Thursday, September 30, 2010

Post Class 4: May I introduce...

(please click on an image to enlarge it)

Say hello to Bertha.
I finished her on 9/26 - which is pretty crazy since I started this build in April and this is by far the fastest build I've cranked out. In what universe is six months fast? But I guess that speed is not really the point now is it?

Since she was built from a kit there were some steps completed for me but as a friend of mine pointed out - the kit didn't put itself together - so it was fun and challenging and I'm already thinking about my next 'kit-build.' Probably this one from Stew Mac.

So, what did I do to this since my last post?
The guitar had been sprayed with Nitrocellulose Lacquer and had dried for two weeks.
Before that final spray I had been sanding between coats of Nitro. I usually sanded with 400 grit sandpaper until the sanding just prior to the final coat of Nitro. That last sanding I used 600 grit sandpaper.

After the guitar had sat for two weeks I 'level' sanded it with 800 grit sandpaper and then 1500 grit sandpaper (I would have preferred to use 1200 but I was out). With sandpaper so fine you are not really taking much material off - it's more removing the 'high' spots on the surface. It seems like you end up wiping off more dust from the sandpaper than from the work-piece.

I will note that prior to the final sanding I was amazed at how level the finish was. Normally there is an orange peel texture to Nitro finish that has been sprayed with aerosol cans - but not this time. Perhaps it was that I was just the right distance when spraying - or perhaps this is a better brand of Nitro. I don't know. But the finish surface was much more level than when I finished my first guitar.

After sanding came polishing. On my first guitar build I had used a foam pad that attached to my drill to do the polishing. But I ran into two issues (one from the last build and one from this build). First, when polishing my Telecaster I buffed through the finish and the stain and got down to bare wood by being a bit too heavy handed with the polishing pad. I wasn't eager to repeat that. Second, the Tele was heavy (it was a solid brick of Mahogany) this was a very light acoustic. The first time I touched the polishing pad to the acoustic it nearly launched it off my workbench. So I decided to try hand polishing.

Hand polishing can be a bit of a grind if you didn't know. Think "wax on, wax off" and you get the picture. I used guitar specific polish (again from Stew Mac) and alternated between a hand-held foam polishing pad to apply the polish and some cotton rags (a ripped up old t-shirt) to wipe away the excess polish. I had two grits of polish - medium and fine - and then what's known as swirl and haze remover - which is a pretty light (and liquid) polish as the final step.

There are ups and downs to doing this by hand - and I don't just mean the aching arms. I didn't go through the finish - which is good. I didn't launch the guitar body off of the workbench - also good. I did not, however, get a mirror gloss on all parts of the guitar. There are a few spots (one big one on the back) that are shiny but not even close to being glossy - which much of the guitar body now is.

Having said that - the beauty of Nitro is that I can spray right over existing coats if I want/need to. And because I put a decent amount on there to begin with I bet I can just keep polishing and any dull spots will shine right up. All in all I'm happy with the way it looks.

Okay but how does it sound? How does it play?

It sounds pretty good. I notice a difference from when it was unfinished. The guitar really did sound 'woody' and alive prior to the finish being applied. It now sounds a little more muffled. Perhaps I put too much finish on it? There's also the possibility that it just needs to settle in a bit more. If I'm honest I'll tell you that it sounded better without a finish. Good enough that I was contemplating selling my Larrivee because this guitar was comparable. Not any more. It still sounds good and has a boominess the Larrivee can't touch but this guitar lacks the mellowness and richness of character that the Larrivee has. Still it sounds good and with the solid spruce top will only get better with age.

It currently plays awful. The action is all off because the thickness of the finish has changed the way the neck joins to the body. The action is too high and it's difficult to play past the 7th fret. Thankfully this is fixable with a little time and patience. I'm letting the guitar 'settle' a bit and then I will see what improvements I can make with the truss rod and the nut/saddle height. If I can't fix the issues with any of those remedies then I can just remove the neck and sand down the finish where the neck meets the body back to bare wood and things should be right as rain.

To sum up: It looks awesome, it sounds good, and it plays awful. Two out of three ain't bad - especially when I can fix the third. And most importantly - I had a good time building this one.

Monday, September 13, 2010

Post Class 3: And now we wait...

