The shop was initially cold because it was 21 F outside. Jim brought pecantree wood and I fed the stove. Pretty soon we were toasty. It began to rain. Tonight is supposed to be freezing rain. (Actually, the freezing rain brought down a big tree limb at 2 am and the city crews were working in the night to clear the street.)
Jim brought the steel mould parts for the gouges we intend to make. Nice work Jim. Thanks.
Richard glued the back to the ribs. He put applied glue to both surfaces and let it dry (mostly). Then positioned the back and clamped it. Then, moving around the violin, successively loosened clamps and applied warm water with a palette knife. Next class he will bring a label. I will bring the glair (egg albumin) for coating the inside of the violin.
Jim worked on the back, using finger planes. It is a long process and very tough on the hands. He still has more to do before he cuts the purfling slot.
For my Titian Strad violin, I am looking at curtate cycloids, trying to ensure tthat the contours of the back are correct.
It is cold enough to start the woodstove, which I did. When Jim and Richard arrived, the shop was toasty warm.
Jim started cutting the channel in his back, à la the David Sora video. I soon noticed that I had negelected to tell Jim to finish the outline overhang to 2.7 mm to 3.0 mm. So he spent the evening with sanding sticks doing that chore.
Richard chalk-fitted his bassbar and glued it with the simple clamps I had made. Then he removed his ribs from the mould and began trimming the linings with a 20 mm wide gouge.
I worked a little on the channel of my Titian back.
We had, I thought, very good conversation.
Well, here it is 2015. I love feeding wood to my wood stove. Richard has his plates thicknessed, f-holes cut, purfling installed. Ready to fit bassbar. He's miles ahead of me. Jim is roughing out the outside of the back plate. Jim asked me if I had slowed down, since I had not worked on my violins. That got me thinking, and actually working. I learned something and here it is.
For cutting the channel, I tried to follow Davide Sora's video here. His gouge is razor sharp and cuts maple like butter. I made my copy of his simple marking gauge. Then I went to work with my 13 mm radius gouge, fingernail profile. This is what he specifies in the video (well actually 13.7mm). I found that stropping with chrome oxide will get the gouge sharp enough, but it won't stay sharp for any time at all. I suspect, with Jim's help, I can make a gouge that will work better than the “Swiss Made” one I am using.
What I realized is that channel cutting requires the maker to be in a focussed, but relaxed, state of mind. It is a tension-filled process. The curly wood changes as you go around the bouts. Changes quickly, unexpectedly. You are constantly looking and feeling your way, trying to avoid tear-out of the curly maple. You need to be aware of when the tool is too dull to proceed. This is just not something one can zoom through.
Davide Sora specifies the following:
--With the little marking tool, mark 11 mm in upper and lower
bouts, and 7 mm in C bouts
--use a No. 6 gouge, 13.7mm with a radius of 13 mm. for upper and lower bouts.
– Cut to 1 mm of the border (edge).
--The thickness of the back at the channel is 3.1/3.2 mm, and 3.4/3.5 in the CC's|
--For the CC's, use a No. 7 gouge, 11 mm wide, 7 mm radius
-- For the corners, use a No. 6 gouge, 10.5mm wide, 10 mm radius of curvature.
Good video on “Violinmaking for the Over-60 crowd”.
Beacham says his doctor recommends that he should not be making a violin. Beacham has donated his wood to the next student who signs up. That is Sabrina Malloy. She plans to attend the next class – December 1, 2014. Today I showed violinmaking tools at the Storytelling and Arts Center of the Southeast. We may have another attendee, in addtion to Sabrina, at the next meeting. I need to vacuum the shop.
I used the router to trim the edges of violins 18 and 19. I made the thickness 4.0 mm in the upper and lower bouts. And 4.5 in the C bouts. The plexiglass plate in my router is too flexible. I need to replace it with something stronger. Suggestions welcome. I am off to Pittsburgh this week. See you all on Monday, Dec. 1.
