Game Piece Holder – #5 Bandsawing Blanks, Centering Blank in Lathe & Turning Outside Face

At long last with the design decisions pretty well done but still open to change as the bowls take shape the turning can begin.  I decided to start with the medium size maple bowl because if something goes badly wrong making another maple blank is pretty easy.  The process starts with finding the center of the top of the blank.  A marking gauge is set to half the distance of the blank with lines drawn parallel from all four sides.  If the gauge is set perfect then only two lines show up so the intersection gets dimpled using a sharp punch and a mallet (red arrow).  If it’s a little off there will be a gap with a tiny box in the center and the center of that will be used.   Once the center is marked a Fostner bit in the drill press is used to drill a flat bottom hole for mounting on the lathe.

Mounting the blank in the lathe is next.  That’s done by setting the just drilled hole on the jaws of the 4-jaw chuck then expanding them holding the blank in place in the top photo.  If everything were absolutely square and parallel with all the glued-up layers then I could mark the center of the bottom face and use that to locate the live center.   Because this blank consists of layers, I want the joints to be 90 degrees to the center axis of the lathe so the glue joints between the layers are parallel to the top and bottom of the finished bowl.  If the bowl’s mounting points are out of alignment then the joint lines will run at an angle and visually that would cause me a problem.  To get it right the tool rest is set so it’s close to one of the blanks corners, the red circle shows that reference point in the top photo while the bottom photo is a close view.  The bowl blank is turned and adjusted until all the corners are the same distance away centering that end about the lathe’s axis. 

With the bowl blank squarely in place the tail stock is brought up to the blank and the pointed live center pressed into the blank.  Out of curiosity I had marked the center of the face and it was really close to where the live center point actually hit.  

Using the center point I could layout an inscribed circle within the square block and also mark where the edge of the bowl would end up.  As this is a medium size bowl its finished diameter is 4 ¼” and the inscribed circle is 4 ½” so there is 1/8” between the bandsaw line and the finished bowl diameter.

Next using the bandsaw I can cut a rough circle which will make the first step of turning of the bowl to a constant diameter cylinder a lot easier.

Mounting the bandsawn piece back in the lathe is next.  Because I am working off of two known center points with the lathe the piece can be taken out of the lathe then put back in with near perfect alignment time and time again.  The first turning step is to get rid of all the bandsawn roughness ending up with a smooth cylinder the same dimension from one end to another.  As the photo shows there is still a little bit more turning needed to get the cylinder down to its final diameter.  The curly shavings and smooth surface of the cylinder indicate the lathe tool is sharp and doing its job.

Here is a straight on view of the blank.  The red arrows point to the joints between the three pieces and the pencil lines indicate the top and bottom of the finished bowl.  Also, on the left you can see the spigot on the 4-jaw chuck that goes into the drilled hole in the blank that centers and holds the blank in place.

Once the blank is turned to a cylinder that is the bowl’s top rim diameter layout can be done using the dimensions off the top drawing.  With three sizes of bowls there is a drawing for each of the sizes.  The drawing shows where references lines are set measured from the top of the bowl.  At these points a notch is cut just short of where the bowls face will end up.  For instance, the notch identified by the red arrow in the bottom photo is 1 9/16” down from the top and if cut right to the bowls surface would be 11/16” deep.  However, it’s actually cut 1/32” less at 21/32” so there is some room to smooth out the shape.  One other bit of work has been done which is to turn the sacrificial layer on the right side down to the diameter of the of the bowl’s base.  Both it and the top diameter of the bowl will be used as reference points when doing the final to size turning.

Using the slots as depth gauges the excess material is cut away leaving a rough profile of the bowl.  This is refined using the template I made earlier to check the profile.  This is important since I want matching sets of bowls.  As I get close to the final size the lathe is stopped frequently to check my progress.  Unfortunately, there is no undo button on the lathe and if too much gets cut away it’s a problem so it pays to be very careful when doing the last little bit of work.

The maple bowls have three black decorative lines near the top and one close to the bottom as shown in the rendering on the left.  The right photo shows their approximate layout with the red arrows showing the eventual top and bottom of the bowl.  However, before making the lines I needed to turn the cherry bowl to verify their location.  That’s because the feature bands in the cherry blank are integral and as they are a part of the glue-up so can’t be changed.  The other feature bands are applied after the exterior profile is turned and so their placement is a little flexible.

The process to turn the cherry bowl is the same as the maple one so I won’t go through that again.  Once turned the centerline of the banding in the cherry bowl is checked against what had been laid out on the maple bowl.  Good news is that they matched so I went ahead and made the black lines.  Unfortunately, I was so concentrated on adding the lines in the correct place that I forgot to document the process.  That’s not a problem as I will cover it when the small maple bowl is made since the process is the same.  The photo below shows the profiles of the cherry bowl on the left and the maple bowl on the right.  Note that both of them have excess material at the top and bottom that will be removed later.

