Monday, September 18, 2017

Everything is Brown!

Ready for my closeup Mr. Lucas
The body has been scraped, sanded, and prepped.  My dyes and shellacs have been mixed.  And I've done my test color strips.  I guess it's now or never...

Let's finish this sucker!

One odd note:  After I sand the body to 400 grit - I usually brush off all the sawdust with a large brush, then wipe the body down with mineral spirits to get off all the dust on the surface and in the wood pores. Finally, I use a tack cloth as a final way of getting all of the dust off the body - so it doesn't get trapped under the finish.  For some reason the tack cloth left a sticky residue on the cocobolo strip in the middle. It was bad enough that I had to remove it with acetone.  I'm not sure what happened - but if you are playing the Luthier Home game - it's something to look out for.

Pictured: "Practical" effects
I taped off the sides of the body with painter's tape so that I would keep the dye to just the top.
Yeah, if you've ever used painter's tape when painting a room - you know how effective it is.

I had mixed up the brown dye earlier in the day.  Again, I'm using TransTint concentrated dye with denatured alcohol as the solvent.  I rubbed the dye on using an old cotton rag - going with the grain.

"Think it'll work?"
"It would take a miracle"
The dye is really wonderful to work with.  It goes on great, dries quickly, and looks fantastic

"You look marvelous!"

The dye dried remarkably fast (a plus over water-based dyes).  Like all of my test strips the color seems to be less vibrant once it drys.  But when I hit it with the shellac it should come right back to life.
Pictured:  Mostly dead (which is slightly alive)

I didn't take any pictures of it but the dye did spill over the top and run down the sides in a couple of places.  I had to drop back to 220 sandpaper to get rid of the blemishes on the sides of the guitar (then work my way back up to 400 to match the rest of the body).  I'm not saying that taping the body off doesn't work - it does.  Just don't use painter's tape.  It's pretty useless.  When I did the second coat of stain I used plain old masking tape to tape/mask off the body and it worked much better.  It has a higher tack which keeps it adhered to the body.  Just be careful - if I had used the masking tape directly on the maple - it probably would have pulled away some of the wood when I removed it.

Round 2: Fight!
After the first pass had dried I sanded it down a bit and hit it a second time.  The color is good.
So, I'm not going to go for a third pass.  It's time to put a coat of shellac on this puppy.

I'm using shellac for three things:  1) To add depth to the color and flame of the maple.  2) To seal the cocobolo (which doesn't take a finish well but does take shellac well - and I can add a finish over that). 3) To act as a sanding sealer - which helps fill the wood pores and seal off the color/dye from the finish.

Now that the top is stained I am going to shellac the whole body (then spray the whole body) so now is a good time to mount the guitar on a spray stick.  This will make it easy to get at the whole body all at once and allow me to hang the body for drying.  It's also useful for mounting the body in my bench vise.  So, handy all around!

On a stick...
One other note about finishing:  After I put on a coat or two of shellac - I'm going to use a true pore filler to flatten out the top (which will require more sanding to even it out) then I will finally be able to spray the Nitrocellulose Lacquer on the body - which is my top coat.

"That's some funky lemonade you got going there baby"

There are a few ways to apply shellac: with a brush, with a sponge/rag, or using a pad (for when you are doing a french polish).  I started out using a foam brush.  It's supposed to cut down on visible brush strokes and give you a smooth result.  Well, that was not my experience...

That's not...
I was, in fact, kind of disheartened by how bad this first coat of shellac looked.  I thought it kind of ruined the color - making it a greenish-yellow.  Or to call a spade a spade - babyshit brown.
A few things were going on here:
  1. The shellac wasn't fully dry when I took the above photo.  
  2. I put WAAAAY too much on - the coat was very thick.  
  3. I went over my mistakes as they were drying - which you shouldn't do with shellac.  You should wait until it's dry before applying more shellac.
Once the first coat was dry I switched to a rag and applied the shellac a bit thinner.  I was able to even out the look, color, and thickness of the shellac with the second coat - and it looks better.
One of the great things about shellac is that it dissolves itself - so when you put on a second or third coat - it is melting into the previous coat.  This helps cover up boo boos.  And I'm good at making the boo boos - so anything that helps cover them up is appreciated.

