Hammered Dulcimer design, construction, and unrelated stuff

Monday, August 7, 2017

Excluding moisture exchange from wood

Wood is hygroscopic meaning it wants to absorb or release moisture based on the humidity of the environment.  Wood reaches an equilibrium moisture content based on whatever the conditions are.  In a humid Iowa summer any wood can get close to 12% moisture content (MC) in a non air conditioned home.  In winter the same wood will pretty quickly drop to close to 6% MC in a normally heated home.   When wood absorbs or loses moisture it shrinks or swells across the grain but not along the grain.  It continues to do this as long as it exists as a piece of wood.  Different species swell or shrink different amounts, but all move to some degree.  We have a coffee table that I built of 150 year old reclaimed walnut from central Illinois.  The top is 2 ft. wide, and it will swell 3/8" from winter to summer, then go back when winter comes again.  This is quite a lot, and if a wood worker doesn't plan how to construct something based on this knowledge, it can lead to trouble. 

Even plywood is affected to a degree, but since it is layers with the grain going alternating directions, it is less affected. 

In order to build a hammered dulcimer that is completely tuning stable, we learned that moisture exchange has to be excluded from the wood.  It is the shrinking and swelling that throws a dulcimer out of tune, and it can happen fast if a dulcimer that is used to one environment is taken to another that is much different.  So we did a lot of research and experiments to find an appropriate coating.  Shellac doesn't work, nor does lacquer or varnish or polyurethane.  Surprisingly, according to the Forest Products Lab the most effective coating is melted parrafin wax!  It does work, but is quite a mess!  Boat builders epoxy also works, but needs to be at least 3 coats to be effective.  Other than that epoxy paint also works, but again needs to be at least 3 coats.

Thursday, July 13, 2017

Organic Japanese Beetle Control That Works

The Japanese Beetles are horrible this year in Eastern Iowa probably due to a mild winter.  I have been using an organic recipe to control them for several years, and this year it has proven its worth.  It really works.

1/4 bar Fels Naphtha Soap shaved or grated in a large bowl.
Add 1 1/2 quart boiling water and stir until well dissolved.
Add 1/4 cup any dish washing liquid.  I use Dawn.
Stir again and let cool.
When cool put in a spray bottle and gleefully go kill beetles.

It doesn't take much, just get them wet and in a couple minutes they will be dropping off.  The soap blocks up their breathing apparatus.  Fels Naphtha Soap is in most grocery stores and farm centers, usually in the laundry section.  You have to go spray beetles every day as more come out of the ground each night.  They like grapes, fruit trees, roses, rhubarb, raspberries best, but if they are hungry will eat tomatoes, potatoes, beans, corn and lots of non garden plants like Linden trees, Virginia Creeper and Stinging Nettles.  They also emit pheromones when they find something to their liking to call in their friends.  Best time to go spray is the early morning when they are least active.

We have a big grape arbor on the front of our outbuilding, and this year the beetles were trying to clean it off.  I was right on them, though, but there were several days where there were so many they were falling like rain out of our grapes when I sprayed.  Yesterday there were probably only 100 or so, and today maybe 20.  Our grapes are a little tattered, but they aren't denuded like other folks'.  So I think we are past the big hatch and my soap spray has definitely worked.  I believe it is the only good remedy for Japanese Beetles.  Other than that you would have to spray something nasty on your garden, and you'd have to go back and do it again every day for at least a couple weeks since new beetles come out of the ground every day.  You'd have a pretty good pesticide load which would get into your food from the garden.  You'd also be killing a lot of other insects that would probably be beneficial.  But the soap you target and only get it on the beetles.  It will kill other insects, but not all.

I adapted this recipe from one in Jerry Baker's great book Old Time Garden Wisdom, and he got it from his grandmother. 

Sunday, November 8, 2015


If you've never had Kimchi, it is sort of a spicy Korean version of sauerkraut, and is a fantastic way to get your probiotics and vitamins without pills.  Oh, and the flavor is out of this world.  I crave it!

