Turned Art Object – #7 Cutting Center from Body & Starting Base

With the tapers finished cutting out the center of the body is next.  It gets cut out on the bandsaw but the arc of the center is too small to be cut smoothly with the ½” blade on my bandsaw so I have to take out little slivers to make a wider opening for the blade to make the cut.  I just know someone is going to ask why not change the bandsaw blade to a narrower ¼” blade which could have made a clean cut.  That’s true but the time needed to swap out the blade, reset the saw’s guides for the narrower blade, make two cuts the swap the blade back out to the ½” one would take longer than what it will take for me to clean up the cut.  While the resulting cut does look a little like it was made with an ax it’s not a problem since everything inside the white line is waste.  One thing a little different is the small tab left at the point of the red arrow.  That was left to hold the plywood backing disk that’s screwed to the center section in place.  I really didn’t know for sure how the assembly would react if the center section and the disk was cut completely free since the main body would now be floating unconnected to the disk.   

Removing the center section is easily done with a little prying with a screwdriver.  Now all that remains is to use the drum sander to clean up the rough edges shown in the top photo so they are flush with the inside edge of the white line.  However, before sanding the oak black wood insert on the back side of the body needs to have the bead protected since the plywood disk that was doing that is no longer there.  The bottom photo shows a layer of tape added to provide a buffer to keep from rubbing the bead on the cast iron top of the sander.

Here is what the setup looks like for the sander.  The drum is 3” in diameter and has a 60-grit sleeve on it.  A few minutes of work and the rough edge is cleaned up.  Changing the sleeve from 60 to 120 grit and another pass across the edge gives a smoother surface and gets rid of most of the scratches.  The rest will get taken care of in a bit.

To make sure the inner half circle is a really round a paper circle is used to check for any out of round spots.  With that done the last little bit of woodworking on this piece is to soften the current sharp edge where the just sanded surface intersects with the dyed face of the oak insert.  The red arrow in the bottom photo points to the rounded edge.

India Ink next gets applied to the inner face of the oak inserts along with the center cherry piece to blacken and blend the three pieces together so it looks like a single surface.

Getting back to working on the base is next.  I left off with the center block glued up in the clamps.  Once it had cured the cherry pieces were glued on to give me a finished glued up blank the bases will be made from.  This photo shows that block with the 2 ½” mounting hole drilled and the circle laid out to be sawn on the bandsaw.

Here the blank has been cut to a rough circle about a ¼” larger than the finished size.

Mounting and getting the blank as close to square with the lathe’s axis is next, using the same method as before.  With that done the tail stock is run up against the blank and its point marks the center of the blank as it’s mounted in the lathe.  All that’s done in the top photo.  In the bottom photo the blank has its face trued up square, the edge brought down to the final diameter and a pencil reference line centered on the outer edge.  There are also a couple of circles on the face that will give me a rough idea of where the bottom of the base will be.   That’s because when the piece is spinning at speed the demarcation line between the cherry and the filler will be blurred. 

Making a template for the outer profile of the base is next.  Unfortunately, it’s not as easy as printing off the bottom of the base and using that because the bottom of the base does not line up with the center point which distorts the shape.  To get an accurate profile the pattern needs to be a section that runs from the middle of the face on the outer edge to the center of the blank.  In the left drawing below the 4 1/16” dimension runs from the middle of the outer edge to the center.  Next is to bring the point where the full width of the base intersects the 4 1/16” dimension (red line) and draw a circle there (red arrow).  Last is to measure the distance from the outer edge to the inner circle which is 5/8”.  From here all that’s needed is to draw a 3” wide rectangle then make an arc whose high point is 5/8” in shown on the right.

The template is made similarly to the previous ones except rather than cutting it out on the bandsaw I used a recent acquisition, a scroll saw which gives a much cleaner edge.  The saw is shown in the top left photo below and the top right photo shows the template ready to be cut out.  In the bottom photo the template has been cut out and it shows how much cleaner the cut is versus the bandsaw.  All that needs to be now is just a little sanding to cleanup and fair the curve then it’s ready to go.

Next Up – Finish Bases & End Cap Prototype

Turned Art Object – #6 Starting the Base & Cutting the Body in Half

I am going to let the body set for a bit while I think about how to proceed with cutting it apart to make the two halves and then shaping those pieces.  I want to make sure that I have thought out in what sequence the different operations need to be done.  I don’t want to get partway through and find out that something should have been done earlier and now I can’t do it.

