Stove of the Week: MSR Rapidfire

OK, so this week's stove is a bit of a "sleeper" in the sense that it's not a stove that you would expect a lot from -- unless you knew better.  But you'll have to read on to find out what's so interesting about this week's stove, the MSR Rapidfire.

First, let's go through our usual run down of the stove, and then we'll get into some of it's unusual qualities.  So, what's with this thing called a Rapidfire?  Isn't it just a Whisperlite?  I mean seriously, just look at it.  It's a freakin' Whisperlite for crying out loud.

Or is it?  Take a look at the bottom of the burner column.  Hmm.  No priming cup.  OK, so what the Dickens is this thing?  Well, it is a close relative of the Whisperlite all right, but made to run on canister gas.

The Rapidfire was MSR's first entry into the gas stove market.  Prior to the Rapidfire, MSR was a liquid fuel only stove manufacturer.  When MSR saw how gas stoves were really catching on, they needed an entrant into the market.  How better to get there than to simply modify their existing "workhorse" stove, the Whisperlite?  Enter the Rapidfire.  Apparently, MSR was pretty paranoid about the volatility of gas as compared to liquid fuel; they really lengthened the fuel line which is odd when you consider that now the majority of MSR gas stoves mount directly on to the canister.

The stove itself is identical to the Whisperltie except for the aforementioned lack of a priming cup.

Instead of a priming cup, there's a threaded, knurled ring that holds the fuel line and legs in place.

At the end of the fuel line, there's a gas connector and valve rather than the open ended tube with aluminum block and catch-arm of the Whisperlite.

Now take a careful look at that connector.

Note the central pin.  It is this pin that depresses the Lindal valve inside the canister of gas.  I've seen these pins go missing.  No pin, and essentially you've got no gas.  Second, note the black rubber "O" ring.  This "O" ring must be in place for you to operate the stove safely.  Without the "O" ring, gas may leak which could be quite dangerous.

Speaking of gas, it's worth mentioning here that the MSR Rapidfire stove can use any standard threaded backpacking gas canister.  Originally, the Rapidfire used a cylindrical gas canister, but that canister had the same 7/16" UNEF standard thread as used on today's dome shaped canisters, so there's no problem with respect to finding fuel even though the Rapidfire is an older stove.  MSR discontinued production, to the best of my ability to discern, in 2001.

OK, so MSR needed a gas stove, so they pressed a modified Whisperlite into service, so what?  I mean does this Rapidfire have any redeeming features or is it just some kludgey attempt to not let all the other stove manufacturers run away with the gas stove part of the stove market?  Actually, the Rapidfire has several features that distinguish it from typical gas stoves, one of which actually makes the Rapidfire potentially pretty worth owning.  I'll get to that in a moment.
First, the Rapidfire, like its progenitor the Whisperlite, is a remote fueled stove.  In other words, the fuel is not directly attached to the burner but rather fuel is brought in via a fuel line from a remote source.  This does several things for us:  1) since there's no fuel tank under the burner, the burner is lower which brings us out of the wind.  2)  Also since the burner is lower, the stove is more stable.  3) Lastly and most importantly, since the fuel isn't local to the burner, we do not have to worry about heat radiating from the burner and overheating the fuel -- which means we can use a windscreen with complete impunity.  Use a windscreen the wrong way on a typical canister stove, and you could turn your stove from a domestic servant into a domestic terrorist.  Overheated canisters can and do explode.

Speaking of windscreens, here's a Rapidfire all set up with a heat reflector and windscreen, a very efficient cooking set up.

Now, I keep blathering about something special about the Rapidfire.  Let's take a closer look at the burner itself shall we?

Do you see that loop in the burner?  That's the fuel line.  That loop is referred to as a pre-heat loop (or generator).  The loop is exposed directly to the flame when the stove is in operation.  Fuel flows into that loop before it enters the burner, which greatly heats the fuel.  In a liquid fueled stove, that heat is what turns the liquid into a vapor so that it can be burned.

Well, that's just great, Jim, but we're working with gas here, so who really cares?

Are you?  Really?  Pick up a full canister of gas and shake it.  Hear that sloshing sound?  That's a liquid in there.

OK, great, it's a liquid in the can but it's a gas when it comes out of the burner, so I still don't care about that pre-heat loop; can we just move on?

Well, not so fast there.  Yes, you're right, it is a gas when it comes out of the burner.  Usually.  But what about cold weather?  Gotcha.  That's the problem with gas stoves.  They lose power when the weather gets below freezing because the liquefied gas in the canister won't vaporize properly.  Remember that pre-heat loop?  There's our answer.  In cold weather, we let the liquefied gas stay liquid, and we let the pre-heat loop vaporize it for us.  In that way, we don't care if it's cold or not.  We don't use the air temperature to vaporize our gas, we use the heat of the flame.

