Matthew Corcoran: I've made a huge mistake

I did mess up today pretty bad... but I made a full recovery.

But I will start from the beginning.

So Last week I had spring break. I really wasnt looking forward to the break because I was really getting into the building and I didnt want to stop. My roommates and I went out for chinese at the end of the week and my fortune cookie read. "You have had a good start. Work Harder!" Weird. Notice my lucky numbers... 18.... well this march 18th I feel very lucky. just wait.

Anyways so Monday morning we started to install our rosettes. First I clamped my top to my workboard and I drilled a hole in the center of where my sound hole would end up... a little nerve racking but it will get even worse.

So I used a compass and drew out my soundhole, 3 7/8 diameter, and my rosette, 1/4 inch outside of the soundhole. I stuck a short pin through the hole and into the work board.

I then set up a router using a circular jig that sat on the pin. I set it for about half the thickness of the top wood (1.5mm)

And the jig gave me a perfect circle... all excet for that tiny chip out... luckily that will be located under the fingerboard and no one will know about it but me and all of you and anyone else who can access the internet... hmm.

I set my rosette in and glued it with titebond.

I used a clamping caul so the rosette wouldnt pop out... I put butcher paper under the bottom so that I wouldnt glue the caul to the top.

It glued in pretty nice.

I scraped and sanded the rosette flush with the top. Now its time to cut out the sound hole. I set up the router again. This time setting it deep enough to go through the top wood and into the workboard. I set the jig up and locked it into place for my 3 7/8 sound hole diameter.... at least I thought I locked it tight.

oh shit.

Somehow the jig was loose enough to slide about 1/16 of an inch... which in luthiery terms is about 4 miles. Luckily I set the rosette pretty wide compared to the original hole. I had no other choice but to continue the route at the new 4" diameter... which I later found out, was a fairly common soundhole size for the Gibson L2 that I am modeling...so thank goodness I was building the gibson style rather than the Martin because the martin has a tighter X brace...are you following all of this mom?

So I went ahead and routed it and now you cant even tell.

phew!

So then I sat down and had a cup of coffee... contemplated a cigarette... but no. The is a lot of work to be done.

so I flipped the top over and sanded the inside to 150 grit from the 80 grit scratches from the thickness sander... drew my center line and marked the lines for my braces.

Other things I did the last 2 days were...

I joined my back. I did it the same way as my top by using a jointer plane and shooting board... checking for gaps with my light table and gluing it together with hot hide glue. Only this time I didnt have 2 level outside edges... you see how they curve in at the top? So I cant just put a level board against the outer sides to push them together.

So I had to put nails in the glue jig that matched along both sides... but first I set a skinny stick under the gluing surface, to lift the middle. then when I took the stick out and pushed the boards down, the nails pushed the two peices tightly together.... does that make sense... its hard to explain... anyways....

I then started to put together braces. I cut down brace stalk to the approximate size using very straight grained engleman spruce stock. I used quarter sawn peices so that the braces wont want to twist or distort. We then sent them through the thickness sander so that they would be the perfect width.

Flat top guitars dont actually have flat tops... the have a slight arc in them to increase stiffness etc. So we had to radius the braces to with this jig. I am building a gibson style so I am using a 20 foot radius.