Sean Couch’s Bench

[Sean Couch]

Hey all, thanks for having me. I am a first time violin maker with limited wood working experience. I have made a few projects out of wood, but nothing like a violin. My past wood projects were glorified wood boxes, no curves, just right angles. 

About a month or so ago I ran across some videos of people making violins and figured I would give it a go. Most of my “making” experience is with metal. I use to make hand forged Damascus knives and writing pens. I don’t have much in the way of wood working tools so I have purchased what I think is necessary for this endeavor. Well, at least for a good start. 

I have my rib garland just about finished. I still need to bevel the inside lower portion of the liners. I have my top and back plates joined and this is where my issue lies. The spruce front is good to go with hardly any evidence of a glue line. The back, on the other hand, has a visible glue seam. Both the top and back plates were rub joints and no clamps were used. When I was glueing the back, I put the hide glue on, rubbed it in for a bit with my fingers, then wiped the excess off and dried it with a hair drier. Then I added more glue and did my rub joint. The joint grabbed after 3 to 5 seconds and I then got my inside surfaces into position and let her sit overnight. There was not much squeeze out of glue.

I have the back plate down to within about 4 to 5mm of final height, but I only have about 5mm extra on each side of the lower bout. As best as I can measure, it looks like the glue seam is about 0.20mm wide. It is not a dry joint and is plenty strong. I can see the glue in the joint when the light hits it and all my plane curls don’t want to split where the glue is located. To me is seems esthetic and not a structural issue.

Here are a couple pictures of the back plate to show the issue. I know that the seam is supposed to be invisible, but would you continue with what I have if you were working on your first violin? Or would you redo the joint? I will work on getting more pictures posted of my work’s progression so you all can have a chuckle at a newbie. lol.

 

Edited April 8 by Sean Couch

[Sean Couch]

Alright, I got my pictures transferred from my phone to my iPad so here goes a picture dump from the beginning to where I am now.

On edit: I guess I hit my limit on how many posts I can make in a day as a new member. I will add more photos and reply to any messages when I can. Thanks for any comments, good or bad, I won’t be offended.

Edit #2: Mike, if you see this, I understand where you are coming from. I can’t reply due to being new, but I think my issue was having my hide glue too thick when doing the joint on the back plate. My joint was light tight before sizing and gluing.

After reading a bit more, it looks like I should be using thinner glue. I have 222 strength hide glue now and did a 1.5 water to glue ratio by weight. I will saw it apart and try a 2.5 or 3:1 ratio of water to glue.

The box of wood from Old Standard in Missouri:

 

Edited April 9 by Sean Couch

[MikeC]

That glue seam is way too open.  You only have 5mm to work with, saw it apart carefully with a thin saw.  Japanese saws are really thin so maybe use one of those.  Then plane just enough to get a good joint.  

That's just my opinion. 

I don't glue size before the actual glue up.  Others do.   You need a light tight dry fit before gluing. 

 

[HoGo]

You can apply moisture to the joint and open it without loss of wood but it will take longer (few days) and will need thorough drying after.

I think your problem was that you didn't clean up the joint with plane again after sizing (just minimal "scrape" pass of perfectly set plane) and that you created thick layer of glue on surface with your sizing effort. The secong gluing could be also thicker than optimal. You should be able to rub the pieces wood to wood with most of the glue squeezing out still liuqid.

[Davide Sora]

9 hours ago, Sean Couch said:

Hey all, thanks for having me. I am a first time violin maker with limited wood working experience. I have made a few projects out of wood, but nothing like a violin. My past wood projects were glorified wood boxes, no curves, just right angles. 

About a month or so ago I ran across some videos of people making violins and figured I would give it a go. Most of my “making” experience is with metal. I use to make hand forged Damascus knives and writing pens. I don’t have much in the way of wood working tools so I have purchased what I think is necessary for this endeavor. Well, at least for a good start. 

I have my rib garland just about finished. I still need to bevel the inside lower portion of the liners. I have my top and back plates joined and this is where my issue lies. The spruce front is good to go with hardly any evidence of a glue line. The back, on the other hand, has a visible glue seam. Both the top and back plates were rub joints and no clamps were used. When I was glueing the back, I put the hide glue on, rubbed it in for a bit with my fingers, then wiped the excess off and dried it with a hair drier. Then I added more glue and did my rub joint. The joint grabbed after 3 to 5 seconds and I then got my inside surfaces into position and let her sit overnight. There was not much squeeze out of glue.

I have the back plate down to within about 4 to 5mm of final height, but I only have about 5mm extra on each side of the lower bout. As best as I can measure, it looks like the glue seam is about 0.20mm wide. It is not a dry joint and is plenty strong. I can see the glue in the joint when the light hits it and all my plane curls don’t want to split where the glue is located. To me is seems esthetic and not a structural issue.

