Ka-Bar BK14 Knife Scales Pt 2

I used my Ka-Bar BK 14 a little bit and thought about how I wanted to color the scales.  I thought staining them might look good.  To test the stains, I prepared some small blocks of the same Water Oak I used on the scales.  I looked through the stains I had and picked a couple that I thought would look good.  Here’s a pic of the stained test pieces.

In the end, I really didn’t like any of the stains.  It didn’t darken the wood the way I was hoping it would so I decided to go with a simple Boiled Linseed Oil finish.  It’s easy to apply and renewable in case I need to touch the finish up later.

While I was using the knife, I went to put it into the sheath and noticed that scales were too long in the front.  As a result, the knife wouldn’t fully seat in the sheath and wasn’t retained as tightly as it would normally be.  In retrospect, this is something obvious I should have checked but I managed to overlook it.  Oops!  Here’s a picture of the knife in the sheath showing where the scales were contacting.

Here’s a pic to compare with the one below to show how I changed the front of the scales.

To fix this problem, I removed the scales again and sanded then down to make them 1/8 inch shorter.  Once I checked to make sure they no longer hit the sheath, I rounded the edges over to smooth it all out.  When I was happy with the overall shape of the scales, I sanded them to 240 grit and put a couple coats of Boiled Linseed Oil on them.  Here’s how they came out.

I had considered stripping the coating on the knife, but at this point I’m going to leave it alone.  I’m curious to see how well it holds up over time.  I think this simple project came out well and helped improve the usability of the knife for me.   I think that anyone could successfully accomplish this project with a little bit of time and effort.  Customizing knives is fun.  So, you might see some more of this kinda stuff.  Ka-Bar has some other cool and historic knives that I have my eyes on.  Just don’t tell the wife!

Fixing Things: Bed Finial

Here’s a short little post on fixing a bed post finial.  At least I think it’s called a finial.  Either way, the top of the bed posts on an antique bed we have has some removable decorative pieces.  My daughter managed to break one the other day by swinging on it I think.  As you can see in the picture, the finial has a peg projecting from the bottom of it that fits into a hole in the bed post.  It looks as if the finial was tugged to the side sharply and it left behind a very rough break.  There’s no way this could be glued back together.  Even if it could be, it’s an end grain glue joint and would easily break again.  I’ll quickly cover the steps I took to fix it.  Nothing too exciting this time around but its a practical use of tools around the house.

 

I decided the easiest way to fix it would be to drill the broken part out to the diameter of the remaining part of the peg.  The first step in doing this was to clean up the broken edge.  I used a sharp chisel and light blows by a mallet to remove the broken wood while being careful not to gouge the bottom of the finial.  The picture below, shows the chisel in use.  Chocking up on the blade of the chisel allows very precise usage.

 

With the surface cleaned the next step is to start drilling.  In order to keep the drill bit from walking, a center spot is needed.  Luckily, there was a preexisting spot created after chiseling the wood that I could use as a center spot.  I’ve pointed this spot out in the picture with a red arrow.  The size of the spot was increased with an awl before drilling.

 

I’ve found the easiest way to measure the diameter of something like the peg is to use calipers.  It gives you a measurement that is more precise than you really need in this case but it’s not a bad thing.  The peg has a diameter of 0.474 inches.  Next, I needed to find a drill bit, that I had on hand, to drill the final to.  Checking a drill chart I have shows that a 15/32 inch drill bit is equal to 0.469 inches which is slightly undersized.

 

To drill the finial, I made use of the Clausing drill press again.  I wrapped the finial in masking tape to keep from scratching it and then clamped it with a wooden clamp.  The clamp didn’t keep the finial from rotating side to side but it did keep it from kicking out at the bottom end.   Steadying is requires lightly holding the top of the finial.  If the finial was rigidly held you could probably jump right to a 15/32 inch drill bit.  But, since it was not, I started with a small drill bit and worked my way up to the final size in with several intermediate drill bits.  This is never a bad idea because it is less likely to grab the part your drilling which, if it is small, can be an issue.

