Headstock design

I'm going to take a break from the binding work. The binding problems took a lot of time and mental energy and I could use a change of focus. Working on the aesthetics is a good creative outlet. I've been playing with headstock design for a little while. I make up a bunch of paper headstock templates, soliciting ideas from those around me. We even recruited the kids to take headstock blanks and draw in their ideas. Since I want to cut my own shell and do all the inlay work myself, I want a simple, yet elegant design. This weekend I was looking at some earrings that Sarah had bought as a gift to a relative, and was stuck by an art-deco'ish idea. I replicated the basic shape in a drawing program and printed out various samples to play with. Sarah came up with an interesting arrangement and so far this is my favorite. You can see it in the mock-up photo. It consists of three geometric figures, repeated in a fan-like arrangement, over a single small square "dot". Each figure is made up of two puzzle-like pieces, one of abalone and one of mop.

I spent some time cutting out one figure and working on matching the mop with the abalone pieces. I like the design even better, now that I can see it in real shell pieces.

Challenge: How to get the best fit of two pieces of shell. Although I'm generally pleased with my pieces, they do not match perfectly when put together. I've read about a technique for getting a good match. The idea is that you take both shell pieces and glue them back to back with the full pattern glued on top. By cutting both pieces of shell at once, you have (in theory) a superior match between the pieces. I have prepared a sample like this will be cutting it next. You can see it in the photo, on top of the shell cutting apparatus.

The second photo shows a black paper mock up of the headstock, with the design arranged. some of the pieces are still in white paper but the central piece is the which I cut today, as well as a small dot. The shell looks beautiful but will be much more striking once it's polished. These are still all practice pieces before trying to go for the real thing.

The plan now is to cut one more figure and then start practicing routing a cavity for the inlay on some scrap piece.

Back to work

It's been a long time since my last posting, indicative of the severe lack of time during the past 6 months. Restored sanity in my (work) life is allowing me to resume work on my mandolin.

It feels great!!

3D Sander

Someone on mandolincafe alerted us to a sale on the 3D sander at Sears. I'd been looking at it for some time as it seemed useful for sanding curved surfaces, but have not pulled the trigger. But at $8.99 (instead of $30) how can I go wrong? This is not a high-power sander, but it does have the unique advantage of having three independently-adjusting "heads", kind of like an electric shaver. The floating heads have Velcro on them and you can get small circular sandpaper rings at various grit levels. In addition, you can pull off one or two of the heads and use a single head for getting into tighter places. I think it can be useful for the top and bottom of the mandolin and getting into places like the recurve area.

Top Binding

The top binding has been a struggle. I ended up ripping off the second half of the top binding because it had pulled away in the tight curved area near the neck. My efforts to soften the binding material with hot water (in a pan) were only partly successful. It took a while to clean up the binding channel and prepare it for a second attempt. I knew that hot water was good enough to pre-bend the plastic material but the flat pan that I used cooled off too fast. This time around I poured boiling water into a tall and narrow flower vase and it did the trick! I could dip the binding in the water and watch it "relax" after about 5-10 seconds. It was easy to pull it out and quickly mould it to the mandolin. I wanted to achieve a close fit so that the binding would not spring back when glued.

The second thing that I did differently was glue the binding about 3-4 inches at a time. I was worried about how I would be able to get the glue in to the narrow area where the already-cured and the new parts of the binding met, but decided to try it anyway. It worked much better than I had expected, allowing me to pay close attention to each part with no rushing. A GOOD thing.

The picture shows the first, completed, binding piece on the left. It's been scraped down flush with the top. On the right side is the new binding, with the "bandages" removed. It's ticking up from the top but that's ok. It will end up flush just like the other one.

New Veneer

I had ordered two quality face plates to replace the paper-thin one that came already-installed on the peg head. I took a while to decide between the rosewood and the ebony but I decided to go with the ebony plate for this mandolin. Preparing to glue the plate on the headstock, I cut out a notch to reveal the access channel to the truss rod. This was easy to cut with a small dovetail saw. A firm blow on a 1/4" chisel left a clean opening, which you can see in the photo. hey - I had to find a use to the wooden mallet I had bought. Very satisfying :) It's not important to have the cut looking perfect since it will be hidden by the truss-rod cover.