Here are a couple pictures of the back plate to show the issue. I know that the seam is supposed to be invisible, but would you continue with what I have if you were working on your first violin? Or would you redo the joint? I will work on getting more pictures posted of my work’s progression so you all can have a chuckle at a newbie. lol.

 

As said in previous posts:

the joint is way too open, unglue it with water and heat to save wood. You can wet the joint area abundantly with hot water, and heat it above a hot plate (without touching it), continuously adding hot water to keep everything wet. It takes time, but once the glue melts the two halves will separate effortlessly and cleanly.

If you glue size (I never do that), you have to plane the surfaces again as they will be swollen and no longer match.

Find the best dilution for your glue by testing on scrap pieces, not in the actual joint. Correct dilution is essential, especially for rub joints. I have never used 222 glue and I don't know what the correct dilution is, for my glue 350 or so, I use about a 1:4 glue:water ratio or just a bit less (1: 3.7).

Rub joints can be fine, but the risks of failure due to unexpected events are greater. I use clamps and recommend doing so.

Just my two cents.

 

PS In case you haven't seen them, these are my videos on how I do center joints:

 

[Sean Couch]

Thanks for the advice all, I appreciate it. I am pondering my options and have moved on to making the top. For the back, I should have plenty of material (about 5mm on each side of the lower bout) to cut out the old glue seam and try again. Hopefully it gets better and not worse after the redo. 

Here are some pictures of my progress up until now. After this photo dump I will try to keep the post updated with my progress in case people are interested. Feel free to reply with any criticisms, concerns, or tips in this thread. I am a hard one to offend.

I practiced planing a bit on the maple rib stock since it came in at 4mm thick. I tried to split them on the bandsaw but my blade has too much kerf to get two usable pieces out of the 4mm stock. I didn’t want to change the bevel on the stock plane blade, so I made one out of some 0.125” 1095 steel that I had lying around from my knife making days. The handmade blade has around a 50 degree bevel.

 

Some rib action. I broke the last strip in the last few minutes of work. Thankfully two of the pieces were big enough to do the C-bouts. They were all pretty consistent at 1.2 mm thick.

 

C-bout ribs glued in and corner blocks shaped:

 

Upper and lower ribs are both one piece. Had some issues getting them clamped to the C blocks. They kept moving when I tried to apply clamping pressure. They turned out OK, but I have gaps between the ribs and the mold. More in the upper bout than the lower.

The linings went in without much trouble, only broke two of them. Lol

Here is today’s work. I got the top plate almost profiled to size. Still trying to figure out the corners. I think they will be parallel to the darker pencil likes, but more symmetrical.

Edited April 10 by Sean Couch

[Evan Smith]

The points on your corner blocks are way too long, best to take the ribs back off and shorten them now.

[MikeC]

I agree with Evan, the corners are too long.  You could take ribs off and do over or since it's your first carry on and do the next one better.  For my current build I used corner block templates from MN member Addie, for the last build I traced them from a poster of the Stradivari Titian.  Either one works well for keeping the corner the right length.  

You're doing well to get the ribs and linings bent and glued, don't worry if there is a little gap between them and the form.  

 

For thinning rib blanks I like to use a toothed plane.  

[Wood Butcher]

I also agree with Evan.

But as the OP has already marked out the belly, and cut it, some thoughtful and careful work will be needed to redeem it.

Otherwise, corners that long are going to bring about a multitude of issues later, and hinder playing.

[Davide Sora]

I agree with previous posts, the corners are too long.

To keep the length of the corners under control, just have the drawing of your form with the corners drawn at hand, and superimpose your real form when cutting the blocks, everything will be immediately evident. Another help is to measure the width between the opposite corners and compare it with the measurement on the drawing.
As long as the drawing is correct, of course.

If you have a poster, you can do the same by superimposing your ribs onto photos of the top and back in full scale, it's less accurate but can give you an idea. If there was a rib scan, it would be more accurate.

[Sean Couch]

Thanks for all the advice, I appreciate it. I think I am going to keep the corners as they are. I can see the issue when I put my template on the rib garland. I’m not sure why I didn’t do that before, live and learn, I reckon. 

The template I have for the profile of the top and back plate is what I used on my last picture to mark out the darker pencil lines. I can keep them where they are and have an uneven overhang, or move them a bit to try and make the overhang more even between all corners, but then the corner length will also be too long on the plates.

I didn’t do any physical work on the violin today. I didn’t feel well today so I just a bit of reading and pondering. Hopefully back at it tomorrow. 

[Davide Sora]

10 hours ago, Sean Couch said:

The template I have for the profile of the top and back plate is what I used on my last picture to mark out the darker pencil lines. I can keep them where they are and have an uneven overhang, or move them a bit to try and make the overhang more even between all corners, but then the corner length will also be too long on the plates.