 

Here’s the finial after being drilled to 15/32 inch.

 

With the hole a little undersized, the peg fit tightly and did not require any glue.  Also, if need be, the peg can be removed with a little effort.  Done.

 

Making Ka-Bar BK14 Knife Scales

I picked up a new Ka-Bar Becker BK14 knife the other day.  This knife is sold without scales, the side pieces that are attached to the metal handle, but I decided I wanted it to have some.  So, I thought I’d document the process of making some and post about it.  Here is the knife.  It has a 3.25″ blade and a total length of 7″.   It’s made of 1095 carbon steel and manufactured in the US. 

This project can be completed with the basic hand tools seen in the picture below plus a drill.   I used some other tools (as I’m sure you expected) but you can succeed using these.  The metal files work well at shaping wood and having a range of cuts (how fine the teeth are) can speed the shaping up considerably.  Drill bits are self explanatory and the coping saw allows you to cut tightly radiused curves.

Some folks like to use exotic woods for their scales, but as this is my first attempt making knife scales, I used some of the water oak I have on hand.  The wood is still in large sections so the first order of business is to turn it into more useful sized pieces.  Here’s what I’m starting with.

To create smaller pieces I’ll use the riving technique again.  Riving is splitting the wood along its grain using a metal wedge such as a hatchet, ax, or chisel.  First, I split out a small wedge of wood.

The wedge of wood is then rived in the other direction to produce rectangular pieces.

The next step is to crosscut the long pieces down to more useful sizes.  You can use the coping saw pictured above or a giant backsaw like this one.  Of course, any machine saw capable of crosscutting would work as well.

With the oak cut down into smaller sizes, I need to create a flat surface that will rest against the knife handle.  To do this, I used my #5 hand plane but this could be accomplished using a metal file and checking it against a reference surface such as a counter.

With a flat side, you can decide how thick you want the scales to be and mark a line.  Offset a little bit to leave a little extra and rive the piece again.

Finally, the wood has been reduced to a appropriate size.   I chose to trace the outline of the knife and then sketch lines where I want to cut the wood.  At this point, write something on the inside surfaces of the scale so that you don’t get the insides and outsides mixed up.  Yes, you can mix them up quite easily.

With the lines marked, the piece can be cut using your coping saw or in my case the band saw.  Be sure to leave a little extra material around your lines, as you can’t add wood back on.  On one of the pieces I cut the back circular portion with the band saw.  On the other, I drilled that section out.  You can imagine which worked better.

Next, start shaping the scale to match the profile of the handle.  At this point, I’m only concerned with matching the edges not rounding the corners.   You can do this using metal files, as I did, sand paper, or a belt sander.  If you’re handy at carving, you can shape them that way as well.  I wouldn’t recommend the belt sander at first.  As you can remove material so quickly with it, you may get in trouble.  Using the metal files or sand paper allows you to sneak up on your chosen shape.  I used my vise to hold the pieces, but you can hold them in your hand to shape them if need be.  Compare the scale to the knife frequently to assure you don’t remove too much material.

Once one scale has been shaped, it can be used as a guide for the second one.  Trace the shape of the first onto the second and start working on it.  Once the second scale is close to the shape of the first clamp or tape them together to work on both of them at the same time.  This assures that both scales will be the same.

Once the two scales are sized, you can start to round the edges over and add any details you want.  Here’s how they look on the knife at this stage.

Here they are sitting on the bench.  See how easy it would be to get them mixed up?  I’m glad I noted which side is the inside.

Round the edges using the metal files, sand paper, etc to whatever shape you desire.  I went with a simple rounding over of the edges and tapered the front and back edges.  At this point don’t concern yourself with making every surface perfectly smooth by sanding to a high grit.  Just get them close because we still need to drill the holes for the screws that hold the scales together.  Here’s how it looks on the knife at this stage.  You can tape them to the knife to see if you like the overall profile.

