My wood is here!

I ordered some wood to do these two violins. I have the two violas that both need to be thinned and glued up, but the starting is always more fun than fixing up some mistake; the vile purfling. The wood came yesterday, about 15 minutes before I had to go to work. I had time to take it out of the boxes, and stack it up in the basement. I don't think the dry upstairs would be good for it just yet.

I ordered my wood from Orcas Island Tonewood http://www.rockisland.com/~tonewoods. I bought the wood for the violas (except the cherry back on the Guadagnini) from him, and I like the Sitka with bearclaw. I needed another back, and found on e on his specials page that matches another I bought from him in the last order. He calls it crazy wood. The grain goes all over the place, and the flames are straight in the middle, and angle up on the top, and angle down on the bottom. It's crazy.

I ordered a neck block with good flame to match the other one I've started carving. This block carves like butter, I thought it would be a pain.

I ordered two bellies, and told Bruce what I like: bearclaw, squiggly wavy grain, shimmer, not the normal stuff, and he delivered. Yeah, he delivered. This set will be for the del Gesu,

and the first piece I saw was the split side of a suntanned belly; truthfully, it didn't look like much:

but, then I turned it over and was blown away! Wowzers! It is perfect for the Montagnana, and hopefully it will sing as good as it looks.

Packed in with that box were these:

What the heck could those be for? A lifetime supply of linings? Well, no. I ordered something more:

Cello wood. How is that going to fit on my Black and Decker Workmate? I have that figured out. Woodcraft has a sale on one of their workbenches; you get the cabinet free. It isn't a huge, really solid bench with 4X4 legs, and dovetail joints; but it is way more than a Workmate. We were going to pick it up on Saturday, and then we realized the sale ends Friday, so we went down there today. They didn't have one in stock, but it is ordered, and will be in Tuesday, or Wednesday next week. That will be another post.

Cutting Out a Neck

I don't have a band saw. I do have a coping saw, and a deep bodied, aluminum fret saw.  I've tried cutting out neck profiles with them, with limited success. I found a new method that works well, and is easy. First I mark a line where the nut and fingerboard meet, all the way around the block. I use spray on adhesive, and glue the pattern of the scroll on both sides, lined up with the line I marked. I put it down about a mm, so the fingerboard plane is proud of the scroll, and the nut can't push on the fingerboard. Then I get my ryobi saw out, and take some cuts until it looks like this.

Then I take a chisel, and whack the waste away. The saw and chisel takes maybe 15 minutes.

Then I get out a cheap, rough rasp, and smooth it out, going right to the line, and trying to keep it square. At this point I used the fret saw to cut some of the throat(?) away.

Then I am at the point where I can mark out the pegbox, and I'm set to cut the mortise.

Total time is about an hour; probably no faster than sawing. It is much easier than using the saw, and with the saw you have to be very careful about the angle you hold it at, you have to keep watching both sides, and an hour of sawing seems like much more work.

I had that worded differently, but SOME people have nothing better to do than to cause problems. 

Thickness patterns

I like the new colored thickness patterns. It is easier to see the colors then read all the numbers and figure out what is going on. But what about when you have two or more different models that you are trying to figure out what the makers plan was? I think I have a good idea.

Instead of real numbers of thicknesses, I chart relative thickness to the rest of the top (or back). I find some sort of calculation that will change a low of 2.2 and a high of 3.4 into a 1-10 range. I assign a color for each number and I have my graph. It is more telling than the thickness graph, but I need a box of crayons! My markers are only 6 colors.

Here are the two violins I am starting on. You can see that the Montagnana is much thinner all around than the del Gesu. But it has a central area from head to toe that is thicker. The average thickness for the del Gesu is about 65% of the range, and the range is quite small; the thickest part is only 50% higher than the thinest. The Montagnana has an average thickness of about 40% of the range, but the range is 2:1. The del Gesu is quite a bit thicker on the upper than the lower bouts, the lower bout is a lot thinner on the treble side, and the upper bout is a fair amount thinker on the treble side.

The Montagnana, besides the thick ridge in the middle, differs mostly in the thin channel. Where the del Gesu channel is about 60% (40-75%) of the range, the Montagnana is only 40% (30-50%) of the range. Ubviolusly they are working with two different concepts. The average thickness of the del Gesu is 3 mm, the Motagnana only 2.1 mm, so that thick ridge must really work.

I did the Montagnana cello as well, to see if it is something that he always did. The thicknesses in the middle by the fingerboard and tailpiece aren't given, but their could be a thicker central band. He uses an even thinner channel (relative to the thickness) and the only difference seems to be the much thicker ceter bout area. But the general thicknessing pattern seems to be the same.

Flattening the Blocks

The next day after the blocks are glued I mark the outline. Then I work to get the ribcage, minus the ribs flat. It is pretty flat on the bottom just by the way the ribs were glued on. The top is fairly flat just by the way they were cut out. But if the surfaces are going all over the place, the glue join to the plates not be as good as it should be. I use a secret weapon.