Richard is installing purfling in the back. Jim has installed linings. Beacham will return soon. The shop is cold today. I will try to warm it up a little. Please take a look at this excellent video made by David Sora on cutting the channel. Notes are in Italian, but you get the idea without them. This shows what can be done with a razor sharp gouge that is sharpened in the shape of a fingernail. David Sora cuts the channel to exact shape before cutting the purfling slot. I don't do this.
What happened to my notes between May 19 and now? Busy with grandkids, I think.
Beacham broke his wrist. He has an in
ternal cast, but cannot use his wrist for a good while. I need to call and find out when he can come back to class.
Richard is moving ahead very quickly. He has the ribs installed. He used one piece for the lower ribs. He cut the spruce linings and planed them to shape. I gave him an UN-SHARP block plane, which made it frustrating for him. Sorry about that. Next time he will bend the linings for the backside. I discovered that I can hone the toothed block plane blade on my wet disc grinder, including the back side. When doing the backside, I raise it slightly so there is a backbevel.
Jim worked on the lower set of ribs. They are installed now. For making the butt joint, he used the slotted maple jig. Results are not perfect. I discovered that the surface on the maple block was not flat, which was probably caused by sanding strokes cross-wise, instead of long-wise. I note that here in the hope that if he makes second violin, the mistake will be remedied.
Richard is ahead of me, so I got to work on my ribs. Hopefully I will be able to get my ribs done and linings installed before he does. Whew! What a tiger he is. Incidentally, Richard and Jim, I want to show you how I plane the linings. It is a joy if the blade is sharp.
Richard, as near as I can tell, next meeting you will
Flatten the backside of the ribs using the sandpaper on glass. I did this on mine today.
Work on the back linings. First on the C-bouts. Cut slots in the blocks with the small saw. I will demonstrate. Finish the cut with a file. Bend the linings. Trim to fit. This needs patience and care to get them to fit. After the C-bouts, do the upper and lower bout linings. These are butt-joined to the blocks. The goal is the have no gaps at the butt ends, which I have found tricky. We want the linings to be 7 mm deep after being trimmed down. So this means when you glue them in, they will stand above the rib by maybe 1 mm, is the lining is 8 mm wide.
Did you wax the mold well? This operation will have glue dripping down to the mould. After the linings are cut, glue them in. This requires protecting the outer side of the ribs with thin cardboard or thin leather. I attach these with masking tape. The protection is from dents made by the strong clothespin clamps. These clamps are modified clothespins with a rubber band added to each one. We don't want gaps between the linings and the ribs. Again, a fussy operation. I think the glue should be on the thick side. You don't want to hurry too much and get a sloppy job but taking too much time will allow the glue to cool too much, which we don't want.
Here are some youtube videos I found: Violinmaking Diary 7, cutting mortices, linings, bending linings, Tom Balzamo is an amateur. Brian Lisus is a pro. If we are going to cut blocks like he does here, I need to make a 2 mm wide chisel.
I demonstrated how I bend the ribstock for the C-bouts and use the wood block and clamp to hold it in place at the glue-up.
Jim replaced an end block, sawed his ribs out of the remainder of the back billet, then used the toothed block plane and scraper to thickness the ribstock.
Beacham watched as I pulled his knife from the kiln and quenched it. He then drilled holes in his mould, cleaned up the corners and shellacked it. He also cut bassbar stock from his spruce billet.
Richard glued his blocks and then spent a good amount of time trying to use my “simple” sharpening method on his violin knife on the 15 micron and 5 micron silicon carbide on glass. I guess my method needs some additional work.
I intend to demonstrate bending of the violin ribs for the C-bouts. I practiced this week on my #18. The ribs are 1.0 – 1.1 mm thick. This is the kind of demo that you need to see. You can do it wrong, as I have done, 3 or 4 different ways.
Richard Faulk will bring his oscillating spindle sander. This is very useful in shaping the corner blocks. It can also be used to thickness the ribs. Set-up for that is a small engineering problem however. Not a big one, though.
Richard will glue his corner blocks and possibly begin to join the wood.
Beacham will finish his mould, shellac it. Cut out the corner blocks. Look ahead to joining the wood.