If you can, try to make use of objects as guides when shaping your scales (or anything else for that matter).  I chose to use this government approved object to size the ends of my scales.

Once the first scale is done, it’s time to start on the second one.

As you’re shaping the scales be sure to check them on the knife to be sure you like the profile.

Due to the shape of this knife, I needed to create a filler piece to keep the scales in place.  I used the same methods discussed above to create the filler piece.  It will hold the machine screws in the correct location so that the scales have more than clamping pressure, which I wouldn’t trust in this application, to restrict their movement.  Be sure to make this filler piece a little less thick than the knife so that it doesn’t hold the scales off the side of the knife handle.  Here’s the filler piece in place.

To attach the filler piece to one of the scales, use some super glue.  Put the filler piece in the knife and put some glue on one side.  Press the scale on the glued side of the knife until it sets.  Be certain you get it in the right place!  This piece only needs to be held in place during the cross drilling so absolute strength is not required.  The super glue dries quickly and allows you to get back to scale making after a short delay.  Once the glue has set, you can pop the part out.

Mark the locations where you want the screws to be on one scale and drill them out with a small drill bit.  I used a 1/16″ bit.  This is only a guide hole at this point, I want it to be small so the Forstner bit I’m about to use doesn’t walk.  Here’s the scale with the holes drilled.

Put the scales on the knife and tape everythin together so nothing can move.  Using the small drill bit again, drill through the other scale using the scale with the holes already in it as a guide.  You can do this with a hand drill, but yes I’m using the Clausing again. You would too.

Your screw hardware will dictate what occurs next.  I wanted to recess the heads and bolts below the surface of the scales.  If you don’t want to, you can skip this step.  You want the hole that the screw hardware sits in to have a flat bottom.   The best way to accomplish this is using a Forstner bit because it leaves a flat bottom.  A Forstner bit centers itself with a small point in the middle of the bit.  If this point can’t dig into the wood, the bit will move around leaving a poor looking holes.  This was why I used a small bit to drill the holes in the step above.  Figure out how deep you want to go and then drill the pockets out.  A drill press makes depth control easy but if you’re very careful you could do it with a hand drill.

At this point, you can go and drill the holes out so that your machine screws will fit in.  If needed, drill the holes a little larger so you can move the scales around a little bit.  The machine screws have round heads which will fit in the Forstner bit holes without issue.  The nuts on the other hand…not so much.  If you oversize the holes then the nuts may spin.  You could glue the nuts in if you go this route.  If you make the holes a little smaller,  the nuts can be pressed into the holes.  You can use a longer screw and tighten the screw to pull the nut into the wood.  Be warned though, you can also pull the screw head down into the wood.  You could also press or hammer the nuts in if the hole is close to the size of the nut.  Another method would be to mark around the outside of the bolt and chisel into the wood.

With the nuts pressed in, you can remove longer screws and put your real screws in.

A view from the back.

Another couple of views.

You’ve probably noticed the scales are still a little rough.  This is intentional.  I’m going to use the knife for a little bit and see what I think of the shape of the scales.  Since you’re building instead of buying, you can customise the shape to be exactly what you want.  If needed, I can come back and change the shape of the scales.  Once I’m happy with the shape, I’ll sand them to a higher grit and finish them.  I’ll probably also darken the nuts to match the screws.  I may also strip the black coating off of the knife at some point.  When I do all of this I’ll post about it.  Here’s what I decided: Scales Part 2

I’ve looked on forums and it always seems people like to show their knives sticking into something.  Since I don’t want to be left out, here is my picture.