Uh, great Jim, but the connector attaches to the top of the canister, and all it's going to draw is gas off the top.  If there's no gas, we've got no fuel.

This is not a problem.  Just turn the canister over.  Note:  Do not invert the canister on a gas stove that does not have a pre-heat loop.  A serious flare up might result. 

The top of the canister is now the bottom.  That portion of the fuel that is in vapor form now acts to pressurize the canister, pushing liquid down, out of the canister, and down the fuel line.  The fuel stays in liquid form until it hits the pre-heat loop where the high heat causes it to change from liquid to gas.  The resultant gas comes rushing out of the burner, and baby you've got flame.  Note that the stove is in operation in the above photo.  When gas is fed in liquid form to the burner, the stove is said to be in liquid feed mode.  Note that I said liquid feed not liquid fuel.  The fuel will still be a gas at room temperature and pressure.  We haven't changed fuel; we've merely changed the form that the fuel is fed in.

Using a gas stove in liquid feed mode is an important capability for a couple of reasons:
1.  Normal gas stoves operate in vapor feed mode, that is the fuel is fed in as a vapor, and you have to rely on the ambient temperature to vaporize your fuel.  In liquid feed mode, you rely not on the outside temperature but on the heat of the flame.  Stoves in liquid feed mode will operate in colder weather than normal gas stoves.
2.  In normal gas stoves, the fuel is typically a propane-butane or propane-isobutane blend.  Propane, the gas that works best in cold, has a higher vapor pressure and burns off faster leaving you, toward the end of the life of the tank, with a tank full of your worst performing cold weather fuel. In fact, you may wind up with a canister that is still 30% full that you can't coax any gas out of because all the good propane has burned off and nothing is left but the lesser performing fuels.  In liquid feed mode, all the fuels are burned at a constant rate.  The fuel towards the end of the life of the canister is the same mix as at the start of the canister.  In liquid feed mode, you don't get such horrible "canister fade" like you do in vapor feed mode.

I normally recommend a cut off of about 20F/-7C for normal gas stoves -- and that's with using "tricks," having to put up with less-than-stellar performance, and potentially having fuel that you can't get to vaporize.  With a gas stove in liquid feed mode, you can easily go down to 0F/-18C without having to use a lot of tricks, with full performance, and without having a portion of your fuel being unusable.

In other words, with a gas stove in liquid mode, you get all of the convenience of gas without all the low performance and hassles associated with gas in cold weather.  Uh, couldn't I just use a regular liquid fueled stove?  Sure.  If you're comfortable with liquid fuel, go for it.  But consider this:  If it's really snowing hard and you need to cook inside your tent do you really want to use liquid fuel?  What happens if your priming gets a little out of hand?  With a gas stove in liquid feed mode, you get liquid fuel performance but without the danger of priming.  And of course you get all of the usual convenience of a gas stove.  One of those conveniences is simmering.  It's pretty tough to get the typical Whisperlite to simmer like this:

And that's without monkeying around with only filling the fuel bottle half full and only pumping a few strokes.  Easy, just about automatic simmering in other words.

Now, in all fairness, other remote canister gas stoves have pre-heat loops. Other remote canister stoves can operate in liquid feed mode.  What makes the Rapidfire a "sleeper" -- a stove you wouldn't expect much from but turns out to be a pretty good stove?  Well, take a look at the price tags on some of those stoves out there that are remote canister stoves and have pre-heat loops.  They're expensive.  The Rapidfire is an older, discontinued stove, most people haven't heard of it, and you can pick one up for a much more reasonable price than you can some of the current production stoves.  All the performance at a fraction of the price.  You heard it here on Adventures in Stoving.  :)  Also, the Rapidfire's fuel line rotates easily at the connector which makes it easy to invert the canister to put the stove into liquid feed mode.  The Rapidfire's more modern cousin, the Windpro, does not rotate easily at the connector.

Yep, the Rapidfire is a "sleeper," but don't underestimate this stove.  It's a lot of stove for the money.

Well, looks like the kettle's boiling.  I'd best get to that cup of hot chocolate before it gets cold.

Thanks for joining me on another Adventure in Stoving.

