Bridge pad caul with a magnetic personality - a question of sorts.

[John Cartwright]

Hello,

I need to repair a bridge pad on an otherwise near mint '63 Epiphone Caballero (as well as replace the plastic bridge, which goes without saying.) I've read in Dan Erlewine's guitar repair book, that a great way of doing this is to use a caul with Bondo smeared on it, waxed paper to separate, and clamp this down in the guitar. The idea being that the Bondo will form to the exact topography of the bridge pad top curvature making for a better fix.

OK, sounds great, but I can see the possibility of the Bondo squeezing out and sticking to something, giving me a one way ticket to Problemville.

Question: What about rare earth magnets? Could I use the magnets against, say a piece of framer's mat board (which is stiff but flexible) then the waxed paper, then do the super glue and sawdust trick? I'm thinking four or five magnets placed along the mat board caul would allow the caul to conform to the shape of things.

Good idea? Bad idea?

Ooooo, just thought of this, what about one of those stress balls (the cheap ones that are basically balloons with sand in them) and just clamping one of these in there with the mat board and waxed paper with turnbuckle clamps?

Thoughts?

Thanks! John

[Ry Charters]

Well...doing anything to a guitar will technically alter the tone, but I don't think it would be significant. The brass plate weighs 5 grams. Less mass than 6 brass bridge pins for sure. The thick maple would have more of a negative effect in my opinion. Plus its metal on metal, so I imagine the vibrations would make their way alright. And the guitar will never have this problem again! If it were an old martin, I'd replace the plate for originality sake. If the top is bowing up, replacing the entire plate is also a good opportunity to bring it back into shape.
Also, I should've mentioned before that you should use a flat caul under the plate to make sure that the epoxy is flat when you go to install the plate onto the repaired area. Use plenty of tape, and maybe that 1/16" maple to flex to the top's current shape.
Lucky to live near woodcraft? I'm lucky that I don't live near one.... too much temptation! But if you can pick up some system three epoxy from there, that's all I use. Everything else I've tried doesn't dry nearly as hard.
Thanks for the compliments! Always a good thing to hear from a colleague.

[Ed Taublieb]

My two cents worth.
Since, the plastic bridge is being replaced with a real (wood)one you have chosen to eliminate a bad manufacturing /design idea rather than preserving the originality. So, IMHO consideration should be given to removing the bridge plate and replacing it with a slightly larger (footprint and thickness) one. I suspect removing the old one will not be all that difficult, given the likeleyhood that the glue used not all that strong. But, the person who owns it has to be convinced that when done the design flaws in the guitar have been eliminated and it will be a better sounding guitar with a very high probability there will be no bridge, top bulge or bridge plate problems in the future.
Ed Taublieb

[John Cartwright]

Boy, I've got to figure out how to keep my inbox from sending these reply notifications to the spam folder, I completely missed both the last two posts! (my vacation didn't help my attentiveness either LOL)

Well, I ended up repairing the bridge plate with both the super glue and maple sawdust in the tear-out area and capped it with that 1/16 maple that I scraped down to about 1/32 and clamped it and later the new bridge, with a flat caul. I used the LMI white glue for both, that's a nice glue! Bone nut finished it off and the guitar has a nice focused yet warm tone, very old school blues kina' vibe. I chose pau ferro for the bridge, very nice wood, I liked working with it a great deal, very pretty but I did stain it to match the rosewood fingerboard. The guitar is actually mine....well, it will officially be mine once I refinishing an old cabinet for a friend who found this Epi in her grandmas closet. Nice trade I think. Thanks to everyone for you helpful advice, what I might not have done this time around I will take to heart for everything in the future. Many thanks! PS. I used a flat wood caul that was taped with packing tape and waxed instead of the Bondo/wax paper, seemed to work quite well.
John

[Donald A. Fortune]

Hi John-- In regards to you getting a respond and it ending up in your spam folder -- here's what ya do--
when ya go to the spam folder open up the mail from Frets.com and then in the tool bar on the top there should be a few places where there are choices as what to do with that mail-- just click on the one that says "NOT SPAM" and it will go to your regular mail box.. after a few times doing that "FRETS.COM mail will go to your regular mail box instead of the "Spam" folder.
I use to have the same problem and thats what I did and I now get "FRETS.COM" mail in my regular mail box.
Peace,
Donald

[Christian Johnson]

FYI Stew Mac makes a rig called the bridgesaver. It reams out bridge plate tear out, the cuts matching plugs to repair the damage. It's a bit pricey, but might save you a lot of time and effort, with good results.

http://www.stewmac.com/shop/Tools/Special_tools_for:_Bridges/Bridge...

[John Cartwright]

Thanks again to everyone for their help. Here is what I ended up with with regard to the bridge plate. I had combined the advice given here with that found in my books and here it is! Came out quite nice I think, considering it's my first attempt. This picture is before (obviously) I drilled the pin holes, but I used some nice brad points and a backing piece of wood to further eliminate tear-out. I chose a 3 degree angle taper for the reamer and pins by the way. Here is the finished bridge too.

Many thanks!
John