Glueing Plates to ribs

[nbar]

Hello Fellow Members,

First, I hope that everyone is safe and staying home as much as possible in these difficult times.  I am relatively new to violin making.  I have heard that you are able to adjust the thickness or consistency of hide glue.  And that you are able to extend the working time of hide glue with the addition of urea.  For gluing the back and top plates unto the ribs how many grams of hide glue is recommended?  And how many grams of urea?  As for using urea I have heard up to 10% but I just wanted to check with more experienced luthiers before I go any further.  

Thank, in advance,  for any of your thoughts.  Stay safe.

Best,

nbar

[J.DiLisio]

You'll find some good tips here..

https://bjornhideglue.com/hide-glue-info/hide-glue-instructions/

I started using Bjorn hide glue about a year ago and have no complaints. 

[Nick Allen]

3 hours ago, nbar said:

Hello Fellow Members,

First, I hope that everyone is safe and staying home as much as possible in these difficult times.  I am relatively new to violin making.  I have heard that you are able to adjust the thickness or consistency of hide glue.  And that you are able to extend the working time of hide glue with the addition of urea.  For gluing the back and top plates unto the ribs how many grams of hide glue is recommended?  And how many grams of urea?  As for using urea I have heard up to 10% but I just wanted to check with more experienced luthiers before I go any further.  

Thank, in advance,  for any of your thoughts.  Stay safe.

Best,

nbar

I would just try and thin it with water. There are methods to glue the plate to the ribs that don't involve putting glue in the whole perimeter of the ribs. 

I like to clamp everything in place, and then use a pallette knife with glue on it to carefully knife it in, taking off 3-4 clamps as I go. 

[David Burgess]

4 hours ago, nbar said:

 I have heard that you are able to adjust the thickness or consistency of hide glue.  And that you are able to extend the working time of hide glue with the addition of urea.

I don't know of any high-level violin makers or restorers who add urea to their glue. While it will retard gelling time, it also makes the glue more hygroscopic, with the result that it will get soft and release under high humidity situations, where unadulterated hot hide glue will still be holding quite well.

[nbar]

Thank you, DoorMouse, Nick, and David for your very quick response.  Great to be involved with such an active and helpful site.  Before I glue it down for real I will clamp the back a few times so that I am more comfortable is using the clamps.  Thanks again.  

nbar

[violinsRus]

9 hours ago, David Burgess said:

it also makes the glue more hygroscopic

Agree.  I would skip urea and stick with straight hide glue, thinned.  I use Nick's method of working slowly around the plate.  Good luck.

[FiddleDoug]

Working in a quite warm area, or warming the parts a little with a lamp, will also extend your working time.

[nathan slobodkin]

Bjorn is great glue and their  info is excellent.

For ribs to back you want medium strong glue which will not release by itself but can be opened for repairs if absolutely necessary. For tops to ribs it is almost impossible to make it too weak. You should be able to easily open the joint with a thin blade and if it should come loose from some stress of wood movement it can simply be glued back and no harm is done.

I put on tops with old almost rotten glue which has been used several times and thinned down again over a week or more.