Kimchi is fermented and eaten raw.  I have never seen it for sale, and since it is eaten raw, I doubt if proper Kimchi is for sale anywhere, so I make it myself, and keep a couple jars in the fridge most of the time.  It is very easy, just a matter of planning ahead.

Both kraut and Kimchi are fermented using the natural yeasts that are on the cabbage.  No heat is applied, so the yeasts aren't killed.  What regulates the kind of organisms that are allowed to grow is salt in proper proportions.  In making kraut, you shred the cabbage then mix in the right amount of salt which draws liquid out of the cabbage.  But Kimchi is brined overnight in a solution of salt and water, so it is a little different, and produces a different result.  Also, Kimchi has other vegetables added for flavor.

2 pounds cabbage chopped into 2 inch squares.
6 cups water (I use distilled)
3 Tablespoons noniodized salt

Soak the cabbage overnight in the brine.  Drain well, reserve the brine, then mix 1 teaspoon more of salt in with the cabbage.

6 scallions slivered
1/2 tablespoon minced fresh garlic
1/2 tablespoon finely shredded fresh ginger
1 cup Daikon radish shredded
3 tablespoons shrimp sauce or anchovy fish sauce
1/4 cup mild dried pepper ground or flaked.

Mix in all these ingredients, then put the mixture in a glass or crock container.  cover with the reserved brine, and allow to ferment on the counter top for 5- 10 days until it stops producing bubbles.  The probiotics in Kimchi are very powerful, and will attack plastic or metals, so only glass or crockery containers should be used.  Also, after it starts fermenting, only handle it with wooden utensils.  The best containers I have found for it are the 1/2 gallon glass canning jars, but a gallon pickle jar would be great.  Don't fill the jars all the way to the top as the kimchi will bubble up while fermenting.  You will need to push a wooden spoon down into it every day to release the bubbles so the Kimchi doesn't overflow onto the countertop.  Since I use the canning jars, I do use the metal lids, just being careful not to let the fermenting Kimchi get so high as to touch the lid.  Screw the lids on loosely so the gas can escape, but tight enough that fruit flies don't discover it.  When fermentation is finished, put the jars in the fridge and enjoy!  The Kimchi will keep indefinitely, and though edible right away, like kraut, the older it gets, the better it is.

The ingredients list for Kimchi is flexible.  Oriental folks usually use Napa cabbage, but any cabbage will work.  Instead of the scallions, I use regular onions.  Shredded carrots work fine instead of the Daikon radish which is rather expensive, but if you aren't using organic carrots, be sure to peel them before shredding.  The fish sauce is optional, but nice, and not expensive.  It also wouldn't be right without some hot pepper flakes or powder.  The critical parts of this recipe are the amount of salt in the brine, and the presence of garlic and ginger in about these amounts.  If you want to make a larger batch, just scale this recipe up.  Korean folks make large batches in earthenware pots called Onggi and keep it outside all winter.

Eat Kimchi as a condiment, maybe 1/2 cup for a serving.  It goes well with many foods; meats,  fish, vegetables, etc., but my favorite way to eat it is with fried eggs and beans for breakfast.


How to make the best home cooked beans from scratch.

I really like beans, I could eat them 3 times a day and not get tired of them.  But how to cook them and get them soft and creamy is something that took me 40 years to learn, so I thought I'd pass it along.

First of all, they must be soaked at least overnight.  Of course you can short circuit this by blanching them, then changing the water, then cooking, but the overnight soak is necessary to eliminate the antinutrients that are in the skin of the beans.  The antinutrients are there to keep the seed from sprouting while it is dry and in storage.  If you eat too many of them, they will interfere with the absorption and utilization of minerals in your body.  All seeds have these, and it is the reason our ancestors knew enough to mill the hull off seeds before grinding them.  It is why we eat white rice and white flour, it is better for us.

Second, you must use soft water.  Beans will never completely soften if they are cooked in hard water.  There must be no minerals in the soak or cook water, this means don't add salt until the cooking is finished.  Since the water here is very hard, I just buy distilled water in gallons at the grocery store.  You can add any flavoring you want to the bean pot like ham hocks, etc., but don't add salt until the cooking is finished.