Mercury Model 1100C Tube Tester

When you’re working on your old radio how do you know the tubes are good?  They made a device for testing tubes called, non-shockingly, a tube tester.  There are different types of testers out and I have a midlevel one that falls into the category of emission tester.  What does this mean?  First I have to give a very simplistic description of how a tube works.  Tubes contain a vacuum and work by passing an electric current through a filament which causes it to heat up.  This heat causes the cathode to emit electrons which, depending on the design of the tube, may or may not be the same thing as the filament.  When a positively charged anode (also called a plate) is placed inside the tube the electrons are attracted to it which creates an output current. The release of electrons is known as thermionic emission and attracting them with an anode is known as the Edison Effect.  You can read more at Wikipedia if you want.  If the plate is negatively charged, no current will be generated.  So, you have a device that will pass current in one direction but not the other.  This is called a diode.  If an additional element, called a control grid, is inserted between the cathode and anode you can control the current out of the tube by varying the current on the control grid.  This is called a triode.  By varying the current on the grid, the current out of the tube can be controlled.  If the output voltage is larger than the grid voltage this results in signal amplification.  Through the same basic principles more complex tubes can be created.  Wikipedia has lots on them.

So, an emission style tester works by measuring the plate current for a constant grid and plate current.  Now you see why it is called an emission tester.  These style of testers do have downsides.  Wikipedia lists that they don’t measure the ratio of current out for voltage in (transconductance), don’t perform tests at real load, voltage and currents, as well as a few other cons.  As a result of this, these style of testers can say that a good tube is bad and a bad tube is good.  Still, it shows if the tube functions and this type of tester is much more affordable than the fancier ones.

Now to the actual tester.  This is my Mercury Model 1100C Tube Tester than my father was nice enough to pick up for me off of Ebay.  It comes in a simple hinged box which contains the tester and the extremely important manual that has the settings for the tester.   The list of settings, called the tube data chart, lists the positions to set all of the knobs and switches in to test the tube.  Without the chart, the tester is worthless.  The manual describes the 1100C as a “compact, ultra-modern tube tester” that is “one of the few truly obsolescence-proof tube testers.”  I’m glad to know it!

Knob A selects which switch to connect to knob B and shorts the others to ground.   Knob B sets the filament voltage and Knob C sets the meter sensitivity.    The switches in the middle, one per tube pin, control whether the tube pins are connected to voltage, ground, or open.    The meter has a 0-100 scale to allow comparison readings between the same type of tubes according to the manual.  The little neon bulb on the lower left hand corner tells you if there is a short or leakage between the element selected by the switch in the K position and the other elements.

 

To test the tube, you first identify the type of tube by locating the label on the tube.   For this post I’ve picked a 6S8-GT Triple-Diode tube which is why it has 4 entries on the chart.  From left to right, the columns list Tube, knob A position, knob B position, knob C position, which switch to set to K, and which switch(s) to set to open.  The tube must be tested with the tester in each configuration to test each part of it.  The dot beside the tube type means you should read from the diode portion of the meter.

 

With the tester configured correctly, the tube is inserted into the appropriate spot and allowed to warm up.  Next, the switch to test the tube is pushed and the meter read.  For this test the tube is “OK”.

 

That’s pretty much it with this tester.  You set it up and then the tester tells you if something happens in the tube.  I’ve read that back in the day, normal stores used to have similar, but larger, testers for their customers to test their tubes in.  If it failed, they’d have one to sell ya.  Imagine that, electronics you could work on yourself!

 

For fun here’s a picture of the tube glowing and some vintage tube boxes.

 

Zenith 8H034 Tube Radio

A while back I picked up an old 1940s Zenith radio.  It uses vacuum tubes unlike radios today.  Of course when I found mine it didn’t work and was well worn.  Here’s a pic of it when I bought it.  The wood veneer had been damaged in multiple places and it appeared that the edge had suffered a little water damage.  The wooden “feet” that are supposed to stick out at the bottom had both been broken.  One of the knobs was missing and the other damaged.  The translucent yellow wheels rotate separately from the black knobs.  The knob’s function on the left is on/off and volume.  The wheel on the left adjusts the tone of the radio which seems to just increase the treble slightly.  On the other side, the knob adjusts the tuning frequency and the wheel adjusts the band.

