Center Joint gap

[Don Noon]

48 minutes ago, Nestorvass said:

What I am against is taking something as traditional as violin making and using cncs to do it. 

Medicine has an even longer tradition, but I for one am extremely glad we have gotten beyond carved whalebone for artificial hips 

Admittedly, it's not all that great of a comparison... but you come across as getting beyond personal preference (which it is) into a judgement of what others should be doing.  

[Guest]

1 minute ago, Don Noon said:

Medicine has an even longer tradition, but I for one am extremely glad we have gotten beyond carved whalebone for artificial hips 

Admittedly, it's not all that great of a comparison... but you come across as getting beyond personal preference (which it is) into a judgement of what others should be doing.  

Well you said it yourself not a great comparison. Medicine had room for improvement, lots of it. The shape of the violin and its mechanics where perfected almost at the beginning before 1700. These instruments survive to this day and where entirely made by hand. Perhaps if Stradivari had cnc or jointer etc he would happily use it. As for the judgement,  you've got me wrong. It was never my intention to judge anyone perhaps I expressed me opinion stronger that it should have. I just dont like the idea of using a machine on violin making. Not saying what you should do or what anyone should do. I am just pointing out what I do.

[Joe Wiese]

When I first started building I had the same problem.  More than once. 

I have had to take apart back joints before.  Water.  An Iron. Keep working it. Water and heat.   It will come apart.  You don't loose any material by sawing but you will need to reflatten it.   

One reason this happens is the wood swells even if you get a perfect fit. 

As far as preventing.   I glue seize my joints twice at least before I clamp the maple. 

I put the wood in a vice with a light behind it in a dark room and look for light.  I look at it from both sides, flipping vertical and horizontal. I use a scraper to take off high spots.  A flattened plane with sand paper on it.  I work it until I can't see light.  When I think it is good. I applied hot glue to swell the wood.  Wipe down. Let dry.

Repeat the process a second time.  No light.  Glue seize. Wipe down.  Dry.

Then I glue the back together. I now created joints that are hard to see the seam. Especially on the spruce  I use clamps on both spruce and maple. 

[Guest]

8 hours ago, Joe Wiese said:

When I first started building I had the same problem.  More than once. 

I have had to take apart back joints before.  Water.  An Iron. Keep working it. Water and heat.   It will come apart.  You don't loose any material by sawing but you will need to reflatten it.   

One reason this happens is the wood swells even if you get a perfect fit. 

As far as preventing.   I glue seize my joints twice at least before I clamp the maple. 

I put the wood in a vice with a light behind it in a dark room and look for light.  I look at it from both sides, flipping vertical and horizontal. I use a scraper to take off high spots.  A flattened plane with sand paper on it.  I work it until I can't see light.  When I think it is good. I applied hot glue to swell the wood.  Wipe down. Let dry.

Repeat the process a second time.  No light.  Glue seize. Wipe down.  Dry.

Then I glue the back together. I now created joints that are hard to see the seam. Especially on the spruce  I use clamps on both spruce and maple. 

Thank you for the input, I ended up having to saw the joint with my bandsaw. Even with lots of warm water and a heat gun it the joint would not come apart. But every cloud has a silver lining, this situation convinced me how strong a rub joint can be. Anyway I have tried to do the joint again several times by now every time i get it perfect i glue size and it turns out even worse than it did the first time. I changed my recipe for glue though this could be the problem. Instead of using  1:3 (glue:water) i used 1:2. That with the combination of my  workshops temperature is about 62 fahrenheit, probably made the glue gel too quickly and by the time I'd be ready to rub the plates together, the glue would have already gelled and the excess wouldn't come out of the joint, creating a gap. I will try again today and i will preheat the two pieces of the plate a little with my heat gun, not too hot, just a bit warm to buy me some time for the glue up.

[Dennis J]

What happens when planing a length of timber a little narrower than the plane's blade?

I've found that, starting with a squared up piece of wood exactly the same width and depth end to end a couple of things invariably happen.