Third, can them up.  It is why beans are always better out of a can or jar.  The beans are good right out of the pot, but since I don't want a big pot of them in the fridge that needs to be eaten up, I can them.  I cook up 3 pounds at a time which makes 5- 6 quarts of cooked beans.  I only use water since I want to flavor the beans in different ways when we use them.  There is nothing in my jars except beans and distilled water.  Beans need to be pressure canned at 10 pounds for 90 minutes.  That is a lot, but the processing really sets the flavor, and makes the beans creamy and delicious.  We bought our pressure canner for using in the summer with garden produce, but it gets used all year long now, and is one of the best tools we have ever bought.

My favorite kind of beans.  We like hummus, so I make a lot of chick peas.  They are very good, and won't cook down to mush.  The flavor after canning is wonderful.  I also like pintos, but my favorite is called Mayo Coba, and is from Peru.  They are available in many grocery stores and are a white bean, but unlike Great Northerns or Navy Beans retail their shape and texture.  The flavor is out of this world.

Sunday, October 18, 2015

On How to Properly Sand, and do a Hand Rubbed Finish

I really like Minwax Wipe On Poly.  I have been using it for years now as a sealer under shellac, but have recently discovered how to do a really nice hand rubbed finish with it.

The secret is in the sanding.  The finer the grit the surface is sanded to, the less poly it will absorb, and the quicker a gloss will develop.  So I currently sand starting at 100#, then 150# over the whole dulcimer.  The edges are sanded on a big edge sander, and the top and back are sanded with a stroke sander.  After that, I sand 150# with an air powered  random orbit sander followed by 180# on a different sander, and 220# on a third.  By this time the surface is feeling silky smooth.  Then I go over the whole dulcimer lengthwise to the grain by hand with 400# on a sanding block.

Then blow off the dust followed by wiping down with a tack cloth, then apply the first coat of Wipe On Poly as thinly as possible, but making sure the whole surface is covered.  I don't wipe off the excess, just make sure there isn't so much on as to drip or drool, then hang the dulcimer up to dry in the clean room.  After a couple hours the poly is cured enough to scuff sand with 220#, just enough to remove any dust motes, and make the surface smooth again, then blow off and wipe down with the tack cloth again.  The sparingly apply a second coat of Wipe On Poly and hang up to dry.

Next day I go over the whole surface very lightly with a worn out piece of 400# paper, just enough to get off any dust motes.  Then wax, and the finish is silky smooth!  I've been using the satin Poly, and it has a beautiful glow done this way.  I think if I wanted a higher gloss, after the 400#, finish sanding the wood with a quick once over with 600#, and in between coats of poly, scuff with 400# instead of the 220#.  The gloss Poly would also help.

Saturday, April 5, 2014

Amplifying Hammered Dulcimers

There are many different performance situations where you would want to amplify your hammered dulcimer.  If you are doing more than just jamming with friends, playing at home, or playing for more than a few people, then sound reinforcement is almost necessary.  There are several ways to do it.

Cheapest and easiest is to just point a standard dynamic mic like a Shure SM 57 or SM 58 at the dulcimer from above, and hook it to whatever sound system is available.  These work well in most situations, but if sound volumes are high, they can start to feed back.  Also, they aren't very sensitive, so the closer they are to the dulcimer the better, and sometimes they can get in the way.  The closer they are, the less they pick the other sounds going on in the room, so there's a happy spot somewhere above the treble bridge, coming in from the top, and just high enough to be out of the way.  If you have two of these mics, you can do a better job of picking up what you are doing pointing them at the dulcimer from either side.  The dynamic mics don't pick up everything that your dulcimer does, but are a pretty good choice for live performance with a band.  Sound techs usually understand them, and can get your sound to come through farily well.  Sometimes you can point a dynamic mic at the back of your dulcimer and get good sound, especially if there is a sound hole there, plus the mic will be out of the way, so it can be really close to the dulcimer which will exclude sound coming from other sources.  You might tell the sound tech to cut the highs back, and try boosting the midrange and possibly basss on your dulcimer.