HJ

The MSR Rapidfire
What's good about it?
Able to operate in liquid feed mode
Economical
Can use a full windscreen with impunity even though it's a gas stove
Simmers well
Connector rotates easily for liquid feed mode
Quiet
Fairly compact
Reasonably powerful
Reliable
Stable
Efficient

What's bad about it?
The wire pot supports are difficult to get back into "true" if they get bent.  (so don't bend them!)
The fuel line is a little stiff particularly when compared to newer stoves like the WindPro.
A tad heavy when compared to newer stoves like the WindPro.

Overall, recommended.

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Stove of the Week: MSR Whisperlite (Pre-Shaker Jet)

In 1980 Mountain Safety Research (MSR) was bought out by Recreational Equipment Incorporated (REI).  Prior to the buy out, MSR was mainly a fairly specialized equipment manufacturer catering mostly to mountaineers. REI wanted to change that and turn MSR into a company that would cater to a wider audience.  One of the first big projects undertaken during the REI years was the MSR Whisperlite.

Prior to the Whisperlite, MSR stoves all had roarer type burners.  As the name "roarer" implies, such burners tend to be rather noisy.  MSR therefore decided to go with a different type of burner, a baffled burner, which is a far quieter type of burner.  To herald this change, MSR named the stove the Whisperlite. Indeed, I've had friends remark on just how quiet the Whisperlite is compared to other stoves. The "lite" portion of the stove's name, as one might expect, reflects the fact that the Whisperlite was at that time MSR's lightest stove.  MSR had another goal:  to produce an economical stove that would have broader appeal than the higher end stoves that they had theretofore been producing.  In this regard, MSR hit a home run, launching one of the most successful of modern white gasoline type stoves.  Introduced in 1984, the Whisperlite is still sold today.  Backpackers quickly adopted the Whisperlite despite its occasional clogs.  In a survey of through hikers on the Appalachian Trail in 1989, the number one most commonly carried stove was the Whisperlite, and this only five years after its introduction.  In about 1996, the Whisperlite's jet was redesigned.  MSR made the jet larger and inserted a weighted cleaning needle.  When the stove was shaken up and down, the weighted needle would move in and out of the jet's orifice, clearing the jet.  MSR named this redesigned jet after its method of use:  the shaker jet.  Unfortunately, MSR stoves with the shaker jet generally do not simmer as well as pre-shaker jet models. Now why the average person couldn't simply use the wire pricker to clean the jet I am not sure, but MSR apparently felt that they needed to do something to allay customer's fears about clogs.

Well, let's have a look shall we?  This week's stove is the pre-shaker jet version of the MSR Whisperlite.    The early Whisperlites came with this red stuff sack, marked with the MSR "Matterhorn" logo:

These older stuff sacks are in my opinion nicer than the newer black stuff sacks.  The old red stuff sacks included small pockets which were handy for holding spares, matches, a lighter, etc.

The Whisperlite is a fairly compact stove, certainly more compact than its predecessors, the XGK line of stoves or the Firefly. 

I should mention that this particular stove is special to me:  This is my very first pack stove.  I bought it from Sport Chalet in La Canada in about 1987.  It has served me faithfully for now almost a quarter of a century with very few problems.

The early Whisperlites came with a fabric covered rubber fuel hose that was crimped at both ends.

Later versions came with a woven metal sheath with brass fittings on either end.  The later fuel lines are generally superior to the earlier ones.

Well let's assemble her and get ready to fire her up.  Here are the basic components (clockwise from top, left):  The burner, the fuel bottle with windscreen wrapped around it and fuel pump in place, and the heat reflector.  Tip: Note that I have wrapped the windscreen around the fuel bottle.  This helps prevent the windscreen from getting all bent up when packed and avoids having to fold the windscreen for storage.  The points at which windscreens are folded often become points of failure.  Believe it or not the windscreen shown in the photo is the original windscreen that came with this stove that I purchased in about 1987.  I keep the windscreen wrapped as shown, and then I put the whole ensemble in a plastic bag before I put the fuel bottle in my pack.  This technique protects not only the windscreen but also the contents of the pack from damage.  I also put my burner in a small plastic bag before placing it in the stuff sack.  This keeps the inside of the stuff sack clean.  Tip:  Note also that I keep the pump in the bottle when in the field.  I leave the bottle's cap at home.  Do be sure to release the pressure when the stove is not in use.  Do not release the pressure near the stove when the stove is hot.  Release the pressure away from flame or heat sources.

Here's a photo of the heat reflector unfolded.  Note the hole in the center.

The legs of the stove, while still folded, are inserted through the hole...

...then the heat reflector is moved up around the mid section of the burner...

...and then the legs are rotated into position.  The "hourglass" shape of the legs holds the heat reflector in position above the fuel line and below the burner.