After a few passes of the plane, measurements taken at each end show a difference indicating the plane has taken off more at the end of the stroke than at the beginning. This becomes quite pronounced as planing continues.

Also about 3-4 cm from the end of the pass the cut dips down slightly.

Only the dip at the end of the cut has any relevance to planing plate wedges. However I've found planes behave quite predictably and that they do what they're supposed to do. And that is to produce surfaces which are straight and flat.

 

[Guest]

13 minutes ago, Dennis J said:

What happens when planing a length of timber a little narrower than the plane's blade?

I've found that, starting with a squared up piece of wood exactly the same width and depth end to end a couple of things invariably happen.

After a few passes of the plane, measurements taken at each end show a difference indicating the plane has taken off more at the end of the stroke than at the beginning. This becomes quite pronounced as planing continues.

Also about 3-4 cm from the end of the pass the cut dips down slightly.

Only the dip at the end of the cut has any relevance to planing plate wedges. However I've found planes behave quite predictably and that they do what they're supposed to do. And that is to produce surfaces which are straight and flat.

 

Generally planes have the tendency to create convex surfaces, meaning a high spot in the middle. I am not sure why but it happens no matter how flat the plane is. Thats why i prefer to hold the plane upside down in the vise and the piece i am planing in my hands. I take a shaving at the beginning it always cuts, as i go to the middle it stops and then it cuts at the end again. To counteract that i pressy lightly at the beginning, really hard as it reaches the middle and then lightly again as i reach the end. If i still have a high spot i will only take shavings in the middle, till the plane stops cutting. This means that the middle will be at the same level as the ends of the board and maybe even a little lower which is optimal for a good suction joint.

[Dennis J]

19 minutes ago, Nestorvass said:

Generally planes have the tendency to create convex surfaces, meaning a high spot in the middle. I am not sure why but it happens no matter how flat the plane is. Thats why i prefer to hold the plane upside down in the vise and the piece i am planing in my hands. I take a shaving at the beginning it always cuts, as i go to the middle it stops and then it cuts at the end again. To counteract that i pressy lightly at the beginning, really hard as it reaches the middle and then lightly again as i reach the end. If i still have a high spot i will only take shavings in the middle, till the plane stops cutting. This means that the middle will be at the same level as the ends of the board and maybe even a little lower which is optimal for a good suction joint.

I don't know how you are getting convex surfaces. I find putting the plane in the vice can sometimes be awkward but it should not make any difference. I counteract what seems to happen when I plane is to take a couple of short starting cuts occasionally before the full length cuts. I've found that the same thing happens when using a shooting board. But I don't bother doing that when planing violin plate wedges.

I can't see how a plane with a flat sole and a sharp blade can do what you say. The only way a blade can come out of a cut is if it is blunt and won't cut to its full depth. The only anomaly I've noticed is the one I mentioned. All I can think about that is that the blade doesn't quite cut at its full depth at the very start of each cut. If the blade is very sharp it will clamp the sole of the plane to the wood's surface during the stroke. It cannot come out of the cut.

It took me a while to notice the end of stroke dip I was talking about. Going by my straight edge I first thought it was caused by a high area in the middle. And it seems to be only about .2 or .3 mm. Anyway to deal with that dip with the last couple of wedges I've done I planed full-length strokes with a number 4 set to a medium depth cut, checked with the straight edge, then made a couple of strokes only in the middle with a small block plane set with a fine depth of cut, and then finished with one long pass with the number 4. I've then checked with the straight edge. And that seems to be a formula that works. So I'm doing much the same as you but I have finished with a long stroke after making a couple of very fine cuts in the middle.

I really don't agree that there is any benefit planing edges hollow, no matter how slight, especially when doing rubbed joints.

[Guest]

19 minutes ago, Dennis J said:

I don't know how you are getting convex surfaces. I find putting the plane in the vice can sometimes be awkward but it should not make any difference. I counteract what seems to happen when I plane is to take a couple of short starting cuts occasionally before the full length cuts. I've found that the same thing happens when using a shooting board. But I don't bother doing that when planing violin plate wedges.