Next Up – Turning Reference Stick & Making Black Feature Lines

Game Piece Holder – #4 Making Thin Feature Layer & Gluing up the Blanks

Assembling the three-layer Katalox-Maple-Katalox stack to be used in the cherry bowls is next.  Here is the rendering of what that bowl looks like.

The first step is to cut the katalox and the maple to the correct size.  That’s done using the chop saw.  In the top photo the left side of the saw is set up to cut pieces to width and the right side is for trimming the katalox to establish a straight square edge.  Cutting that straight, square edge is first.  Because the katalox is so thin I am concerned that when the saw blade starts cutting it could crack or worst case shatter the thin piece.  To prevent that thicker layers above and below the katalox will reinforce it.  On the right you can see the three layers identified by the red arrows.  The left most one is a base layer, the middle is the katalox and the right is the top layer.  To use, all three layers are aligned to the left so the katalox is supported above and below as shown in the bottom photo.  The cut is made giving me a nice splinter free straight and square edge as in the bottom photo.

With a good edge the piece of katalox gets set on the base on the left side, a top layer added and the cut is made trimming the katalox to length.  That’s followed by turning the piece 90 degrees and trimming it to width so the piece is square.  The process is repeated for the two more katalox layers and the maple layer per bowl.  The katalox piece on the right side of the saw is one of the finished pieces.

Gluing the three layers together is next.  The method is the same as when I glued up the cedar test block early on.  The left photo shows the cedar test piece where the large red clamps align the edges of all the layers and the grey ones provide the vertical clamping force to hold the layers together.  The right photo shows the final clamping of the katalox and maple layers with the glue cleaned up.  A couple of things need to explained regarding this stack.  Only the two katalox and center maple layer are glued together.  The thick top and bottom layers are not glued on but are there to act as flat platens so the three glued layers stay flat and true.  When glue is applied to the thin wood layers, they absorb the moisture from the glue causing them to warp.  The thick pieces help with aligning the thin layers when the red clamps are added along with keeping the layers flat while the glue cures.

After the 3-layer feature piece has cured overnight I moved on to cutting all the layers of the four different woods for the large bowl.  Only the walnut is thick enough to make the whole bowl out of one piece.  The maple had three layers, the oak two and the cherry because of the integral katalox and maple feature layers ended up with seven layers.  All of the bowl blanks are made a little tall and will be trimmed during the turning process on the lathe.  The top and bottom cherry layers will be made oversized and trimmed later but because the center layer is sandwiched between the feature layers it has to be cut the final size before the stack is glued together.  My drawing say that layer is 1.441” thick for the large bowl so I ripped the 5 ½” square blank down slightly thick on the bandsaw then using the thickness sander crept up on the required thickness.  As the bottom photo shows it’s 1½ thousands thick which is thinner than a sheet of paper so that’s OK.

Gluing the stacks together for the walnut, oak and maple follows the same process as when I glued the prototype cedar bowl.  However, trying to glue up all the layers in the cherry at once gave me a little pause as I was concerned that I could get outside the glue’s working time before the glue got applied, the layers stacked, aligned and clamped.  To get around this the glueup will be done in two steps.  First the bottom three layers get glued together and the top two layers get glued together then the whole group is clamped.  Not applying glue between the center thick piece of cherry and the three-layer feature strip and leaving the sacrificial base off saves me enough time in glue application, alignment and cleanup that I am comfortable proceeding.

Here are the walnut, maple, oak and cherry glueups done and clamped.  All have the sacrificial base except for the cherry.  Tomorrow it will get added along with gluing the two subassemblies of the bowl together.

This photo shows the four large bowl blanks ready to start the turning process.  Assembling the medium and small bowl blanks follow the same process albeit with smaller pieces.

All went well making the medium and small bowl blanks with one exception.  When I cut the oak pieces for the small bowl to size some internal cracks showed up.  They are outlined by the red boxes but all except one are small and are located near the edges.  I think that when the square blank is cut round all those near the edges will be removed.  The last one is really tiny and while not at the edge is in the area that gets narrowed down toward the base so it may get cut away too.  I won’t know for sure until I start working on it in the lathe.  If more show up or they get bigger when I start turning then it may require making another blank.

I did have one extra step in making the small cherry bowl’s middle cherry piece which needs to be .86” thick.  After bandsawing it close to thickness it needed to be run through the thickness sander to get it to the right size and make the faces parallel.  Problem is it’s too short to run through safely so two rails were glued to either side shown in the bottom photo.  With them in place the sander reads the assembly as one long piece and could be safely run through the machine.  Once the thickness is achieved they get cut off.