This is a good design and when combined with the windscreen makes for efficient cooking.  In later models of the heat reflector, MSR removed the center hole.  This is most likely a cost cutting measure.  The heat reflector, instead of sitting just below the burner now sits underneath the whole stove.  This is a bad idea for two reasons:  1.  Now the reflector is farther away from the burner which is less efficient and 2. the aluminum reflector is slick.  Putting a stove on a slick surface on uneven ground invites the disaster of the spilled supper.  The original design was better.  One can improve the newer heat reflectors by cutting the hole oneself or one can simply omit the heat reflector.  The heat reflector does make the stove more efficient, but the reflector is not essential on newer stoves.  On older stoves that have the fabric covered fuel line, I recommend that you always use the heat reflector lest heat damage the fuel line in some way.

After the reflector is in place, emplace the windscreen.  Early MSR windscreens had a diagonal cut on the lower corners of the windscreen.  When the ends were joined, a small "V" shaped opening remained.  One is supposed to thread the fuel line through the "V" as shown.

The only problem with this is that if one has a smaller pot, then a substantial gap will exist between the edge of the pot and the windscreen.  Wind can enter via this excessively large gap, reducing the effectiveness of your stove.

What I prefer to do is to wrap the windscreen more tightly and hold it in place with a paper clip.

Note that in the second photo, the gap is reduced but not eliminated.  Because of the reflector, it's difficult to reduce the gap further than shown, but the reduced gap that we do have should buy us some increased efficiency.  If one were having trouble in higher winds, one could curl the edges of the heat reflector upwards so that the windscreen could be drawn more tightly around the pot.

Now, in drawing the windscreen more tightly around the pot, we've closed the little "V" shaped opening, but this is no big deal.  Simply place the windscreen on top of the fuel line.

Yes, there is now a bit of a gap between the ground and the lower edge of the windscreen, but in practice I have not found this gap to cause any trouble.  In really windy conditions if wind were sweeping in through this small gap, one could pile up dirt to close the gap.

Now, let's get some water from the creek.  By the way, boiling water is the most effective treatment for killing water borne pathogens and is more effective than filtering, ultraviolet treatment, or chemical treatment.

Now, we'll need to prime the stove.  You can prime the stove with the stove's own fuel, white gasoline, but I prefer to bring a small squeeze bottle of denatured alcohol.

Why alcohol?  First, it's hard to control the amount of fuel dispensed when using the stove's own fuel.  Too much fuel, and you can get a very large "soccer ball sized" fireball (MSR's words).  It's easy to control how much alcohol is dispensed from a squeeze bottle.  Second, alcohol burns more cleanly and leaves less soot on your stove.  Third, alcohol is less volatile which further reduces the chance of a fireball.  To prime, squirt in some alcohol, fire it up, let it burn down a bit, and then just as the priming flame is about to go out, open the stove's valve a bit to add fuel.  I typically open the valve just a crack and then immediately close it, allowing the flame to burn down a bit before opening the valve again.  I go through a couple of iterations of opening the valve a crack, closing the valve, letting the flame burn down a bit, and then opening the valve again before I leave the valve open.  This sounds complicated, but after a few times of doing it, it becomes second nature.

When your stove is fully warmed up, your flame should be a nice steady blue and should look something like this.

As I mentioned, with pre-shaker jet Whisperlites, it is possible to get them to a relatively low flame.  Compare this flame.

With this flame.

Yes, a Whisperlite can simmer.  It's not automatic, but it can be done fairly easily on a consistent basis.

Well, it looks like my water is boiling,

so it's time I had a cup of cocoa...

...here in this little nook that I call "Stove Test Area 2.".

I thank you for joining me on another adventure in stoving.

HJ.

The MSR Whisperlite
What's good about it?
Economical
Quiet
Fairly compact
Reasonably powerful (not as powerful as an XGK)
Reasonably Reliable (not as reliable as an XGK)
Stable
Efficient

What's bad about it?
Difficult to simmer (although pre-shaker jet models simmer pretty well)
The wire pot supports are difficult to get back into "true" if they get bent.  (so don't bend them!)
The fuel line is a little stiff particularly when compared to newer stoves like the Simmerlite.
A tad heavy when compared to newer stoves like the Simmerlite.

Overall, recommended.  This is a good, economical basic stove for those who want a liquid fueled stove.