There are several different onboard pickup systems that can be built in to your dulcimer, or installed after the fact.  They are all piezo type pickups which is the same thing installed in the street which senses your car is there when you stop at a light.  The pickups are small and light and can be adhered to many different points on your dulcimer.  Some folks just buy the piezo elements which are very cheap, and glue them to the under side of their soundboard in several different location, then wire them to a jack.  Drawbacks to these systems are they will need some type of active (battery powered) control box to run through before sending the signal on to the sound system.  The control boxes are readily available, since this is guitar technology, but can be quite expensive.  Then there is hammer noise to contend with which these systems will pick up strongly.  If the pick up elements are on the sound board, hammer noise can be very bad, and distracting.  They are also prone to feedback with the pick ups installed on the sound board.  This can be lessened by putting them on the rails or pin blocks of the dulcimer, but this also lessens how sensitive they are, so you have to turn the control box and possibly the sound board way up.  You'll never get rid of hammer noise completely with these systems.

There are a couple professional systems made for hammered dulcimer that work.  Schatten makes a two element system with the pick ups embedded in a silicone block to lessen the noise, and they sort of work.  They also sell a control box to go with the system, but it is pricey.

Another company called Pick Up The World makes a nice system which is complete based on two ribbon pick ups which I have found best to install one on the lower rail, and the other on the upper rail.  There is also a control box, and the system works quite well.  Their system is meant for retro fitting to the outside of the dulcimer, but then there are wires running everywhere, and things to get banged up.  It could be installed inside, but that would be best done while the dulcimer is under construction.  Then there's the cost, some where north of $500.00.  But if properly installed, it works pretty well, sounds surprisingly warm, and is quite feedback resistant.

So since I don't like the piezo systems, I stick with microphones, and have found what I believe to be the Holy Grail of hammered dulcimer mics.  The Audio Technica 2035 is a studio quality condenser mic at a very affordable price.  Condenser mics are more sensitive than dynamic mics, and the AT 2035 hears everything your dulcimer is producing very clearly.  Since there is more and better information being sent to the sound board, it can be adjusted, and you can get the sound you want out of the speakers.  Condenser mics need power fed to them from the sound system, it is called 48 volt phantom power.  Most sound systems have this capability, but free standing smaller amps do not, so small, cheap battery powered boxes are available to put in line between the mic and the amp to make the power.  You can sometimes pick them up for $20.00.  The AT 2035 new price is around $150.00, and will include the shock mount holder to put on the mic stand, and a bag for the mic.  The mic has a 10db pad switch, and a low cut switch, both of which I use when recording with mine.   The only drawback I can think of with this mic is it could be feedback sensitive in high sound volume situations, like a loud praise team at church.  For general use, though, I think it is the best.  When recording, two of these mics would be good, one on either side of the dulcimer from above.  They would be out of the way, and the sound will be very clear.  But then, of course, we are forced to be really good with our playing!

My friend Rick Thum told me about another mic which he uses, and it is good.  It is called DPA d:vote 4099G.  DPA stands for Danish Professional Audio.  The mic is very small, and used for all different sorts of instruments.  The G at the end stands for guitar, and indicates the type of holder they include with the mic system.  You attach the mic to the cool little holder, then attach that to the edge of your dulcimer and point the mic, which is directional, across the sound board.  It requires phantom sound, and is amazingly expensive, full retail is $600+.  The mic is really hot and faithfully picks up every nuance of what the dulcimer produces.  It doesn't color the sound at all, very transparent.  If you are prepared for that, it is wonderful.  Great for solo performance, and in a small group onstage.  I used one in church, and it was picking up the neighbors on either side, too until the sound guy figured out how to set it.  Then it worked well.

