Day 1 (Carve end blocks, trim and glue sides)

February 3, 2013 (Superbowl Sunday)

First order of the day is to carve once face of the end blocks to match the inside curvature of the sides at the bottom and top of the guitar body.  Find and mark the exact center of the end block (and the top block for the neck attachment).  This is critical to make sure the block sides are perpendicular to the sides.  Especially, the neck block.  If you get this wrong, the neck/side alignment will be all jacked up…

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After marking the center, trace the curve profile onto the side of the block.  Using a belt sander, remove stock to the line, then test fit.

Either before or after carving the blocks, fit the sides in the mold and mark them for cutting.  Use the center-line marks on the mold as a reference.

Make sure to mark the lines on the INSIDE of the sides.  It will make them easier to cut on the band saw and trim up on the belt sander.  Marks on the outside, not so much….












Then place one side in the mold to test fit the marks at the centerline.  Once one of them is good, clamp it into the mold as a guide for trimming the other side to fit.  At this point, it’s a good idea to have the sides marked to indicate which will be the front/top of the guitar.  Mark the mold as well to make sure everything stays consistant.













Jason jumps in to show me how to mark for trimming the other side.  A white marking pencil is handy here  to show up on the dark wood.

Once marked, go back to the belt sander and trim until they fit properly.



















There is a slight gap on one side here, but this is not a problem since this portion will be carved away for the end graft and neck attachment.  You will never see it….

Sides are ready to get glued to the blocks.







(No, you did not have some bad mushrooms.  I moved my phone during this pic.)











Next we will do the final fit of the blocks to match the inside curve of the sides.  Due to the thickness of the sides, this curve is slightly different than the curvature of the mold.

Check out the cool little trick to make this final fit:












Some adhesive backed sandpaper is attached to the sides at the center line of the guitar body.  The center-line previously marked on the blocks is lined up with the mold from front to back.  Then clamp some small pieces of wood on either side of the block as alignment guides.  Now slide the block back and forth along the sandpaper to get a perfect fit.  Color the block with pencil marks on the sanded surface to give you an indication of what you are sanding away.  When all the pencil is gone, you are done and it should fit perfectly.  Take care when sanding to not rock the block along its axis.  Use short strokes and keep it over the mold which is strong.  Pushing hard towards the back will flex the sides and result in a distorted block.  Periodically, turn the block around to get even sanding from front to back.  Several short strokes followed by a couple of long ones will help blend the sanded surfaces to a perfect finish.












Remove the sandpaper and use the block to place a guide for the glue up.  Once the block is glued and clamped in place, the guide will be removed to allow for cleanup of glue squeeze out.

For the neck block, use your finger at a 45 degree angle to wipe the glue away from the neck mortise to reduce glue squeeze out in this area which will make attaching the neck difficult.


Repeat with the other end block.  Glue and clamp them.

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Cleanup tip:  Take a drinking straw and cut it off at a 45 degree angle.  Use the sharp point to scoop up the glue in the corners.  Follow up with a moistened q-tip to remove any glue residue.  This is so you don’t see a messy joint through the sound hole of the guitar when finished.

Also, screw clamps are used at the front of the blocks where the mold is behind the sides.  On the back without the mold, use lighter quick clamps to avoid stressing and cracking the side boards.

Now the whole thing sits in the mold until the glue cures.












And Jason gave some homework….










Next week, the kerfings will be glued to the sides to provide a gluing surface for the top and back.  Also, I think we might also start on the bracing for the back.  We’ll see what there’s time for.  Until then, back to watching the Superbowl…