Much more better!
What you can't see is how uneven the shellac really is still.  The back has drips and streaks and the cocobolo has a gummy film of shellac that needs to be dealt with.  My next task is to sand the shellac a bit to even it out (but not too much) and apply a third coat.

Tuesday, September 12, 2017

Guitar Chemistry

Anyone for a cocktail?
It's time to start mixing up some liquids in the lab!  

It's funny - if you are doing all the steps yourself - Luthiery includes Math, Chemistry, Woodworking, Electronics, Music, Art, History and a dash of Engineering.  It's like an entire high school curriculum in one.

There are many ways to finish a guitar: varnish, mineral oils, shellacs, lacquers, etc...
And those are just the top coats - the protectants for after you've dyed, stained, or painted your guitar.
The list goes on and on.  

I am planning on dying the top (the maple parts) and using shellac and nitrocellulose lacquer on the rest of the guitar.  The shellac will deepen the color I dye the maple, really make the wood figure of the butternut "pop," and it will also allow the nitrocellulose lacquer to bond to the cocobolo (and it will make the cocobolo look good too).  The Nitro will protect the wood from temperature and humidity changes while also protecting the wood from impact damages and my bodily secretions...

...get your mind out of the gutter.  My sweat!  Sweat and skin cells can stain wood all kinds of weird colors.  So, we protect the wood.  How?  Let's start with the Shellac.

Shellac is a natural substance that comes from lac bugs.  I want to know what madman first realized you could take what looks like a bug cocoon and mix it with alcohol to make wood varnish.  You'll note the word "alcohol" is in that sentence...

Anywho, shellac comes as a pre-made liquid (in cans and sprays) but it also comes as raw flakes.
You add denatured alcohol to the flakes to make your own mixture.
I won't go into excruciating detail but the amount of flakes you add to the alcohol changes the strength or "cut" of it.  For this Guitar I am using a 2 pound cut.  If I was not going to use nitro over the shellac I would use a 3 or 4 pound cut - essentially adding more flakes to make a more viscous shellac.  But I'm essentially using the shellac as a colorant and grain enhancer and not the top coat - so it can be thinner.

Shiny, Captain
I like to use a sealable jar as I won't be using the shellac right away and it does take a while for the flakes to completely dissolve in the alcohol.  Also, seeing as the major solvent in shellac (alcohol) evaporates kinda easy - it just makes sense to me to cover it when I'm not using it.

Uh, muddy, Captain
I'll let this mixture sit for a day or two to fully dissolve the flakes and by the time I'm ready to use it - it'll be ready to go.  A few thoughts:  All kidding aside - don't use vodka to dissolve the shellac flakes.
Use denatured alcohol.   Stir, shake, or mix the shellac every now and then to help the process along.
Finally, I'm running the mixture through a paint strainer before using it on the guitar.  This stuff comes from nature (tree bark, dirt, and bug body parts included).  Any paint store will have strainers.
So, let's let the shellac sit for a bit and move on to dyes.

Should I be making a Trans joke?
Nope, I should not.
Because I'm going to be dying the maple on the top of the guitar and not staining it (and I have no idea what exact tint I should use) I'm going to make my own hue.  Or is it shade? Art class was so long ago.

For those of you wondering what the difference is between using a wood stain and using a wood dye we turn to Alan Noel, wood worker and teacher.  Quoth Alan, "Very simply put, stains are very thin paints and dyes are why your socks are red out of the washer. With stains, the pigment tends to remain on the surface of the wood and lodge in the pores, while dyes penetrate deeply and color the wood from within."

I'm using TransTint dyes for this project.  TransTint is super super concentrated dye in a liquid form. TransTint is neat stuff because it can be mixed with water, alcohol or even mixed with shellac or nitro - it's pretty versatile. Since this is my first time out with it I am doing some test strips.  I have two colors to work with: Black and Coffee Brown.

Mmmmmm.  Coffee...

In my last post I talked about trying to use real coffee to stain/dye the maple.  It didn't work out that well. One of the biggest issues being that it dries too light and because it's water based it raised the grain every time I applied a new coat of color.  So, I scrapped that idea but I still wanted the coffee color for the guitar.  The dye will go on darker and because I'm using alcohol as the solvent - it won't raise the wood grain.  The reason why I bought the black pigment is to make the color richer - but probably not how you think...

