The Hank Roberts Stove -- With a Proper Canister

What's one of the most enduring designs of gas stoves? The Hank Roberts mini stove.  It's compact design truly makes it a pocket stove.  I typically carry mine in a Ziploc sandwich bag, and it really does fit in my shirt pocket.

A Hank Roberts Mini Stove

The stove was designed in the late 1960's -- the late 1960's for crying out loud -- but still has a loyal following today.  The stove was made by EFI and marketed under a variety of names, the most well known of which were probably the Hank Roberts stove and the Gerry stove.

Now, if we were to separate the two halves of the "clamshell" that forms the stove, what might we find inside?

Inside the "clamshell" is the burner head and the valve assembly.

Cleverly tucked inside is a burner and valve assembly.  I've added a couple of napkins to prevent rattling, but the napkins are not strictly necessary.   The smaller, longer threaded piece (dark colored) seen above screws into the top half of the clamshell, forming a stand.  The bottom half of the clamshell slips over the wider shorter threads (silver colored) to form a windshield/pot stand.  The burner then screws in place over the top and holds the wind screen/pot stand in place.

When assembled, the stove looks something like this:

An assembled Hank Roberts Stove

A few months ago, I published a blog post on how to use the Hank Roberts stove with an adapter that will allow you to use a modern threaded gas canister.

Today, I thought I'd go fully retro and show you how to use one of the original type canisters.

A canister of the type used by a Hank Roberts stove.  This particular canister is an Optimus 702 canister.

Canisters of this type were marketed under a variety of brands including Optimus, Hank Roberts, Prepo, Thermos, and Coleman.  There were were some minor variations among the various brands, but most had a rubber fitting typically referred to as a "rosebud" that looked something like this:

The "rosebud" on a canister of the type used by a Hank Roberts stove.

The canisters of the type used by a Hank Roberts stove were used by a variety of stoves back in the day. The canister I'm showing here is an Optimus 702 canister which was intended for the Optimus 731 "Mousetrap" stove.

These canisters all contained 100% butane.  Butane is a fairly easy gas to work with in that it has a fairly moderate vapor pressure.  Gasses like propane require much heavier canisters and fittings because propane has a much higher vapor pressure.  Of course, the one problem with butane is that butane doesn't work very well in cold weather.  Butane vaporizes at 31F/-0.5C (at sea level), which isn't all that cold, particularly for "shoulder season" (early spring, late fall) or winter hikes.  Add to that the fact that canisters typically get colder as you use them, and you soon realize that 100% butane typically needs weather above 50F/10C to really work well.  50F/10C?  That's pretty limiting.

But not the Hank Roberts.  You see the canister had a very special feature.  The canister when used with a Hank Roberts stove lay on its side.  Inside the canister was a wick, a wick that would conduct liquefied butane to the burner.  Then the heat of the burner would turn the liquid butane into a vapor which can be burned by the stove.  Gas stoves do not work properly when the fuel is still liquid.

A gas canister attached to a Hank Roberts stove.  Note how the canister lies on its side.

Since the fuel is fed in as a liquid, all you really need is just a smidge of vapor pressure to get the liquid to wick into the valve assembly of the stove.  Whereas modern vapor feed canisters require that the fuel be at about 10 Fahrenheit degrees above the vaporization point of the fuel (about 5 Celsius degrees) for there to be enough pressure, a Hank Roberts stove can operate when the fuel's temperature is only a few degrees above the vaporization point.  And, since the fuel feed is in liquid form, you don't get the same degree of canister chilling that you get with vapor feed.

Of course, there's just one itsy bitsy little problem.  The burner assembly isn't hot when you first fire up the stove.  Since the burner assembly isn't hot, the fuel doesn't get fully vaporized, and your stove will flare until it warms up.

A cold Hank Roberts stove flaring on start up.

The trick with a Hank Roberts stove is to turn the gas down low at first and let the stove warm up before you turn the gas up.  On a cold day, it can take some time for the stove to warm up.  One has to be very patient when starting the stove on a cold day.  On the day these photos were taken, it was cold and gray, and a hail storm passed through.  It was quite chilly, and it took several minutes for the very cold stove to warm up enough to fully vaporize the fuel.