Here are all twelve of the blanks cut, glued and ready to start the turning process.

Next Up – Bandsawing Blanks, Centering Blank in Lathe & Turning Outside Face

Game Piece Holder – #3 Sacrificial Bases, Walnut & Cherry Blanks plus Making Veneer

With the designs pretty well set yet always subject to change it’s time to start making some sawdust.  My plan is to make the bowls out of one piece whenever I can because I want to eliminate, hide or minimize any glue joints.  However, that’s not always possible given the thickness of material I have and what’s available here.  In some instances, the joints can be hidden behind the decorative bands or inlays.  In others I will have to rely on careful grain matching to make them as inconspicuous as possible.  This means that the bottom layer in the turning block where the 4-jaw attaches needs to be sacrificial to preserve as much of the bowl material as possible.  Since I wanted something more substantial than a softwood, I raided my scrap box pulling out all sorts of different sizes and types of hardwood.  They then got sorted into common lengths and thickness and glued up to get the various widths required.  Here they are all glued and clamped together.  In the background you can see some of the material selected for the bowls.

Since I didn’t spend a lot of time making sure all the joints were exactly flush during the glue up there was more variation than normal but it’s not a problem.  That’s because it’s more time effective to just run the glued up the blanks through the thickness sander to bring all the joints flat and level.  To speed the process the normal finer grit, wrap in the sander gets removed and a coarse 60 grit wrap is installed.  For those that don’t know 60 grit is like a playground sand.  Below is a photo of a six-inch ruler with 220 grit paper above it and 60 grit below.

Once sanded here is what the blanks look like with how many and what size bowls get cut from each written on them.

The first set of blanks to be made are out of walnut.  The top photo is a rough sawn plank almost 4” thick that’s a little cupped, warped and twisted.  I cut down the tree about 45 years ago, had it sawed into planks and it has been drying ever since.  First step is to cut it into a couple of more manageable sections.  From there it gets loaded into my Planer Sled, leveled then run through the surface planer to flatten (bottom photo).

The cleaned-up planks are shown in the top photo.  The part to the right of the white line in the top plank is what will be used to make the bowl blanks.  That’s shown in the bottom photo with the oversized templates for the bowl blank shown.

Working on the cherry blanks are next.  Pulling out my thick cherry slab left over from the Maloof Rocker project and using the bowl templates I marked the size piece needed then cut it out on the bandsaw.  Because the layers of contrasting woods in the bottom photo are not inlays but go all the way through the piece, I will need to define the thickness of the layers then use that to determine the thickness of the cherry blank layers. 

The first step in making the feature layers for the cherry bowls is to rip the Maple and Katalox that make up the feature layers into thin strips.  First is the maple and here is the setup for ripping the blank on the bandsaw into four pieces just a little over 1/8” thick.  Process is to rip a piece off then run the remaining thick piece through the thickness sander until all the bandsaw marks are gone and the blank has a smooth face.  Another piece gets ripped off and the sequence gets repeated.

The same process is repeated with the Katalox except the pieces being ripped are thinner at 3/32” thick. When sanded smooth this gives pieces just under 1/16” thick at .058” shown at the top with the maple sheets in the lower left.  Next is to stack the cherry, katalox and maple to see if the layers look in proportion.  They didn’t, the maple looked too thick so I ran it through the thickness sander shaving off about 1/100 of an inch then restacking the pieces and evaluating to see what it looked like.  The lower right photo is the result with the maple piece at .084” thick giving me a total layer thickness of .2 inches.

Because the piece of katalox is not wide enough to make the layers multiple pieces need to be edge glued to get the required width.  With them being so thin I was worried about splintering when run through the table saw.  To prevent that from happening they get taped down to a sacrificial backer board per the left photo and cut to width.  Gluing thin pieces presents its own challenges since when trying to clamp the pieces just buckle.  That’s solved by taking the three pieces needed and setting one tight to a backer clamped to the non-stick surface laminated particle board shown in the top right photo.  In the bottom right photo, a second backer is lightly clamped down leaving a little space between the katalox and the second backer.

After a very thin bead of glue is applied to the edges of the katalox the pieces are set between the backer boards and lightly clamped together.  Since one of the backer pieces is also lightly clamped in place it is movable.

Last is to add another piece of laminated particle board, clamp it down snuggly to hold the katalox pieces flat then tighten the clamps that were lightly clamped in the previous step and leave it for the glue to cure until the next day.

When the piece is unclamped the joints, all looked good but there had been some glue squeeze out from the vertical clamping.  You can see the shine of the glue in the left photo.  It’s pretty easy to remove using a card scraper followed by a little sanding.  The right photo shows the majority done except for a little at the bottom between the clamps which will get done when I reverse the piece.

Next Up – Making Thin Feature Layer & Gluing up the Blanks