Playing with color

Spent some time this morning playing with dye colors and trying them out on some wood samples. I had gotten some guitar spruce top "rejects" to use as stain samples as well as some pieces of maple. I sanded them "through the grits" all the way up to 220 and then applied a wash coat of shellac to one piece each of maple and spruce. Sarah was most helpful in mixing colors. She has a very good sense for these types of things.

The dye is power from LMII, dissolved in denatured alcohol. The shellac-covered wood shows more defined figure and at the same time has less blotching than the bare wood. I will be applying finish to the stained woo, to see what the final effect is

In the meantime here is a photo from today's color session

in the white

Here is the mandolin "in the white". I still need to do final sanding and finish work on it, but otherwise it is functionally complete.


The tuners have been changed yet again. My first "upgrade" to Ping tuners did not yield all that much improvement. Not only did the Pings slip and and have to much play, but the edges of the string holes (in the posts) were actually sharp - sharp enough to cut and break more than one string!! I ended up ditching them and getting a set of Grover tuners from International Violin. They work perfectly and look very nice as well. I will have more close ups of the headstock and tuners once I complete the finish work

fitting the bridge

I had bought an ebony bridge to replace the one that came with the kit. A good tight fit of the bridge against the contour of the mandolin top is critical for extracting maximum sound. I used a piece of sandpaper on the top and ran the bridge across it to develop the right contour. In order to help the bridge stay upright during the sanding, and not lean over, I created a simple "wagon" jig as you can see in the photos. The bottom part of the bridge screws into the jig and then you have a much wider base to run along the top. Again - this was home made. Better jigs are available through StewMac but I had to slow down the acquisition of specialized tools, at least temporarily. There is also some degree of satisfaction in making your own tools, so I was not exactly heartbroken either. By the way, the black block in the back of the jig is a piece of closed-cell foam that I stole from my kayak outfitting materials. It cuts easily, stiff enough, and glues very well. It would have been better to have a small wheel there, but this was ok.

The photos show the jig but also show the beginning of the sanding, where it's quite clear that only a small part of the bridge is coming in contact with the top. The sanding is done when you can see a full mark on the sandpaper, or when your own mark on the bridge is sanded off.

setup

Once I took a close look at the frets, I realized that they were uneven in height. Using a few small straight pieces of aluminum, I was able to find the high frets. There were several of them along the neck. This needed to be corrected by sanding them flat and then crowning the tops and polishing them. For the sanding I used another sanding "stick" which I made out of a very flat angle aluminum. I cemented a piece of sandpaper onto it, as you can see below.



The flattening process was quick but it left the top of the frets quite scratched. Next time I think I'll use finer grit sandpaper even it it takes longer to flatten. To re-form the round tops of the frets I decided to use a simple triangular mill file. These are common and very inexpensive compared with the specialized crowning files on the market. However, I needed to modify the file so that the long edges would not harm the fretboard. To do that, I used the Dremel tool to grind the edges smooth. This made my tool into a safe-file as shown in the next photo.


I surrounded each fret with masking tape for the filing and then used the Dremel tool with a polishing wheel + compound to get the file scratches out as much as possible. This worked very well. I'm constatly finding new uses for the Dremel.



A big part of the setup was the making of the nut. My camera malfunctioned during that time so unfortunately I have no photos to show.

closing the box

I have fallen behind on updating the blog. It's time to catch up and document what has been achieved in recent months. In spite of me acting as the world's slowest builder (not by choice...) I am close to completing the mandolin. The mandolin was officially born on February 7th, 2009. To me, this means that on that date it became functionally complete, albeit without the finish. I will post a photo of it's current state in next posting. For now, let's go over what's been done since I've left off

First, let me address my neck angle worries which I stressed over in the last posting. Although I suspect the angle is not ideal, I was able to get decent string action by cutting down the bottom of the bridge saddle to facilitate lowing it. Problem solved = major sigh of relief!

Going back in time - gluing in the lining was fairly straight forward. The kit came in with a solid thin strip for lining, rather then the more common kerf lining. I needed a lot of small clamps, and ended up using everything I had, including wooden clothes line clips with a rubber band reinforcement for extra clamping power. It worked just fine. No need to always buy specialized tools!



Once the glue dried, I continued to flatten the entire edge of the ribs/lining area so that the back plate would sit flush on it without rocking. I feared that clamping the back onto a non-flat area would induce twist in the body. In order to flatten the edge, I created a long sanding stick by taking a flat piece of wood and gluing sandpaper to it with some pray adhesive. This sanding stick method is very useful for various operations.



The big moment of closing the box came next. I approaches the task with a mixture of excitement and apprehension. The back plate was within may be 1mm of the width of the body, so aligning it for gluing was crucial. The glue would make the join slippery and every clamp would pull the back a little this or that way. The solution was a locator pin, pre-installed on the tail block. At least one end wouldbe anchored in place. I could not use a locator pin in in the neck block because , again, the precision needed in alignment. So this was a good enough compromise. I used a...wooden toothpick as the pin and drilled a hole for it in the tail block. Once it was glued in, I cut it short and put a little black marker ink on it to transfer the location to the top plate. I then drilled a shallow hole in the top plate and made sure I had a snug and perfect fit. By the way, the photo below also shows another problem with this kit. The ribs (which came pre-glued to the block) were done....less then perectly...and a visible gap is evident. Luckily most of it would be hidden behind the tailpiece. Same for the gap in the binding. No worries.


Gluing the back on took some fast and careful alignment, before the glue had a chance to set. It's really true what they say - you can never have too many clamps! I used them all - cam clamps. small F clamps, a dozen violin spool clamps. Wherever extra protection was needed, I used some leather scraps to avoid denting the wood. I love this shot. So....industrial.