I can't see how a plane with a flat sole and a sharp blade can do what you say. The only way a blade can come out of a cut is if it is blunt and won't cut to its full depth. The only anomaly I've noticed is the one I mentioned. All I can think about that is that the blade doesn't quite cut at its full depth at the very start of each cut. If the blade is very sharp it will clamp the sole of the plane to the wood's surface during the stroke. It cannot come out of the cut.

It took me a while to notice the end of stroke dip I was talking about. Going by my straight edge I first thought it was caused by a high area in the middle. And it seems to be only about .2 or .3 mm. Anyway to deal with that dip with the last couple of wedges I've done I planed full-length strokes with a number 4 set to a medium depth cut, checked with the straight edge, then made a couple of strokes only in the middle with a small block plane set with a fine depth of cut, and then finished with one long pass with the number 4. I've then checked with the straight edge. And that seems to be a formula that works. So I'm doing much the same as you but I have finished with a long stroke after making a couple of very fine cuts in the middle.

I really don't agree that there is any benefit planing edges hollow, no matter how slight, especially when doing rubbed joints.

Take a look at 7:30 in this video. Rob probably is the most experienced person I can think of when it comes to planes.  He says that planes leave convex surfaces. I am not sure why but I've seen it happen when I plane my own boards. I'll take his word for it.

 

[Peter K-G]

I think planing and gluing joints is a skill that should be practiced before starting making violins.

I also had to learn the hard way with a lot of failure

 

 

[Guest]

Just now, Peter K-G said:

I think planing and gluing joints is a skill that should be practiced before starting making violins.

I also had to learn the hard way with a lot of failure

 

 

Well you are not wrong, had I not been doing woodworking for a few years using a hand plane chisels etc I believe I would have a much harder using them on violin making. Making a board flat straight and with square edges is one of the most basic woodworking tasks and yet it does require a lot of practice and mistakes to reach a level where you are comfortable to do the same things on a violin plate. Especially when it comes to plane maple. Its funny if you think about it, violin making requires you to use a plane on the easiest wood to plane (spruce) and also one of the most difficult woods (figured maple). There is no in between.

[David Burgess]

2 hours ago, Nestorvass said:

Take a look at 7:30 in this video. Rob probably is the most experienced person I can think of when it comes to planes.  He says that planes leave convex surfaces. I am not sure why but I've seen it happen when I plane my own boards. I'll take his word for it.

 

Is dragging the plane on the backstroke considered to be good technique?

[Guest]

28 minutes ago, David Burgess said:

Is dragging the plane on the backstroke considered to be good technique?

Go to 8:20 in this video, he explains this exact myth. Even if it did dull the blade which it doesnt by any significant degree since wood is way softer than the steel of the blade, it would still take 30 seconds to sharpen that blade. So in the end its more efficient and less exhausting.

 

[David Burgess]

"Go to 8:20 in this video, he explains this exact myth. Even if it did dull the blade which it doesnt by any significant degree since wood is way softer than the steel of the blade, it would still take 30 seconds to sharpen that blade. So in the end its more efficient and less exhausting."

_____________________________________________________________

I've done a bit of planing myself. It does dull or round the edge of the blade. Greater skill, and being in better physical shape would render his his comments mute.

[Guest]

4 minutes ago, David Burgess said:

"Go to 8:20 in this video, he explains this exact myth. Even if it did dull the blade which it doesnt by any significant degree since wood is way softer than the steel of the blade, it would still take 30 seconds to sharpen that blade. So in the end its more efficient and less exhausting."

_____________________________________________________________

I've done a bit of planing myself. It does dull or round the edge of the blade. Greater skill, and being in better physical shape would render his his comments mute.

