This is a write-up I did a few months ago, then forgot to post it. I ran across it
today looking for a file and thought I should show it.
I have a 237 and was having some trouble with it lately. The tip kept getting plugged,
even though I twirled the tip cleaner often. I couldn't figure out why it kept plugging
in this particular manner.
The tip would build up a long piece of carbon. The carbon is in the shape of a cone, with
a hole through it similar in size to the pricker wire. The lantern would still run as this
"cone" grew, but it kept getting dimmer and dimmer, and finally the lantern would flame
and soot up.
I found that the problem was the pricker wire on the pricker rod did not go completely
through the gas tip. It only went through enough to barely stick out the top side of the
gas tip, and that allowed the carbon cone to build up over time.
Trying a new generator didn't help. The new one also had a slightly short pricker wire,
and it produced the same problem.
I checked an old 237 pricker I had, and found that the wire on it was about .050" longer
than the newer ones I have. That pricker worked well, since it came through the gas jet
far enough to push the carbon completely out and off the tip.
This write-up shows how I made a new pricker using only simple tools. I have a small
machine shop, but realize that not everyone here has the same equipment, so I did this
one with tools most everyone should have.
These are the tools I used. A good quality pair of cutting pliers. A good quality file,
and a good hammer. I say "good" because these things are made here, on the American
continent. You can buy whatever junk you like. I have a Chinese made hammer that is so
poorly made it cannot be used. I figure if they can't even make a good hammer, I am sure
not going to trust them to make something complicated, like pliers or a file.
One thing I used that is not shown in this picture is a medium hardness arkansas stone.
The material needed for the pricker is about 5" of 1/16" diameter brass tubing.
And a piece of wire for the pricker. You can get small diameter wire from a piano repair
place or a place that sells spring wire, like McMaster.
To make a pricker, you need a wire that is approximately .001" smaller than the actual gas
tip jet in your generator. For instance, if the gas tip is .008" diameter, you need
.007" spring wire, or music wire.
Also in the above pic, you can see I've bent one end of the brass tube to mimic the shape of
a factory pricker rod. Take your time and use the needle nose pliers to roll and shape it.
Use the file to remove any burrs and flat spots that are left, and try it in the eccentric
on your lantern to make sure it fits.
Once you have a good fit, cut the brass tube to the same length as your factory one.
I use a piece of wire that is about 1.5" long, so I can put a goodly length inside the brass
tube. Don't try to get the wire length exactly right at this point. Leave about 1/2 to 3/4"
sticking out of the brass tube so it's easy to work with. You can trim it later.
Use a ball pien hammer if you have one, and start tapping with a mind to close about 1/2" length
of the brass tube around the wire. Tap, then roll the tube between your fingers, then tap
again, over and over. You want to try to get the end peened around the wire somewhat evenly.
It won't be perfect, but give it a try. Don't just smash it flat on one side. It will be
unusable if you do that. Tap, roll, tap, roll, rinse and repeat. Eventually you will have
the wire captured in the tube, and the end of the tube will have a moderate taper to it.
Once you have the pricker rod and wire together, and the end closed to hold the wire,
it should look something like this.
Now, where you have cut off the wire, there will be a burr that will prevent it from entering
the orifice in the gas tip. Put your arkansas stone in something steady so it doesn't move
around and you can stone off the burrs on the wire.
Start at one end of the stone, and put your finger on the wire and press down.
Now, with your other hand, pull the pricker rod to the right while holding down on the wire.
You must also twirl the pricker rod as you pull it across the stone. At one end of the
stone, my fingers are holding the rod like this....
....and as I pull the rod to the right, I twist it between my fingers, so as the stone is
taking off the burrs, it is also making smooth edges where the wire was cut.
Do this four or five times, and the wire should be smooth on the end so it will go easily
into the orifice in the gas tip.
Finally, use the file to round off the shape of the peened end of the tube, so it will fit up
inside the hole in the threaded end of the gas tip. Same thing here as when dressing the
end of the wire. Push it against the cutting edge of the file while rotating the rod.
Note: Files only cut in one direction. They cut on the fore stroke. That is, the direction
that you would normally push on the handle. They do not cut on the backstroke.
That's about it for this thing. The new pricker with the longer wire fixed the problem
with my 237. You can make a new pricker for most any lantern you have with these few tools.
Thanks for looking.
Whether you think you can or you think you can't, you're right.
Ontario knights of the White Mantle
Birthday Lanterns: 7-91, 10-93
Darien the prickerless. HA!!
“All of us are creatures of a day; the rememberer and the remembered alike.”