Your dark lines that mark the corner length are too close to the tips of the ribs, you wouldn't have room to do the rounding. To get an idea of the overhang, you can see how I round the edges (it's the same for the corners too) in this video: https://youtu.be/JCc9SfFiiuY?si=-tm8HG0RHu98ahdX&t=91 (English translation on the video description page). There are two possibilities, either you lengthen the top and back corners, or you shorten the tips of the ribs. Shortening the ribs is not a very good thing to do, but in this case, I would. Probably shortening the ribs a little and lengthening the top and back corners a little to balance the effects would be the best thing.

In reality, the best thing to do would be to unglue the upper and lower ribs from the corner blocks, reshape the blocks to shorten the tips of the Cs, and glue back the ribs. Removing the ribs from the corner blocks is not very difficult, you wet them and place them on the bending iron and they should come off quite easily, but if you don't feel like doing it, I can understand.

 

[Nick Allen]

On 4/8/2024 at 7:52 PM, MikeC said:

That glue seam is way too open.  You only have 5mm to work with, saw it apart carefully with a thin saw.  Japanese saws are really thin so maybe use one of those.  Then plane just enough to get a good joint.  

That's just my opinion. 

I don't glue size before the actual glue up.  Others do.   You need a light tight dry fit before gluing. 

 

He can also add little winglets if it ends up too narrow. 

[MikeC]

2 hours ago, Nick Allen said:

He can also add little winglets if it ends up too narrow. 

True,  I thought about that but didn't mention it.   I think there are some historical instruments that have some of that.  

[Sean Couch]

I perceive undoing the ribs as quite difficult. I can’t picture how they would come off easily since I already have the liners glued in and mortised. Maybe it is easier than I think. I am not opposed to not having a rounded overhang. This violin will never leave my possession. Even if it was perfect, which I never expected, I would keep it because it is my first.

I have seen a picture of a three piece back on a violin. I think it was a Strad and you could see the little sections of the 2nd and 3rd piece in the lower bout. If I run into trouble when redoing the center joint on the back I will keep that option in mind.

Thanks again for the replies and advice. This is a huge learning experience for me and so far I enjoy it very much. I am so remedial at wood working with hand tools that I am still learning how to use a gouge and not get big chunks splitting out when I am going in the same direction as the grain (or maybe against it). The chunks haven’t done any harm, yet, but it feels weird for it to happen. Maybe that is how it always works. Instead of going directly with the grain, I have noticed that if I slide the chisel a bit left or right while cutting with the grain that it helps. Kind of like using a plane at a bias so the blade is not perpendicular to the motion of the cut. Maybe that is how it is supposed to be done, but idk.

Below is my days work on the belly. Trying to establish the “shelf” (not sure what to call it) before having a go at the arching. The marked line that can be seen in the C-bouts is at about 6mm. I am going slow as to hopefully not continue my screw ups, and also get the feel for using a chisel/gouge. Once I get her down to 6mm, I will mark and go for a 4.5mm line. This is stressful work for a newb like me. Lol

 

Edited April 12 by Sean Couch

[MikeC]

Don't get stressed, just enjoy the process and learning.   

[Davide Sora]

10 hours ago, Sean Couch said:

I perceive undoing the ribs as quite difficult. I can’t picture how they would come off easily since I already have the liners glued in and mortised. Maybe it is easier than I think. I am not opposed to not having a rounded overhang. This violin will never leave my possession. Even if it was perfect, which I never expected, I would keep it because it is my first.

Yep, it's more straightforward to leave everything as it is and remember the lessons for the next violin.

In any case, I intended to unglue the ribs of the upper and lower bouts, leaving aside those of the C with mortised linings. You will have to make the top and back corners almost unrounded on the underside, but you can always say that you did this intentionally as a personal stylistic choice.  Certainly, the corners will be less fragile if supported by the ribs until the end.

[Sean Couch]

Made some more progress. I abandoned my “shelf” method. I didn’t like trying to create the 90 degree wall. Seemed too difficult. I guess if I had a router, it would be easier. Instead of continuing the same method, I took a convex hand plane, some finger planes, and a large gouge to it to remove some material.

I originally used the shelf method because of my lack of confidence with using my gouges and planes. At the time it seemed more controllable, but after a few minutes with the convex hand plane, I had a big smile on my face. Using the finger planes during this process has been the most enjoyable session yet.

I still have quite a ways to go, but now it is starting to look like a violin top.

[Sean Couch]

Nothing to show in any progress pictures but I put in some time today. I’m messing with the arching and getting the edge thickness down to 4.5 ish mm so I can start on the purfling before moving onto finalizing the arching.

Does anyone have any recommendation for a purfling cutter/marking tool? I have seen people use many different types, or none at all, not sure what is the best method.