In the meantime, I am going to do some work on the bases.  The rendering on the left is the current version of the project and the top right shows a closer view of the finished base.  In the bottom right is the blank that goes in the lathe that the bases will be cut from.  The cherry pieces on the top and bottom of the blank are what’s needed while the white center part is just filler. 

Making the cherry parts are first.  That start by roughing the needed pieces out oversize on the bandsaw then using the thickness sander to smooth and flatten the bandsawn face.  I will probably save the thin cherry cutoffs for another project.

Here the cherry pieces have been roughed out and are ready to glued up to get the size needed.  The filler is made out of scrap construction lumber sized and ready to be glued up.  All the pieces are a bit oversize so once glued together they can be trimmed to the final size.

Here is the first round of gluing pieces together.  The cherry pieces are in the left two clamp sets and right two are for the filler.

After an overnight cure the clamps are removed, the parts have their faces flattened and edges cut square as needed.  The cherry parts are set aside for a bit while the two pieces that make up the center waste section get glued together.    However, before they actually get glued up, I carefully align the edges then run a couple of screws in to keep them that way.  This is shown in the top photo and done because parts can slip around during clamping and I didn’t want that to happen.  The bottom photo shows the pieces glued and clamped up.

While those pieces were gluing, I went back to work on the main body.  I had been concerned about doing the future machining operations on it without marring the black dyed center oak insert.  This is because the rounded bead on the oak insert is the high point so it will be the main point of contact on the equipment.  The pieces are going to be run the through the bandsaw multiple times, cleaning up and shaping the various cuts on the disk and drum sander etc.  All of these tools have cast iron tops the wood is going to be rubbing against and while the tops are pretty smooth, I am not convinced they won’t blemish or damage India Ink on the bead.  To prevent this one of the plywood disks that was used as a buffer when gluing gets screwed to the waste part of the main body.   The top photo below shows the main body where the red highlighted area identifies the area the screws will be run into.  The ridge just outside this area is the same height as the top of the bead.  In the bottom photo the disk is set up in the drill press getting four counter sunk holes drilled.  There are four holes so the disk stays attached in place when the body is cut in half.

Here the photos show the disk partly screwed in place.  The center screw goes in first to center the disk on the reference hole and the others follow.  Once the outer four screws are in the center one will be removed before the body is cut in half.  This is because the saw cut will go right through where the screw is.

Cutting the main body disk in half is next and I was a little apprehensive about it since if the bottom plywood disk did not provide enough support the cut could go haywire in a hurry and I could damage both halves.  The top photo shows the setup ready to go and is straight on facing the blade (red arrow) which is not easy from this angle to see since it’s so thin.  Fortunately, everything went smoothly with the bottom photo taken after the cut has been made.

Looking at an edge on view of the just cut body here in the top photo shows all the various empty spaces in the piece which will get cut away later.   The bottom face view shows what the half body looks like now and the white line where the center cutout will be.

Sanding the bandsawn edge smooth is next which is done using the large disk sander.  The top photo shows that work in progress and the bottom photo shows it all smoothed out.  

Next the top edge gets its taper.  The rendering shows the 6-degree taper that gets cut off the top edge of the half body which is this case works out to be 3/8” at the rim.  The bottom photo shows the taper marked and all set up ready to cut on the bandsaw. 

These two photos show the closer view of the marked out taper before and after it has been cut.  Once cut the bandsawn face is smoothed out with the disk sander just like when the body was cut in half and those edges sanded smooth.

Next Up – Cutting Center from Body & Starting Base

Turned Art Object – #5 Turning, Dying & Gluing in the Oak Insert – Part 2

Now the in-progress blackwood insert needs to have the roughly 1” wide profile turned.  Below in the drawing at the top the red arrow points to the needed profile shown in white so it’s easier to see.  The bottom photo is of the template that will be used to check my turning.  One change from the drawing is rather than have an angular ridge I changed it to a bead.  Process for making the template is the same as the previous.

Mounting the insert on the 4-jaw chuck in the lathe requires a 1 1/8” diameter hole.  This is smaller than the mounting hole on the other side because if I drilled a 2 ½” hole like the other side I would have ended up with a good-sized hole in the center.  This is due to the larger center point in the 2 ½” drill and the relatively thin section between the two holes.  The resulting hole would make it hard to use the live center in the tail stock to stabilize and center the insert.   The photos below show the size difference between the two sets of jaws.

