Damaged Bridge Plate

WebertRLZ · #1 01-31-2021, 02:05 PM

Hello everyone, I've recently acquired this old acoustic guitar.

Overall, it looks pretty solid except for the bridge plate underneath the soundboard.
It looks like the bridge plate was made out of laminated wood (or it was poorly patched up) and external layers are falling apart. See pictures:

https://imgur.com/a/KpxmLP1

I would like to ask:
- is it safe to string this guitar? I was expecting to use 12 gauge on it, but could it crack the soundboard?
- should I remove this loose layers of wood out of it?
- can I easily patch this up at home?

Cheers,

--------

UPDATE: I removed the external layers, it looks good now, I think it's safe to string it as there is no belly on the soundboard. The plate is thin but workable.

jricc · #2 01-31-2021, 02:12 PM

Hi, I'm not a qualified repair person, but something like this might work...
https://www.stewmac.com/luthier-tool...oaApieEALw_wcB

or u can avoid the bridgeplate altogether with these pins. https://www.stewmac.com/parts-and-ha...-pins-2-0.html

Hope this helps.
jricc

UncleJesse · #3 01-31-2021, 03:16 PM

A tech also might able to put a maple cap over that plate.

1Charlie · #4 01-31-2021, 03:26 PM

The easiest and cheapest solution is a plate mate.

WebertRLZ · #5 01-31-2021, 03:33 PM

Quote:

Originally Posted by jricc

something like this might work...
https://www.stewmac.com/luthier-tool...te.html]<br />

Quote:

Originally Posted by 1Charlie

The easiest and cheapest solution is a plate mate.

This looks like a good option, I think I could remove the parts there are dangling, they look very thin foils of wood, and put this on top of what's left of the plate. But I can't find it nearby. I'll have to look more.

Quote:

Originally Posted by jricc

or u can avoid the bridgeplate altogether with these pins. https://www.stewmac.com/parts-and-ha...-pins-2-0.html
jricc

Hah, this is very interesting. I forgot this existed. I wonder thought if that would transfer too much pull pressure to the soundboard and crack it.

WebertRLZ · #6 02-06-2021, 06:28 AM

I left it with a luthier to evaluate the cost of repair. Will know more next week.

srick · #7 02-06-2021, 06:35 AM

I’ll second the ‘plate mate’ as an interim or semi-permanent repair. Easy to place and remove. It’s a lot less expensive than a new bridge plate. The extra mass (it’s not much) May color your sound a little. In the case of my Martin D35, IMO, the overall sound was improved.

Good luck. Best,

Rick

WebertRLZ · #8 02-06-2021, 10:50 AM

Quote:

Originally Posted by srick

I’ll second the ‘plate mate’ as an interim or semi-permanent repair.
Rick

Yes that's really good advice but I don't find these in Germany. Unless I try to cut one myself, I'd have to look for a proper brass piece.

Does anyone know what's the thickness of the platemate?

Thanks,

Webert

John Arnold · #9 02-06-2021, 11:51 AM

PlateMates are about 0.025" (0.6mm) thick and 1/2" wide. Whatever you do, don't make it out of brass. Aluminum works just fine, and weighs less than 1/3 as much as brass. A maple or other hardwood overlay (1/16 thick by 5/8 wide) is IMHO a better option.
That said.......
Probably the simplest and cheapest is to repair with CA. Remove all the slivers with a small sanding block. Tape over the holes with a strip of masking tape on the inside. Drop thin CA from above. You can drop some wood dust in the glue, but it is not imperative. Let dry, then remove the tape. Clamp a backer block on the plate and redrill the holes with a 3/16 (5mm) bit. Taper ream the holes to fit the pins. It's a 10 minute job, at most.

blindboyjimi · #10 02-06-2021, 12:07 PM

Quote:

Originally Posted by John Arnold

PlateMates are about 0.03" (0.75mm) thick and 1/2" wide. Whatever you do, don't make it out of brass. Aluminum works just fine, and weighs less than 1/3 as much as brass. A maple or other hardwood overlay (1/16 thick by 5/8 wide) is IMHO a better option.
That said.......
Probably the simplest and cheapest is to repair with CA. Remove all the slivers with a small sanding block. Tape over the holes with a strip of masking tape on the inside. Drop thin CA from above. You can drop some wood dust in the glue, but it is not imperative. Let dry, then remove the tape. Clamp a backer block on the plate and redrill the holes with a 3/16 (5mm) bit. Taper ream the holes to fit the pins. It's a 10 minute job, at most.

John, did you look at the picture?

I’m not seeing a simple chewed up bridge plate. I’m seeing a whole portion of the spruce top has been removed and replaced. There is either a large cleat or the remnants of the old bridge plate on the treble side and there is a chunk rosewood laid over that! The rosewood has split since it wasn’t flush to the top and now your spruce patch is the only thing that the ferrules would sit on. This needs way more than a plate-mate or a CA glue patch. The rosewood overlay needs to come out and that cleat/remnant of the old bridge plate to come out and a new bridge plate to be placed flush to the spruce top.

WebertRLZ · #11 02-06-2021, 01:35 PM

Quote:

Originally Posted by John Arnold

PlateMates are about 0.025" (0.6mm) thick and 1/2" wide. Whatever you do, don't make it out of brass. Aluminum works just fine, and weighs less than 1/3 as much as brass. A maple or other hardwood overlay (1/16 thick by 5/8 wide) is IMHO a better option.

Thanks a lot for all these tips. Extremely valuable.
About filling up the pin holes, i think this won't be possible given the state of the bridge plate. But maybe if I remove the outermost layer which is falling apart, i can patch it up when a new maple plate as you said.

WebertRLZ · #12 02-06-2021, 01:39 PM

Quote:

Originally Posted by blindboyjimi

The rosewood overlay needs to come out and that cleat/remnant of the old bridge plate to come out and a new bridge plate to be placed flush to the spruce top.

That would be the ideal. If cost is too high for it, i would try to remove the overlay and try a platemate at least temporarily, so i can at least string it, adjust neck and string action and hear how it "truly" sounds.

Then I could make a decision wether I would keep it (and get it a proper repair) or sell it as it is.

rstaight · #13 02-06-2021, 01:55 PM

The old plate needs to come out. The surface cleaned up and a new plate installed. It may cost but it is the best repair option.

I wouldn't skimp on this one.

blindboyjimi · #14 02-06-2021, 06:46 PM

Quote:

Originally Posted by WebertRLZ

That would be the ideal. If cost is too high for it, i would try to remove the overlay and try a platemate at least temporarily, so i can at least string it, adjust neck and string action and hear how it "truly" sounds.

Then I could make a decision wether I would keep it (and get it a proper repair) or sell it as it is.

I guess I’m seeing it very differently. If you remove the rosewood overlay, there is no plate below it to put the platemate on top of. It looks like the bridge was torn off taking a portion of the top with it so a repair attempt was made to cut a square piece of spruce and make a new portion of the top. If you put a platemate against that and add tension the platemate will pull right through that spruce. Perhaps I’m seeing it incorrectly, but this is how I see it.
IMG_1612658822.594129.jpg

WebertRLZ · #15 02-07-2021, 08:02 AM

Quote:

Originally Posted by blindboyjimi

If you remove the rosewood overlay, there is no plate below it to put the platemate on top of.
Attachment 51394

I didn't have a mirror, those images are from my phone. I stuck it in the soundhole, made a video and took screenshots.

It seems to me that the top is fine.