The 1976 Martin D-18 I'm working on has the classic shrunk pickguard with obligatory top crack. I've repaired the crack and am ready to glue the guard back on (well, I still have to make some cauls). Problem is that there are no little wood fibers stuck to the pickguard, as in Mr. Ford's demonstration on the .com site. I got to use that method on an old Gibson a while back and it worked like a charm. I was bummed when this Martin's guard came off so nice and clean!
Could/should a guy spray a few coats of nitro on the raw wood & then use double stick tape to stick it back on? Any suggestions, as usual, are a greatly appreciated. Thanks.
Oh, I'm almost done repairing the back damage that I posted about a while ago. Will post picks/info when I'm done.
If this were my repair project, I'd definitely lacquer the bare wood and use the 3M pickguard tape that Stew-Mac (or the supplier of your choice) sells for the adhesive. Another option is a properly sized new PG with adhesive backing.
In my opinion, Martin's traditional method consistently caused problems (the ubiquitous top crack from the PG to the bridge). A '76 Martin is not an especially valuable guitar (money wise, but D-18's & their 000's & 00's are their best kept 'secrets') and vintage accuracy isn't a prerequisite. You have a chance to correct 'the mistakes of the past'. I encourage you to do so :)
Best of luck :)
Thanks guys. I have Sealcoat shellac as well as a Preval sprayer and instrument lacquer. The shellac would be a helluva lot easier, that's for sure.
I have some stew-mac double stick and a few new self-stick pickguards. I guess I'll have to see how flat I can get the pickguard before I commit. I know for sure that a new guard just would not look right, and I don't think the customer would go for that, given a choice. Still...
I agree with the others in that you do want some finish, not just bare wood, under the new guard.
For the folks that do Martin warranty work Martin wants us to have finish or something similar to finish under the new guard. Lacquer works, shellac too, and recently we were turned on to another method where one uses a thin layer of very viscous epoxy such as the stuff that folks encapsulate insects, leaves, mementos... in. The guitar is carefully placed as level as one can and then the epoxy is brushed or poured into the area under the pick guard with great care. What you want is to have just enough epoxy so that it's no thicker than the original lacquer and as such the leveling process where the original finish meets the new epoxy will require very little sanding to get it all level with the two substances. Then install the new guard with the 3M transfer film.
What you end up with is finish under the guard, a level transition, and less time is required with this method than say using lacquer which needs to cure a bit before being sanded and/or have adheasive in contact with it. We've done it this way lately and it works well.
Can't remember who turned David onto this method or I would have provided attribution. I'll ask him tomorrow and check back to make sure that I have the process right and give credit where due.
Interesting...I've built many fly rods over the years and have some great quality "rod finish" epoxy that levels out really nice on a guide wrap. Maybe that would work. I'd consider it a low viscosity epoxy though, as it flows really well. Hmm, maybe it would get under the guitar's finish...
I'm starting to think more about the pick guard itself now, too. The back edge is warped up at a pretty significant angle. I've got it under a pile of heavy books right now, but if it doesn't flatten out, I don't think I would feel comfortable putting it back on, as might just curl up again. The Stew-mac pickguards I bought fit right, but would be too shiny and new looking on this old guitar. Is it standard procedure to replace old pickguards with new ones on 40ish year old Martins? I suppose it is possible to "relic" (yuck) a new guard, too.
For years I have been sealing the bare wood under a removed Martin pickguard with acrylic urethenes. KTM 9 sourced from Luthiers Mercantile, is what I am using these days. This material builds and dries quickly ( v. laquer), has no noxious fumes and cleans up with water if any is accidentally brushed outside the pickguard footprint. Regluing the original Martin pickguard is, in my opinion, a bad idea since they continue to shrink and gas off; plus they are always a bit smaller than the original footprint. It's just a piece of plastic. Don't sweat it, just replace it. Just seal the bare wood and fabricate nice repro which just covers the original footprint. A carefully made repro, with beveled edges, can look almost like an original.
In response to your last post, Brian, how well it flattens out is key. A little heat is necessary- Paul Hostetter suggests putting it in a glass dish with water and a flat piece (like a tile) on top and heating in a microwave until the water boils. Let cool completely before taking the top piece off. Safety is important with flammable old celluloid.
A word of caution about boiling water in the microwave. It's possible to super-heat water well beyond boiling point without it actually boiling. In this case, any movement can cause it to erupt explosively, splashing super-heated water and super heated steam around catastrophically. If you use this technique, it would probably be safest to just leave it all in the microwave to cool down once it's heated.
If I remember correctly, the issue is about bubble formation. Most of us use clean porcelain or glass for heating water in the microwave. It is possible that these surfaces can be too smooth for bubbles to form as the water heats but moving the water or adding something will induce sudden bubble formation. I guess I should have said earlier that putting a (non-metal) item in the water should keep keep this from happening.
I don't know how high the risk really is but having been subject a some third degree burns a time or two in my life makes me cautious.