Spraying Nitrocellulose Lacquer takes time.
You are supposed to spray anywhere from 8 to 12 coats of the nitro for a guitar body (according to Dan Erlewine - and who am I to argue?). These coats should be light, sprayed from a distance of 10 to 12 inched from the body, and only about 2 or 3 a day. For example: Spray one light coat at noon, wait an hour, spray another light coat at 1:00, wait an hour, finally spray a final coat for the day at 2:00. Let it dry overnight and then lightly sand (scuff sand) with 400 or 600 grit sandpaper. Your goal with the sanding is to gradually level the surface - so you don't want to remove too much finish.

Then repeat the next day...

For three or four days...

Then you wait.

And wait.

And wait some more.

Supposedly the nitro won't completely harden for 2 to 4 weeks after the final coat.
Once you have finished waiting - then you start sanding for real. You start with 600 or 800 grit sandpaper and work your way up to 1500 to 2000 grit sand paper. The idea is that you are not so much trying to remove the lacquer as flatten it in preparation for polishing it. Once you have finished sanding you polish with 2 or 3 different grits of guitar polish and then 'swirl and haze' remover.
This is when you really get your karate kid on (wax on, wax off).

This is what you are supposed to do. Here is what I did:

I started out spraying this guitar, the lapsteel, and a bass neck my friend asked me to help him with all at the same time. I did not spray light coats. I was a bit more heavy handed than that. I sprayed heavy coats (and got away with it for the most part). The problem with heavy coats is that you only have to mess up once to really make your life more difficult.
At one point or another I over-sprayed the bass neck, the acoustic (neck and body) and the lapsteel. Over-sprayed = getting a run. So at various points I had to sand down a drip/drop of dried Nitro from one of these guys. I am aware of my mistake - I take full responsibility. I just hate spraying and anything I can do to speed up the process - the better.
Of course sanding out imperfections takes longer than spraying another light coat - so who's fooling who?

In the end I used 4 cans of Nitro to spray a bass neck, a lapsteel, and the acoustic. That's about right when you consider I didn't use a sanding sealer for any of them - just more coats of nitro. I would guess that I did 6 or 7 heavy coats on the lapsteel and the acoustic. The Bass neck probably got 4 or 5 (enough to duplicate the previous finish on it).

And now I wait...

For two weeks…


Post Class 2: Process Con't

So, how do you finish an acoustic?
This is how I finished mine:

1) Sanding.
Sand like there is no tomorrow in some places and gently in others.
The Spruce top and mahogany neck can be sanded to your heart's content (and should be for a nice smooth finish). I had to sand the top a bit more than I would normally because while playing it the sweat coming off of my arm on the upper bough had stained the guitar top yellow - kind of like the underarms of a white dress shirt. It's not pretty, and it sure ain't dainty but it's the truth and it has to be dealt with.
I sanded it with 80, 150, and finally 220 sand paper to clean up the white top.

I did the same thing for the neck and headstock - being careful not to sand the coin inlay. The copper sands off easily.

The sides and back - being laminate - were similar but not the same. I used 150 and 220 sand paper very sparingly. The instructor said it wasn't that hard to sand through the top laminate to the less pretty layers below. So I went slow and easy. I also used some rounded rubber sanding pads which made all the difference on the sides.

2) Taping
I covered the top of the guitar with newspaper and painters tape to protect it from the stain I was about to apply to the side. Note to self: buy low tack painters tape. Removing the blue tape from the body took some wood fibers with it. Nothing bad but still there.

I also bought some 1/4 inch automotive pinstripe tape from a local AutoZone and used that to mask off all of the plastic binding around the sides of the body. The tape was good to work with but I'm not sure how necessary it was to use it. A few bits of the binding got stained by accident and they cleaned up pretty easy. I could see this being imperative if you used wood binding but in the future if I use plastic again I may try going without - just to see what happens.
In conclusion: I'm glad I taped the top - I have no regrets that I taped the binding.

3) Staining
I had some "Early American" miniwax stain on-hand and decided to use that for the back, sides, and neck of the guitar. No one is going to confuse this guitar with rosewood but it looks less like Mahogany/Sapelle and more like rosewood now than it did before. I'm a fan of both - but if I had my druthers - I would use rosewood every time. I applied the stain with both a brush and a rag. I did two light coats of stain and let it dry overnight. I now wish I had used three coats of stain on the neck but such is life. I decided not to stain the headstock but rather to shellac it (I had plenty left over from my lapsteel build). So, the headstock looks much lighter than the neck, back, and sides.
One Note: once the first coat of stain had dried I lightly sanded the guitar body and neck to smooth out the wood. Staining wood (like wiping water on wood) will raise the grain. By lightly sanding it you smooth everything out again which will make finishing it easier.

