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Being in need of a bridge plate, I found in my woodpile a nice piece of 1/8" thick maple, flatsawn. Any reason why some of that can't be used for bridge plates? Commercial maple bridge plates, at least the ones I found, are quartersawn and .100" thick. Swapping the quartersawn for flatsawn but .025" thicker makes some intuitive sense, but does it make luthier's sense?

Thanks, folks.

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Peter Havriluk

I would think that should be fine - my current build in progress OM has a rift to flatsawn maple bridge plate at 0.09".
Not so sure that you need to make it thicker than a quarter sawn one. Not much if any difference in strength/flexibility/rigidity between quarter and flatsawn, and it would increase weight where you may not want it.

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The name catgut is confusing. There are two explanations for the mix up.

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.

It'll likely want to curl more than quarter sawn if you glue it with a water based glue.

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Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au

You can always dampen the other side with water to help keep it flat. I do that with FB's.

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The name catgut is confusing. There are two explanations for the mix up.

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.

I don't think you need to make it thicker. If you use Titebond clamp it for 12 hours. I've never tested bridge plates but I have tested braces and they are stiffer in general then their quarter sawn counter parts. The issue with a sheet as large as a bridge plate though is the expansion would be greater with the flat sawn piece. I'm gonna guess however it's nothing to be worried about, I could be wrong. The ones I use are usually off quarter and I orient them so that the annular rings slant towards the head block in the direction of string pull. Seems to make intuitive sense. Flat sawn also seems intuitively to be better at handling the ball end string as a mounting point. A ball end might tend to want to split along the annular rings, again speculation but something to think about, or at least not worry about

I was under the impression that Maple in the flat sawn form is what works best. I hope it's ok. I've used it on every guitar I've built.

Anyone else using other woods besides maple.? I have some pecan wood which seems at about the same density or slightly higher than maple , the density of pecan is roughly between eir and maple ???

thanks, folks. I'll sleep easy. And thin the plank down a bit.

About maple, no fixation about the species. Happened to have it, wanted to use up the stuff I owned if it was usable.

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Peter Havriluk

use the flatsawn.
Much more difficult to split then quartered!
Thickness depends on -string tension .& top thickness.
2.5mm-3mm is best !

I'll let ya all think about that for awhile.

Mike

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Mike Collins

The only real problem with flat sawn bridge plates in general is that it's the cut that has the highest tendency to crack. Basically that's because the medullary rays run perpendicular to the surface, and act as weak points in the bond between the cells. Quartered wood gets part of it's stiffness and strength across the grain from the rays, which have cells that run along the radius of the tree, and tie the cells together in that direction.

Probably the best cut for bridge plates is 'skew' or 'rift', where the annual ring lines are at 45 degrees to the surface. This gives the lowest cross grain stiffness, and the highest shear modulus and splitting resistance. The low cross stiffness is actually a good thin in this case, as it allows the bridge plate to deform along with the top as it bellies, helping to avoid a stress riser along the front and back edges of the plate.

The two biggest problems with bridge plates come in when the wear through, and when they crack along the line of the pin holes. Skew cut rock maples is a good choice because it resists both problems. Persimmon is even better.

I'd use flat sawn too and IIRC when I was building my plates were around .090" thick. Rift is preferable but I think that flat is fine too provided that you don't mimic 70's Martins and make the plate bigger than the guitar....

What's in my view more important if you want the instrument built as well as we know how is to use 3 degree (5 degree is nearly as good) unslotted pins and slot the bridge, top and plate for the strings. This is how it was done back in the day before the advent of cheap-arse, mass produced plastic pins.

The 1870's and later guitars that we work on that had unslotted pins usually have bridge plates that look like new and have no issues requiring repair or replacement. The same is not true of instruments that had slotted pins.

Slotted pins permit the string balls over time to start to migrate upward eating away at the sides of the pin holes in the bridge plate. This leads to bridge plates developing a crease and even a split along the pin holes which leads to lifting bridges, loose braces, top deformation, depressions in front of the bridge and a partridge in a pear tree.... Sorry I actually speak like this in person.... at times.

Anyway that's my 1.5 cents, use the flat stuff, make it .090" thick or no thicker and obtain and use unslotted pins.

Thanks, everybody. I feel like I started a symposium about bridge plates.

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Peter Havriluk

I totally agree with Hesh but want to make sure this point does not get over looked


"unslotted pins and slot the bridge, top and plate for the strings."

When done correctly I have found that the strings will stay in place even without pins!

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Ken Cierp

http://www.kennethmichaelguitars.com/

Exactly!

Preaching to the choir!

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Peter Havriluk

On the contrary -- Look to see how many modern guitars have this feature instead of slotted pins and rarely have I seen any of the no name hand made's or other factory guitars that even have bridge slots/ramps. Keep in mind that posts are for all forum members including those getting started, not just the OP.

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Ken Cierp

http://www.kennethmichaelguitars.com/

Why is it so hard to find unslotted pins?
Or have I not looked hard enough?

B

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My memory is so good, sometimes I remember things that never happened.

I use these: https://www.lmii.com/products/mostly-wo ... nd-plastic

Or just use the slotted ones and flip them around.

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Bri they are harder to find and the 3 degree ones are really hard to find but they are out there.

I was fond of using BRW 3 degree unslotted pins and had to have them made for me.... so I did....

The problem with using slotted pins and turning them around is if anyone else ever restrings the guitar and puts the slots forward not understanding what you intended the extra large slots will encourage the string balls to migrate upward right away and damage things.

I'll add that since I mentioned BRW pins no... I do not and did not include them with my guitars for sonic reasons. I just liked the look. I also had African Blackwood pins made and used those too again for the look.

If bridge pin material has any sonic impact at all, and it actually likely does.... IMO... it's the change in mass of different pin materials on the sweet spot of a guitar top, the bridge. Long ago in another thread this was Al C's belief about pin material and tone and it's worked for me ever since Al shared it. Thanks again Al!

Some guitars may benefit from more or less mass in the bridge area. How do we know which? We can't without trying them out and wondering if we are imagining what we hear.... Anyway they look nice.....

I hesitate to ask, but that is exactly what I had planned to do. Is there a problem with just putting the pin slot opposite to the string slot?
thanks,

See the response from Hesh above. It will work fine if it's just for you.

LMI has the 3 degree unslotted pins. Make sure your pin reamer matches.


Sent from my iPhone using Tapatalk

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Does anyone have a link to a discussion that lays out why one would choose 3 degree rather than 5 degree?
I have been using 5, have the reamer and pile of unslotted pins to match.

3 degree has a larger opening. More room for the ball end to get through, normally a non-issue, unless you have a thicker than normal bridge/top/plate sandwiche.