[MikeC]

I use one like this from amazon.  It has two blades to make a parallel mark all around the plate.  It's not for cutting to depth, just use it for initial marking of parallel lines around the edge. Then I used an exacto knife to follow the lines down to depth.  

The blades supplied were un-usable as they are.   They are sharpened to a needle point, so I had to reshape them to a knife edge that will cut wood fibers in a controlled way rather than trying to drag a sewing needle around the wood.  

Once the blades were shaped properly it worked well to mark the purfling channel.   

There are lots of other purfling cutters besides this one though, probably much better ones, but it worked.

There are some older discussions here on the site about purfling cutters,  do some searching for those 

Here's a link to a good thread on the subject

 

 

[Sean Couch]

I think I saw that post yesterday morning when I was searching around the forum for purfling cutters. I also found this one and it seemed pretty easy to make: 

I ran down to the local hardware store yesterday afternoon to see if they had any dowel nuts, and surprisingly they did. Bought a couple nuts, some fancy bolts, and some little knife blades. Out the door for around $10.

I sketched out the tool on some old 3/4 pine I had laying around and made a working tool. I tightened the blades too much and cracked the pine, so I glued on a couple piece of left over rib material to give it some more strength. I also drilled a hole along the length of the handle and epoxied in a piece of brass tube. My thought is that the brass will be a better bearing surface than the pine and I had some lying around from past projects.

Anyway, it turned out ok. If the blade holding part fails to do its job even after the maple reinforcement, I will make a new one for it out of some other wood, or try pine again and change the grain direction. It seems to cut pretty good on the test piece.

I cut some small pieces of 0.004” phosphor bronze stock to shim the blades to the correct distance. With three shims it is close to 1.3mm. I will have to find a good way to measure it, or just rely on test results from some practice runs at cutting, clearing, and gluing purfling in the channel.

 

[Sean Couch]

Slowly, but surely I am making progress. 
 

[Sean Couch]

I spent some time trying to get the back center joint undone. I tried to steam the joint with a rigged up kettle and some 1/4” silicone tubing. Steamed it for 45 minutes or so and could see and feel some glue coming out of the joint, but it was a no go on separating the wedges.

I then wrapped it in aluminum foil and put it in a 150F oven for an hour, no luck. Wetted it a bit with a rag, put it in a large plastic bag and back into the oven for 2 hours. Took the back out of the oven, cleaned up some more glue that came out, tried to get the joint loose and it was not budging. I even put a piece of 3/4” copper pipe on the floor, set the center joint of the back plate on the pipe and stood on both sides of the plate and it was solid. I guess I need to gain some weight.  Lol

An hour or so ago I ended up cutting it apart on the band saw. I reckon I could have saved myself quite a few hours if I would have done that first. I looked at the plates yesterday morning (about 12 hours after coming out of the oven) and the glue seam was almost invisible. I planed the seam a bit and the curls were falling apart at the glue joint. It may have been structurally sound before the oven treatment, but I wasn’t going to trust it after.

My two pieces are both about 20.5mm in the center and 15mm on the sides. Since maple is more difficult to carve than spruce, should I use the band saw to make them more wedge shaped? If yes, what measurements should I aim for? Does 18mm in the center and 8mm on the edges sound good?

Tomorrow will be attempt #2 at gluing the center joint. I am going to go with the way @Davide Sora shows in his video. I like the idea of pouring the glue on the seam instead of brushing it on. 

[Davide Sora]

To detach the joint I usually heat it by passing it over the hotplate (very close but not in direct contact), keeping it constantly wet with hot water. It takes time but it has always worked. I personally only did it once many years ago, but more recently I had some students do it and it worked. Of course, sawing it with the bandsaw is much faster, if the dimensions of the piece allow it it is the way to go.

Before making the joints I flatten one side, to be able to use it as a reference for the square, then I bring the thickness of 18/18.5mm by planing the external part, to reduce the thickness to be planed and also because my clamps do not apply the pressure in the right direction with a greater thickness. The flattening and thickness must be done before starting to plane the joint because if carried out subsequently they could cause distortions of the pieces and nullify their perfect fit.

The advantage of pouring the glue instead of using the brush lies in the greater speed of execution, greater uniformity of the glue applied, and avoiding possible fragments lost by the brush from creating unwanted thicknesses, which could prevent perfect contact of the two halves, a risk I prefer to avoid.

[Sean Couch]

I’m sure the heat and moisture method works to get the joint apart, I just didn’t want to wait.

Now I have a new problem, imagine that. lol.  I cut some thickness out of my wedges so now the center is at 18mm and the edges are at 7.5mm. Before cutting away some of the thickness, the two pieces were dead flat on one side. After cutting they are not flat anymore.

Was this caused by the moisture I added trying to get the center joint apart? I don’t know what else could have caused it. How long should I wait before continuing working on the pieces?

I should have stuck with metal working. It is so much easier than wood working. Ahaha