Monday, September 11, 2017

Coffee, Sand, and Grains

Oh la la!


The job of getting a guitar body prepped for finishing is a funny thing.

As you sand one area - you find another area that needs to be rescraped, that superglue you used to fix a bit of binding is going to cause havoc with the staining process, or you realize a seemingly harmless mistake you made five steps ago is now going to impact you going forward.

I’m sure if I was a more fastidious craftsman - this wouldn’t be this hard. There would be fewer mistakes to correct. But I’m not - so here we are.

I know there are a few more steps to go before I’m ready to actually finish (as in put a “finish’ on the guitar body) but I’m gearing up for it. Now is the time you really want to clean up after yourself. Here’s what I’ve been doing.


Gritty
Smooth
Sanding: Me and the sandpaper are getting reacquainted. I like this process - so it ain’t no thang. At this point I am using 150, 220, 320, and 400 grit sandpapers to get the body smooth enough for a transparent color with a semi-clear finish coat. I’ll be using dies, shellacs, wood fillers, and nitrocellulose lacquer for my finishing process. I’m going to go over these steps in detail as we get to each stage but that’s what’s on the horizon. And to get the body ready for that - the wood has to be prepped to accept all of those processes. So, we sand.

Doing dishes, sanding guitars.  It's all the same.
I found this little trick by accident. Wrap your sandpaper around a sponge (or in this case a scotchbright pad) and have it stick out a bit. The binding wood - cocobolo - has a tendency to discolor the wood next to it when sanding. The scotchbright not only gives the sandpaper some rigidity but it keeps it away from the cocobolo and polishes the cocobolo to boot.

Hello darkness my old friend...
Scraping: I’ve found that the glue that I used to adhere the binding squeezed out in more places than I originally thought. These are tiny tiny tiny things that you can’t see normally but once you put a finish on the guitar - you will see them. The glue seals off the wood from the finish - so those spots look much lighter and brighter than the surrounding wood. So, we scrape the squeeze out out!

It is amazing how much time you can spend just going over the body millimeter by millimeter looking for this kind of stuff to fix.



I'll have a vanilla


Staining and Grain Raising: Way back when I started this guitar I was hemming and hawing about whether to use coffee or wine to stain the top. Since the top is flamed maple - I thought it would look cool with a finish that would show off all that flame (sometimes called figure or curl). I did scraps with cabernet sauvignon vs. pinot noir and drip coffee vs espresso.

...it was all pretty pretentious, really.

The one constant in all this testing was that - none of the colors was all that vibrant. Not like a really well finished guitar. Here we are eight years later - and I hadn't really given up on the idea.

Keeping that in mind - when I got to the point where I needed to "finish" sand the body I thought - well maybe one last attempt...

"I'll have a half double decaffeinated half-caf, with a twist of lemon."


As I alluded to above - part of the final finishing process is to sand the whole body down using higher and higher (finer and finer) grades of sandpaper. What this does is removes all the surface imperfections in the wood and preps the body for any color or finish. One of the last steps in the sanding process is to raise the wood grain by wetting it. The individual wood fibers will stick up after you wipe the body down with water. Then you sand them off with your highest grit sandpaper. It's a good idea to do this before you put the finish on as it makes the finish smoother. However, there's nothing that says that water can't be coffee. So that's what I did.

As you see in the above photo. It still just "kind of" works. I wiped the whole body down with espresso roast coffee that was super concentrated. Once it had dried it looked just okay. So, I didn't feel all that bad about sanding it down and removing most of that coffee accent (while at the same time getting rid of the raised grain.

I guess we'll have to do this the old fashioned way...

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