Dark joint line on cedar... (Full Version)

Foro Flamenco: http://www.foroflamenco.com/
- Discussions: http://www.foroflamenco.com/default.asp?catApp=0
- - Lutherie: http://www.foroflamenco.com/in_forum.asp?forumid=22
- - - Dark joint line on cedar...: http://www.foroflamenco.com/fb.asp?m=221268



Message

TANúñez -> Dark joint line on cedar... (Jan. 21 2013 17:05:29)

I have this set of cedar I was using for a top. After joining it, it was very hard to tell where the joint line was. However, after I brought it to working thickness, I can now see a rather dark line where the joint is. I don't like it. Has anyone ever experienced this with cedar? I'm not even sure if I should still use it. It bothers me.



Images are resized automatically to a maximum width of 800px



Wayne Brown -> RE: Dark joint line on cedar... (Jan. 21 2013 17:31:47)

Here's a thought. Wet it with naptha to see if the joint line blends with the top. If so, it may look ok when finished. On the otherhand, cedar tops are not nearly expensive as some spruce tops.



Anders Eliasson -> RE: Dark joint line on cedar... (Jan. 21 2013 18:07:18)

to me it looks like you have two annular rings running together and then it looks darker. If so, its only visual and since the cedar looks nice, I would consider it a waste to throw it away. The naphtha test sounds like a good idea.
But it also opens a good question: How perfect do things have to be? If the joint is good and sound it'll only be a darker line and nothing else.



jshelton5040 -> RE: Dark joint line on cedar... (Jan. 21 2013 18:13:31)

You could always cut it back apart and reglue it. That's what I would do.



TANúñez -> RE: Dark joint line on cedar... (Jan. 21 2013 18:42:15)

Here's the naptha test. Pretty much the same.

Anders, very good point. It would be a waste to not use. I am confident I can produce a nice instrument with this top. What scares me is that as you probably know, a lot of people buy guitars with the eyes instead of the ears and hands.

John, very good idea. I actually thought of doing this. I don't have much extra room to work with as I only leave about a 1/4" of extra material all the way around the plantilla. This may be more than enough though if I get it right without having to take much off when joining.



Images are resized automatically to a maximum width of 800px



Marcus McGuinness -> RE: Dark joint line on cedar... (Jan. 21 2013 19:59:31)

Tom,

I ended up with annoying, dark lines on a heel stack. I'm a new builder and possibly the separate blocks of Spanish Ceder were not truely flat (my fault, I planed them), and I suspected that the lines were glue. The problem didn't emerge until I carved the heel.



I'm not sure whether this has anything to do with the problem you are having, but I thought it was worth showing you anyway.

Mac

Images are resized automatically to a maximum width of 800px



TANúñez -> [Deleted] (Jan. 21 2013 20:06:14)

Post has been moved to the Recycle Bin at Jan. 21 2013 20:07:05



Sean -> RE: Dark joint line on cedar... (Jan. 21 2013 20:08:52)

quote:

What scares me is that as you probably know, a lot of people buy guitars with the eyes instead of the ears and hands.


I would re-do it for this reason.
Someone may get the wrong impression about how well it was joined, or simply be bothered enough by it visually as you are.



TANúñez -> RE: Dark joint line on cedar... (Jan. 21 2013 20:09:10)

Mac,

That actually doesn't look bad. I see that a lot. I wonder if it could be the glue staining the wood? I use fish glue and that is known to stain so I don't use it on parts that show. Although I ran out of yellow glue and I did use it on this cedar top joint. Wonder if that is what I'm seeing?



estebanana -> RE: Dark joint line on cedar... (Jan. 21 2013 21:11:22)

Turn the lights off in the room except for one strong bulb and hold the seam up to the light. See how good the glue joint is.

Then cut it open and do it again even if the seam is good. [:D] That way you will know if it is the glue or the grain lines. But the seam looks good from here. Give it the light test.

Gene Clark built a guitar for a well known local luthier who sent him over some wood and a joined top. Gene held it up to the light and showed me the terrible joint. You could have slipped dime through the seam. He cut it apart and did it over, of course.

Just an aside:
If you use a metal knife to spread fish glue or hide glue and you leave the knife in your glue pot the tannins in the wood will react with the metal and make a dark joint. Make sure your glue knife is crome plated or wood or plastic.



TANúñez -> RE: Dark joint line on cedar... (Jan. 21 2013 22:28:19)

Stephen,

I double and triple check these top and back glue joints because I'm nit picky and probably too much of a perfectionist. It actually drives me crazy. I remember this dark line not being present when joining because I couldn't see the join line when checking my work. It wasn't until after it dried and I cleaned up the squeeze out that it showed up and drove me nuts. Oh well. Part of the job.



estebanana -> RE: Dark joint line on cedar... (Jan. 21 2013 23:15:17)

You should in lay a gold leafed strip of Brazilian rosewood to cover the dark joint.



