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PostPosted: Wed Jan 15, 2020 6:30 pm 
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Walnut
Walnut

Joined: Wed Jan 15, 2020 12:30 pm
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First name: Jim
Last Name: Cheoros
City: London
State: London
Zip/Postal Code: SW154NL
Country: UK
Focus: Repair
Status: Amateur
I've got a CA Acoustics "Cargo" guitar that I like, but which has terrible intonation (which is a particular bugbear of mine).

I was thinking of filling in the saddle slot with something like epoxy and the using a length of steel or titanium wire bent into the right shape to act as a new saddle.

The bridge appears to be made of some composite itself:

Image

Can anyone recommend a suitable (ie, resonant) filler?

Thanks!


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PostPosted: Wed Jan 15, 2020 7:21 pm 
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Contributing Member
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Joined: Mon Aug 23, 2010 11:42 pm
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First name: John
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A strip of ebony, level it and reroute the slot where you think you want it maybe a little wider to give you room to intonate. It is easy to build a jig that will allow you to route a new slot with the bridge on the guitar. Just put in another bone saddle.

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PostPosted: Wed Jan 15, 2020 8:18 pm 
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Koa
Koa

Joined: Thu Nov 04, 2010 1:46 pm
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First name: Freeman
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That is a pretty common "repair" for those guitars with the saddles in the wrong spot (old Martins). If the bridge was ebony for sure I would fill it with ebony, not sure if what to use if it is a composite or CF. I do own the StewMac jig for slotting a bridge on the guitar - you will need something like that. However just looking at the saddle, have you tried compensating a new bone saddle in the existing slot? Also, that saddle looks really low, how is the neck angle on the guitar?

Edit to add, you probably won't be able to bend a piece of wire into the proper shape to get each string in tune. The second string, needs a lot more compensation than the third due to core wire diameters. You can use this to see how much you need to move the break points

https://www.liutaiomottola.com/formulae/saddle.htm

or this to calculate them from the raw data

https://www.liutaiomottola.com/formulae ... sation.htm



These users thanked the author Freeman for the post: BigJim (Thu Jan 16, 2020 9:18 am)
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PostPosted: Wed Jan 15, 2020 9:38 pm 
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Brazilian Rosewood
Brazilian Rosewood

Joined: Fri Aug 19, 2005 4:02 am
Posts: 2363
Location: The Woodlands, Texas
First name: Barry
Last Name: Daniels
That guitar needs a neck reset. I worked on a CA guitar that was less than a year old and it needed a neck reset too. Problem is you can't reset the neck. It is part of the structure of the guitar and there is no headlock. Terrible design.


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PostPosted: Thu Jan 16, 2020 6:36 am 
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Old Growth Brazilian Rosewood
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The best material to fill a bridge is the exact same material that the bridge is made out of. In this case though you may be sol if this bridge is a composite and/or not solid.

As others have rightly mentioned moving a saddle is common practice for folks who are certified Martin repair people like our business is. We even have a $4,000ish mill specially made for plugging bridge saddle slots and cutting new ones in the correct position. The entire mill vacuum clamps to the guitar top and has a level of precision that is second to none.

But I would be concerned that this bridge is hollow and not solid like the ole g*bson pl*stic bridges found on the 50's "L" series. I also would be a bit concerned about wearing a pretty good respirator if milling compost materials as well.

Moving to what Barry said if this guitar has the neck folding into the body and it was not engineered to be serviceable and reset why bother, moving the saddle is addressing a symptom of a greater, unaddressable issue it needs a neck reset.

Welcome to the forum as well.

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PostPosted: Thu Jan 16, 2020 9:30 am 
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Walnut
Walnut

Joined: Wed Jan 15, 2020 12:30 pm
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First name: Jim
Last Name: Cheoros
City: London
State: London
Zip/Postal Code: SW154NL
Country: UK
Focus: Repair
Status: Amateur
Thanks for the replies.

Yes, the neck angle is terrible (I'm told the newer Peavey-produced ones are better in this respect) but CA went out of business the week after the guitar arrived so I couldn't send it back (and Peavey refused to honour the warranty after they'd bought the brand and restarted production). As noted, the neck can't be reset, so I cut the saddle down as far as I could and the action is ok now. And the neck had too much bow; it doesn't have a truss rod, so I had to get a luthier scrape the fretboard flat, which sorted that out.

But I like the sound (it's surprisingly loud for its size) and the guitar is practically indestructible, making it a great travel instrument, so - having sunk so much time and effort getting it into semi-decent shape - I'm willing to put a little more time into getting the intonation right. But the intonation is too far out on most strings to fix by cutting a new saddle, unfortunately.

Do you people think a sliver of ebony would be more resonant than filling the slot with epoxy (or some other glue)?


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PostPosted: Thu Jan 16, 2020 9:49 am 
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Brazilian Rosewood
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Joined: Tue May 13, 2008 10:44 am
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Location: Virginia
If it were me I would rout it out for a 1/4in saddle and that shoudl give you plenty of room for intonation unless it's completely whacked and in that case nothing would fix it.


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PostPosted: Thu Jan 16, 2020 10:47 pm 
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Koa
Koa

Joined: Wed Feb 17, 2016 8:54 am
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State: Texas
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jfmckenna wrote:
If it were me I would rout it out for a 1/4in saddle and that shoudl give you plenty of room for intonation unless it's completely whacked and in that case nothing would fix it.


The 1/4 saddle is the easiest solition. That'll keep you from having to find a filler and will probably save aloy of time.


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PostPosted: Sun Jan 19, 2020 4:22 pm 
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Walnut
Walnut

Joined: Wed Jan 15, 2020 12:30 pm
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First name: Jim
Last Name: Cheoros
City: London
State: London
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Country: UK
Focus: Repair
Status: Amateur
Thanks for the further advice.

I must admit I was hoping to do this myself to save some money, and I don't trust myself to rout the slot wider with any accuracy!


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