Aria CSB 380... Bridge falling apart?

[JakeAM77]

Hey all,
I'm looking for feedback on what is maybe the strangest damage I have ever seen on a guitar/bass. Just bought this '82 Aria Pro II CSB-380. Lovely little bass, but when I was checking it out, the bridge looked like it was covered in little hairline fractures (I mean, all over the place).

I thought it might just be some thin veneer or plating peeling off. Nope. Just today, I was adjusting the intonation and one of the pieces holding the saddle screw in place just broke off. Has anyone seen anything like this before?

 

[Matt Liebenau]

Taking a look at the broken part and the way it broke it looks like the bridge is cast metal and as worn as the plating is I’d guess that it got exposed to something that attacked not only the plating but the metal of the bridge. It could be normalish wear and tear but I have several cast parts on instruments that are decades old and don’t show any similar wear.

 

[JakeAM77]

Taking a look at the broken part and the way it broke it looks like the bridge is cast metal and as worn as the plating is I’d guess that it got exposed to something that attacked not only the plating but the metal of the bridge. It could be normalish wear and tear but I have several cast parts on instruments that are decades old and don’t show any similar wear.

Yeah, the specs say it is cast, but this still seems ludicrous to me. It's like the bridge by itself got ran over by a truck. The frustrating thing is that it's going to be hard to replace. It's a long bridge and it actually sits recessed into the face of the bass.

 

[Deathblade Eric]

I've never seen an Aria bridge go like that, but have seen it on a knockoff 3-point Gibson-style bridge on a Vantage (same factory, Matsumoku).

It's called "Zinc Pest" & can be a feature of Magnesium/zinc alloy castings (aka Zamak/Mazak or pot metal).
One cause is lead contamination in the casting process that causes brittleness & eventual self-destruction (it's become a thing among die-cast toy/model collectors).

There's no cure other than total replacement. Can't solder or braze it, but if you know anyone that's handy with a milling machine, it wouldn't be too hard to re-manufacture one.

The Aria SB series (1978-1981/2) had an almost identical bridge, but in solid brass. Beware of the later models (SBR, Elite & RSB) as they have a wider string spacing.

Also worth putting out a call on the APII thread; maybe someone has a spare.

Pete.

 

[JakeAM77]

I've never seen an Aria bridge go like that, but have seen it on a knockoff 3-point Gibson-style bridge on a Vantage (same factory, Matsumoku)...

Thank you for this detailed and metallurgically proficient post. I couldn't find anything about this anywhere and the not knowing was killing me (engineer). I figured replacement would be the way to go, but I don't have a lot of options that wouldn't require filling and painting. I'll ask around for actual replacements, but the only thing that would work dimensionally otherwise would be a Babicz and I wasn't hoping to throw down that much money... Unless I can get some refund from the seller who didn't advertise this.

 

[Bruce Johnson]

I agree with Deathblade Eric, it's a weak casting that got bumped or tweaked somehow and snapped.

If you have the broken-off chunk, you could put it back on with epoxy. The intonation screw shouldn't normally be taking much load. Just be careful when moving the saddle; don't try to pull it hard with the screw.

 

[JakeAM77]

I could try that, but frankly, I'm worried that the same thing is going to continue happening in different locations. I don't know if you can see in my picture, but there are similar cracks on nearly every post and running around the edges of the bridge too.

 

[Bruce Johnson]

I could try that, but frankly, I'm worried that the same thing is going to continue happening in different locations. I don't know if you can see in my picture, but there are similar cracks on nearly every post and running around the edges of the bridge too.

Yes, my suggestion is just a patch to get you by for cheap. Unfortunately, that's a unique design bridge and there's nothing out there that will be a bolt-on swap. To fix it right, you are going to have to either modify the bass to fit some commercial bridge, or make up a custom replacement bridge from scratch.

It's a fairly simple design. Making up a replacement isn't a big deal for someone with a small machine shop and a milling machine. I used to make custom bridges (I don't any more), and I would have made up a replacement base from aluminum, using the original saddles, for about $100.

Check with Frets On The Net. I haven't done any business with them, but they specialize in custom metal hardware for instruments.

Frets On The Net Home

 

[Deathblade Eric]

It's a fairly simple design.

The brass version is simpler still (from a fabrication point of view) in that the tailpiece is a separate item that fits into a slot in the baseplate:—

There are two set bolts underneath that clamp the whole shebang together.

 

[Bruce Johnson]

The brass version is simpler still (from a fabrication point of view) in that the tailpiece is a separate item that fits into a slot in the baseplate:—

View attachment 3783126

There are two set bolts underneath that clamp the whole shebang together.

Yes, that's exactly how I would make it. The base is a flat plate with some holes and milled slots. The cross bar is attached to it with screws from underneath. Really not a difficult thing to make, if you have a milling machine. You could even make it with hand tools, a drill press and files. Aluminum or brass.