Chapter 4

Milling the Soundbox Material

    Now we begin the process of milling down this 2" X 7" X 7' slab of Hard Maple into thin (1/4") sheets that we can build the soundbox sides with.  The first step was to cut the length down to 4 feet.  This will be long enough to cut the various side pieces from, and a lot easier to handle than a piece 7 feet long.  The radial arm saw makes short work of this step.

    This slab of Maple was S2S, or surfaced on 2 sides.  That means the edges of the board were very rough, just as they came from the lumber mill.  To make the re-sawing job a lot easier, I like to clean up and square the edges. The first step is over to the table saw to take a light cut on the edges to remove the rough surfaces on both sides.

    Next I double check the fence on my jointer, making sure it is perpendicular, or square to the bed.  The guard is removed here, and the machine is unplugged.  Better safe than sorry.

    Now we can true up the edges of the stock, making sure they are flat and square to the faces.  Hmm, looks like I forgot to put the guard back in place.  Don't do that! 

     Now we've got this slab all cleaned up and squared up.  Notice the 3 dark pencil lines I've drawn across one edge.  I've gotten to the point where I do this out of habit before any re-sawing operation.  Later, when I've turned this into several thinner pieces, these marks serve as a guide, making it a lot easier to re-position all the pieces just as they were when the board was one piece.  When you're trying to "book-match" the pieces, this will save you a lot of time and guesswork.

    Now the real fun begins.  Setting up the band saw to make these difficult cuts is time consuming and demanding.  But making sure everything is right before jumping into this operation can save you a lot of grief.  The scariest part of the whole job was unpacking the saw blade.  I bought a brand new, carbide tipped band saw blade for my re-sawing operations.  It is 1 inch wide, 3 teeth per inch, and 154 inches long.  It arrived to me tightly coiled into 5 loops.  Now I don't know about you people, but the idea of releasing a tightly wound spring coil bristling with over 450 razor sharp carbide teeth just scares the hell out of me.  I put on heavy leather gloves, held the coil tightly while I cut the restraints, and then went out to the lawn and threw the darn thing away from me.  WAY away from me.  My plan worked, I was safe while this monster uncoiled itself and chewed up everything within reach.  It then lay there calmly in the grass as I cautiously approached it, and prodded it with a long stick, just to make sure it was safe.  I know it sounds comical now, but I spent 25 years in the machine trades, and I've seen people chewed up pretty badly from band saw blades. (John E., sound familiar?) Cutting tools have my absolute respect.  Now it is safe to mount this monster blade in the band saw and set up the fixture.

    In this photo, I have the band saw fitted with the new blade, and all of the guides, tracking and tension have been adjusted. Clamped to the table of the saw, I have my re-saw guide. This is 2 pieces of 3/4" ply, glued and screwed together at a 90 degree angle. The edge of the upright, closest to the blade is rounded.  I've tried at least half a dozen re-saw guides in the years I've been doing this, and this is the type of guide I prefer to use.  Standing to the right of the work piece, I can hold it firmly against the guide with my right hand, while pushing and steering it with my left hand.  The plastic cup on the dust exhaust port serves as an adapter to fit the end of the hose on my shop-vac.  Trust me, this operation creates a LOT of dust!

 

    And now we're cutting the thin pieces.  I want to finish with 1/4" stock for this harp, so I'm cutting off slabs that vary from 5/16" to 3/8" thick.  The kerf on this band saw blade is about .065" wide, so even with a little bit of blade wandering, I'll be able to clean these up at 1/4".  It's just a matter of running this board through over and over again, until I've sliced it all up.

Ronco  never had a slice and dice like this!

    After all that sawing, I've got a nice stack of 5 thin Maple boards.  More than I'll need for this harp, but I've got 2 Aeolian Harps going that need some good Maple for the bottom pieces.  Nothing goes to waste.  At this stage, the surfaces of these boards are pretty rough.  That carbide band saw blade is great for chewing through hard woods and difficult cuts, but it wasn't designed to leave a pretty finish.  So the next step is over to the surface planer, to clean these up and take them down to thickness.

    One problem with thin stock is that you can't get really aggressive with it or it or it will start to splinter and come apart on you.  It can be a really rude surprise when your surface planer starts spitting out sharp shreds of hardwood at 100 mph, so the surfacing operation requires a degree of patience and perseverance.  The results are well worth it though, when you finish with a nice supply of thin stock ready to go into an instrument. Or 2, or 3.

    This is the one really depressing sight.  That's a lot of expensive hardwood lying on the shop floor there.  Enough planer chips to fill a large trash bag.  Oh well, at least I can use it to mulch the grape vines in my vineyard.

    I don't know about you, but I'm worn out.  Time to go relax with a cold one, and think about laying out the sides of the soundbox on all of this nice new 1/4" stock I've got.

    Be sure to check back soon for more fun and good times.  Thanks for your company.

Move on to Chapter 5

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