The above picture is a mixture of probably an 1/8 to a 1/4 of a cup of alcohol and maybe 4 or 5 drops of the Black TransTint dye.  Like I said - super concentrated.

I feel so naked...
I still had a scrap of maple that came from the same board the guitar top is made from.  I sanded it down with 220 grit sandpaper and hit it with one coat of the dye.

Thank you, that's much better.
It looks a little purple in this photo but it dried gray (grey?).  You can see some of the maple "flame" in the above picture.  The dye sticks to the flame more than the non-flamed parts of the wood.  That'll be important later.  I wasn't satisfied with this - so I hit it a few more times with the black dye.

Too far!  Now I'm overdressed.
The flame or figure is pretty hidden right now.  Although a good coat of shellac would still probably make it pop quite a bit.

Everything is Brown!
Then I turned the scrap over and did the same thing but with the Brown dye.  This time the camera made it look a bit more red than it is - but I have mixed lighting in my workshop - so who knows what's going on.  Then after all this coloring we act like a 1st grader and erase everything and start over.

Black - Naked but unafraid
The key here is to remove all of the dye except the stuff that's in the "flame" or figured part of the wood.  So I sanded the color most of the way off on the Black side...

Brown - feelin' worn down
And the Brown side.
Then I mixed up a 1/4 cup of the brown dye again and hit both sides of the scrap.  
And this is what we have:

First coat Black, second coat Brown

First coat Brown, second coat Brown

...and that's pretty frickin' subtle...
Did that even work?

Okay full disclosure - there's more going on here than at first glance.  After I did the second coat of dye I let them dry and hit them both with a coat of the Shellac (remember the shellac we made all the way at the beginning of this post?).  The shellac is making them both look fabulous but they are also pretty shiny and hard to photograph.  Since it's not easy to see - what's supposed to happen is the black gives the flame more depth - making it look more three dimensional.  And it does...
...a bit
...but only when you tilt the wood back and forth
...which is hard to show with a picture.
...maybe it's time to switch to video...

But really, they both look pretty sexy - and this is just scrap that I haven't sanded (or photographed well). If I had chosen a lighter brown (or any lighter color, really) the flame would probably pop a bit more because of the black.  I'm going to lightly "finish" sand them both and see what looks better.  But I think either process would work for what I want.  So, I guess this was a successful test.  I now know that either will work well.  Time will tell which will work out better.

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.

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. 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...

Thursday, September 7, 2017

Getting fiddly with it

'O sole mio!

I'm now at the point where pretty much everything that's left to do on this guitar build is fiddly work.
Before I can final sand the body I need to clean up the bindings.  Before I can test fit the pickups I need to chisel out a tiny bit for the pickup ears to fit in the pickup cavities.  Before I can put a finish on the guitar I need to fill the pores on anything that can't be sanded out.  Fiddly work.  It's not the work I was built for.  I have big, impatient, shaky hands.  Not the kind meant for detail work.  But here I am again - trying to be a Craftsman with a Demolition Man's hands.

I'm at the point with the binding on this build that sawdust and superglue are my best friends.  There are a couple of places where the binding has separated from the body or the binding has cracked - or there are small voids.  Unlike the previous post about reworking the binding - I'm no longer worried about broad strokes - like replacing a section of the binding or joining two pieces.  This is more about hiding mistakes.
Here's how you do it:

Mmmmmm.  Crusty...

Take some 180 to 220 grit sandpaper (320 will take longer but will work) and make some sawdust (I think of it more as powder) with the same wood you used for the binding.  If you have thin enough superglue (CA glue) you can pre-wet any cracks or voids with a light coat of glue and then fill that void with the sawdust.  Then lay another layer of glue to harden up that first layer of sawdust -then add a little more sawdust on top of that - to make it proud and to help blend with the wood.

Pictured: Blending

After this dries you scrape and sand the patch until it's flush.  And if you did it right the fix should be hard to see.  The only problem with CA glue is that it doesn't stain.  You've pretty much sealed the wood - so either scrape/sand it down as much as you can - or don't plan on tinting that section.
I'm planning on using shellac on this build (which pretty much binds to anything) but I'm not planning on staining/tinting the cocobolo - so I should be okay.