But warm up it did, and the yellow flames as seen above quickly settled down to nice well-behaved blue flames.

Blue flames from a fully warmed up Hank Roberts stove

Now, let's back up a minute.  Modern canisters are threaded.  How do Hank Roberts type canisters work?

Well, if you'll recall from the photo where I showed the interior of the clamshell, our burner assembly has a "needle" on it.

Note the needle on the right hand side of this photo of the Hank Roberts stove's valve assembly

That needle works much like the needle used to pump air into a basketball, soccer ball, or football.  On a ball, the needle is pushed into a "rosebud" like fitting on the ball to be inflated.  Once connected, air is transferred from a pump to the ball.  On a Hank Roberts stove, the needle is pushed into the "rosebud" on the canister until the rosebud pushes up against the base piece of the needle.

A Hank Roberts stove with the needle fully inserted into a canister

When fully inserted, the needle depresses a valve, allowing liquid butane to flow into the stove.  Nowdays, canisters typically have valves, but the Hank Roberts type canisters with valves were a real innovation for their day.

Well, now that we're all hooked up and warmed up, we'd better put the kettle on to boil now hadn't we?  A cup of hot tea on a gray day is just what the doctor ordered!

A kettle fresh dunked in the stream, set to boil on a Hank Roberts stove

The Hank Roberts Stove is my absolute favorite out of all my old gas stoves.  I highly recommend them if you can find one on eBay or a garage sale or something and can find either some old canisters or get an adapter to run the stove on modern canisters.

The Hank Roberts Stove:  Highly Recommended.

Thanks for joining me on another Adventure in Stoving,

HJ


Technical Appendix

Hank Roberts Mini Stove, Mark III
Weight     209g/7.37oz

Hank Roberts Stove -- Related Posts

• The Hank Roberts Stove -- With a Proper Canister
• Stove of the Week:  Hank Roberts Mini Stove, Mark III

Kovea MoonWalker vs. MSR WindPro II -- Packability

I'm not quite ready to review either the Kovea MoonWalker or the new MSR WindPro II (look for my WindPro II review in the next couple of weeks), but I thought I'd let people at least have a look at the two stoves and take a quick look at their relative packability.

First the Kovea MoonWalker (also know as the Kovea Camp 4).

The Kovea MoonWalker (Kovea Camp 4) stove compared to a can of Coca Cola

Second, the MSR WindPro II.

An MSR Windpro II compared to a can of Coca Cola

Next, I thought I'd try putting a Kovea MoonWalker (Camp 4) into a Snow Peak 1000ml pot.  It fits just fine.

A Kovea MoonWalker in a 1000ml Snow Peak pot

Of course the real question is can I also fit a canister of gas in there?  As it turns out, you can.

A Kovea MoonWalker and a Snow Peak 110g canister of gas in a Snow Peak 1000ml pot

And how does the MSR WindPro II fit?  Well, it fits too although the MoonWalker was just a bit more compact.

An MSR WindPro II and a 110g Snow Peak canister in a 1000ml Snow Peak pot.

I also tried fitting a 220g canister of gas into the pot -- it didn't work with either stove.

Well, that's it for today.  Like I say, I'm not quite ready to publish reviews just yet, but look for a review of the WindPro II in a few weeks.

Thanks for joining me on another Adventure In Stoving,

HJ

Technical Appendix

Weights
Kovea MoonWalker    294g  10.37oz
MSR WindPro         193g   6.81oz  (not shown in above photos)
MSR WindPro II      187g   6.60oz

Interestingly, the WindPro II as measured on my gram scale at home is just a bit lighter (6g) than the old WindPro.

Other Kovea Related Posts

The Kovea Camp 5 Remote Canister Stove

The BushBuddy Ultra

Well, Saturday.  Time to get out on the trail!  :)  I'm looking forward to testing a new wood stove.

Heading up the trail

Arriving at the creek, I see some recent blow down.  The fuel depot is open.  :)

Plenty of fuel

It only takes a minute to gather enough wood for a wood stove, a distinct advantage to just using a pot over an open fire.

Fuel for today's tests

And today's stove?  The BushBuddy Ultra.