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Stove of the Week: The Borde Stove

Stove of the Week:  The Borde stove

I've been blogging about lightweight winter capable stoves for the last three weeks (the Coleman Xtreme, the MSR Simmerlite, and the MSR WindPro).  I'll conclude this series within a series on lightweight winter stoves with this week's post, but I'm going to continue to feature winter capable stoves for a few more weeks, but this is the last on lightweight ones. Next week will feature the MSR XGK II (pre shaker jet version).

So to conclude my mini-series on lightweight winter capable stoves, this week's stove is the Borde Stove, also called the Borde benzin brenner (Borde gasoline burner).  (ボルドーバーナー)  The Borde stove burns good and hot.  Note the color of the tips of the flame spreader in the below photo.  That stove is HOT!


The Borde stove is a diminutive cult classic with a very loyal following among mountaineers. It's compact and, at about 8.5 ounces (241g), relatively lightweight.
 


However, with respect to the stove's weight, two things should be noted:  1)  There is no integrated pot support and 2) the capacity of the fuel tank is perhaps only 250 ml -- if that.  As with most "white" gasoline type stoves, air space must be provided within the tank in order for the stove to work properly.



One should also note that there is no valve knob on this stove. How then is it controlled? The "star" burner itself is rotated with a control hook. Rotation to the left increases the flow of fuel, to the right decreases the flow. Unfortunately the original control hook for my stove has been lost somewhere along the way. Fortunately, it is relatively easy to make a new control hook from steel wire. Home made control hooks:


Rotating the "star" burner plate assembly with a control hook.


Here's a closer look at the "star" burner plate assembly. Note how the assembly is threaded and that the base of the assembly screws into a short tube directly attached to the coils. It is here, at the point where the assembly screws into the coils, that fuel is emitted.



OK, let's get started shall we? Now, since the Borde is a white gasoline type stove, we'll need to prime (pre-heat) the stove. The directions say that one should open the valve (by rotating the "star" burner plate assembly to the left), turn the stove upside down allowing a small amount of gasoline to come out, and ignite the gasoline while holding the stove in one's hands. Let's see, holding a lighted container of dripping gasoline in one's hands. Uh, is it just me or does this sound completely nuts? lol. There is a better way. First we'll need the following set up: a bottle of alcohol, a small pan, and of course our Borde stove:


Next, we'll undo the plug in the end of the stove and add white gasoline (Coleman type fuel). We'll then tighten the plug firmly using the flattened end of the wire stove holder.


Now, we'll place the little pan under the coils of the stove, fill the pan with alcohol, and ignite the alcohol. Since the pan is at an odd angle, it won't hold a lot of alcohol, so I went ahead and primed the stove twice (aka a double prime).


After double priming, I open up the burner just a bit allowing the now vaporized gasoline to flow out of the burner. Here, the Borde stove is just warming up:

The pot stand I'm using in the above photo is an aluminum US GI cup stand. It works, but I generally wouldn't recommend a GI cup stand for use with the Borde stove. The top of the burner plate should be about 3/4" (2 cm) from the bottom of pot you are heating. A GI cup stand is simply too short to provide the appropriate clearance.

Here, I'm heating water for my morning tea.
 
A word of caution:  Since the burner is directly attached to the fuel tank, the Borde stove gets hot.  Always pick up or move the stove by the wire holder.  It should be noted that the Borde stove has no safety devices of any kind whatsoever.  Overheat this stove, and it will explode.  Indeed, the nickname of this stove is the Borde Bomb, although some claim that the nickname derives more from the method of priming than the way in which the stove operates.  The plug at the base will sometimes fail first, but the plug failing first may not always happen.  In short, you are the safety device.  It is up to you to turn down the stove if it seems to be surging too powerfully.  You must be mindful at all times of how the stove is sounding and performing.

I'm not completely sure when the Borde stove was created.  I've seen several patents taken out by Josef Borde in the 1940's and 1950's.  Somewhere in that time frame the stove that we know today was developed.  There have been multiple variants of the stove, including versions where the burner is mounted on top of the tank rather than at the end, but generally all of the stoves are considered the Borde stove.  
My information is a little bit sketchy, but apparently the Borde stove went out of production some time in the mid 1960's until production was resumed some time later by Norbert Bader.  Alas, the most current information that I have is that the aging Mister Bader has discontinued production again, perhaps this time for good.

OK, let's finish up now with a couple of flame shots.





Thanks for joining me on another Adventure in Stoving!


HJ


The Borde Stove

What's good about it
Super high cool factor!  :)
Compact
Extremely simple
Relatively light

What's bad about it
Hard to find
Expensive
No longer in production (parts hard to find, no factory repairs available)
Small capacity tank
No integrated pot support
No safety devices.

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