I also decided not to use the plastic nut that came with the kit. For a very small price, I got a nice bone blank and will be able to custom fit it in. I used the blank to space the ebony plate away from the fingerboard, and glued on the plate. Trying to clamp the plate on, I found it fishing around too much. Next time I will consider installing two small wooden locating pins to help with the position. As you can see from the photo, one can never have too many clamps. I used as many clamps as I could to ensure a solid fit. Once it dries, I will have to cut out the tuning peg holes. They are already drilled in the headstock but not in the face plate. Any additional shaping of the headstock will be done at one shot, including the face plate to ensure a nice finish.

re-working the binding

The first attempt at binding the top did not go too well. When I removed the "bandages", I found out that some of the binding pulled away from the body and the seam where the binding meets the sides was not clean either. I pulled off the binding and went about making corrections to my method.

The first thing I did was use hot water to pre-bend the ABS binding to be almost perfectly aligned with the body. The idea was to remove most of the resistance that the plastic has and require much less force to hold it against the body as the glue sets.

The second thing I did was more detailed cleaning of the routed binding area, to improve the seam with the sides.

The result - a much better fit. I am happy with how tight the binding hugs the top. The interface between the wood and the binding, on the side, could still be better but I will keep this one and plan to improve as I put additional binding on.

I scraped the binding flush against the top and sanded the side wood to meet the binding.

By the way - the clamp that you see in the picture has nothing to do with the binding. The kit came with one of the sides not completely glued to the neck block. I just glued it back and it's being held tight to dry with a cam clamp.

Binding the top

The kit came with white binding material for the top only. Since I wanted to bind the back as well, I needed additional binding. The white binding was ok but I wanted to try something a little more interesting and so I bought some striped (wbwb) abs binding from LMII. This binding is thicker than the one that came with the kit and so, the routed area in the top of the mandolin would have to be deepened. I've been thinking about this operation for a while. If not done well, the results would be very evident. An uneven ledge would show gaps. If the ledge is too shallow, then sanding/scraping the binding would show up as uneven stripes. Better make the groove a little deeper than needed but not too deep. The sides can be sanded down a bit to meet the binding.

Since the IV kit comes with the sides already attached to the top, it's not easy to clamp the mandolin in various positions. I needed to hold it with side pointing up so that I can run the router around the edge. In order not to break the (unsupported) side piece, I used a piece of heavy close-cell foam, borrowed from my kayak outfitting. You can see it in the photo. This kind of foam is stiff enough and cuts very well using a saw.

I used the Dremel tool with the binding routing attachment, as I did on my straight test piece in the previous posting. There were two potential problems with this tool. First - it's not easy to hold it straight and steady. Small movements can cause the Dremel to dig deeper into the top. It turns out that I could not hold it as steady as I wanted and wound up spending a lot of time fixing an uneven ledge. It's not as nice as I was hoping but - hey - it's my first time. Second - I didn't want to damage the nice straight routed edge on the sides. I decided to set the router to a shorter distance than the actual ledge. This kept the blade away from the "factory" edge. The price was much extra work cleaning out the remaining un-carved piece inside the routed area. I think this was worth the effort. The photo shows a section of the groove after enlarging it. You can see how much deeper I need it to be, compared with the original. A little while ago I bought a cheap set of needle files, in various shapes. They came in very handy today when I needed to clean up the inside of the routed groove.

One the enlarged ledge was clean, I had to figure out how to bend the binding into the tight curve near the neck joint. The binding is somewhat flexible but could not be bent to the small radius that's called for near the neck. I tried using a hair drier to heat up the binding but could not get enough focused heat. I then tried hot water and got much better results. Pre-bending the binding would mean a lot less stress when gluing/taping it on.

Although the binding pieces are long enough to do the entire top in one shot, I decided to do it with two pieces, joining at the tail block. That joint will be covered by the tail piece and so it will be invisible. Binding the top with two pieces has the advantage of pre-bending each side and gluing each piece starting with the tight curves.

