Finished Binding and Trimming the Bridge

Sunday, August 30, 2009

I haven’t spent a lot of time on this project for the last few weeks - spending more time with family and work instead - so I have also been lax in updating this blog. But I have made some progress.

I strung up the mandolin and fully tuned it and, much to my pleasant surprise, the top did not collapse or even make any cracking noises, for that matter (as you may recall, I was worried about this since I managed to make my soundboard way too thin at the base and had to reinforce it). But while there was good news about the soundboard, there was also not-so-good news elsewhere; the action (distance from the strings to the fretboard) was WAY too high. Looking at it (sorry - no photos) you would have thought I hadn’t even tried to get it right. That was pretty disappointing. But I figured out how to handle it (I hope).

The bridge that I bought is made of two halves; the lower half that makes contact with the soundboard and the upper half that the strings rest upon. The two halves are then held together (and spaced apart in an adjustable fashion) by two thumbscrews. By cutting down the thickness of each of these two halves, I brought the action down to what I believe will be a workable distance.

In this photo, you can see the mark on the upper half of the bridge where I then trimmed to - a lot of material to take off, I know! Similarly, I took off about half that much material from the lower piece. After trimming, I held a long straight edge between the nut and the bridge assembly and I think the height is just about right. I will have to wait until I string it up again to see for sure. I also have yet to shape the base of the bridge to the soundboard. That will reduce the height a even more.

Aside from the bridge work, I also managed to finish gluing on the remainder of my binding and then trim it to height and width. The final pieces were on the peghead and this is how it looks now.


I still have to do some fill-in work around the binding similar to what I did with the inlay and then a bunch of sanding, but I think it came out alright for my first attempt. Next time I intend to do several things differently (shape and bind the peghead veneer before gluing them in place, for starters) so that one should look much better.

With those completed, it has become time to get my finished sanding done in preparation for staining. I haven’t yet stained my second trial soundboard but after the results I got on my first trial, you can bet I will do the second before committing the mandolin itself to this.

Binding the Soundboard and Installing the Fretboard

Sunday, July 12, 2009

Progress this week was hampered a little bit by a couple things - a short business trip that kept me away for a couple of nights and my most recent order from Stew-Mac is being held with one item on back order. Consequently, about all I was able to accomplish was gluing on some of the binding, attaching the fretboard extension, and gluing on the fretboard.

I finished up last weekend by hand carving the remainder of the grooves for the bindings and then, this week, I shaped and glued the binding around most of the soundboard. Rather than attempting to shape this binding with the heat gun like I did for the fretboard, this time I chose to use a similar to the one I now use to heat my hide glue - hot water. Since the temperature of water does not have to reach boiling to soften the binding, the likelihood of burning oneself and the binding is pretty slim and it is also easier to fine-tune the shape since all you have to do is dip the specific section into the water. I will probably drop the heat gun method now that I know how easy water is to use.

This picture shows the binding being glued on to the outer ring of the scroll. I have used painters tape to hold it and have chosen to glue the scroll first while leaving the body free. This allowed me to focus all my attention on getting the scroll binding tight without having to worry about the body, too. I came back later, after the scroll binding was dry, to glue the remainder of the body binding on.

Next, having run out of binding to glue (I did not order enough to do both the front, back, peghead, and fretboard and the rest is coming in the back-order I mentioned before) I chose to move on to installing the fretboard extension. A couple of weeks ago while waiting for my inlay glue to dry, I spent time making the fretboard extension fit with the soundboard. This meant a good deal of scraping and sanding on the soundboard and the extension itself, but eventually I got the two to fit pretty well. So now, having installed a short strip of binding in between for cosmetics, it was time for gluing

To securely hold the extension while the glue dried, I drilled a hole through it and into the head-block. The screw, being on an angle as it is, creates force both down and back toward the neck. For glue, I used Tite-bond on the base and weld-on cement in the joint that mates with the binding.

After allowing the glue to dry over night, it was time to level the extension with the neck. Checking regularly with a straight edge, I sanded the extension until the two were level.


Finally, I glued the fretboard on. Once again, because it is a relatively normal practice to have to remove or replace a fretboard, I used hot hide-glue for this job. I left approximately a 1/8” gap between the fretboard and the peghead for the nut and I hope to be fine tuning this gap to size and cutting the nut to fit this week.

Inlay and Routing for Binding

Friday, July 03, 2009

Well, as I said on Monday, I have been able to spend quite a bit of time on the mando this week. For starters, I unclamped the body and am really pleased with the way the back came out. Nice and tight and no apparent gaps. Although I said I was planning to use the belt sander to cut down the edges of the top and bottom to match the sides, I chose instead to use my Dremel with a sanding drum attachment instead. This worked really well and I felt a lot more comfortable that I wasn’t going to take away any more wood than need. With that done, it was time to install the point protectors.