4) Filling the pores
Mahogany and Sapelle have big pores. Big enough that if you tried to slather or spray some type of finish on top of them - you would see little pits in the finish. These pits need to be filled. It's best to fill them sooner rather than later.
I chose not to put a sanding sealer between the stained wood and the pore filler. The woodworking gods will probably smite me for hubris but them's the breaks. It is recommended that you do this - put something in between the stained wood and the pore filler. An old fashioned method is to rub on a coat of shellac. Shellac can also add to the luster of the finished guitar. As I'm writing this now - I can't remember why I didn't do this... @#&*!!!!

Ah well. I'm sure it'll be fine.

Just FYI - another option is to spray sanding sealer or a light coat of lacquer to act as a barrier between the wood and the pore filler. So, now that we know what I didn't do - here's what I did do.

I wiped on three coats of clear pore filler. I like clear pore filler for two reasons: You can use it with any wood and it won't bleed color. Having said that - I've never used colored pore filler and other people swear by it.

You wipe on the pore filler, squeegee off any excess, and let it dry. Once it is dry (30 to 60 min) you sand it flush with the body. Note: Another reason to use a sanding sealer of some type between your stained wood and the pore filler - you don't sand through to the unstained wood. Which I did on the neck (hence why I wish I'd used 3 coats). If you are super precise - you can get away with it. I was not super precise and had to 'touch-up' a few areas on the neck and body after I finished pore filling.
Depending on how well you applied, squeegee’d and sanded you may only have to do one or two coats of pore filler. I had to do 3 - so that will tell you how well I did it. But since this was my first go 'round with filling the pores on an acoustic. I feel good about it.

5) Spray Finish
Technically, you don't have to spray. You can wipe on boiled linseed oil or tunge oil or you could do a french polish (20 coats of shellac applied by hand). You have to do something. If you don't protect the wood in some way the oils and dirt from your skin will eventually break down or ruin the wood.

I went with a spray Nitrocellulose Lacquer. Nitrocellulose Lacquer is nasty stuff. It is the definition of V.O.C. But if you wear the correct protective gear (gloves, eye protection, and a respirator) it is easy to work with and gives great results. I don't have a compressor or a spraying rig - so I buy spray cans of Nitrocellulose Lacquer. You can buy them online from Stew Mac or in person at Rockler and Woodcraft.

The great thing about Nitrocellulose is that it partially dissolves the previous layer. So, if you goofed or if the spray can 'spit' you can usually just spray right over it and it will dissolve/cover your mistakes. Also, once a Nitrocellulose Lacquer finish is sanded and polished - it's purdy.

As you can see from the pictures - I had to tape off the fingerboard and the areas where the neck meets the body. I'd like to tell you that it's because I want that wood on wood contact that is going to make all of the Sapelle molecules line up in one harmonious ringing, joyous symphony of sound. But it's really because the guitar fits correctly now. Even a 1/2 a millimeter of thickness will change the fit. I spent too much time fussing over that fit for it to change now. So the neck/body connection doesn't get sprayed.

I taped off the fingerboard and bridge because they don't need to be sprayed. The Rosewood of these parts is so dense it is almost waterproof and can face a life without a finish.
I also filled the soundhole with a crumpled up paper bag. The paper bag will keep any extra spray from coating the inside of the guitar - which doesn't need any nitro and can't be properly sanded/polished anyway.

Post Class 1: Process

Wow, have I been bad about keeping this build blog up to date!
So, here's where we stand:

The class finished up at the end of April. At that time the guitar was 'together' but not finished. Most of the pieces were in place and it could be played but the neck fit and playing action were pathetic. It was better as a lap steel than anything else with the action so high. But then I went to Spain for a few weeks and this got left by the wayside.

In June I got back together with the Instructor (Scott Dixon) to finish this up. Scott went out of his way to make sure that anyone from the class who wanted to come back and tweak their instruments was welcome to do so - free of charge. I have no idea how this guy is making any money off of this endeavor - but he's got another loyal and thankful customer in me. So, he and I tweaked the neck fit and the action so that it played like I prefer it to (neck relief, action, intonation, etc.).

In June and July I played the heck out of it. Keep in mind the guitar was complete (and it played well) but it was not finished. Literally. I had to put a protective finish on it. True to my previous builds I wanted to play this guy a little to see if there were any issues that should be resolved prior to putting a finish on it. This is partly practical and partly impatience. I really wanted to play this but once you go down the finishing path it's usually 3 weeks to a month before you play the guitar again. For me it usually ends up being 1 to 2 months for whatever reason. A few notes: It sounded amazingly 'woody' without a finish on it. And it sounded pretty close in character to my Larrivee - which is odd as the Larrivee isn't a dreadnaught and is made from solid rosewood back/sides as opposed to this guitar which is made from laminated mahogany (Sapele actually). The only thing these two had in common was the solid spruce top and that they were both being played by me.