The gluing went fast and with no issues. I used lots of painters' blue masking tape - the "delicate" type - to keep the binding attached while curing. Instead of gluing both pieces, I started with one and will see how it works and trims before putting effort into the second piece.

Experimenting with binding

I bought some plastic binding from LMII. The idea is to bind the top and back of the mandolin with a WBWB pattern. The kit came with a white piece of binding, long enough only for the top, some some changes will have to be made. First, the top binding channel (that exits already in the kit) will need be deepened to accept the thicker new binding. Then a channel will have to be cut from scratch on the back, after it's assembled. In the meantime, I decided to experiment a bit with routing, gluing, and trimming this binding.

For cutting a channel, I'm trying to use the StewMac Dremel attachment with routing bit. People have conflicting views on it but I thought I'd give it a try. I can see that one needs a very steady hand to prevent variation in the channel depth. It doesn't take much to rock the router across the edge of the instrument and to cut deeper. I practiced for a while on straight edges of scrap wood, until the channel began to get cleaner and more even.

For gluing, I am using Weld-on 1874 cement. This was recommended by LMII, when I bought the binding. The glue is clear and fairly thin. I applied some to the empty channel and let it sit for a bit to dry. I then applied glue to the binding strip and pressed it into the channel, securing it with strips of masking tape. I don't have the blue painters tape yet so I'm using "standard" office masking tape. It's ok for the scrap piece, which is made of Maple. I'll have to get some blue tape when I deal with the spruce so avoid lifting grain when I remove it. The binding glued on very well and sees to be holding strong.

After a couple of hours I was able to scrape the edge down to the wood. This went very well, using my wood scraper, and left a perfectly clear WBWB pattern against the wood. On the side, the channel was a bit deeper than the binding (on purpose) and I used a sanding block to bring the side down to meet the binding face. I was worried about having sandpaper scratches on the plastic but it turned out to sand very nicely and left a smooth non-glossy face. I'm very pleased with the result.

Carving x braces

I finally got around to carving the braces today. It's been too long between work sessions but I'm grateful for the little time I could put into it today. I understood the main idea of tapering the braces towards the outside of the mandolin and feathering the ends to blend with the top wood. Tool-wise I tried using one of my chisels but gave up on it since it was too long and I could not get it inside the body. Another point against the pre-assembled top/sides unit. Since I don't have a thumb plane (yet) I resorted to a chisel-end craft knife. The handle is short and stubby and fits well in my hand. I sharpened the knife before using it and got fairly decent control over the size of the chips. The big mystery is just how much material to remove? There is no general guideline that I could find. I listened for voices in my head to give me spiritual guidance appropriate for the task but alas - no voices :) I could carve it down to nothing. No clue. What I did was create an even taper from the cross towards the ends and knocked the edges down, sanding it all nice and smooth. At this point, unless I get some new information, I plan to leave it as is and continue.

Feels good to make wood curls again

Removing the headstock veneer

It's been a long while since I worked on my mandolin. Too long. I finally had some today and decided to start working on the headstock. The kit comes with an already-applied veneer. It's very thin. While it's perfectly ok for what it is, I want a more substantial and more interesting veneer.

To remove the veneer. I used a clothing iron and spent time steaming it off. I used a rag in between, to protect the iron. It did not come off easily. I had to scrape some of it off as the glue did not want to give, even with the heat and steam. You can get an idea of how thin the original veneer is, from the picture.




It did eventually release but left a big glue mess to deal with. I tried to sand it off with a low-grit paper (50-80) but it was too gummy and didn't want to release. I used a paint scraper to remove the bulk of it and then applied some mineral spirits.



The solvent method worked the best and the headsotck cleaned up nicely. I then sanded it down by hand with a sanding block. It's looking pretty good for gluing up a new veneer.


Of course - now I need to decide which veneer to use. I have both a nice piece ebony and a rosewood veneer that I had bought from StewMac.

I'll settle on the design first.

I also spent some time today practicing sharpening and honing my chisels. I'm using the ScarySharp method and found it very easy for flattening the back of the chisels. Nice polished mirror finish. However, I could not hold the chisel steady enough when working on the bevel side. I broke down and ordered a honing guide to get me through this step.