Point protectors, if you did not already know, are hard plastic tips that are glued on to the two body points to help minimize damage. The plastic, as I ordered it, comes as a rectangular block that must be shaped to fit. Mr. Siminoff suggests shaping them first, and then gluing them on, but I decided to do it the other way around - glue first, shape in place. Here is how they looked before, during, and after shaping.



For the last couple of days have been focused on cutting out and installing the inlay work on the peghead and then preparing for the installation of the binding around the body. Because this build has taken so much time and I have come to the conclusion the value is minimal, like the ivy carving on the scroll, I have now decided not to do the ivy inlay on the fretboard. Instead, I will simply put my name on the peghead.

From what I have read, the way to go about installing inlays is to cut out the inlay material first (Mother of Pearl, or MOP), use it to trace the outline onto the wood, route out the pattern and, finally, glue it in place. So to start, I printed out a full-scale copy of my pattern and glued it directly to the MOP. Once the glue was dry it was time to start cutting.

It seems that most of the information I could freely find on the web indicates that most people use hand-held coping saws to cut out their MOP inlays, so that is what I figured I would do. To begin, though, I needed a working platform on which I could rest the part while cutting but one that would allow as much motion as possible. For this, I took a scrap piece of 3/4” plywood, cut out a slot with a hole in the center and a tongue that I could clamp in my vice. Here is what it looks like.

I have no idea what those other people use for a saw blade for cutting this stuff, but the saw blade I tried (finest I have) would hardly make a dent in it and the teeth would catch on the material every stroke. I abandoned the coping saw and moved to a cutting wheel on my Dremel. Much better (and quicker).

Now before anyone can jump on this, let me point out that I already knew that breathing MOP dust is bad for ones health so I was sure to wear a good dust mask while cutting. I also rigged up my shop-vac to suck away as much of the dust as possible.

Once I had cut away as much as I could reach with my cutting wheel, I still had some pretty major areas (and some really small, remote ones) that I couldn’t reach with anything I had on hand. I ended up making a run to the hardware store to purchase both a very fine cutting bit for the MOP and a small router bit for later when it came time to route the mating shape in the peghead. Both bits are for the Dremel.

Here I am using the fine cutting bit - also quite time consuming but well worth it.

And here I am cleaning up the finished shape with my jeweler’s files.

Once I was satisfied that the shape was ready, I located my desired position on the peghead, clamped a bottom guide in place (the blade from a small hand-plane, in this case) and traced the shape with a mechanical pencil.

Using the jig I made for cutting my dovetail as a support for the peghead, I clamped the neck to the jig and the jig in the vice in preparation for routing. I attached my Stew-Mac routing base and new bit to my Dremel, I carefully routed out as much of the shape as I could.

Even though the routing took out the vast majority of wood, there was still a fair amount it couldn’t reach. For this I reverted once again to my carving tools and jeweler’s files.

Of course as I carved and filed I would regularly check my fit against the MOP shape. What I found was that regardless of how careful I tried to be, working with the ebony wood made it really difficult to find the high spots and occasional point I had not yet notched. As a result, the cut-out ended up being quite tight in some places and much too wide in others. Here is how it looked before I glued it in.

One of the techniques that Mr. Siminoff shares in his book is that the gluing in process and gap filling process are one-in-the-same. What you do is to mix fine ebony wood dust with white glue (Titebond, in my case) until you have a very dark, almost black, mixture.

Then, using a small trowel, fill the cut-out with the glue mix and gently press the MOP into the cutout until it is fully inserted. Leave the extra glue which will shrink and suck in to where it is needed.

Once everything is dry, scrape and sand smooth.

I ended up having to add extra glue mix to fill in some gaps where I had not left enough extra the first time. Overall, though, I am quite pleased with the way it turned out.

Finally, then, I got started routing and carving the body for the binding. For this I used a router bit and binding router guide, both from Stew-Mac.

I read that this is a very delicate operation and that it was really easy to mess up, so I took extra precaution and I am glad I did. You really need to pay attention to your wood grain, router bit speed, and feed direction when doing this operation. I found that the most important thing was the feed direction. As long as I made sure to feed opposite the direction of the bit (so that I was trying to run over my chips), the tool never tried to get away from me. On the couple of times I tried it the other way, it jumped and pulled away (fortunately without causing any irreparable damage). As with the routing the peghead, there were, naturally, places I couldn’t reach with the router bit. For these, I am having to cut out by hand. That’s where I am right now.

Installing Fretboard Binding and Frets

Sunday, June 28, 2009.

This week was dedicated to binding the fretboard and then installing the frets. I know it doesn’t sound like much, but these two steps took an unexpectedly long time (true for a novice like me, I am sure, less I suspect once you have done it a few times).

