Ken's Corner (Bass Forums Sponsored By KSB)

Go Back   Ken's Corner (Bass Forums Sponsored By KSB) > Double Basses > Luthier's Corner

Reply
 
Thread Tools Display Modes
  #141  
Old 04-29-2011, 03:48 PM
Ken Smith's Avatar
Ken Smith Ken Smith is offline
Bassist, Luthier & Admin
 
Join Date: 01-18-2007
Location: Perkasie, PA
Posts: 4,851
Ken Smith is on a distinguished road
Cool yes..

Quote:
Originally Posted by Ruben E garcia View Post
Correct.
So Ken To answer your previous question the bar is 1" thick
Yes, you mentioned that earlier indirectly. Ask a few Luthiers that have done a lot of Bars, maybe Arnold or Jeff and see for that size bass what might be best. Most Bars blanks I have seen are thicker in the rough form. I just don't know what to advise here other than the thickness might matter.
Reply With Quote
  #142  
Old 05-02-2011, 10:12 AM
Ruben E garcia Ruben E garcia is offline
Posting Member
 
Join Date: 10-04-2010
Location: Atlanta GA
Posts: 108
Ruben E garcia is on a distinguished road
Default Springing?

Springing or not springing the bass bar, at least a little?
Reply With Quote
  #143  
Old 05-02-2011, 12:26 PM
Ken Smith's Avatar
Ken Smith Ken Smith is offline
Bassist, Luthier & Admin
 
Join Date: 01-18-2007
Location: Perkasie, PA
Posts: 4,851
Ken Smith is on a distinguished road
Exclamation no..

Quote:
Originally Posted by Ruben E garcia View Post
Springing or not springing the bass bar, at least a little?
NONE, Ever, unless you want the top to sink at the ends sooner or later. Flush fit only. Sprung Bars break basses, period.
Reply With Quote
  #144  
Old 05-02-2011, 01:47 PM
Ruben E garcia Ruben E garcia is offline
Posting Member
 
Join Date: 10-04-2010
Location: Atlanta GA
Posts: 108
Ruben E garcia is on a distinguished road
Default

Quote:
Originally Posted by Ken Smith View Post
NONE, Ever, unless you want the top to sink at the ends sooner or later. Flush fit only. Sprung Bars break basses, period.
Yes I remember you mentioning something similar before, thumb pressure on the bar, very little or no pressure
Reply With Quote
  #145  
Old 05-02-2011, 02:51 PM
Ken Smith's Avatar
Ken Smith Ken Smith is offline
Bassist, Luthier & Admin
 
Join Date: 01-18-2007
Location: Perkasie, PA
Posts: 4,851
Ken Smith is on a distinguished road
Lightbulb none

Quote:
Originally Posted by Ruben E garcia View Post
Yes I remember you mentioning something similar before, thumb pressure on the bar, very little or no pressure
The Bar should be fit Flush to the Top, no pressure at all. Even clamping without forcing the ends down at all.
Reply With Quote
  #146  
Old 05-06-2011, 10:09 AM
Ruben E garcia Ruben E garcia is offline
Posting Member
 
Join Date: 10-04-2010
Location: Atlanta GA
Posts: 108
Ruben E garcia is on a distinguished road
Default 911

Ok I am going a little crazy with the Edges:
I can not make the south part of the top to flush, everything else is making contact with the surface, and If I keep removing material from the whole top so the south part can touch, I am going to be removing a lot of material from the original top... I don't know what is wrong... I also notice that the top curve from west to east is not perfect should i be concern about that? u can see it the pictures ???






Reply With Quote
  #147  
Old 05-06-2011, 11:54 AM
Ken Smith's Avatar
Ken Smith Ken Smith is offline
Bassist, Luthier & Admin
 
Join Date: 01-18-2007
Location: Perkasie, PA
Posts: 4,851
Ken Smith is on a distinguished road
Default Fit

Show me/us the Fitting problem you are having and do not remove anything original.

Sometimes the Blocked frame shifts. Sometimes you have shrinkage of the Top grains and the Top is shy of the Ribs i n the lower bout. In this case, The Ribs are cut and trimmed at the Block. For this you have to remove the lower Ribs from all blocks and re-fit it o the Corner possibly but if not, just at the Tailblock, Cut and pull together to fit the Top and maybe Back. The Plates should overhang just a bit. In the Blocks with Ribs twisted inwards, then the Top will overhang more. Still, nothing is ever perfect on an old bass.
Reply With Quote
  #148  
Old 05-06-2011, 01:45 PM
Ruben E garcia Ruben E garcia is offline
Posting Member
 
Join Date: 10-04-2010
Location: Atlanta GA
Posts: 108
Ruben E garcia is on a distinguished road
Default

Quote:
Originally Posted by Ken Smith View Post
Show me/us the Fitting problem you are having and do not remove anything original.

