Thursday, May 31, 2012

Fiberglassing lesson from Anthony

I have some pictures from yesterday evening, when my friend Anthony gave me a beginner's lesson in fiberglass. (Thanks Anthony!) He has done this on a few wooden kayaks, so I wanted the benefit of his experience when trying it for the first time.
The project was to protect and stiffen the blades of this kayak paddle that I made, but never finished, last summer. I gave a final sanding/scraping , and then we got to fiberglassing.

wetting out the cloth
First we rough-cut the fiberglass cloth to size, with an extra inch or more to spare on all sides. The cloth stretches on the bias easily, so we laid it down on a table and tried to get it to lay flat first. We put our gloves on for this part because apparently fiberglass is not so nice to skin.

Once the work area was all set up and the cloth pieces were ready, we started mixing the epoxy. We had a tough time initially figuring out what to use to measure it, but ended up using some little pvc pipe caps that probably held less than 1 oz. each. The hardener seemed to react with the pvc, but it wasn't in there for long. Next time, I'll probably get some pumps that measure as they dispense, which Anthony has convinced me are the way to do it.

We laid the cloth down and painted the epoxy on with a couple of disposable chip brushes, taking care to avoid bubbles or other unevenness. When first "wetting out" the cloth with epoxy, it goes from opaque to invisible in the span of about 3 seconds, starting when a dollop of wet epoxy lands on it. That was worth seeing!
Epoxy looks the same whether wet or dry.

I took a look at it this morning and the epoxy has gotten harder, but looks exactly the same. I tried slicing a little bit of the excess cloth off just to try it, but that's all the time I had today. At the next opportunity, I'll apply another coat of epoxy before moving on to marine varnish.

Excess cloth slices off easily once dry.

It would seem that applying fiberglass is a straightforward task for anyone with a bit of finishing experience. I'm definitely not going to hesitate to try it again.

Tuesday, May 29, 2012

Cutting up a neck blank

Yesterday I made some more guitar building progress. Every time I work on them, I realize that it's not quite as tough as I sometimes make it out to be. I also decided that I like breaking the process into individual steps, and posting about each one. I think it helps pace myself, or process my thoughts, or something.
I drew out all the steps some time ago. Now I just have to stick to the plan.
The plan was to rip off a piece to use for the headstock. It comes from behind where the fingerboard will go. Ideally, the neck ends up about the right thickness, and I have a nice piece left over to use as the headstock. This way the headstock will end up matching the rest of the neck.

Unfortunately, I had set myself up for a challenge by making a really dumb mistake when I prepared the layers of the neck blank. The piece of cocobolo in the middle is not the full thickness. I tapered it off when I cut it out of a large piece, apparently attempting to save wood. This means that I have just barely enough wood for a headstock, and next to no room for error.
The middle layer of the sandwich doesn't reach the bench. D'oh!

In order to cut out a headstock piece without wasting wood, I needed accurate lines to follow, and before doing that, I had to bring the surfaces up to snuff, accuracy-wise.

There is foamy dried glue showing near the top, but it will get covered by the fretboard.
I planed the fingerboard-facing surface first, making sure to keep it perpendicular to the glue lines. Since the veneer layers were out of alignment, there was some dried glue where there should be wood. Wanting to conserve wood, I planed down far enough to get a completely clean surface only where it will show. There are a few glue bubbles visible in one of the narrow walnut stripes, but these will be hidden by the fingerboard. A relatively fine setting on my cambered jack plane was useful for focusing efforts on one end for a little while. This ebony is difficult stuff to plane, so anything that focuses energy in one area can make planing a lot easier. I finished up with my jointer plane, set as fine as possible because otherwise it's very difficult to push. A 90-degree fence on the jointer helped make planing the two sides easier. I didn't bother with pictures of planing because it's not unique to this project. I left the back and ends rough, and moved on to marking out some lines.