I guess it's not secret if I tell you, but it is a used up cutoff wheel. We use a couple a month, on average, at work for cutting hardened bars of M2, A9, S7, H13, good hard steel. They are dirt cheap. It think they are only made of some kind of rubberized clay and diamond dust. They start out maybe 2 foot diameter, and when they get about half that they are too small to use, the wheel won't make it through the stock, the vise gets in the way. So we throw them away. They work great for sharpening stuff, and are much easier, and faster to use for this task than sandpaper.

I lay the wheel down on my glass top, and start with the bottom where the back will glue on. I rub it in a figure eight pattern, and switch it end to end, so I don't get it tapered. I work a little, and then check the pencil lines, and see where the blocks are being cut. Usually on the bottom it doesn't take long before it is smooth and flat. You can watch the progression as the pencil lines wear away.

On the other side it is flat from the bottom block to the top corners, so I do the same for that side as I did for the others. I may find that one block is too high, so I'll file it down, because files work best on the end grain. When I get it satisfactory, it is time to get the top half of the upper block. That is easy to do with the diamond wheel. Just rub it sideways on the wheel, pushing down on the upper block area, and letting the other side rest on the edge of the upper corner blocks. Here is where you might need a file to start the taper on the block. Soon that will be done, and it is ready to be marked up again.

This one ended up 1-3 tenths of a mmm short from the upper corner down, and maybe a couple tenths high at the neck. Close enough. I may glue a little strip on one corner near the inside where about 3 mm didn't clean up.

When marking the outline it is best to have a centerline drawn on both side, and the ends of the end blocks. Then no matter if your holes are off slightly, you can be assured that the outline at least started out somewhat symmetrical. This pattern has a top hole that is oval, and the bottom hole through the mould is drilled on an angle to the side, must have had chips under it. But with the lines drawn I got them in the right place.

Starting the Ribcage

I really don't like planing a lot of wood off the end blocks, and corner blocks. I saw them close to finish length, and plane/scrape them flat. I check to be sure the gluing surface is square with both the top and bottom, especially the bottom, and get the glue ready. I'll have to do this in the dining room. The light is bright, and it is warm. The basement is not.

I have some metal blocks that I use to set the mould on so that the blocks are glued so they stick up about the same on both sides. Since most models have a taper somewhere on the top, this should be considered. The del Gesu is 30 mm thick from the bottom to the top corner, then it drops to 28 mm. My mould is 1/2" MDF. I like MDF. It is nicer than plywood, and much nicer than that smelly chipboard I make the other mould from. If it was 30 mm straight across, 8.7 mm blocks would get the mould centered perfectly. If the block were that high, the space above the upper block would only be 6.6 mm. That doesn't give you any room to put the liners on. The blocks I have now are 8.8 mm. I guess I only have 6.5 mm, unless I can find something else. They will work fine for the Montagnana, it is a straight taper from head to toe from 31 to 28 mm, but the chipboard is only 10 mm thick. They may even be a little short for that.

I found three 5/16 tool bits, so I'll use them. That way I gain .9 mm. Make sure to check that the corner blocks are positioned so that they have stock on them, or you will have to move them later. Everything checked it is time to glue. It doesn't take more than a few minutes.

I usually use my bench downstairs. I put a glass top on it from an aquarium that broke, and it make a great surface for glue ups and varnishing. Every mess is easy to clean up, and the surface is flat, and smooth. If you are glueing on the dining room table I suggest poster board like I used.

Moulds for the 2 violins

I finished the moulds for the 2 violins. I make a half template, and put two holes in it with a 3/16 drill. I drill matching holes in the mould body, 10 mm MDF for the del Gesu, and some 12 mm board I picked out of the trash at work. It has a horrible smell like Harbor Freight, (must be the cheap chipboard), but maybe it will go away. With the template you can get the mould fairly symmetrical. Both of these violins are the most symmetrical of any I have posters for, and both are off only a little on the lower bout, and a corner or two are off very slightly. Quite unbelievable.

The template can then be used to mark off the corner and end blocks.

I used the one I cut for the Plowden, and never got around to. I had to trim it a lot. Now it fits the Plowden right too. What was I thinking? Checking with the poster photo of the back is the best way to get them right. Probably most are too big.

I cut a couple of the notches out too big before. Again what was I thinking? So I decided to glue 5 mm plywood pieces in as glue pads. That should work better for gluing than directly on to the MDF. On the other one, I decided to glue the 5 mm plywood strips on the top and bottom of the notches, and just glue to them, and not directly on the mold. I usually (always) end up gluing little blocks to the top just like that anyway. That should work good.

Do any of those ideas seem good?

While looking for something to make a template for the Montagnana, I saw this Bergonzi one that I used on the first one I made. It fits the Montagnana almost exactly! The c bout is flatter, and not as deep, the corners are very slightly different, and the ends are slightly rounder, and not as square looking. But just looking at them, the differences are hard to see.