I know you have, whatever works for everyone. But even if it does round the blade its not a big deal to sharpen it 30 seconds and he is back in business probably quicker than if he was lifting the plane at every stroke. As for the skill he is a very skilled craftsman i doubt anyone in the violin making world can use a plane better than he does, no offense but not even you. It has to do with the nature of his professionx a violin maker will a bench planes only for flattening the plates and making the center joint and perhaps a little bit when making the neck. A woodworker like him uses these planes on almost every step in the process of making something. So again no offense at all, I mean it, i respect you, your work and your skills but I think when it comes to bench planes (emphasis on bench planes) he is more experienced than anyone in this forum. So respectfully I will take his word for it over yours.

[David Burgess]

20 minutes ago, Nestorvass said:

I know you have, whatever works for everyone. But even if it does round the blade its not a big deal to sharpen it 30 seconds and he is back in business probably quicker than if he was lifting the plane at every stroke.

That's another issue, the sharpening method he shows: Honing one side, and then the other a single time is guaranteed to leave a burr or "wire edge". But maybe it's good enough for planing rough lumber.

[Guest]

3 minutes ago, David Burgess said:

That's another issue, the sharpening method he shows: Honing one side, and then the other a single time is guaranteed to leave a burr or "wire edge". But maybe it's good enough for planing rough lumber.

9 minute mark looks pretty good to me. What do you think? 

 

 

[David Burgess]

Can't tell. I would need to check it using oblique light.

[Guest]

2 minutes ago, David Burgess said:

Can't tell. I would need to check it using oblique light.

Anyway I use the same method here are my results (this is curly maple) 

[Mark Norfleet]

55 minutes ago, Nestorvass said:

 As for the skill he is a very skilled craftsman i doubt anyone in the violin making world can use a plane better than he does, no offense but not even you.

I can assure you from years of personal experience and observation that David is every bit as skilled at using a plane as this guy shows in his videos, probably better.

His “myth busting” isn’t.  It’s simply statements of his personal preferences  and reasoning behind them.

[Guest]

3 minutes ago, Mark Norfleet said:

I can assure you from years of personal experience and observation that David is every bit as skilled at using a plane as this guy shows in his videos, probably better.

His “myth busting” isn’t.  It’s simply statements of his personal preferences  and reasoning behind them.

Whatever works for everyone. We overanalyze a subject that has nothing to do with my original post wouldnt you agree?

[Jay Higgs]

Since planing a joint suffers from anomalies at the beginning and end of the stroke, I wonder if some extra work clamping 3-6 inches of  sacrificial wood before and after the actual violin piece would help.  Sacrificial wood is common to use in power planers, but I haven't found anything similar for hand jointing.  Admittedly, the clamping process might be more difficult than just dealing with the anomalies.  

 

[jacobsaunders]

31 minutes ago, Nestorvass said:

Whatever works for everyone.

The centre joint you posted at the top of the thread, doesn’t exactly look as if it “worked” for you or anyone

[catnip]

5 hours ago, Nestorvass said:

He says that planes leave convex surfaces. I am not sure why but I've seen it happen when I plane my own boards. I'll take his word for it.

I think the reason for this is might be that the front end of the plane rides on a flat surface and the back end of the plane rides on very slightly lower surface since the blade has already removed a very thin slice from that area.  Also, I think the plane cuts more aggressively at the start of the cut than at the finish which may also add to this.  Just a thought.

[Mark Norfleet]

40 minutes ago, Nestorvass said:

Whatever works for everyone. We overanalyze a subject that has nothing to do with my original post wouldnt you agree?

I'm not going to make a call on at what point anything becomes over analyzed, but do think the subject has everything to do with your original post and the various contentions you've made and positions you have taken along the way.

It's good that you know as much as you do.  Hopefully one day you can sort it all out and put it to good use.

[Guest]

9 minutes ago, Mark Norfleet said:

I'm not going to make a call on at what point anything becomes over analyzed, but do think the subject has everything to do with your original post and the various contentions you've made and positions you have taken along the way.

It's good that you know as much as you do.  Hopefully one day you can sort it all out and put it to good use.

I hope so too