Violin Forum/Message Board

[BK]

Wow, purfling work is not as easy as I thought it would be!

It's been difficult for me to not bruise the wood during the work. I'm starting to think it might be easier and neater for me to devise a sort of machine to do this work. Perhaps some sort of dremel tool concoction. Have others devised some sort of homemade tool for this work?

[actonern]

http://darntonviolins.com/purflingmachine.php

[BK]

Wow. Nice. I like it.

[BK]

I was reading Courtnall, and it sounded like they were advising to put a light coating of diluted hide glue along the purfling surface area. Do you do this?

I didn't do this originally because their description of the method was not really clearly written, from my perspective. But, in thinking about it, I would imagine that the light coating of glue kind of preserves the integrity of the wood and prevents it from bruising and squishing while cutting. I was imagining it as being kind of like snow with a crusting of ice over it.

[okawbow]

Cutting the purfling channel by hand is one of the most satisfying jobs in violin making, in my opinion. I'ts not nearly as hard as it first seems, and the results can be as good or better than machining the groove.

You must have the proper tools to do a good job. a good purfling marker with perfectly sharp blades, will cut the outline of the groove. The lines are then carefully deepened with a knife. A super sharp, thin knife is essential. It cuts, instead of tearing and mashing the wood. A proper size and shape pick is also needed.

The more practice; the better the result.
http://www.flickr.com/photos/20524843@N03/6147379737/in/photostream/

[BK]

That is a beautiful purfling job! And you did it by hand? Very impressive.

I have quite a bit more practicing to do in order to catch up with you!

This is where I am out now:









I have a very thin bladed knife and a purfling channel scraper that I have been using. My knife is quasi-factory sharp. I will admit that I am a very poor sharpener. I have all the tools to hand sharpen (Japenese water stones sitting in a water bath, sharpening guides, a sharpening book, ect), but it seems that even when I do things according to the correct sharpening procedures, they come out more dull than when I began. Not sure why. I must be missing something, or maybe I just haven't got the "knack" yet. I think, perhaps, I need to take a sharpening course, or something to that effect. But, in any case, I am very hesitant to sharpen any of my tools right now for fear that they will become more dull than when I began. And the reason I have this fear is because it has happened several times already. They either become more dull, or they become sharp, but the edge is not even.

That being said, I have become very creative in my tool usage.


I try to use the Dremel tool and drill press whenever I am able to. I also have been heavily relying on two Japanese gouges which seems to have an uncanny ability to keep their keen edge.

But, I am keeping my eyes peeled for a sharpening class in my area. I know that my days are numbered as a luthier if I do not have good sharpening skills.

[okawbow]

I have cut purfling channels with an exacto knife. The blade tips break occaisionally, but they are razor sharp, and the blades can be changed when dull. The pick is only used to pop out the wood from the groove when the lines on each side are cut the proper depth. The knife does most of the work.

There is plenty of info on the net about how to sharpen tools. Keep at it until you get it. A sharp tool can make an incredible difference.

I have tried coating the wood with thin glue. It does help somewhat to keep the spruce from chipping, but seems to dull the knife quickly.

As far as the difference between cutting the channel by hand, or using a power tool; both take an aquired skill, and both need practice. You still have to cut the corners by hand, anyway, even if you cut the channel with power tools. I have always thought I may as well do everything by hand. I even saw out the plates and neck by hand. I can cut the purfling channel and install the purfling by hand in an afternoon. I'm not sure I could do it faster or better with power tools.

[BK]

OK, that's good to know. Hopefully by the time I get the channel cut on my first top, I can pick up the pace a bit on the ones to follow.

[Dave Chandler]

I don't let power tools near my wood after cutting out the rough outline. For purfling, I use a two-knife purfling marker but just light enough to mark the surface, then its exacto knife with fresh tip. I use at least one blade on the back, and another fresh one for the spruce. For the corners, I sketch them with a sharp pencil first, then lightly start with the exacto knife first making sure I have clean lines, then cutting deeper.