Here’s a close up of the right hand corner.  This radio has three bands: Std Broadcast (AM), FM 100 (today’s FM band), and an older FM band extending from 42-49 Mhz which is no longer in use.  Also in this picture are replacement “feet” I made for the radio out of some red oak.

Here’s a picture of the back showing the hookups for external antennas.  The power cord comes out of the hole on the lower left but had been cut off by someone.  That’s not a bad thing though because the old cords apparently had a good amount of resistance in them resulting in them heating up.  When the coating broke down and the heated up…it could be bad.

The back can be removed after taking out four screws.  After removing four more screws from the bottom the chassis can be removed from the housing.  The top of the chassis is pretty clean.

Here’s a better view of the tubes.  Note that the silver metal can at the far right isn’t a tube.  It contains some capacitors for cleaning up the converted DC electricity.  More on that in a bit.

Underneath the chassis is a little messy though.  Here’s a couple of pictures.  The plastic rectangles and multicolored plastic cylinders are resistors.  They hold up well over time.  The paper cylinders are capacitors and, over time, they tend to dry out and die.  They’re the main source of problems on old radios.  Obviously, there are other bits and pieces but those are the main two.

If you’re lucky, and I was, you can find a schematic available for free online.  Once you have it you can go through and identify everything.  I took a picture of the bottom, printed it out, and labeled it to make replacing things easier.

There’s a good chance all of the capacitors are dead or will be soon once you try to run the radio again.  So, it is best just to replace them all.  One at a time I removed and replaced the old paper capacitors with new “orange drop” capacitors.  If you look around online you can find them from multiple sources for pretty cheap.

Here’s the view after I’d replaced most of the capacitors.  The big one in the middle isn’t hooked up so I left it in there.  I left a few paper ones in there because I didn’t have the right size replacements.  I did remove and test them though.  If you look in the lower right hand corner you’ll see some black cylindrical capacitors.  These are electrolytic capacitors that clean up the converted DC electricity for the radio.  The capacitors that they replace are all crammed into the metal can I noted above.

Here’s a closer view of them.  I’ve taped over the ends to make sure they don’t contact anything.

The top remains pretty much untouched.  I replaced some wire whose coating was coming off.

To repair the case I mixed up a blend of stains to closely match the original color.  Next, I lightly sanded the entire surface except for the areas around the knobs with the script.  I had no way to replace them that would match the original.

Here’s the radio put back together.  I looked around for some replacement knobs but didn’t find any I liked.  One of these days I plan to turn a couple now that I have a lathe.

So, does it work?  Check out the video below.

Update:

I thought I’d add a few more pictures.  Here’s a view of the top of the cabinet showing some of the damage before restoration.

Here’s a view of the inside of the cabinet.  The white pad is asbestos and helps to keep the heat away from the cabinet.  I’d read that you could seal the asbestos up using a clear coat spray paint to make it safer.  I haven’t messed with it other than that. If you do find an old radio be aware that it may contain surprises.

The finned object in the metal housing is the air spaced variable capacitor.  When you turn the dial to tune the radio, some of the plates move while others stay stationary.  This varies the frequency of the signal the radio picks up.

Unlike modern speakers with permanent magnets, my Zenith makes use of an electromagnetic speaker.  This type of speaker creates a magnetic field with electricity for the speaker’s voice coil to interact with.  This means that you cannot simply swap a new speaker in for an old one without some work.

If you are interested in restoring an old radio there a numerous sites online that provide information and a couple of forums such as antiqueradios.com.  One book I found very useful on antique radio workings and repair is “Old Time Radios!  Restoration and Repair” by Joseph J. Carr.  If you have a desire to restore an old radio, give it a try!  Just take you time, do your research, and be mindful of electricity.