Jim will finish his corner blocks, re-do his end block. Work on cutting his ribstock from the back chunk of wood, or he will use some of mine.
There will be no class on May 26 or June 2, since I will be out of town.
The wood arrived from The Woodwell. Good looking wood. Enough for ribs and neck block as well. Cost is $125 each for Beacham and Richard.
Richard Faulk and Beacham McDougald have joined our group. Beacham has made dulcimers and fretless banjos. Richard has lots of experience in woodworking. I ordered wood for them from The Woodwell (thewoodwell.com) It should arrive by Tuesday, May 13. Viola back billets should have enough wood to cut ribstock from them.
The plan is for Richard and Beacham to work on their moulds. I will have their violin knives in the kiln when they arrive and I will quench them as they watch.
Jim is working on trimming his corner blocks. Next, he will cut the rib stock and begin thicknessing the ribs.
Three people in the shop is the max. Any new people will go on a waiting list. I will seek suitable space from the County, from a local college, or somewhere else. Any downtown buildings?
I feel the need to keep ahead of Jim. Why is that? Anyway, I glued in the blocks and began carving them. One came loose. Had to re-glue. Then another one did the same. I needed to scrape the shellac away to help them stay put. I spent time sharpening the outcannel gouge that is used for carving the corner blocks.
The Zen of rib thicknessing: For me, this process, involving the scraper and toothed block plane, requires a special focus. I need to be focused, but relaxed. Not hurrying. Working but not forcing. Being sensitive to the vagaries of the particular wood with which I am dealing. Is the scraper sharp enough? Is 1.1 mm ok? Or do I need to go to 1.0? Is the depth of cut of the plane correct?
So Jim will work on shaping the blocks and if that is completed, then sawing the rib stock and thicknessing the ribs.
I saw Richard Falk today at the St. Mary's fish fry. He may be interested in making a violin. Maybe....
The temperature was 72. Just perfect. I had the glue ready. Jim showed up with some very nice collectable Marples patternmakers chisels. Too long for violin making. But nice. He also had a small, but VERY nice gouge. About the size of the ones used for carving lineolium blocks for block printing.
He looked at the back, jointed up last time. Took some divots at strategic places to check the glue joint. Everything was perfect. A 300 year joint. Next he used the jack plane, with a curved edge blade to level the inside surface of the back. I was really surprised at how little trouble he had doing this. He seems to either have had lots of experience or maybe he is just a natural.. So, the back is now flat and put away for later.
He joined the spruce for the top plate. All by himself. Looks good. Glue temp was 145 F. My little clamping mechanism seems to work.
Next we cut my big chunk of Engelmann spruce (Picea engelmannii) to 33 mm for the corner and end blocks. Used the table saw with the blade way up high at a dangerous level. But it went fine, even though I was tense for fear of wood being caught between the fence and blade and being thrown into our faces. Jim marked the wood and cut it out for the blocks. Then sanded them flat. He installed wood screws in the mould to hold the mould 10 mm away from the glass plate. Hot glue was applied and the blocks were clamped. One thing we forgot to do – wax or soap the mould. We can take care of this next time.
Finished right at 9 pm and had a beer and good talk about the important things in life. Poker is not about poker. (And other things were discussed as well.)
Next time Jim will flatten the spruce top and carve the blocks to shape.
Forgot to say Jim greased my squeaking table saw. Wow. Thanks for that.
I planed the wood (no. 6 maple from Mike Anderson in Louisburg, NC). It has an sg of 0.56. I glued the halves together. Looks good. The next day, I decided to re-sharpen the plane blade of the old No. 8. I put a riser, about 0.5 mm on the back side to provide a little micro-bevel on the back side. Then honed on 5 micron mylar on glass. About one minute of honing on the back. Then attached my (not yet patented) honing guide and honed for another minute. I theorize that the 5 micro breaks down and eventually provides smaller particles, because when I installed the blade in the plane and put some Englemann spruce through the plane, well, wow! Beautiful shavings. I glued the spruce, sg 0.35 from simeonchamberstonewood.com. It's nice to know that 5 micron abrasive does the job.
