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 Post subject: Shaved bridge.
PostPosted: Sat Sep 12, 2020 6:26 pm 
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Joined: Fri Jul 10, 2009 4:44 am
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First name: colin
Last Name: north
Country: Scotland.
Focus: Build
Status: Semi-pro
Anyone ever dealt with a shaved bridge by filling the slot, then building up and reshaping the bridge?

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Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.


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 Post subject: Re: Shaved bridge.
PostPosted: Sun Sep 13, 2020 10:28 am 
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Brazilian Rosewood
Brazilian Rosewood

Joined: Thu Nov 04, 2010 1:46 pm
Posts: 2150
First name: Freeman
Last Name: Keller
Focus: Build
Status: Amateur
I've filled the slot on a couple of those bridges with the adjustable saddles but never to make the bridge taller. Actually I have only encountered two shaved bridges in my short repair career - one was an A&L with their simple bolt on neck I just set the neck to the bridge and told the owner that if the bridge ever split we would deal with it then. The other was a lovely Guild 12 string that needed a neck reset before the bridge was shaved - I sent it away to be someone else's problem.

Is replacing the bridge an option?


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 Post subject: Re: Shaved bridge.
PostPosted: Sun Sep 13, 2020 12:00 pm 
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Koa
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Joined: Wed Feb 17, 2016 8:54 am
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State: Texas
Country: United States
Focus: Repair
I've start doing this lately and having good success but there's some caveats.

If the bridge is wafer thin then I usually opt to replace it. If it's only been shaved a bit then it's not a big deal to add arpund 1/8 or so to give it some meat for a higher saddle.

I'll only do it if it's not badly cracked and not damaged.

This is one of the times where I employ 24hr epoxy for a strong bond. It does help to take the bridge off but sometimes it's not necessary. Pre drill the pin holes and use them for alignment during the glue up if you leave the bridge on.

I try to match the wood species as best as possible. Ebony is fairly easy to blend and make it look natural
Rosewood not so much.

Ymmv but I've found it to be a decent way of saving the customer some money and extending a guitars life when it's appropriate.


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 Post subject: Re: Shaved bridge.
PostPosted: Sun Sep 13, 2020 12:40 pm 
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Brazilian Rosewood
Brazilian Rosewood

Joined: Thu Nov 04, 2010 1:46 pm
Posts: 2150
First name: Freeman
Last Name: Keller
Focus: Build
Status: Amateur
Dan, I'm having a hard time envisioning how you would do this. First, my assumption is that the reason someone shaved the bridge is that they had lowered the saddle as much as they could and the action was still too high. They didn't want to reset the neck so they shaved the top of the bridge so they could continue lowering the saddle. Lets say they too 1/8 inch off a 3/8 thick bridge.

Are you trying to bring the bridge up to its original thickness? Do you route out a big area of the bridge around the saddle slot, fill that with a piece of wood that stands above the shaved bridge and then route a new slot? I would assume after that you would set the neck to the new bridge height.

If you are going to remove the bridge to do this work why wouldn't you just make a new one the proper thickness and then set the neck to that?

As I said, I have filled the wide slots on a couple of those adjustable acoustic bridges but I did not have to make them taller. I've got that StewMac jig that lets me route a new saddle slot with the bridge on the guitar - it is kind of figity to set up but seems to work fine.

I have always been under the impression that shaving a bridge was a stop gap measure that would have to be corrected if and when the neck was finally reset. I'll admit to doing it once on an Ovation that was on its dying legs, we agreed that was the only option to get a little more life out of it (and I was conservative with my shaving). Anyway, I would love to see pictures of exactly what you are doing.


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 Post subject: Re: Shaved bridge.
PostPosted: Sun Sep 13, 2020 1:33 pm 
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Brazilian Rosewood
Brazilian Rosewood

Joined: Fri Aug 19, 2005 4:02 am
Posts: 3263
Location: The Woodlands, Texas
First name: Barry
Last Name: Daniels
Shaving the bridge is an old technique to avoid a reset, but in this age it is not advisable due to the irreversible nature of it. I consider it something only done by ill informed or lazy repairmen.


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 Post subject: Re: Shaved bridge.
PostPosted: Mon Sep 14, 2020 9:02 am 
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Koa
Koa

Joined: Mon Feb 13, 2012 8:49 pm
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First name: peter
Last Name: havriluk
City: granby
State: ct
Zip/Postal Code: 06035
Country: usa
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Status: Amateur
It seems to me as if shaving an overthick bridge down to nominally routine bridge thickness would go virtually unnoticed and doing so wouldn't be a shortcut to anything. Whether the guitar that bridge is attached to is folding in on itself is another matter. Perhaps it just found an equilibrium?

I suspect there are times when shaving a bridge is the difference between a playable instrument and a wall decoration.