Coleman Blues #67. ICCC #1242. Searching for 5-1940. 6-36.
Coleman Quick Lite Crew #8
Coleman Blues 243's #16
it online from an ebay seller that sells five 3' lengths for $15. Look for K&S tubing.
I've never seen it at a regular hardware store.
Guys, thanks for all the comments. Glad it's something useful.
I see a trend.. and I LIKE IT!!!!
MILSPEC_OPS & 275 Appreciation Syndicate Member #9999
In Search of (ISO): evidence of a 220/228 series lantern dated 2/63
(I think the "AYEs" have it)
"At least it's not a complete wretched pulsating ball of fail and suck." dpatten
Coleman 275 Appreciation Syndicate Supporter #42
Coleman Quick Lite Crew #42
There is another similar hobby retail web sales site that I use, but can't find the
link right now. Also, there is an ebay seller that sells this 1/16" tubing in 36" lengths.
You will have to search that one out. A google search for K&S metal should return
a number of sources. K&S sells world wide, so be sure you order from a retailer
that is in your home country.
One other thing; K&S sells two types of brass tubing. One is annealed (soft), and
you often see that sold as "bendable" tubing. That is the kind you want for making
things like pricker rods and kero genny springs.
The other type they sell is usually sold as "telescoping" tubing, which is rigid walled
and meant to fit inside or outside other tubing they sell. It is primarily for building
projects and modeling, and is hard drawn, which means it is quite stiff. It will kink
if you try to bend it. It is also very thin walled. If you can only get that kind of tubing
for projects that you want to bend, like the prickers, you will have to anneal it before
you can work it. Annealing is easy enough, but it's even easier to buy the soft bendable
tubing in the first place.
Edit for a bit more. Here is a search on ebay for some sellers of the 1/16" brass tube:
Brass tube sellers.
The ebay seller I've bought from in the past is called bigdoghobbies. He's in the States.
I see one in Canada called qualityhobbyguy. I have not purchased from him, but
he should be better on shipping for our northern brethren. Same product.
and tapering done on shop made pricker rods. Lot of pics, but I hope to explain it well this way.
First, the kind of drill chuck needed.
For this to work, you need a drill chuck that has fairly "sharp" jaws, that come nearly to a point as
shown in the pic above.
Avoid this kind of chuck. Obviously, the one shown above will not close down enough, but also some
of this type, even though they close down all the way, have very rounded places where the three
jaws meet. That kind does not work well from what I have tried.
In general, the drill chuck has to be pretty heavy duty. The way to have some assurance of getting
that is to use a chuck that will hold large diameter drills, like 1/2". It will be made to take a lot of
torque on the scroll inside the chuck, and will be heavy enough that the jaws won't spring.
You may have to shop for a used chuck on ebay, or at yard sales. It's okay if the chuck is a cheap
brand for this chore, as long as it will close down all the way and is big enough that it doesn't break
when you put the muscle to it.
Start with a clean cut on your brass tube. File it square across the top if it has been cut at an angle.
Here's the brass tube in the chuck, which has only been snugged by hand.
Now tighten the chuck until it refuses to go any tighter. It doesn't look like it has done much, but
it will surprise you.
This is after the first tightening in the chuck. You can see the end of the tube has closed down to
almost nothing. Also, I think you can see at the edges of the now triangle shaped tube that there is
some excess material which has been extruded out of place by the chuck jaws. That extruded part
has also caused the chuck to stop tightening any more because it has become wedged between the
jaws as they closed.
This line shows where the jaws were squeezing, and the part outside the line is the part that was
extruded out, and flowed in between the chuck jaws. You need to get rid of that so the jaws can
squeeze it some more to mash the end onto the pricker wire.
Use a file to flatten those extruded parts just a bit, so they conform to the flat surface where the
drill chuck squeezed against the tube.
As shown above.
And an end on pic so you can see that the extruded parts have been reduced.
Now, an important part. Get your small torch and anneal this end. You only have to heat it until
it is orange, just starting to turn red, and then let it cool or dunk it in water. It will be soft again
and ready for the next step.
Put in your wire.
And back into the chuck as tight as you can get it.
You can see the chuck has started to make those lines again. The tube is once again extruding into
the space between the jaws. You can pull the tip out of the chuck about 1/8" and give it another
squeeze, then see if your wire is tight.
If it is not tight, file the extrusions again just like before, and give it another squeeze in the chuck.
It usually takes about three tries to get the squeezing down enough to make the wire tight.
Now you can go at it with a file until you have it slimmed down enough to fit into a gas tip.
About like this.
That's all I've got.