Before I actually marked anything, I wanted to sanity check the dimensions in my drawings. I made a full scale cardboard mock-up to make sure I liked the size. I didn't end up deciding to change anything significant, but I did end up deciding that I will need to beef up the headstock a bit. If the picture of the mock-up looks weird, that's because it's going to be a weird guitar. The whole thing will be tiny, and the body is not integral to the design.
The neck blank with hardware, tape & cardboard gives me an idea of what this thing will look like
The part of the neck blank that goes through the body will stay full-thickness. The rest needs to shrink down a bit to be playable. Since I won't be using a truss rod, all of the strength of the neck needs to come from the wood itself. This is why I've chosen very stiff species. Still, making it too thin now would be a mistake. I'm going to make a final decision on the thickness later, after I've seen it under string-tension. For now, I'm comfortable with 3/4" at the headstock end, and 1" where it meets the body. This leaves just enough excess to use as a headstock.

Chalkdust makes knife lines visible.
I used a marking gauge set for 1" and a 1/4" brass set-up block to mark both depth settings. A square and marking knife defined the other dimensions. These knife lines are great for accuracy, but they're almost invisible. Chalkdust fixes this. I scribbled over the marks with chalk, then wiped off the excess, leaving sharp white lines to follow.
This spacer might have been overkill, but I like not having to change a gauge setting until I'm sure I won't need it again.

I clamped down a ruler to connect the dots with a marking knife. This is important, because if I make two lines by accident, I will undoubtedly end up following the wrong one.
The chalked knife line is crisp and noticeable.
With the lines marked, all that remains is the straightforward task of sawing to the lines. I'm pretty sure I have Chris Schwarz to thank for putting the idea in my head that this is a very important skill. Being able to saw to a line is liberating, because you can draw a line almost anywhere.

I used my favorite saw for this, which also happens to be the only decent rip saw I own, an inexpensive ryoba made by Vaughan (no financial connection etc.). It was important for this step to use a saw that cuts a thin kerf, and to stay right on the line--for at least two reasons. For one, I need to avoid wasting wood. For another, because of the shape of the neck, it will be very difficult to plane the back. Better sawing means less work later.
Sawing to a line is the key.
The saw I was using has a pretty thin plate and only very minimal set. This means it's very hard to steer. This makes it hard to correct for errors, but also hard to make them in the first place. The key to doing a good job is simply vigilance. I watched the line every second I could, and when I got off track, I corrected immediately, before it got any worse. I flipped it a few times so I was always sawing the line I could see. This was easier than I thought it would be, because patience and vigilance make up for a lot of raw talent that I don't have.
Ripping exotics is a good way to work up a sweat. Good thing I had a sharp saw!
To fully liberate the headstock piece, I had to make a small compound-angle cut. This is where sawing to a line has such an advantage over say, a table-saw. I could have done this on my table saw, but it would have required quite a bit of error prone setup. I think it would have ended up taking 10 times as long, plus I probably would have made a stupid mistake along the way. Seeing the line as you cut is reassuring.
This begins to suggest what the back of the guitar will look like.
 After I got the pieces free, I was pleased to discover very little roughness, but still plenty of room for improvement. This is one of those things that just gets better with practice, I guess. The scrap I was left with does look big enough for a headstock, so I'll call this a success.
This scrap should be just big enough to make a matching headstock.
 Next time I have a chance, I will do the same steps on the other guitar. It's softer wood and without the missing chunk, so it should be significantly easier.

Tuesday, May 22, 2012

Gluing up a guitar neck blank

ebony, maple, walnut, maple, cocobolo, maple, walnut, maple, ebony
Guitars are the reason I'm interested in woodworking. Building them is also very intimidating for me. I've built 2 in the past, neither from scratch. I've been designing, working, and mostly procrastinating towards the next two for the last two years.

Chalk demistifies planing dark woods. The high spots are gone.
Fortunately, my other projects have increased my basic skill level, and made these guitars a little less scary.