TANúñez -> RE: Dark joint line on cedar... (Jan. 22 2013 2:26:07)

Gold leafed strip of Brazilian rosewood [:D]

Good one!



TANúñez -> RE: Dark joint line on cedar... (Jan. 22 2013 12:31:56)

I came across this photo online of a cedar top with what appears to have the same dark line down the center. You can see it below the bridge. Maybe this is common?



Images are resized automatically to a maximum width of 800px



Andy Culpepper -> RE: Dark joint line on cedar... (Jan. 22 2013 12:51:21)

I haven't used fish glue but if it's known to stain I wouldn't be surprised if that's it. I don't think it's a grain line because you can see other grain lines running into it at a slight angle. If the joint is good I can't think of anything else it could be...
I haven't run into this problem with cedar tops before.



Jim Kirby -> RE: Dark joint line on cedar... (Jan. 23 2013 17:18:07)

My last cedar topped guitar had the same line, using fish glue. Not quite as distinct as yours, more like the finished guitar picture you show. I really like fish glue but may start using something else to join cedar tops. It doesn't seem to happen on spruce.



TANúñez -> RE: Dark joint line on cedar... (Jan. 23 2013 22:47:34)

quote:

My last cedar topped guitar had the same line, using fish glue. Not quite as distinct as yours, more like the finished guitar picture you show. I really like fish glue but may start using something else to join cedar tops. It doesn't seem to happen on spruce.


Your right. Nothing has even showed up like this on any of my spruce tops.



estebanana -> RE: Dark joint line on cedar... (Jan. 23 2013 23:54:42)

Blame the 1917 Sturgeon rebellion against the use of cedar platters to serve caviar. Just before Red October was Dark September. Sometimes referred to as The Isinglass Surprise.



TANúñez -> RE: Dark joint line on cedar... (Jan. 25 2013 0:11:17)

quote:

Blame the 1917 Sturgeon rebellion against the use of cedar platters to serve caviar


Wow those were my exact thoughts when I saw this [8D]



constructordeguitarras -> RE: Dark joint line on cedar... (Jan. 27 2013 16:04:23)

I wish my joints in spruce would do that because I find it nearly impossible to find them when I want to pencil on a centerline.



Anders Eliasson -> RE: Dark joint line on cedar... (Jan. 27 2013 18:31:09)

Mark the endgrain with a pencil and stop showing off.[;)]



estebanana -> RE: Dark joint line on cedar... (Jan. 27 2013 22:08:38)

Yeah I have the same problem, can't find that stupid center join.

The solution is: before you glue them together take a plane and put th top on shooting board and cut an angle at the end each corner on the ends of the two halves where the top will be joined. Then join the halves and you end up with a little triangular shaped arrow at each end of the joint. On many of my joints I can't even find the the join on the end grain so the two arrows find it for me. A Gene Clarkism.

I put together a guitar where I could not see the joint, only for it to be revealed when I finished the top that the actual center line was an 1/8th inch off center. Because I thought center line was a grain line. OOPs.



Andy Culpepper -> RE: Dark joint line on cedar... (Jan. 28 2013 0:30:14)

quote:

I wish my joints in spruce would do that because I find it nearly impossible to find them when I want to pencil on a centerline.


I have the same problem all the time... sometimes I'll run the pencil across the area where I think it is and the glue line will always feel a little bit harder than a grain line.



TANúñez -> RE: Dark joint line on cedar... (Jan. 28 2013 3:04:27)

quote:

The solution is: before you glue them together take a plane and put th top on shooting board and cut an angle at the end each corner on the ends of the two halves where the top will be joined. Then join the halves and you end up with a little triangular shaped arrow at each end of the joint. On many of my joints I can't even find the the join on the end grain so the two arrows find it for me. A Gene Clarkism.


Great idea! I just pencil two arrows pointing to each other on the end grain so that I know where the line is. Works great, when they are pointing to the actual line. [8D]



Anders Eliasson -> RE: Dark joint line on cedar... (Jan. 28 2013 7:53:47)

I still think its easyer to just mark the endgrain with a pencil, where the gluejoint is going to be. Both halfes and both ends of course.



Andy Culpepper -> RE: Dark joint line on cedar... (Jan. 28 2013 13:48:15)

quote:

Great idea! I just pencil two arrows pointing to each other on the end grain so that I know where the line is. Works great, when they are pointing to the actual line.


I actually join my tops offset by 1/8" or so so I can always find the line after joining them, but my problem comes when I have cut out the outline and planed it down to thickness, when I go to layout the bracing, soundhole, etc.



Anders Eliasson -> RE: Dark joint line on cedar... (Jan. 28 2013 15:58:15)

If you put a pencil line (3rd time i write this[:D]) before you cut the outline, and then make a small pencil line in the endgrain afterwards, you´ll always have the centerline.

You guys are complicating life.[8D]



Page: [1]

Valid CSS!




Forum Software powered by ASP Playground Advanced Edition 2.0.5
Copyright © 2000 - 2003 ASPPlayground.NET