the 111T and the 111C. These came standard with a third type of burner which is designed to operate very quietly straight from the factory, no aftermarket caps needed.
111T:
Screen Shot 2015-10-31 at 2.12.41 PM
111C (out of it’s case ‘cause I was working on it):
111C
The 111T is much more common, but both stoves show up on eBay from time to time.
I hope this helps explain things. Good luck to you if you decide to pursue a 111T or C on eBay. They are really nice stoves – you wouldn’t go wrong if you bought one.
Happy Camping!
BernieDawg

Coleman 345 (and 348!) paperwork

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Hi BernieDawg
I’ve heard you have lots of documents in your collection. I have a Coleman 345 marine stove and I would really like to get the instructions for the operation of the stove. Do you have such a thing?
Sincerely,
Coleman Searcher

Hi Coleman Searcher
You bet! I have the instructions for both the 345 (kerosene) and the 348 (denatured alcohol) versions of these awesome old marine stoves. Here is the paperwork for your stove:
(just click on the thumbnail images for the larger versions)
Coleman 345 pp
Coleman 345-2pp

I don’t believe that these sorts of documents on old stoves should be kept behind membership requirements or pay-to-view mechanisms on the internet just to promote the sites that hold them hostage. I believe that the free exchange of information without strings attached is what best promotes the collection and preservation of old stoves. Isn’t that what the internet is supposed to be about?

I hope this helps you with your stove. It’s a nice one!

Happy camping!
BernieDawg

UPDATE! Here are the instructions for the Coleman 348 alcohol burning version of this marine stove set.
large 300dpi PDF, about 3MB

Coleman 348 Marine Alcohol Stove Instructions large 300dpi PDF, about 3MB

Smaller 72dpi JPG images – about 300KB each:

BernieDawg Cap Instructions

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Hi Berniedawg
Where can I find instructions on how to fit/mount your silent caps on various burners, say like the Svea 123R? Youtube maybe?
Best,
“Hans”

Hi “Hans”

Thanks for your BernieDawg cap question.

The instructions for the caps can be found at:
http://tinyurl.com/lvv3syn

That same link to the instructions can also be found at the main page of each of my product manufacturing pages. (it’s down at the bottom of the text.)
http://www.shapeways.com/shops/BernieDawgShop
https://i.materialise.com/shop/designer/gary-adams

The link can also be found at the end of the description of each cap product at my manufacturers, Shapeways and i.materialise. When you decide to order a silent damper cap product, you can just cut and paste the link into your browser to get to the instructions webpage.

Happy camping!
BernieDawg

Hank Roberts & Gerry Stove Adapters

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Hi BernieDawg
I have a Gerry and a Hank Roberts mini-stove and I want to adapt them to use todays fuel canisters. Do you have and sell a conversion kit or can you refer me to someone who does? Should you have one, how can I order it and how much does it cost? Thanks for your help.
Signed,
Gerry Guy

Hi Gerry Guy
Thanks for your question. I’m going to tell you the honest truth. It may not be what you want to hear. I hope you won’t be mad.

As you know, the cartridge style used for Hank Roberts, Gerry and similar stoves has been out of production for many years now. The Hank Roberts and Gerry branded stoves have gone the way of 8-track tape players, Sony Betamax VCRs, and crystal radio sets – they are outmoded and obsolete, having been replaced by much better modern alternatives. On the other hand, I do understand that some people enjoy collecting these old dinosaurs. Heck, I have a few of them myself!

I did a small run of custom-machined adapters for Hank Roberts conversions back in 2010 for some fans of this budget-priced stove of yore. I no longer have any in stock. The machined brass adapter connects the Hank Roberts/Gerry 7/16 x 20 stove thread to the Chinese M6 x 0.75 threaded hose/valve set.

HR adapter HR adapter burn

If you’d like me to custom-machine a brass adapter on my precision mini-lathe it’d cost you $45 plus shipping (about $3 in the USA). You can buy the Chinese-made valve/hose set shown in the photo for about $12 on eBay. If you think I’m out of line on the cost of that custom machining, you can give the thread data and show the photos above to your local machinist and see what he’d quote you.

There is no one anywhere else in the world that I know of that does any sort of conversions for these. So, there is no need to knock yourself out searching the web further.

All this said… most people (including me!) don’t think converting a Hank Roberts/Gerry is worth it. You can get most modern brand name isobutane stoves new at under $50-60. That’s what I would encourage you to do. Why? Well…

Modern lightweight backpacking stoves are designed to specifically burn the gas mixtures in present day isobutane cartridges. Hank Roberts and Gerrys, on the other hand, were designed to burn straight butane. Isobutane works much better in cold conditions and comes in canisters you can find all over. The Hank Roberts/Gerrys simply aren’t designed or jetted to work as well as a modern stove with isobutane canisters. They are cute “collector item” stoves, but they are not serious outdoor stoves compared to modern alternatives. (Sorry if this isn’t what you wanted to hear.)

Here are a few name brand modern stove candidates you can Google that would make good replacements for your Hank Roberts/Gerrys:
Snow Peak Gig, manual – $39.95 msrp
MSR Pocket Rocket – $39.95 msrp
MSR Micro Rocket – $59.95 msrp
Kovea Tornado – about $41 with shipping via eBay
Optimus Crux – $59.95 msrp
Optimus Crux Lite – $39.95 msrp
Primus Classic Trail – $25 msrp

And… if you are looking for even cheaper, but still usable stove alternatives, there are many, many imported isobutane stoves coming out of China and Korea that are really quite good. You can find them on sale on eBay for under $20 with the shipping included in that price. Here are three I’ve purchased that I found work just fine and all for under $20 shipped:

Screen Shot 2015-10-06 at 8.47.28 AM Screen Shot 2015-10-06 at 8.47.54 AM Screen Shot 2015-10-06 at 8.48.17 AM

You can curb recycle your old Hank Roberts/Gerry stoves as aluminum in many communities in the USA. Or, you can try to sell it on eBay, though most people have figured out they are pretty much useless now that cartridges for them have been gone for 10+ years. Or, you can make a nice display of vintage backpacking gear in your home to remember those great old times on the trail. (I still have my old 1977 Kelty frame pack hanging on my wall!)

Happy Camping!
BernieDawg