After having completed cutting my fret slots, my next step was to bend and install the binding on the fretboard. The binding I bought is a white plastic strip that measures .060" thick x .250" wide. Being stiff and relatively brittle, the first step is to shape it to the contours of the fretboard and then glue it in place. Shaping is done with heat and the recommended glue to attach it to the ebony fretboard is weld-on cement.

During my research, I read several stories by folks who, using heat-guns to shape their binding, had overheated it and “turned it to ash”. This is good to know since I already have a heat-gun and it is the method I chose to use. Other heating methods include boiling water and hot sand or glass beads and I will probably try the boiling water method when it comes time to shape the binding for the body, but for this, I used the heat gun.

At the base of the fretboard there are several relatively sharp curves around which I needed to be quite sure that my bends were accurate, especially with respect to each other. To accomplish this, I made a small jig out of some scrap wood and drill bits.

To make this, I traced the outline of my fretboard onto the wood and then found appropriately sized drill bits that roughly matched the inside diameter of each of the bends. As you can see, I drilled the holes and then used the bits themselves as my “posts” to bend the binding around (these photos are of my first attempt at this jig where I tried to use a rod in one location rather than a drill bit - it didn’t work out so well, so I ended up making another jig). By holding the binding between the bits and then carefully applying heat, it was pretty easy to get the curves where I needed them.


Because I have a sharp corner at the base of the fretboard, I made my binding from two pieces. If you have a different contour for yours, you might want to make this from a single piece of binding. Using weld-on cement from Stew-Mac, I glued my first piece to the fretboard and held it with a combination of spring clamps and C-clamps.

Gluing turned out to be a less than perfect operation. It seems that the cement needs to be applied relatively heavy and then dries pretty quickly. I did not expect this and was not as speedy when applying my clamps as I should have. Consequently I ended up having to re-glue several places. Once I did, though, it seems to hold well.

In the second photo above, you can also see a shiny spot where the glue got on the surface of the fretboard. When this happened, I was worried that it might damage the wood or cause a stain but this turns out to not be the case. Once everything dried (24 hours) and I scraped the binding down to the thickness of the fretboard, the glue scraped right off.

Time to install the frets.

Fretwire seems to come generally in two forms - long rolls and short, straight sections. If you are a serious builder looking to make many instruments, it probably makes sense to buy your fretwire in bulk, or roll form. If you are only making one or two, like me right now, it makes sense to buy just what you need. So I bought two lengths of straight sections.

Now one of the things I read, written repeatedly by various luthiers, is that it is best to curve or arch the fret wire a little bit so that when installing it, the ends make contact before the center. This is to prevent the ends from popping out again after they are installed. Apparently this is relatively common when the wire is not arched but not so much if it is. So, wanting to do this, I looked for a way to do it. As it turns out, you can bend it by hand (the method I ended up using), cut a groove in your workbench and pull the wire through it (similar to the method you might use to curl strips of paper by pulling them down across the edge of a table), or build/buy a bending device from one of the luthier supply houses. Bending by hand, while being pretty easy, was also pretty inconsistent, but I think it worked out well enough for me.

Once I had a gentle curve in the wire, it was time to cut to length. The method I ended up using for the majority of my wires was to hold the wire against the fretboard and, using a standard set of side cutters, cut the wire as closely as possible to the edge of the fretboard. This method allows the wires to hang most of the way over the binding when installed.


Obviously, since the binding itself does not have slots cut in it, I needed to trim the “tang” on the wire at both ends. To do this, I used a grinding disk on my Dremel to cut away about 1/8” of the tang.

Then it was a simple case of hammering the frets into the slots on the fretboard. For this I used a hard plastic mallet while holding the fretboard back against the anvil section of my vice. To aid with the ends-before-center idea of the curved fretwire, I tapped in both ends first before tapping in the center. Here is what it looked like after installing the first three frets.

I don’t really like the look of the first two fret wires so I decided going to replace them but figured I better wait until all the other frets were installed before doing that.


Here it is after all the wires were installed. I do have some extra wire left so I will be replacing those first two frets.


And, finally, here is what I did toward making the fretboard extension. It is made from a scrap piece of maple and will be attached at the base of the neck under the fretboard for extra support.


As you can see from this picture, something is not quite right. I suspect that the soundboard is too thick right below where the extension makes contact so my current thought is to scrape and sand it lower and then, where needed, trim the extension to match.

With the fretboard laying on the neck and the nut (yet to be shaped) in place for spacing, it looks and feels pretty good. It even appears that the 15th fret is pretty much aligned with the break line where the neck and body meet as it should.

As I looked at this side view for the first time, I was concerned with the gap between the neck and the back of the fretboard. Having laid the two together before, I did not find the gap then, but now I do. Then it occurred to me - the difference is the frets. With them installed, there are 30 small “wedges” forcing the top surface apart and, therefore, causing it to bow. Once I have it glued on the neck and fretboard extension, this should straighten right out. It also lets me know that I don’t want to do any form of fret leveling until then, either.