Mike's Oud Forums

Closing old string holes in the bridge

rojaros - 4-21-2014 at 09:44 PM

Hello, I would like to drill new holes in the bridge of my Copcuoglu oud a bit lower than the old ones, because they are getting too worn out and too big, and I cannot lower the action far enough with the old ones.

How do you go about closing the old holes? How about gluing in pieces of tooth pics with Titebond?

Advice much appreciated

best wishes
Robert

BaniYazid - 4-22-2014 at 04:02 AM

Hello,

You should drill the holes, melt the dust produced while drilling with Titebond and close the holes. I think the Titebond Original is the less coloured glue.
I drilled new holes on a valueless oud, it's not easy to stay straight.
Tooth pics may work, if the diameter match the holes.
This operation is not an effective way to lower the action, just try by placing a string manually before drilling to know what it will give.
And wait for other advice... I'm not a luthier.
:wavey:

Jody Stecher - 4-22-2014 at 09:48 AM

If a string hole in a bridge was wearing out and getting larger, wouldn't it wear out at the part where there is most contact with the string? That would be the part of the hole closest to the soundboard. That should have the effect of lowering the action, not raising it. I think the action may have gotten higher for some other reason.

Fritz - 4-22-2014 at 11:29 AM

Jody... I think : The part of the hole nearest to the soundboard isn´t treated... unlike the upper part. The knot of the wrapped string is too tight... the "slung" string will be pulled up by the knot.... never touching the bottom surface of the hole... Hmm ?

It´s possible to close the holes with another (harder ) wood... then drill new in the wanted height, leaving some of the harder wood in the top of the inner diameter of the hole.. The harder wood might protect from wearing out by using the new hole. Glue the wood-"sticks" tight in the holes, make some scratches on the sticks to force a fine joint inside the bridge, using a good amount of glue (Titebond Original is a very good idea) on both surfaces of the joint. Let it dry for some days... may be 3 days are enough. Drill the new holes in another angle as the originals have been drilled... Take care to match the line needed to drill all holes in an exact level hight from the surface of the soundboard. Drill with a Dremel from the front of the bridge to the back... the front holes have to be higher than the ones where the drill comes out.

But... in general : Jody is right with his idea : The higher action is rarely an effect of the bridge... make sure the neck has the angle aganist the soundboard. The strings will be higher some hundreds of an inch when the bridge holes are worn out, but they will be higher some mm when perhaps the neck end is about 1 mm higher as usual.

rojaros - 4-22-2014 at 02:49 PM

Jody, you lost me completely. The strings are always pulled against the upper part of the hole so it gets larger upwards, not downwards.

I'm not missing much, something like one millimeter at the bridge. I'm quite sure that the neck angle isn't too wrong, the oud is quite stable.

Also a raised neck would have it's strongest effect at the portion towards the nut to the joint with the body, but this is not at all the case with my oud.


Fritz, thanks for advice on closing and drilling. Why do you think that the whole should start higher than end? And what is the idea about drilling from the front to the back?
I would rather drill from behind against a block of would in front making sure not to chip out the holes (???)

best
Robert

Fritz - 4-26-2014 at 12:03 PM

Quote: Originally posted by rojaros  
Jody, you lost me completely. The strings are always pulled against the upper part of the hole so it gets larger upwards, not downwards.

I'm not missing much, something like one millimeter at the bridge. I'm quite sure that the neck angle isn't too wrong, the oud is quite stable.

Also a raised neck would have it's strongest effect at the portion towards the nut to the joint with the body, but this is not at all the case with my oud.


Fritz, thanks for advice on closing and drilling. Why do you think that the whole should start higher than end? And what is the idea about drilling from the front to the back?
I would rather drill from behind against a block of would in front making sure not to chip out the holes (???)

best
Robert



Hi Rob

Perhaps my english isn´t good enough to tell what I really mean... Let me try again :)

With the term "higher" I meant, that the hole in the bridge, where the string comes out in direction to the neck... has to be higher than the end of the channel on the back side of the block, where the string is pulled up to tie. The hole isn´t parallel to the soundboard (or the upper surface of the bridge), it goes down a bit... to take grip in the most of wood possible ! This is making sure the string doesn´t loose its position horizontal and vertical.

When drilling the holes, I start at the front side of the bridge for absolute precision of every holes height above the soundboard. I begin with a hard needle to make a small pin-sized mark in the wood... checking how the wood will tend to deplace the marked hole-position when drilling. Than with drill diameter at about 0,5mm I carefully drill slow half mm for half mm in a special angle. The drill comes out a bit lower than it began... so the channel for the string is going a bit downwards. Where the drill is going to come out, I hold a matching piece of wood against the behind end of the tie-block to prevent splitting. When every hole is drilled in this way, I take the next size drill ( 1mm) to drill the holes again until the special diameter of string is going through the specific hole.

The line of holes I make in a special way : Keeping in mind, that the treble strings aren´t oscillating as wide as the bass strings do, I give the 1st string pair (the highest) a lower height for the holes... the last string (11th) has its hole a bit higher. Pair for pair getting lower distance between soundboard and underside of string from the 1st bass to the last treble. This difference is from 1st to 11th only about 0,8mm... but it increases the playability !

And... the plus of this method : You can do all this on a mounted bridge ! I glue the top complete with bridge and pick guard on the bowl.

Hmm... I hope, this was a bit more understandable :) Wasn´t it ? :)

Best wishes

Fritz

rojaros - 4-28-2014 at 02:18 PM

Thanks, Fritz, that was perfectly understandable for me. Sounds like a sweat task ... One can do a few things wrong, I guess.