The BushBuddy Ultra

The first thing to note is that a BushBuddy Ultra is a tall stove.  You'll need a pot with some height in order to be able to put the stove in the pot.

Here, I'm using a Snow Peak 1000ml pot which has a frying pan type lid.  Without this lid, I couldn't store a BushBuddy Ultra inside a pot with these proportions.

A 1000ml Snow Peak pot with a frying pan type lid will hold a BushBuddy Ultra

 A BushBuddy Ultra pretty much needs to be stored upright.  It won't even begin to fit in my pot sideways.

A BushBuddy Ultra will not fit sideways in a 1000ml Snow Peak pot

A wide, short pot without a frying pay lid may have trouble accommodating a BushBuddy Ultra.  For example, an Evernew 1.3L pot cannot hold a BushBuddy Ultra.  You really need a taller pot.

A BushBuddy Ultra will not fit upright in a wide, short pot like this 1.3L Evernew pot

Neither can you lay the stove on its side.

A BushBuddy Ultra will not fit on its side in a 1.3L Evernew pot

Well, let's pull that BushBuddy out of the pot and have a look.  The pot support cleverly fits upside down inside the body of the stove.

A BushBuddy Ultra with the pot support upside down stored inside the body of the stove.  

Note the grill in the above photo.  This is important.  The grill keeps the wood off the floor of the stove, allowing air to flow up from underneath during a burn.

Pulling the pot support out, I notice a row of vent holes just below the rim of the stove.

Note ventilation ports just below the rim of the stove

There are more vents on the outside at the base of the stove.

On the exterior, there are additional ventilation ports at the base of the stove.

Basically, the BushBuddy Ultra is a chimney type stove.  Cooler air enters from outside at the base, is heated between the inner and outer walls of the stove, and as the air is heated, it expands and accelerates out the ventilation ports just below the rim of the stove in the interior, causing a strong inflow of oxygen rich air.  It's a pretty good design.  Someone obviously knew what they were doing.

The pot support rests on the rim of the body of the stove.

The pot support emplaced on a BushBuddy Ultra

The pot support has a gap in it that can be seen at the left in this photo.  Additional wood can be inserted through the gap during use.

Looking down from above on a BushBuddy Ultra.  Note gap in pot support at upper left.

Taking a step back from the details, the first thing I notice is the craftsmanship.  Everything is really well made and well put together.  Just look at how regular the pattern of the spot welds is on the bottom of the stove.

The base of a BushBuddy Ultra

This stove is not something that someone just slap dashed together.  This is a well thought out stove with truly excellent build quality.  A lot of labor clearly goes into the manufacture of these stoves.

Well, let's fire her up!

A BushBuddy Ultra starting a burn

Today, I'll be testing with a 1.3L Evernew pot with 500ml of cold creek water.

A 1.3L Evernew pot on a BushBuddy

A 1.3L pot like the Evernew is a little bit wide for the BushBuddy, but I found the BushBuddy to be reasonably stable.  I was careful to pick fairly level ground.

One thing I notice with a BushBuddy Ultra is that it's a little hard to predict where the flames will come out.  This make it a little tricky to keep the pot handles out of the flame.  I found that by simply watching the burn and periodically repositioning the pot as needed kept the pot handles reasonably cool.

Flames can arise from any point around the perimeter of a BushBuddy Ultra

The other thing I found during testing was that one load of wood wasn't enough to boil 500ml of cold creek water.  I had to reload the stove.  It's possible to insert some wood through the gap in the pot support.

Inserting additional wood through the gap in the pot support

However, to really get even loading, I found it easier to remove the pot.  If one is inserting wood through the gap in the pot support, it's important to watch the ends of the sticks you insert.  Burning bits can fall of the ends of the sticks.

Burning ends of sticks can fall out if wood is inserted through the gap in the pot support

When additional wood is inserted, the excellent ventilation of the BushBuddy Ultra quickly causes the additional wood to become part of the fire.

The excellent drafting qualities of the BushBuddy Ultra quickly cause inserted wood to ignite.

I didn't time it, but I was quickly able to get a good boil using the BushBuddy Ultra.

Boiling water on a BushBuddy Ultra

Now, here's one of the nice things about a wood stove:  There are more heat settings than just "boil."  I let the wood burn down to just coals.