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 Post subject: Re: Shaved bridge.
PostPosted: Mon Sep 14, 2020 1:02 pm 
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Brazilian Rosewood
Brazilian Rosewood

Joined: Fri Aug 19, 2005 4:02 am
Posts: 3263
Location: The Woodlands, Texas
First name: Barry
Last Name: Daniels
Like I said, no experienced repairmen would even consider shaving a bridge, unless it was overly thick to begin with. For example, you would never want to take a bridge below about 5/16".


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 Post subject: Re: Shaved bridge.
PostPosted: Mon Sep 14, 2020 2:11 pm 
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Joined: Mon Aug 23, 2010 11:42 pm
Posts: 1703
First name: John
Last Name: Parchem
City: Seattle
State: Wa
Zip/Postal Code: 98177
Country: USA
Focus: Build
Status: Amateur
Going back to the original question, I see no issue with laminating a 1/8" veneer or so on a shaved bridge; especially if it is ebony. If it is a rosewood bridge it would take a bit more care. Filling the slot and using a plane to get a flat surface and building up the bridge seem like a good idea. I just assumed that the neck would be reset as well to eliminate the need for the shaved bridge.

On the flip side planing off a bridge is clean and easy. If you can get or make a replacement that might be a way to go as well with close to same amount of work.

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 Post subject: Re: Shaved bridge.
PostPosted: Mon Sep 14, 2020 3:03 pm 
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Joined: Sat Jan 31, 2009 8:50 pm
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Location: Seattle WA
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Shaving Bridges is great option for any clever repairman to have in his bag. I do it all the time to $2-300 guitars. The decision is just a function of value. I've gone down to 1/4" without any discernible performance degradation. Half the time I'm only taking off less than a 16th.

I usually start with a smoothing plane then coarse and fine hand stitched rasp b4 sanding. I highly recommend it! When your client gets their guitar back with super low action they will be glad you did.

Pat

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 Post subject: Re: Shaved bridge.
PostPosted: Tue Sep 15, 2020 10:13 am 
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Koa
Koa

Joined: Wed Feb 17, 2016 8:54 am
Posts: 854
State: Texas
Country: United States
Focus: Repair
Freeman wrote:
Dan, I'm having a hard time envisioning how you would do this. First, my assumption is that the reason someone shaved the bridge is that they had lowered the saddle as much as they could and the action was still too high. They didn't want to reset the neck so they shaved the top of the bridge so they could continue lowering the saddle. Lets say they too 1/8 inch off a 3/8 thick bridge.

Are you trying to bring the bridge up to its original thickness? Do you route out a big area of the bridge around the saddle slot, fill that with a piece of wood that stands above the shaved bridge and then route a new slot? I would assume after that you would set the neck to the new bridge height.

If you are going to remove the bridge to do this work why wouldn't you just make a new one the proper thickness and then set the neck to that?

As I said, I have filled the wide slots on a couple of those adjustable acoustic bridges but I did not have to make them taller. I've got that StewMac jig that lets me route a new saddle slot with the bridge on the guitar - it is kind of figity to set up but seems to work fine.

I have always been under the impression that shaving a bridge was a stop gap measure that would have to be corrected if and when the neck was finally reset. I'll admit to doing it once on an Ovation that was on its dying legs, we agreed that was the only option to get a little more life out of it (and I was conservative with my shaving). Anyway, I would love to see pictures of exactly what you are doing.


Well keep in mind I only do the repair when a neck reset is done but the bridge doesn't really warrant being replaced. It's usually when I feel like it would benefit from a higher saddle but there's not enough meat to stand up to the new saddle height.

I also only shim a maximum of 3/16" tall. If you have to add anymore than that I'll opt to replace the bridge. If the bridge is a wafer I'll replace it. Also if the bridge is a complex design like a J200 or a late 70s Heritage bridge it's just a time and money saver to shim it if all it needs is a little extra meat.

Your assumption about bridge shaving is correct. It's a way to get a guitar to play better without a neck reset.

A good example of when I do it, I had an early 00s J200 studio in the shop recently where the saddle and pin portion had been cut down to a crazy low point. The mustache portions were just fine and it was glued really well to the top. To bring it back to a good height (in this case it was to match it with the sides of the mustache) I decided to shim it. Once the neck reset was done it was definitely needed in order to make things work correctly.

My method.
1. Glue in a fill for the saddle slot.
2. Sand area to be glued as flat as possible to 220. I use a diamond sharpening stone with sticky sandpaper attached to do this.
3. usually the shim covers the pinholes, I pre-drill the shim so I can use the pins to hold it in place when it's glued up.
4. Wax the pin holes and pins and then glue the shim with 24hr epoxy
5. Sand everything clean and flush. Route for the new saddle and setup.

You can vary it a bit for certain guitars. Again I don't do this all the time. And if the bridge needs to be reset but is undamaged I'll just remove it and do the shim work with it off the guitar, glue it back on and then route the shim for the right saddle location.

Again if the bridge is badly damaged/cracked/wafer thin I'll replace it completely.


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