For recording videos in my little office, I have found the best setup is just two Shure SM58s.  Since the room is small and not well sound proofed, both the AT2035 and the DPA mic will pick up too much room noise and echo.  So the video setup is a Canon EOS Rebel T2i SLR camera which I bought for still photographs, but will also record video in full HD.  But the camera has an automatic gain control which is annoying.  If there isn't sound coming in, the AGC turns up the gain trying to pick up stuff, then turns it back down when something comes in.  It makes a rumble on the video.  So to take care of that, I have a Beachtek DXA SLR interface.  It will accept two mics, and record in stereo, but uses one channel to make a low hum which is below the threshold of hearing, but which the camera hears, and sets its gain accordingly, so the level going into the camera is uniform.  It works great.  I can plug two mics into the Beachtek but have found that it only records one side that way when set to kill the AGC, so I also have a little Mackie 1202 VLZ3 mixer.  Plug the two mics into that, then two outputs into the Beachtex, then into the camera, and I have stereo.  The mixer has tone controls, and also pan knobs, so I can set one mic to go into one side of the stereo, and the other into the other side.  I only need a little bass boost, and usually set the treble and mid at unity since I am trying to get the most accurate recorded representation of the actual sound I hear acoustically.  I also have a decent pair of headphones so I can hear exactly what is going into the camera as I am recording.

Saturday, June 15, 2013

Wooden Bicycle

Melanie saw a program from Europe about bicycles made of wood.  She thought it would be cool if I built one, and pestered me enough that I finally started on this.  After drawing the design, I was hooked!  This was a lot of fun to do, and now my head is full of ideas for more.  I was going to call it "Honeydo" because of how she kept at it, but when it was finished, we decided "Re Cycle" would be a better name, because that is what it is, mostly recycled bike stuff.  Melanie being an ex sign painter is designing a logo for it.

The wheels are from a Raleigh 3 speed, these have alloy rims.  Most of the rest of the metal parts are from a 60s Huffy, also a 3 speed, and it had the original twist grip shifter.  The rear drop outs I made from plate steel.  The geometry is taken from the Huffy, and it is comfy old style cruiser.  The saddle is an old Wright's from England which we found for $20.00 at an antique store.  It was really dry, but Neats Foot Oil brought it back to life.  

The way you go about designing something like this is lay it out full size on a sheet of plywood.  First plot all your points; the centers of the wheels, how far apart they are, the center of the crank, and its exact position relative to the wheels.  Then the center lines of the seat tube and head tube.  These are both 71 degrees off horizontal, which is pretty laid back by modern standards, but gives the bike that really comfy, upright feel.  On this bike, these points and center lines are a duplicate of the Huffy, except I moved the rear wheel back an inch.  After plotting the points and center lines, sketch in the frame around them.  I wanted a frame of bent laminations, so I just took a thin piece of wood, and flexed it around the points, then drew around it.  It looked cool right away!  This is the point where you really can see something taking shape, and get excited.  

The main frame is bent lamination of 1/8" Baltic Birch ply, it took about one sheet to do the two pieces 3/4" thick.  I built a frame to do the laminating around, then just clamped the laminations up with glue.  The sheet of Baltic Birch was the only thing I bought for this project except for quite a bit of epoxy.  The rest of the wood was mostly pieces that were laying around the shop.  The laminating was done with Titebond 2, but the rest of the assembly was all done with epoxy.  The holes for the head tube, bottom bracket shell, and seat tube were difficult.  A bicycle is a sort of 3 dimensional sculpture, and everything has to be right in line for it to work, but I got it!  This bike will ride very easily hands free, and that is the test.  After the frame was glued together, I installed a set of wheels and sat on it to see if it was stiff enough because I had my doubts.  The front triangle was too flexible as I had thought, but the rear was good.  So I made the web of 1/4" Baltic Birch ply and glued it in with fillets of epoxy, a standard technique in boat building.  That did the trick, plus gave it a cool look all its own.  Another mistake was the joint between the wood part of the seat tube, and the doughnut for the bottom bracket shell.  It was just butt glued with epoxy, but on the first test ride, it broke.  So I made the large piece you can see to completely surround it and strengthen it.  Next time, the post and doughnut will be one piece.  

As pictured above, the bike is almost finished.  It just needs its logo, one hand grip, and figure out how to get a rear brake mounted.  Other than that, I have been riding it, and it is very comfortable, and lots of fun.  If you want to be anonymous, though, don't ride something like this.  People love to see it.  I have been stopped and photographed.  I've been thinking about carrying a donations jar, and asking for a quarter each time.  Melanie was right, it was a fun thing to do.