Even though this is not the goal, these ebony shavings really are beatiful.
The reason I first got into building guitars is because I wanted to own crazy ones that couldn't be purchased. The first one I built included two pickups that each covered only 3 strings. My next one was an electric baritone fretless 7-string from Warmoth parts. And this time I wanted a short-scale, 7-string, neck-through acoustic body guitar on a stick. No wonder building them is intimidating. If that didn't make sense, just keep following the blog and it will become clear at some point.

tape lets you open the layers like a book, but one continuous strip didn't leave expanding gorilla glue anywhere to escape.
Anyway, I thought it might be wise to also build something more simple and mainstream. So I'm also working on a normal-scale 6-string version of the same design. Since I didn't want to use truss rods, I looked up young's modulus on a bunch of wood species to figure out how to make a very stiff neck. I already glued up a neck blank for the 6-stringer out of hickory, with some walnut veneer.

spread the layers
Hickory is kind of a sleeper. It's much harder and stiffer than just about any other North-American hardwood, but not extremely expensive or flashy. Yesterday, I finally swallowed my fear and glued up the other neck blank. This one, for the over-the-top 7-string version, is made from cocobolo (center) and ebony (sides) with walnut and maple veneer layers. This kind of combination of exotics would probably look awful and be ridiculously costly in furniture, but for a guitar, I find it to be neither. Guitars are supposed to be weird.

The Ebony pieces I had were still a little rought from when I hand-ripped them, so I jointed them. A freshly honed 50-degree iron in my bevel-up-jointer did the trick. Very thin shavings were necessary to keep it moving at a reasonable pace through this dense stuff. After the planing, I aligned the wood, taped the flat side, opened it like a book, and temporarily removed the veneer. Taping along one edge is a great way to save time in face gluing, and I needed all the time savings I could get. In retrospect, I should have used several strips across the layers instead of one lengthwise. I used gorilla glue, which expands. Leaving the glue nowhere to escape on one side meant it kept trying to push the veneer out the other side.

wiped off some color
Supposedly cocobolo isn't very good at accepting glue, and I wouldn't be surprised if the same is true of the ebony, as dense as it is. I tried something I read about and wiped the faces down with acetone to remove oils from the surface. It also wiped off some of the color.

Next up, more procrastination. But just a little. I was about to glue up 9 layers of wood in one session. That means spreading glue on 18 surfaces and getting everything aligned accurately, and doing it all really fast. I'm not really sure what the open time is for gorilla glue, but I don't think it's a lot. So I paused and asked myself if this is really what I wanted to do. Maybe it would be safer to break it up into a couple of gluing sessions? I decided to just go for it. What the heck, you only live once.
the right glue spreader is KEY.

I misted the surfaces with water, because apparently that makes gorilla glue work better. Then I got my glue spreader and started working fast.

spreading glue like the wind.
As I went, the veneer started escaping, being pushed by the expanding glue. Eventually I had to get my hands messy, rip some tape off the back and start clamping in a hurry before the veneer moved again. Then I thought about how I wanted the glue lines to look (not full of bubbles), and applied every clamp I possibly could.

my first look at the results
A couple hours later, after the glue was dry but not petrified, I returned to clean up the excess foam and take a look at the results. Getting it all off took some effort, but luckily the glue lines were tight and invisible. Once I hacked off the large chunks with a knife, I used a block plane and a chisel to clean it up a little more.

It was all worth it. Well, maybe not the procrastination.
This part made it all worthwile. Seeing shavings with veneer stripes included was incredibly satisfying.

I think you can expect to see more on this project in the near future. This little success has got me jazzed about the project. Also, since I had the idea to build these guitars a couple of years ago, I've gotten a lot more comfortable with things like sawing to a line. Now that I imagine the next step, cutting off a piece to use for the headstock, I realize I'm not even too scared to do it. Hooray!

Step-by-step drawings
Speaking of procrastination and being too scared to work, one positive thing did come out it. While I was having trouble imagining the order of operations for building the neck, I solved the problem by drawing out the steps. Drawing helps me think and it's probably underrated. I'm talking pencil and paper, by the way. It's graph paper for me.

2X each: bridges, neck blanks, fingerboard blanks

Monday, May 21, 2012

Shuttle for mother's day

I enjoyed practicing subtle shaping & surfacing.
Here's a gift I made a few days ago for my mother. (late because I got food poisoning on mother's day). This project is 100% joinery-free and is all about surfacing. This is a giant version of a style of weaving shuttle that is normally used on small inkle looms. Yarn is wound between the two holes. in addition to shuttling the weft from side to side, it also acts as a beater-bar, packing the yarn into position with the shorter, thinner edge of the shuttle. This is the second oddly-sized shuttle I've made for my mom. I figure if I make odd sizes of things, I won't be getting her something she already has. I was also drawn to the elegantly simple utility of this style of shuttle.
The finish is drying in this shot.