Clean and neat edges are a must before marking the purfling. I prefer (and this is just my way and it works for me) to purfle after the body is all assembled, edges are at their final dimensions and all edge lines neat.

And this is a little tool I ground out of a wood chisel bit, to clean out the bottom of the purfling groove.


[img]
purfling1 by David Chandler, on Flickr[/img]

Some other purfling photos....

[/img]
purfling2 by David Chandler, on Flickr[img]

[/img]
purfling3 by David Chandler, on Flickr[img]

[/img]
purfling4 by David Chandler, on Flickr[img]

Anyway, that's the way I do it!!
_________________
Dave in the Blue Ridge
Southern Violin Association

"Success is the ability to go from one failure to the next with no loss of enthusiasm" Winston Churchill

"I took the road less travelled, and now I don't know where I am." Marco Polo

[Janito]

A few observations from the OP's photos:

- The outline is not clean enough to define a good path for the purfling channel. It looks like the conventional marker tools would be following a very bumpy ride

- The central seam is very suspect and has a high probability of failing when you carve down to final thinkness.

I would strongly suggest that you practice making clean purfling channels in scrap pieces of wood first.

[Dave Chandler]

Actually, you might want a new chainsaw blade to finish up with. (Is this some sort of test?)
_________________
Dave in the Blue Ridge
Southern Violin Association

"Success is the ability to go from one failure to the next with no loss of enthusiasm" Winston Churchill

"I took the road less travelled, and now I don't know where I am." Marco Polo

[BK]

Thanks for your comments. Much appreciated.

Yeah, this is my first attempt at making the spruce top. Kind of learning as I go. Not beautiful. I know. But we all have to start somewhere, I guess.

For gluing the two spruce pieces together, I used the wringing method. I agree that the seam is too noticeable. I think the next time I attempt to glue up, I'll use the wringing method again, but also use clamps to hold the two pieces together tighter and hopefully get a less noticeable seam.

I also agree that the edge is too bumpy. When I was cutting the purfling groove I definitely ran into trouble due to the "bumps" along the edge. Will need to neaten that up on my next attempt.

[Dave Chandler]

Let's take some baby steps first.

I would take this piece and cut it neatly down the center with a bandsaw, and plane and reglue a couple times till you can get a nice seam. Then practice edge work, and purfling. This piece will be a good be a practice piece, as I would not go any further with the seam that I see. I'm not familiar with the wringing method. I plane, glue, clamp with the wood warm and glue at about 140 degrees, somewhat thick.

There are lots of postings here, search out the ones on joining. When you can join a good top, then move on. You're really not going to make progress, till you learn to sharpen your tools. Baby steps...

What about the back and rib garland? What stage are you there?

Most makers do the rib garland, then use that as template for back while still on the mould. Attach back, then use rib garland outline as template for the top.
_________________
Dave in the Blue Ridge
Southern Violin Association

"Success is the ability to go from one failure to the next with no loss of enthusiasm" Winston Churchill

"I took the road less travelled, and now I don't know where I am." Marco Polo

[BK]

Thanks again Dave for your advice. Always appreciated.

I think I will continue on with the top that I have. If it cracks, it cracks. It will at least be a learning experience for the next one.

I came across this quote today which I really liked. Thought I'd share it with everyone:

"The remarkable thing we have is a choice every day regarding the attitude we will embrace for that day. We cannot change our past... We cannot change the fact that people will act in a certain way. We cannot change the inevitable. The only thing we can do is play on the one string we have, and that is our attitude."

-Charles R. Swindoll

[Dave Chandler]

Here's another saying for you -- "if its worth doing, its worth doing well"

If making is just for the fun of it, then the reward is in the doing, so don't be disappointed if thats all you end up with. If it becomes work, there's no joy in that either. So "Carry On!!"
_________________
Dave in the Blue Ridge
Southern Violin Association

"Success is the ability to go from one failure to the next with no loss of enthusiasm" Winston Churchill

"I took the road less travelled, and now I don't know where I am." Marco Polo