New saw blade, jig work for the fretting to come soon

 My new, thin kerf (1/16"), saw blade arrived today.  This got used today to notch my new jig for 15" scale fretboards and will get used on the fretboard for some inlay.

I used a new insert to allow for a zero clearance fit.  It's 1/8" fiberboard cut to fit.  Then just start the saw and raise the blade to appropriate height for your cut.  No big gaps at the sides of the blade and the work piece is supported giving cleaner cuts.

Here is the fret pattern jig with the new slots cut.  I cut this from the back side of the table so I could get good alignment without leaning over the blade to get things lined up.  In use, the pattern will sit on top of the back side of the fretboard.  This will put the front face down on the table saw to cut the grooves.  The jig and fretboard will be held together with double sided tape, then I can just align the slots with the pin you see in the second photo and cut a slot.  Move to the next mark and cut another slot.

I noted yesterday that since the fretboard is slightly wedge shaped that I'd need to use the opposite cutoff to give me a flat (parallel to the table) surface to attach the jig.  I cut it off today and it looks like it'll work.

I haven't cut the fret slots yet.  I'm still thinking about the process order for the steps I need to take to complete the fretboard.  They include cutting fret slots, inlay slots, and then tapering the fretboard.

Brian

tiny steps today

 Today I determined that I needed to order a couple things for the fretboard, so I've got those coming and there may be a delay for a week before proceeding too far.

I did start on the jig for cutting the fret slots.  I'll need my new saw blade (coming tomorrow) to finish this pattern jig.  Then I'll show the rest of the jig that fits on the table saw.  

Thinking about it now I'm going to need to do some tweaking since my fretboard isn't flat on the bottom... this could be tricky.  Then again, I've got the matching piece so maybe just cut that off square and double stick tape it to the bottom of the fretboard.  This would square it up so I can cut fret slots on the top side of the fretboard using the jig.  That should work!

Brian

trim the top and start on the fretboard

 Took the top out of the clamps and proceeded to sand the overhang back to the body.  Also sanded a couple dings on the top, that Western Red Cedar is stiff but has a soft surface.

Then it was time to lay out the fretboard across a nut stand-in, and the bridge.  I took a number of measurements and then it was time to cut.  This was a picky operation as it needs to fit tight to the neck but also extend over the top plate of the body for a bit.

Some hand sanding on the bottom of the "ledge".  I did this on the edge of the table saw.  This gave a nice flat surface and a good 90 degree angle to hold things in alignment.

I needed to cleanup the end of the head plate towards the nut.  It was straight but not quite perpendicular.  Got it squared up with an exacto and a chisel.  My design requires a 1/2" piece of maple on the headstock side of the nut so I cut and fitted that.  The fretboard will be maple to match.  Nothing glued up today, I have a bunch of work to do on the fretboard still.  The neck will have to be thinned down a bunch too now that I have a fretboard thickness.

Starting to see the end of the tunnel!

Brian

Time to glue on the top

 I did some clean up on the back stripe first.  I haven't touched it with sand paper yet.  I used a card scraper on the surface to get the zipper stripe flush with the back plate.  I love this wood!  I then used a rasp/file to bring the edges back flush with the sides.  I won't do any sanding until the top is also attached and flush.

I then did a bunch of looking and reflecting on the top, and decided it was good to go.

I signed the under side where no one will ever see it.  Then I glued it up and "clamped" it just using weight, but the bottom/sides/top are clamped between 2 matching radius dishes so they have even pressure all the way around.

Then I spent a little more time working on the bridge.  I don't know final dimensions yet for the bridge but I'm getting it closer.  

Once the top glue is set up I can start measuring for the nut/fretboard/bridge(saddle) dimensions.  When I know those dimensions I can get to work on the fretboard, which I'm kind of excited about.  

Hope I can pull it off!

Brian

my mistake is now a feature!