Below in the left photo the hole for the small jaws has been drilled and the right photo shows the blank flipped and mounted on the smaller jaws.  You can see how much difference there is between the mounting holes.

Turning the profile to match the template is next.  First step is to cut a notch to the finished depth of the profile which is marked by the two red arrows shown in the left photo.  Turning the profile consists of working from the inside out cutting away a little at a time then checking it against the template.  The right photo shows the finished profile.  In that photo the red arrow shows the approximate location of the inside face of the insert.  Later on, everything inside of the red arrow will get cut away.

Dying the oak insert black with India Ink is next.  This needs to be done before insert gets glued in so I get a good clean demarcation line between it and the turquoise inlay.  I am pretty sure that I could not dye the oak after it’s installed without getting some on the turquoise.  The ink gets rubbed into the oak and all of its pores using a small cloth.  Even being careful there are some specks that invariably show up once the ink is dry as white spots which is the undyed oak pores.  It’s not a big problem as a small fine brush is used to spot fix them.  The center does not have ink applied since everything from the red arrow inward will be cut away later on.

Turning a mirror image of the cherry body profile on the second side is next but first a mounting hole gets drilled in the finished body face so it can be mounted facing the chuck.  Once lightly mounted the center reference hole is used to square the piece to the lathe’s axis, then the chuck is tightened and the turning can start.

Process for turning the second face is the same as the already completed face although making a mirror matching face can make one want to pull their hair out.  Free hand turning a single face is pretty easy but when you try and match it things become a lot harder which is why I spent so much time turning the first face to the template.  The left photo shows the profile finish turned and the right photo shows an edge on view that shows how the two profiles match.  The mirrored face is actually closer than shown because the camera setup is a little off to the left causing some distortion. 

The rest of the work for this face; adding the turquoise inlay and cutting the recess for the oak insert is almost the same as the first side.  The one exception is that it does not need the 2 ½” diameter mounting hole on this side for reverse mounting.

The oak insert is made the same way as the first one for the other side.  The left photo shows the second insert fitted into the body.  The right photo is a closer look at how the insert ends up with no gap where it meets the turquoise.  The pencil line is a reference for adding a radius to that edge.

The fine fitting of the oak insert requires sharp tools and a very light touch since the difference between being too tight to being too loose is only a couple hundredths of an inch.  An example of the shavings that come off the turning tool when doing this is below.  The top photo gives some scale of the shaving while the bottom photo is a closer view. 

With the back of the insert sized to fit, the blank can be flipped and using the template turned to match the first insert’s profile.  Below the left photo is the first side and the right photo is the second just completed insert.

Once the second insert gets its India Ink black coloring the two inserts can be glued in place.  Here are the pieces in the order they will go into the clamps starting with the plywood disk on the far left followed by the insert, the body the second insert and ending with the plywood disk.  The plywood disks are being used as a buffer between the clamps and the insert so the India Ink won’t get scratched or marred by the clamps. 

Here are the first couple of steps in the glue up.  The photo on the left shows the protective plywood disk down and the insert with a band of glue around the inside face (red arrows).  The right photo has the body set in place with the grain running the same direction as the insert.

The last steps are to apply glue to the second insert, set it into place shown in the left photo then set the plywood disk in place and add the clamps shown in the right photo.

After an overnight cure the clamps, plywood disks and glued body are removed with this result.  Because the glue was applied only to the inner face of the disk and not to its edges, I didn’t have to worry about any glue squeeze out messing up the clean edge between the dyed insert and the turquoise band.

Next Up – Starting the Base & Cutting the Body in Half

Turned Art Object – #4 Turquoise Inlay & Oak Insert Part 1

Inlaying the turquoise into the recess is next.  The inlay consists of an ultraviolet cured resin used as a carrier and bonding agent for the fine turquoise granules.  The photo below shows the resin, turquoise granules, a small UV light for curing and the small spatula used for mixing and application.  Process is to mix the turquoise with the resin at about four parts resin to 1 part turquoise then carefully put it in the recess.  Because the turquoise granules block the penetration of the UV light three layers are needed with each cured separately.