Not Pictured: how you hold a scraper
FYI - the tape is to protect the things you DON'T want to scrape
While the first round (there were three rounds) of binding repairs were drying I went to work on the pickup cavities.  I really wanted to do this with just a 1/4 inch chisel - by hand but it was turning into hamburger.  The maple cap was trimming well with the chisel (which was reasonably sharp) but the butternut (most of the body is made of butternut - aka white walnut) was just crumbling under the chisel instead of cutting cleanly.  It WAS working but the pickup cavity would have looked a mess. So I brought out a Dremel to see what kind of havoc I could wreak with that.  Seriously, I think of a dremel as a destructive tool - not a creative one.  There have been several projects that have been solidly marred by the dremel I own.  But I remain hopeful.

You got some funny lookin' ears there kiddo.

In this case - it did okay.  I used a grinding/sanding bit to make the sides of the pickup cavity larger to accommodate the pickup "ears."  It did okay - not great.  Remember the tool is only as good as the Tool wielding it.  The pickups now fit and the cavity looks acceptable.  So, let's get back to binding.

"Alright, alright, alright."
From this angle it looks pretty good.  Like I said - I scraped the sawdust and superglue mixture flush to the wood and then repeated the process until al the voids and cracks were filled.  There were a bunch all around the body but this one was the most obvious.  There's still some sanding to do - but I had another fish to fry first...

All wrong, all wrong, all wrong
What are we looking at?  This is the back of the guitar where the strings are strung through each of those tiny holes and out the front side of the guitar body.  This giant ferule came with the 12-string bridge I bought for this build and let's just say I didn't install it all that well.  The dark stuff you see around (and on) the metal ferule is a mixture of wood glue and coarse sawdust (probably made with 80 or 100 grit sandpaper).  When I routed the hole for this ferule I must have sneezed or something because it's not remotely straight.  I filled in the gaps with a strip of wood veneer and packed it with sawdust and glue.  I must have forgotten to wipe off the excess glue (or thought it would sand out).  I don't know what I was thinking, really.  But it's time to fix it.

 I stuck a screw driver through one of those holes in the wood (from the front side of the guitar) and gave it a few gentle taps with a hammer.  That made the ferule pop out of the hole.  Then I scraped and sanded all that gunk off the back of the body until I got to this point.  And I can go no further.

That's gonna have to do.
If you look closely you can see the light strip of wood veneer that I glued to the side of the hole to square it up.  The dark spots just below it are more of the glue and sawdust mixture (what kind of wood did I use - ebony?).  Those two lumps were made by a router bit - so they're not going to sand out.  I'm stuck with them unless I want to do some serious surgery to this part of the guitar (which I don't).  

With the ferule back in place it looks much better than it did but it's still kind of shabby.  When I shellac the back of this guitar it will become less noticeable (and since it's on the back no one will see it).  But still...

There is one last thing I need to do before I can start finish sanding the body - and that's fill a couple of holes.  There are a couple of tear-outs on the butt of this guitar.  I'm guessing caused by the router when I first cut this body out of the block of wood from whence it came.  They are too deep to sand - so they need to be filled.

Fill 'er up!
This is grain filler.  In this case clear wood filler.  They are usually tinted to match the wood.  You use it with porous woods like mahogany to fill the tiny pores in the wood.  It helps give the piece a nice smooth finish when you are applying your topcoats.  However, they can be used to fill small voids as well - and that's what we're doing.  This brand of filler goes on kind of like hand sanitizer gel.  It's slightly thick - just enough to stay in one place.  Normally you spread it on the entire body (and I will later in the process) but for today I'm just filling a couple of spots.  Give it a few minutes to start curing then trowel the excess off.  You are left with this.
Such cute dimples!
The spots there in the middle have one coat of filler.  Once it dries I'll sand off all the extra and put a little more in there.  And repeat the process until the holes are filled.

Then it will be time to finish sand this sucker!

Wednesday, August 23, 2017

Oh, look... More Binding...

That'll buff right out...

Now that the body has most of the holes routed/drilled it's time to start fixing my earlier mistakes.
When I left off with this build (seven years ago!) the binding was incomplete and in the intervening years it has developed a few additional - oh let's call them "issues."

Looks fine (if you turn your head and squint a bit).

A piece fell off around the smaller horn (and that broken piece is long gone), a couple of cracks have been there all along, a section came unglued, and I never did the bend around the bigger horn properly in the first place.  So!  There's much to do.

Don't be so picky. 