I started with 1/4" x 24" x ~3" piece of padauk that I had lying around after deciding not to use it in a guitar neck. I drilled a couple of holes with an auger bit on a drill press (carfully!). It would have been better if I had a forstner bit big enough, but I didn't. I pre-drilled a 1/4" hole through the workpiece and the backing board to disable the drive screw first. This prevents the auger bit from pulling the chuch right off the drill press. It also prevents splitting the board.

I used a cambered jack plane to get one side thinner than the other, then try-planed both faces. various tools aided in smoothing out every edge and corner. I used card scrapers a lot also. A curved goose-neck scraper was instrumental in leaving a slight groove between the two holes (too subtle to photograph, but it is obvious when you feel it with your thumb.

Note that the thickness is not constant. The shaving on top was the only way I could get my cell-phone camera to focus.


In a recent post, I had some unkind words about my WoodRiver #5 jack plane, so I think it's only fair that I provide an update now that it's been fixed.

whole again
The yoke changed color
Apparently I had purchased version 2 of the plane. Woodcraft has since come out with V3, to fix the brittle yoke issue I ran into. I called my local woodcraft store looking to return the plane. After a short goose-chase, I was talking to customer service, who readily agreed to send me a steel yoke from the new version.

It installed easily, and just like that, the plane worked again. What a relief! Now I can take advantage of the iron I finally cambered.

The camber is visible here. It's an imprecise 8" radius, iirc.
Now I'm taking nice, thick shavings again, and I'm happy. It seems WoodCraft has good customer service and makes quite a servicable jack plane.

Friday, May 11, 2012

Large excuse to practice

Matt keeping it square, and keeping it from crashing to the floor.
Recently that I've made an effort to develop my woodworking skills. I've got several ambitious projects in the works with little room for error. And that's why I'm about to sing the praises of simple, quick projects. I'll take any excuse to practice.

My friend Matt approached me about helping him build a cat-tree recently, and we knocked out the main structure in a couple of short work-days. The one being replaced had a structure of cardboard, plastic, and termit-barf. It was designed to last for 3 months. We decided to build something that would last at least 3 years, so we decided to use metal and termite food instead.  Since it's all going to be covered in rope and carpet though, we had a lot of leeway. Solid but rough was the goal for the project.

It doesn't look much like a tree.
But solid, precise and fast is the goal of the practice. This is a perfect change to get a lot of practice. For most of the cuts, we marked them square and cut to two lines with a hand-saw--quickly. We both improved our skill & confidence with a saw without having to resort to marking 100 lines on one practice board (a wonderful method of practice, no doubt, but not one that yields a useful object).

We also tried using paraffin on the screws at one point when we needed to be quiet near a sleeping baby. Not wanting to make electric-motor-sounds, or loud screw threads squeaking, we twisted the screws past a hand-held chunk of former candle, then pushed them home with my Yankee screwdriver. This was mostly fast and quiet, but occasionally neither.

Being a cat must be fun.
In addition to driving screws and sawing wood, this was also a perfectly good opportunity to practice all sorts of simpler skills: Wood selection, screw staggering, alignment/measuring, squaring/structure, efficient work sharing, etc.

Also, getting something as large as this done in a short time is very satisfying, no matter how simple.

I guess I'm coming around to the conclusion that rough projects are very relevant to fine woodworking, if approached with some of the same care. Also, try doing the quick and dirty version of a new skill, and see how bad it really is. I find that it demystifies processes and removes the temptation to procrastinate before eventually doing something the "right" way.

I expect you will see more simple projects from me in the near future as I get all the practice I can.

Wednesday, May 2, 2012

Glue joint test

A single shaving that comes from both halves of a glue joint always makes me feel good about the joint itself.

This picture comes from yet another night of smoothing surfaces of the plant bench.