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Just an interesting issue. I have had two backstrips on two different guitars start to delaminate - very minor but for example, the one strip is like standard Martin style checker made of maple and perharps ebony. I noticed cracks along the strip in different areas. Wicked in some Cyano very carefully and then level with razor blade (and ends taped). Not real concerned about finish because plan on re-doing back anyways - french polish.

My point is - wonder if others see this problem from time to time. Bought the back strips from either Stew Mac or LMI so good quality. Thhinking that in the future, after backstrips are installed and prior to refinish maybe it is a good idea to flood with Cyano and sand as prevention.

HI Rich
    I to had that problem . What I have been doing since is to wick CA into the back strip after glue up. Didn't see on since. I don't know what caused it , or why
john

Thanks John and Todd.

Todd, both strips were inlaid into the back vs. sandwiched between the back plates. No concern about structure since the back strip is in place doing its job.

John, I thought at first might have been humidity change but you would think it would have showed in other areas. I dont usually buy my backstrips just in time for build so guessing they were sitting in the same encvironment for months at a minimum.

Oh well, wicking in the cyano and leveling worked out well and resulted in a near invisible repair. It could have been invisible but I wasnt concerend as planning to add finish.

Another good reason to pore fill with epoxy...

I think this may be dryness Rich and the backstrip did it's job which is to provide an area that can move instead of the back plates cracking.

Recently I've also changed from using a cross grained reinforcement strip on the inside to one with the grain parallel to the back grain. Romanillos explained that this is to provide a place which will crack prior to the back plates under extreme conditions. As you have now experienced, it is far easier to repair and hide a crack in the strip than the surface of the plate.   

Best

Thnaks Rich and Dave

Good insights from both of you. I tried the epoxy approach long time ago and made a mess of things but I often read how many have good results. Probably need to give it another try and read directions this time arond

Dave, running the inside center seam reinforcement parallel grain is an interesting idea. Makes good sense and might adopt this approach on my next build which is coming up soon.

If you dome the back, shrinking is not much of an issue.