The answer to all my problems.

This binding (unlike the plastic binding I used on the Les Paul build) is made of Cocobolo.  A fabulous wood that is dense, oily, aromatic, and water resistant.  If you have ever tried to bend wood before then you know water is usually an important part of the process.  Not so much with Cocobolo. This stuff is so dense and oily it's one of the few wood types in the world that doesn't float.  You pretty much just use heat to bend cocobolo.  In this case - the same heat gun we used for the Les Paul binding.

Feelin' Hot, Hot, Hot!

Also, because Cocobolo is so naturally oily you have to "degrease" it before you glue it.  So keep some Acetone on hand prior to gluing. Wipe all of the cocobolo pieces down with a rag dipped in acetone. Again, this stuff isn't the best thing in the world for you (according to the State of California) - so don't bathe in it.

Look! I found my Special-purpose!

I can't speak for other woods but with Cocobolo you really have to "listen" to the wood while you're bending it.  I usually use a stethoscope...

I'm sure there is a joke in here somewhere about men "listening" so I'll just let you fill in the blanks.

But seriously, as you apply the heat the wood will very quickly go from stiff to pliable.  It's not a specific amount of time (or heat) but usually it's less than a minute of direct heat before it starts to bend.  If you see the wood turning black or the wood resins bubbling you've gone too far - ease back on the heat.  You want it JUST before that point.

The thing about heating and bending wood this way is that you really need a third hand.  One hand to hold the heat gun, one hand to bend/reshape the wood and a third hand to tape it down.

A fourth hand to photograph it all wouldn't hurt either

If you don't tape the binding down immediately - as it cools it will start to go back to it's original shape.  It won't completely go back to it's original shape but you will lose a lot of those lovely curves you just created.

Quick tip: Don't use foil duct tape (or actual duct tape) like in the picture.  Use low tack masking tape or painters tape.

Like with plastic binding - you can use a bunch of different things to glue the binding down with.  On this particular evening I used medium viscosity super glue.  Since this is a wood binding being glued to a wood guitar body - you could use PVA (Wood) glue and it would give you more working time.
I wanted to scrape and sand the body in the same night as gluing the binding down - so I chose superglue.  Also - it's supposed to work better with cocobolo.   I'll let you know.

Remember to use just enough to glue your fingers together but not enough to glue what you actually wanted adhered.

Mmmmm... Toasty
So, remember when I said use enough heat to bend the binding but not enough to cook it?
Yeah, "Do as I say.  Not as I do."  This is a little cooked.  I'm hopeful the charred parts will scrap off.
Patience is a virtue.  Just not one of mine.

The glue on the above piece of binding has dried and this little section is ready to be cleaned up.
You use a similar process as you would for plastic binding: scrape the sides with a card scraper (or small plane) and sand smooth.  One thing that is different about using cocobolo is that the oils can stain adjacent wood while you are sanding (which it did for me).  I also used a utility razor blade as a card scraper as it is good for detail work.

Pictured: A lack of virtues
You may be able to see that in the picture above the bit on the end is broken.  I tried to force the cocobolo to bend too much too soon.  Take your time and this won't happen.

Oh look!  New problems.
One of the things that you learn working with wood bindings is that if you heat up an old section of previously glued binding for too long - it may come UN-glued.  I'm not sure how you would avoid this (tape the old binding down?) but thankfully it's an easy fix - and in this case not completely unhelpful.  I plan on trimming the two pieces of binding until the meet in the middle. Having them free like this let's me test the fit as I trim them to the correct size.

In process...
 I was able to clean up quite a few of the binding issues but not all of them.
...and I was starting to get sloppy - so I stopped for the night partway through the process.

I'll be honest - probably the most valuable lesson I've learned from building guitars is knowing when to just stop for the night and pick it up the next day.

There is more fiddly work to be done but this body is one step closer to being a guitar than it was yesterday.

Not quite there yet...
Lessons learned?  For those playing the Luthier Home Game (or anyone who works with wood) some people find the sawdust of Cocobolo irritating to their sinuses.  I did. Wearing a mask when using it is probably a good idea.

Cocobolo is still one of my favorite woods to look at.  Maybe not one of my favorites to make bindings from.  But as it's the only wood binding I've tried so far - I have no basis for comparison.
Still, it cleans up real nice.

Getting purdy.