Coals in a BushBuddy Ultra

Then I add my noodles. 

Preparing noodles over coals

I add a few dried vegetables.

Adding vegetables to the mix

And a few minutes later, everything has re-hydrated nicely.

Nicely hydrated noodles and vegetables

And the best part?  No scorching, and no burning.  It's wonderful to have multiple heat settings on a stove.

And after the burn?  Nice, complete combustion.

The white ash of thorough combustion.

In short, the BushBuddy Ultra is a really nice wood burner.  It has a fairly small combustion chamber, so you do have to add wood while a boil is in progress, but no big deal.

Of course, there are times when you can't burn wood every meal.   For example, sometimes fuel is scarce (or wet) or perhaps you're at too high of an altitude or perhaps you're in such a popular area that wood fires are restricted.  Whatever the reason, there are times when wood fires just aren't going to work out.  With the BushBuddy Ultra, do you have a plan "B?"

To find out, I thought I'd try a quick experiment with an alcohol stove. 

An alcohol stove resting on the grill of a BushBuddy Ultra

Using a Trail Designs 12-10 alcohol stove and 0.75 fl. oz. of SLX denatured alcohol, I thought I'd try to boil 500ml of cold creek water. 

An alcohol stove burning inside a BushBuddy Ultra

Normally, I'd expect 0.75 fl. oz. of SLX denatured alcohol to bring 500ml of cold creek water to a boil.  It didn't. 

I added an additional 0.75 fl. oz. of SLX denatured alcohol and re-lit the alcohol stove.  This time, toward the end of the burn, I got a boil.  Not a strong boil, but the water did boil.

A weak boil was achieved with 1.5 fl. oz. of SLX denatured alcohol

In other words, it took 1.5 fl. oz. of SLX denatured alcohol just to get a rather uninspired boil.  So, do you have a plan "B" with a BushBuddy Ultra?  Well, yes, but the BushBuddy Ultra really isn't an alcohol set up.  The BushBuddy's strength is wood burning.  While the BushBuddy Ultra can be run on alcohol, it doesn't work all that well.  The BushBuddy Ultra is a wood burning stove and is best used for that purpose.

I didn't get a chance to test with hexamine (e.g. ESBIT), but I believe the results will be similar to running with alcohol.  The best use for a BushBuddy Ultra would seem to be for trips where you can almost always burn wood and then go to a secondary fuel only if you really have to.

Are there other ways to use the BushBuddy with non-wood fuels than what I've shown?  Of course, and I think they're worth exploring.  However, a simple substitution (as done above) of an alternative fuel did not produce good results.  Got a better way?  Lay it on me.  :)

CONCLUDING REMARKS
Cooking with a wood fire using a stove is so much easier than using an open fire.  There's also much less chance of starting a wildfire given the contained nature of a wood stove and the complete nature of the combustion, and there's very little trace left when you're done.  Having tested a couple of wood stoves now, I really wouldn't consider going back to an open fire for cooking except in an emergency.

I have to say that it was a real pleasure to be able to use a BushBuddy Ultra.  Special thanks to Christian D. for the loan of his BushBuddy Ultra for this testing. 

Thanks for joining me for another Adventure in Stoving.

HJ

Other wood fired backpacking stove posts:

• The BushBuddy Ultra.  Craftsmanship has not gone out of style.
• The Ti-Tri Caldera Cone -- The Ultimate Ultralight Stove System?
• Why a Wood Stove?  More Thoughts on the Caldera Cone Ti-Tri.
• Wood Fired Cooking on a Caldera Cone.  Cooking real food with wood.
• BushBuddy vs Ti-Tri Caldera Cone.  Wood stoves, compared.

Appendix
BushBuddy Ultra,
Weight ..... 139g/4.9oz
MSRP  ..... $120.00 CAD including shipping within Canada.  $128.00 CAD for shipping to the US including Alaska and Hawaii*

Per the bushbuddy website:  All stainless steel construction, with an outer shell of .004" fully hardened 304 stainless steel,  firebox walls of .010" annealed 304 stainless steel, and a hand made grate of nichrome wire for long life with minimum weight.

*Note that prices are in Canadian Dollars not US Dollars.