Here is the first layer application in progress.  The small spatula is used to fill the recess about a third of the way full.  Once the recess is partly filled the mix gets cured using UV light.  The process requires a slightly different mindset since it’s not like epoxy, other types of glue or fillers that have a working time where all too frequently one is up against the time limit to get what needs to be done before the material sets.  Not so here because the mix of resin and turquoise does not harden until it’s exposed to UV light.  

In other projects I have used a small battery powered UV flashlight and it works OK but does take some time to get the resin to cure because the light is not all that intense.  Here in the Southwest, we do have a rather large natural UV generator – called the sun.  It’s not that usable in the summer due to the heat and the potential for causing problems with glued up pieces.  However, this time of year the UV radiation is still high but the weather is much cooler.  My process is to sit in a lawn chair with the turned blank in my lap facing the sun while the UV flashlight helps the curing along.  The photo below shows the first layer cured.

Once all the needed layers are in place and cured the body gets put back in the lathe and the turquoise inlay gets turned down flush with the wood.  The whole part is then sanded smooth with the turquoise being sanded up through 800 grit dry paper.  The next step is to start cutting the recess the oak blackwood accent piece will go into.  The top drawing shows the area where the recess will be cut greyed out. The bottom photo between the two arrows shows the initial starting cut.

Here the recess is mostly done with the depth good and the width almost to the finished dimension although to give a margin of error when the center section gets cut out later it does need to be made a bit wider.  I will explain why when I get there.

Drilling the reference hole deeper is next so it is available later on.  The required finished depth from the face is ¾”.  To drill that I first set the tailstock to show a one-inch extension shown in the top photo.  The whole tail stock is then moved until the tip of the drill bit is at the edge of the ruler which is tight against the face of the body. 

Drilling the hole to the proper depth is a simple matter of turning the hand crank on the tailstock until the gauge reads 1 ¾” as shown in the top photo.  The bottom photo has the completed hole drilled ready for the 2 ½” hole to be drilled down so it’s about 1/16” deeper than the bottom of the recess.  

With the center hole drilled to depth the material between it and the recess is removed and cut a little bit deeper leaving the bottom of the recess just a tiny bit higher.  The bottom of the recess marked with the red arrow is then very carefully flattened.  In the photo you can see that there is no light shining between the ruler and the bottom of the recess meaning the bottom is flat and in a single plane.  Moving toward the center there is light between the ruler (at the 2” mark) and those surfaces meaning that there is clearance.  This is so when the blackwood piece gets glued in, I only have to worry about the piece lying flat along the outer red arrow marked surface.

With the recess cut to size the first oak blackwood insert can be started.  In the top right the red arrows point toward the two finished blackwood inserts.  They start out as a glued-up blanks.  The top left shows the first one being glued up while the bottom photo shows it being flattened using the thickness sander.

Once the oak blank is flattened a circle slightly larger than the finished insert is cut out on the bandsaw.  For symmetry in the finished piece the disk is centered on the glue joint between the two pieces.  The joint is a little hard to see because both halves are from the same board and adjusted so the grain matches up pretty well.

Once bandsawn a 2 ½” hole is drilled centered on the disk just like I did earlier on the main body blank.  After mounting the disk in the lathe, the face gets aligned so it runs true or as close as I can get it followed by taking a very fine facing cut to bring it truly square.  Turning the outer edge flat and square is next.  Once that’s done a very shallow cut leaving a raised circle is very carefully turned down until it just fits inside the recess cut in the body.  The red arrows point the this.  Note that the edge is at a slight angle.  This along with some trial and error lets me sneak to a perfect fit where the body will fit over the slightly narrower outside edge but the inside is still a little too big.  

With the outside diameter set a tenon needs to be turned to exactly match the depth of the recess in the blank.  I got as close as possible measuring with the dial calipers overshooting the tenon length by a few thousands of an inch leaving a tiny gap between the lip and the turquoise.  From there the tenon is carefully shortened until the lip on the piece just touches the turquoise band. Accomplishing this took quite a bit of trial and error because I couldn’t see how the tenon was to fitting to the bottom of the recess.  

Here is what the oak blackwood piece set into the body looks like.  It’s not black yet but it will be when dyed with India Ink.  There is still quite a bit of turning and other work before this piece can be installed but it gives an in-progress idea of how it looks.

Next Up – Turning, Dying & Gluing in the Oak Insert Profile – Part 2