In Mid-July I dissesembled the guitar and started the process of finishing it.

Monday, April 19, 2010

Homework 1: Day of Inlay - Part 2

(click pictures to enlarge)

I spent the day doing headstock inlays. To see the other headstock I worked on go here:

Class #2 - Fit the neck

What we did:
1) Routed out the neck pocket on the body to accept the neck
2) Used an awl to enlarge the holes of the tuning pegs and end pin (I biffed my end pin - now it's too big. I'm hoping a different end pin will fit better. Otherwise it's gonna be me and some glue to fix this). I could also install a piezo (in which case the end pin hole is too small. Save that for later.
3) Adjusted the fit of the neck so it was flush and flat with the body - hence straight and level with the top.
4) Installed the truss rod (shaped the truss rod valley for a snug fit)
5) Fit the fretboard to the neck.
6) Glued the fretboard to the neck
7) Took the kit home to personalize

(pictures soon)

Tuesday, April 6, 2010

Class #1 - Getting the kit and joining the top with the body

(click on any of the images to enlarge)
Well, I finally broke down and did it. I'm makin' an acoustic.
Since I've built my other guitars by the seat of my pants - I figured maybe it would be a good idea to take a class for this build. I am taking the class at Woodcraft in Woburn. Building an acoustic is much more difficult than building an electric. There's more precision involved and more opportunities to make mistakes. I'm glad I decided to try a class first. I can safely say (already) that I'd be pretty lost without the guidance. This is a five week course and we've only completed week one - so there's a ways to go but his is how the first class went down...

The guitar we are building comes as a kit (US guitar Kits). To look at the kit - it looks pretty far along already. And it is. Many steps were bypassed in order to get the class under 6 weeks (and around $600). So, I didn't put the back and sides together - this was done for me. I can see why the kit company does it this way - to bend the side wood and put the sides on the back - you need to make or use a form that is shaped to the guitar size you want. I'm guessing the act of making the form is pretty involved and by cutting that step out - it's easier to make everything come together at the right price and time. So, let's call this luthiery with training wheels and run with it. Hey, you gotta start somewhere.

So, what did we do on the first night?

We shaped the braces on the back side of the top. This is crucial for the stability and tone of the guitar. The top is what vibrates the most on an acoustic. The back and sides do as well - but the top of the guitar is the 'sound board' to use a piano term. You want the top to vibrate as much as possible when the strings are plucked/strummed. The problem is that if the top vibrates too much it'll fall apart under all the stress of the string tension. So the top braces give the top the stability and structure it needs to stay together - but by shaping them (i.e. making them thinner and more light-weight) you help the top vibrate more. Each brace does something different but the big "X" down the middle is where the strength comes from. My goal was to chisel and sand all of these braces until they were small - but not too small.

We also sized the top to the back/sides. We put the back/sides over the top and traced out where the braces should meet the body and where all the excess wood should be trimmed. We then cut and chiseled the braces until they would fit inside the back/sides (but with the top itself resting on top of the back sides). It pretty precise. Then we used a band saw to trim the excess top wood - so that the top matched the back/sides more closely in size.

Finally we chiseled out little grooves in the sides (on the inside) so that the top bracing would fit snugly against the sides. After that was done we test fit the top and sides a couple of times to make sute it was a good fit - then we glued the top to the back/sides with wood glue and all these funky clamps. They look wierd - but they do a great job. Now we wait for the glue to dry (and the next class).

Believe it or not the carving, fitting, and gluing took over four hours. But the satisfying "thump" you hear when your top fits snugly onto the back/sides makes it worth it. As a side note - when you make an acoustic one of the ways to judge the sound before the guitar is finished is to tap-test it. It's exactly what it sounds like. You tap the top in various places to hear what it sounds like. Having never done this before - I wasn't sure what I was listening for (and the instructor gave no hints interestingly enough) but what I did hear was a deep and satisfying 'thume' sound. Almost the equivalent of hitting a gong - but made out of wood. I dug it either way. And look forward to the end result.

Another neat thing was that we all took the guitar necks that came with the kit home with us - so we can personalize the headstocks. I already have my plan in place. I just have to get some ebony laminate this weekend and I'm on my way...