Shooting the Edge...

I guess I lied in my last post about getting back to the shop soon.  It was over a week from then before I made it back in yesterday.  I have been dying to get back to my maple.

The first step was to thickness plane my pieces down to 1/4" thickness.  They started somewhere around a heavy 3/8".  It's crucial when thickness planing figured wood or hardwood that you take off ever so little with each pass.  If you don't, there is a likelihood of blowout in the wood as the blades try to take off too much.  Passing the boards through the thickness planer, we took a light 1/32" off each pass.  Five or six passed later we had removed a full heavy 1/8" off of all four pieces.  Here they are on the table saw:

Figured Maple Milled to 1/4"

The figure came out quite a bit after milling them down since the blade smooths the surface.  Photos, I'm afraid, will never do it justice until the guitar is finished and I take it out of the shop and take a picture with something other than my low resolution iPhone.  Both book-matched pairs came out pretty well - a little blowout on one of the pairs, but it was my backup pair anyway.

A bit about blowout in milling up wood...  When you pass wood over/under/around a blade such as through a jointer, thickness planer, router, etc, you have to take into account the direction of the grain in the wood and the direction the blade is going to contact the piece.  If the blade hits the wood against the grain, it is like petting a bird's feathers from tail to head - all the feathers get messy and ruffled.  If the grain is aligned properly with the blade, the blade helps keep the grain smooth - like petting the feathers in the right direction (Who comes up with an example like petting birds, anyway!?  It's just an image that works for me.  If it works better for you, imagine petting suede against the grain.)  Blowout is easy to avoid with quarter-sawn wood or edge grain pieces of wood.  However, if the wood is full of cathedrals, the grain goes one way half-way through the piece and the opposite direction through the other half.  It becomes difficult since the blade is going against the grain for half the piece no matter what direction you put it to the blade.  So, not only are my maple pieces FULL of funky cathedrals and swirls, but they are also figured.  The figured part is essentially a type of grain running perpendicular to the regular grain.  It becomes impossible to line up the grain with the blade.  You just do the best you can.  That's why you have to take so little material off with every pass to avoid blowing out large pieces as the suede grain feathers ruffle.  It's also important when milling up lumber to avoid mixing metaphors.

Here is another angle of the pair I picked as my favourite.  The figure might be more evident from this angle:

Figured Maple - A Team

Keep in mind that the figure will continue to come out more as the surface gets sanded and finished.  Now that the surface is smoother, the pieces my might be qualified more as quilted than tiger-striped.  That denotation might change after it is sanded.

The next step is to join the inside edges together in an invisible joint (ie. with no gap).  The process is to put the inside seems together as if they are glued book-matched together and then I "close" the "book".  This puts the two joining edges on the same side together.  I just line them up and clamp them down to the bench.  Now I can work on the two edges as if they are one edge which helps to make that invisible joint.  Whatever I do to the edge of the one piece, I necessarily do the mirror image to the other edge.  Exactly what I want...
I used my wonderful (recently sharpened) block plane to clean up the edge.  This whole process is called "shooting the edge."

Shooting the Edge

(You see more of the quilting in this shot...)  Just to be clear, I am planing down the edges of two pieces of maple - one on top of the other.  It might not be obvious from this small of a picture, but I also drew a pencil line with a straight edge about a 1/32" from the edge.  This way, I know how much to plane off before the two pieces have a straight edge.

Now I make it sound easy, but it is not at all.  Shooting the edge involves constantly unclamping and hold the joint together to the light to see if light can get through the gap.  If so, clamp it back down and try to make the joint tighter until no light spills through the joint.  It's a game of patience and accuracy and not settling for anything but the invisible joint.  I clamped and unclamped and shot (shooted?) the edge over and over.  I even had to let Ed take a pass or two while he refined my technique a bit.  I just don't want to underestimate how hard it is to make an invisible joint sometimes.  I have a long way to go.  Practise, practise, practise...

By the end, I was happy with how tight I got the joint.  A little glue and some tape on each side and voila - a glued up invisible joint.

"And the two shall become one..."

Next time I make it in to the shop, I will take the tape off, give the bottom a quick sand, trim my piece to the size of my marine ply rectangle and vacuum bag the two together.  Once that's glued up, I'll use my MDF body shape as a guide to trim route my body shape out of my marine ply and figured maple blank.