Jim arrived with his knife handle. What a great job he did. The blade is a perfect fit. Slips in and out just like it should.
He ran his maple over the No. 8 jointer. Perfect fit. He loved doing this, as I do. I think it's the most fun of violin making. We glued he maple and clamped. That was enough for tonight.
Glue is heated to 145 F. Overheating will damage its properties. The glue I have is 315 strength. This is on the strong side. For the center joint it will be diluted somewhat. For tonight, I sharpened the No. 8 plane iron only to 5 micron grit, which is apparently 4,500 grit size. I got impatient with finishing the back bevel. It should be sharpened to 1 micron. And if you are really nuts, use 0.5 micron chrome oxide or diamond paste.
When you think the joints have been planed properly, hold the boards together to see if any light can be seen. To join, make sure the glue is ready, with a 1 inch brush. Dry clamp the boards in place to see if there are any gaps or mis-alignments. If all is well, place the boards together so the two joint sides can be brushed with glue quickly at the same time. Quickly brush glue on, liberally. Then place the joint. And quickly to the clamping board. Clamp.
In class, Jim cut his maple down and now has the left and right half rough, with not much wood left to waste. It was a challenge to make the bandsaw cuts just right. But the wood really looks promising now. Specific gravity 0.55.
might attend. If she does, she will work on a knife and get No
introduction to violin making. Joe and Jim will work on knives. Make
handles. Sharpen them.
Jim will work on blocks and if his wood is here, his back wood.
Joe will drill holes in his mould and shellac it.
Blocks: 32 mm tall. Maybe 32.5 mm which will later be sanded down.
I will show the beautiful job Jim had done on my No. 8 jointing plane. Basics of hand planes will be covered.
Jim cut out his mould. He is going to use the Sauret Guarneri model. He used the router for the outside edges and the Forstner drill for the holes. Then shellacked it. We also looked at sharpening of plane blades using Mylar backed abrasiives on glass. Also the jigs to hold the angle of the plane blade constant while sharpening. Jim will order his wood this week. The #6 from Mike Anderson and the Spruce from adirondackspruce.com. I made a 12 mm knife for Jim and for Joe. I had it in the kiln when Jim arrived. At 7:30 pm, I pulled them from the kiln and quenched. They will be ready for sharpening next Monday. We could make handles for the knives at that time, if we choose.
Joe could not attend. See you next Monday, Joe.
Jim is going to regrind the sole of my old No. 8 Bailey plane. This thing is 24 inches long. It will make an excellent plane for jointing tops and backs of instruments. Thanks Jim. I can't wait.
The beer after class was Kennebunkport Porter. My current fav.
Back – red maple,
specific gravity 0.56
Top – specific gravity 0.38
Suppliers: For red maple No. 6 from Mike Anderson in Louisburg, NC, email: firstname.lastname@example.org, tel. 919-496-4299. For spruce AND maple, http://adirondackspruce.com/
30 degree angle is most common. Use jig. 15 micron Silicon Carbide mylar on glass plate. Then 5 micron.. Then 1 micron. The back of the iron may be microbeveled, so that the entire back does not have to be mirror polished.
Will be inserted here.
They must be very flat. If not, there will be problems jointing the two halves. Plane the back across the grain, not along the grain. Use scrapers if necessary on the back, or the toothed plane.
Violin maker's knife is a straight blade that slips into the wood handle. No clamping.
3 mm wide bridge knife, 6 mm wide f-hole knife, 12 mm wide general purpose, 16 mm for heel carving. For purfling channel, 6 mm knife. See a purfling knife here. Curved edge knife is needed for cutting the soundpost. For a double beveled knife, to achieve 30 degree angle, it is 15 degrees on each side. Still, the width of the bevel is twice the thickness of the knife. So it is easy to deal with.
The Sauret Guarneri mold will be supplied. You are invited to choose your own model, but it will require making your own, or purchasing, your own drawings. François Denise has done remarkable work on violin geometry. I cannot afford his book, but an interesting free file is here.
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