Official Luthiers Forum!

Owned and operated by Lance Kragenbrink
It is currently Thu Nov 28, 2024 5:59 am


All times are UTC - 5 hours





Post new topic Reply to topic  [ 8 posts ] 
Author Message
 Post subject:
PostPosted: Mon Jul 09, 2007 3:24 am 
Offline
Cocobolo
Cocobolo

Joined: Sun Jan 28, 2007 4:43 am
Posts: 219
Location: United States

Thanks to Todd (I think it was him) for the kraft paper idea when bending the sides. My second set bent well and they are beutifully free of resin spots.


The problem:


This side bending gets easier, and this set went well except for a crack. The crack is about 1/3 of the way from the top of the side, it runs with the grain, is about 1 to 1.5 inches long at the butt.


This is where i  am going to glue the tail block, but the crack will still be visible a little bit after trimming and putting in the tail piece.


Should I leave it for now and glue the tail piece and then flood any visible area with glue and dust or try some sort of fix now before I glue in the block ?


Thanks in advance, and one of these days I will post from home and post some picsWink


 


 



Top
 Profile  
 
 Post subject:
PostPosted: Mon Jul 09, 2007 3:51 am 
Offline
Brazilian Rosewood
Brazilian Rosewood

Joined: Tue Feb 15, 2005 10:31 am
Posts: 3134
Location: United States
Jon,

I'm sure you'll get more experienced advice here, but I'm thinkin' that the best time to repair a crack is when you can squeeze it together and glue it. It'll disappear.


Top
 Profile  
 
 Post subject:
PostPosted: Mon Jul 09, 2007 6:34 am 
Offline
Old Growth Brazilian
Old Growth Brazilian

Joined: Tue Dec 28, 2004 1:56 am
Posts: 10707
Location: United States
Yep with the grain, the repair will disappear if done with care.

This often cause when removing the side from the bender if you use a spring loaded hand pull over type lower bout caul and stiff slats. If you do not have a restraint on the sandwich and you slide the hand pull caul back up the toward the waist area the bottom slat wants to spring out and causes a slapping action and this action if unrestrained will easily cause the side to crack along the grain at the lower bout.


Top
 Profile  
 
 Post subject:
PostPosted: Mon Jul 09, 2007 7:08 am 
Offline
Cocobolo
Cocobolo

Joined: Sun Jan 28, 2007 4:43 am
Posts: 219
Location: United States

Actually, I know what i did.


I think I took too long on the waist and the other side. This is only my second set to bend (first is on the wall as a reminder of what NOT to do  LOL ).  I used kraft paper that was wet, and by the time I got to the bending the lower bout I think the heat had dried most of the moisture. I bent a little too fast and heard it happen. I was glad that was the only crack.


I don't have springs, I have what I call a Ghetto Bender (patent pending). My bender is a typical 1/2 mold with wierd long screws that twist a mahoganey scrap block tight by with lawn mower wheel handles.


Thanks for the input guys,


Now, what type of glue would be best. I seem to have not advanced much beyond the titebond for everything phase yet. I want to ask if other types of glue would be better before i go and use titebond.



Top
 Profile  
 
 Post subject:
PostPosted: Mon Jul 09, 2007 7:51 am 
Offline
Old Growth Brazilian
Old Growth Brazilian

Joined: Tue Dec 28, 2004 1:56 am
Posts: 10707
Location: United States
HHG would be best, TB will work and if the crack is tight enough thin CA applied with an extra fine capillary tube will work with darker woods


Top
 Profile  
 
 Post subject:
PostPosted: Mon Jul 09, 2007 8:26 am 
Offline
Cocobolo
Cocobolo

Joined: Sun Jan 28, 2007 4:43 am
Posts: 219
Location: United States

Being that the side is so thin (about 0.080") what would be the best way to clamp it tight.



Top
 Profile  
 
 Post subject:
PostPosted: Mon Jul 09, 2007 8:38 am 
Offline
Old Growth Brazilian
Old Growth Brazilian

Joined: Tue Dec 28, 2004 1:56 am
Posts: 10707
Location: United States
It needs to clamp in a way the holds the crack tight and not flex the side I do this with the assembly mold some wax paper and some bias tape as lashing. I glue the joint and quickly lash it to the assembly mold with the wax paper between the mokd and the side. but not to tightly just enough to close the crack nicely.


Top
 Profile  
 
 Post subject:
PostPosted: Mon Jul 09, 2007 11:20 am 
Offline
Brazilian Rosewood
Brazilian Rosewood

Joined: Mon Feb 21, 2005 6:16 am
Posts: 2244
Location: United States
First name: michael
Last Name: mcclain
City: pendleton
State: sc
Zip/Postal Code: 29670
Status: Professional
i would also want the crack supported by a caul clamped to the side to keep it flat against the mold if your are going to do it this way. the caul can easily be made with friendly plastic or bondo.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 8 posts ] 

All times are UTC - 5 hours


Who is online

Users browsing this forum: No registered users and 19 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
Powered by phpBB® Forum Software © phpBB Group
phpBB customization services by 2by2host.com