Sometimes the Blocked frame shifts. Sometimes you have shrinkage of the Top grains and the Top is shy of the Ribs i n the lower bout. In this case, The Ribs are cut and trimmed at the Block. For this you have to remove the lower Ribs from all blocks and re-fit it o the Corner possibly but if not, just at the Tailblock, Cut and pull together to fit the Top and maybe Back. The Plates should overhang just a bit. In the Blocks with Ribs twisted inwards, then the Top will overhang more. Still, nothing is ever perfect on an old bass.

I see what are u saying, I am sorry I did not explain my self clearly, the problem that I am having is the south part of the edges are not making contact with the flat surface, in this case the Edges thickness is about 7mm, for me to make the south part to touch, I will have to remove original material from the top edges bottom and this will result and a thinner than the original edge… I know that is not right… I don’t know if the top got distort during my repairs or what should I do…
Should I clamp it knowing that there is a little stress anyways?




but the rest of the top is resting ok
Reply With Quote
  #149  
Old 05-06-2011, 02:09 PM
Ken Smith's Avatar
Ken Smith Ken Smith is offline
Bassist, Luthier & Admin
 
Join Date: 01-18-2007
Location: Perkasie, PA
Posts: 4,851
Ken Smith is on a distinguished road
Default ??

Show the Top sitting on the ribs, dry clamped around lightly. See what gives and doesn't. The bass Bar is in already?
Reply With Quote
  #150  
Old 05-06-2011, 02:44 PM
Ruben E garcia Ruben E garcia is offline
Posting Member
 
Join Date: 10-04-2010
Location: Atlanta GA
Posts: 108
Ruben E garcia is on a distinguished road
Default

Quote:
Originally Posted by Ken Smith View Post
Show the Top sitting on the ribs, dry clamped around lightly. See what gives and doesn't. The bass Bar is in already?
It still have some of the old bar or most to the old bar since I did shave down the bass bar hump only.
Reply With Quote
  #151  
Old 05-06-2011, 02:51 PM
Ken Smith's Avatar
Ken Smith Ken Smith is offline
Bassist, Luthier & Admin
 
Join Date: 01-18-2007
Location: Perkasie, PA
Posts: 4,851
Ken Smith is on a distinguished road
Lightbulb bar hump?

Quote:
Originally Posted by Ruben E garcia View Post
It still have some of the old bar or most to the old bar since I did shave down the bass bar hump only.
Let's see what you did with that Bar. Was it angled slightly across the grain from top to bottom or straight with the grain? Is there a crack under the bar or only up to the bar at the bottom?
Reply With Quote
  #152  
Old 05-06-2011, 03:22 PM
Ruben E garcia Ruben E garcia is offline
Posting Member
 
Join Date: 10-04-2010
Location: Atlanta GA
Posts: 108
Ruben E garcia is on a distinguished road
Default

Quote:
Originally Posted by Ken Smith View Post
Let's see what you did with that Bar. Was it angled slightly across the grain from top to bottom or straight with the grain? Is there a crack under the bar or only up to the bar at the bottom?

I did shave it a lot just enought so the bar let the top to sit in a flat surface to make sure that it's flat:

Original:




now:







a small crack in the botom
Reply With Quote
  #153  
Old 05-07-2011, 04:00 PM
Ruben E garcia Ruben E garcia is offline
Posting Member
 
Join Date: 10-04-2010
Location: Atlanta GA
Posts: 108
Ruben E garcia is on a distinguished road
Default today I removed the old bass bar

Question, this is where the old bass bar used to be, I am thinking on putting the new one right on the same spot, but is the bar could be way to align with the top grain, that could cause a crack later on!!!















Reply With Quote
  #154  
Old 05-07-2011, 06:25 PM
Ken Smith's Avatar
Ken Smith Ken Smith is offline
Bassist, Luthier & Admin
 
Join Date: 01-18-2007
Location: Perkasie, PA
Posts: 4,851
Ken Smith is on a distinguished road
Lightbulb ??

Scored lines? Black ink?