 So as I noted previously, I tried a new glue on this build for the top and back plates.  It was a water proof glue meant for boat building.  Since I force my plates from flat to hemispherical I thought that maybe using heat and moisture might help the plates conform with less stress.  However, instead the glue just failed and let go, leaving the back plates hemispherical but not glued together.  They also would NOT go together without re-jointing.  So, I re-jointed and tried to glue them together, but with curved surfaces there was no good way to clamp them up and this is what I was left with.

I could have started over with different wood but my other option is to do something with the gap.  As seen in earlier pictures I glued in a support strip on the inside covering the gap.  This is a normal step but I did use a wider strip than normal.  Then, with the back glued to the body it was time to fix it.

I knew that I wanted to install a "zipper" to cover this.  Here is what I am calling a "zipper", it's a piece of inlay used on guitar backs or as purfling around the edge binding, etc.

Next step was a jig to guide the router while routing a straight groove across that curved, hemispherical surface.  I had the jig I'd used to create the radius dishes so I grabbed the guides that matched the 8 foot radius.  I cut square blocks that matched the width of my router base and nailed them between the radius guides.  Then these got clamped across the back of the uke body.

I used a speed controller on the router to slow it down quite a bit and proceeded to cut the groove.

Then test fit the zipper.

While most of the groove was a good fit there were a couple TINY gaps along side the zipper.  I grabbed a bit of sawdust from sanding these plates to thickness and proceeded to glue the zipper in place and then rub the sawdust into the gaps where the glue had squeezed out.  The masking tape should help a lot with cleanup later.

The zipper is proud of the surface by about 1/32" so the card scraper and sand paper should clean things up nicely after the glue is dry.  Looks like my earlier mistake is now a feature!

Brian

brace carving complete, time to glue the back on

 I didn't post yesterday but I carved most of the braces.  Here are some pics.  

First pic is showing how the bridge will be supported by the braces (but obviously on the outside).

Next pic didn't get focused correctly but maybe you can see how the straight edge reveals about a 1/8" gap on each end due to the curved radius top.  This is hemispherical so round like a ball in all directions.

Started carving in the center.  Tapering from the sides and reducing the height.

The ends sticking out all get tapered and reduced.  This is kind of by gut feel.  You want to reduce the mass to help it vibrate but also stiff enough to maintain it's shape and not collapse.

Here's my best guess right now.  I can still take off more up until I glued it onto the body.  Occasionally during carving I pick it up by a corner and tap on the top in various places.  You can start to get a feel for how responsive it is... hopefully.  If it sounds dull, might need to remove more.

I trimmed the top a little closer to the line and marked the top and body on the outside to help align it when it comes time for glue.  I also wanted to make sure the sound hole is lining up with the neck.

And finally, I glued the back into place.  I'm doing the back first since it will be visible through the sound hole and glue cleanup will be easier.  I think I'll give the interior a single coat of finish before I button up the top.  Note, the back book match didn't pull together tight enough when I re-glued it (noted in an earlier blog) so I'll need to make a jig to allow me to route a 1/8" slot up the joint to install a "zipper".

It's getting there slowly but surely.

Brian

glue the top braces

 First up before I forget I signed, dated, numbered the back plate.

Then I cleaned up the sound hole brace or patch.  I used the Dremel with a small sanding wheel.

I cut the sound hole into the top.  I used masking tape front and back to help control any tear out.  Did some light sanding of the edge, then glued the brace/patch into place.  I put the top plate onto the radius dish to allow for the slight 25 foot radius curvature.  Then I glued and clamped the ring using the go-bar deck with fiberglass rods for clamping pressure.

Note how I put the sides in before clamping.  This allowed me to position the rest of the bracing accurately without the sides glued into place yet.  I think I used every rod I had!

When the glue is dry it will be time to carve those braces to lose some unnecessary bulk and weight.  They'll also look a lot better.  Funny how I want them to look good when the only way to see them will be putting a mirror or camera down through the sound hole.  But, it's one of those OCD things and the conviction that if I'm going to do this luthery thing then I want to do it "right" as much as possible and be proud of my builds.

Brian