The shadow of the oxidation difference is plenty enough to see where the old bar was for reference regardless of where the new bar is going.
Reply With Quote
  #155  
Old 05-08-2011, 03:56 PM
Ruben E garcia Ruben E garcia is offline
Posting Member
 
Join Date: 10-04-2010
Location: Atlanta GA
Posts: 108
Ruben E garcia is on a distinguished road
Default

Quote:
Originally Posted by Ken Smith View Post
Scored lines? Black ink?

The shadow of the oxidation difference is plenty enough to see where the old bar was for reference regardless of where the new bar is going.
No ink just pencil marks, but should I place the new one on the same spot?
Reply With Quote
  #156  
Old 05-08-2011, 04:53 PM
Ken Smith's Avatar
Ken Smith Ken Smith is offline
Bassist, Luthier & Admin
 
Join Date: 01-18-2007
Location: Perkasie, PA
Posts: 4,851
Ken Smith is on a distinguished road
Default same?

Quote:
Originally Posted by Ruben E garcia View Post
No ink just pencil marks, but should I place the new one on the same spot?
I can't see top to bottom well enough on a straight line but if not angled, angle it slightly more. There is a formula I read years ago for this but forgot where I read it. It has to do I think with the length of the bass and possibly the width. Not sure. Ask Arnold or Jeff. They have dome more 'correct' bars than the average 10 or more luthiers.
Reply With Quote
  #157  
Old 05-18-2011, 07:47 AM
Ruben E garcia Ruben E garcia is offline
Posting Member
 
Join Date: 10-04-2010
Location: Atlanta GA
Posts: 108
Ruben E garcia is on a distinguished road
Default Some Progress, Finger Patch by the Bass Bar Bottom












In my check list of Top repairs:

Cracks -Done
Sound Post Patch -Done
Edges -Done
Finger Patch - Done
Cleats -50% -Next
Bass Bar -Next
Reply With Quote
  #158  
Old 05-18-2011, 08:19 AM
Arnold Schnitzer Arnold Schnitzer is offline
Senior Posting Member
 
Join Date: 01-22-2007
Location: Putnam County, NY
Posts: 453
Arnold Schnitzer is on a distinguished road
Default

Ruben, most luthiers agree that patches with straight edges that parallel the grain lines are not the best idea. There is a good deal of strength along this line, which can contribute to forming a new crack. Hope this is helpful.
Reply With Quote
  #159  
Old 05-18-2011, 02:01 PM
Ruben E garcia Ruben E garcia is offline
Posting Member
 
Join Date: 10-04-2010
Location: Atlanta GA
Posts: 108
Ruben E garcia is on a distinguished road
Default

Quote:
Originally Posted by Arnold Schnitzer View Post
Ruben, most luthiers agree that patches with straight edges that parallel the grain lines are not the best idea. There is a good deal of strength along this line, which can contribute to forming a new crack. Hope this is helpful.

Click image for larger version

Name:	DB_Hunter_052.jpg
Views:	2698
Size:	236.5 KB
ID:	2097

I did not think about that, I have seem many repairs made this way, its does make sence that an
straight grain patch can cause problems, in this case the patch is being feather in all 4 the edges, and its also small.
I suppose next time that If I do an square patch make sure it doesnt align with the grain, or make it oval.

Arnold! Any advise on the bass bar placement ???
Reply With Quote
  #160  
Old 05-19-2011, 08:34 AM
Arnold Schnitzer Arnold Schnitzer is offline
Senior Posting Member
 
Join Date: 01-22-2007
Location: Putnam County, NY
Posts: 453
Arnold Schnitzer is on a distinguished road
Default

Quote:
Originally Posted by Ruben E garcia View Post
Attachment 2097

I did not think about that, I have seem many repairs made this way, its does make sence that an
straight grain patch can cause problems, in this case the patch is being feather in all 4 the edges, and its also small.
I suppose next time that If I do an square patch make sure it doesnt align with the grain, or make it oval.

Arnold! Any advise on the bass bar placement ???
Yes. It goes on the E side.

Ba-dum-bump!

Seriously, you want to first choose your bridge width. In general this is not much wider than the distance between upper f-hole eyes. Then you lay out the bass bar so it is slightly outside the center of the bridge imprint. The angle cannot be set by the violin-maker's method because basses are not standardized. I personally like the distance from the center line to the bass bar to be a bit more than half at the top what it is on the bottom.
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -4. The time now is 03:13 PM.


Powered by vBulletin® Version 3.7.2
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright © 2007 - Ken Smith Basses, LTD. (All Rights Reserved)