Rise in back strip

[William F.Eden]

I have a small problem with a zipperd back strip when I cut the channel for it I got it a tad to big. So I sliped a piece 1/28 maple veneer into one side now when you run your hand over the strip you can feel a rise on that side.This is after it has all the finish on and rubbed down.I tryed masking just the 1/28 and running some super glue in and right away taking the tap off. Two days latter I sanded it and buffed it up again.It never changed.I looked it over with the Magnifyers and there seems to be little pits in there like air holes. I s there any of my Luthier friends out there know what I can do next??????? Bill:::::::

P>S I am afraid To try the Lacquer on it because of the way it eats into the rest of the finish

[Ronnie Nichols]

Sounds like you've run into the old man they call Mr.Murphy. His law seems to dominate the luthiery craft. We've all run into these kinds of problems and they are frustrating. You may want to read what Frank Ford says on his site about finish touch-up. As I recall, he talks about using CA glue to do some repairs and scraping it down with a specially prepared single edged razor blade. He fills the voids and sands and buffs the CA glue as if it were lacquer. The lacquer and CA glue both are acetone based and are capable of softening the old finish. The CA repair is immediate instead of taking several days (or weeks) to completely harden. After this, if the repair is noticable you can refinish the back. I wish I could give you an easy way to repair this but I don't know one. I hope your repair goes well. It is this kind of problem that teaches us patience (and God knows we need that to work on guitars).
Ronnie Nichols

[Bob Webster]

Actually, there is no acetone in CAs. I've looked up MSDSs on various preps and the only thing in there with solvent action is the CA itself. The various viscosities, from original through mega-gap filling just differ in the amount of acrylic polymer is included in the glue. That's why you can glue Lucite with CA; strictly through its solvent action. Chemically, there's nothing in the Lucite that the CA can react to. By the way, CA will buff out to the same shine as lacquer so, unless there are witness lines, you could save yourself the trouble of shooting more lacquer over it.

As for the tiny air holes, they're the result of the glue kicking off too fast and trapping the normal outgassing that occurs then. Try consolidating it with carefully applied acetone.

Bob.

[William F.Eden]

That is what I tryed the first time Ronnie.As far as PPPatience goes I think I have abundence of that --I have been Maried for 54 Years .Thanks for the help Bill""""""""

[William F.Eden]

Bob do you think that the acetone will not get under the masking and bled into the rest of the finish? I will be useing plastic Elc. tap for the masking. I did mask it last night and run some water base filler in it and was going to sand that to-day .After all that I have done so far. Do you still think the Acetone is the way to go??? Bob the Super glue is C.A is it not? Bill""""""""

[Bob Webster]

Hi, Bill. If you mask it with tape, it certainly will wick under the tape and wreck the finish. At this point, however, it makes no sense to try the acetone trick because the water based filler isn't going to allow penetration of the acetone. Better just to go ahead and follow through on your present course.

Using acetone to clear the CA would have required you to apply it with a very fine tipped nozzle or tip like you can get for the CA bottles. My trick is to just load the nozzle by holding it horizontally and contacting the tip to the acetone. The acetone will wick well up into the tip and dispensing it on the surface can be controlled by the angle you hold it. I also use this method for dispensing CA along frets and one tip load is just right for one side of a fret. And, yes, CA or cyanoacrylate is the same as super glue.

Good luck,
Bob

[William F.Eden]

Well Bob I din't think the Acetone would touch the water base filler.And this morning it just looked the same. so I took it to the shop and sanded it right down to and through the pits with 320-600 & Kerosene until I could not feel any rise .Then I went over it with all my Mico pads and buffed it up :::: presto you can't see it or feel it, Thanks for every ones help I am sure glad that is over. Bill''''''''

[Bob Webster]

Super. All's well that ends well.

Bob

[Ned Knepp]

Bob,
I've filled some crack repairs using blue masking tape to contain the CA. I stretch the tape a bit as I lay it down then use a razor blade to smooth the tape down firmly, making sure that all of the fine wrinkles in the tape are flattened. I also make sure that any overlapping tape is pressed firmly against the edge of the strip beneath it. So far, I've had no seepage doing this.

Ned

[William F.Eden]

I ALWAS USE Electiric tap to mask with I have had very good luck doing that. With only one exception do not leave it on for days or it will telagraft into your finish and you will have to sand a lot of finish off to get rid of the mark,I have never had any lacquer seepage under it or C.A. But when I am doing a repair with C.A I will only leave the tap on a very short time and when I take it off I will pull the tap towords the repair as i remove it. Bill::::::::

[Bob Webster]

Okay, Bill and Ned, so call me tape-challenged.

Bob

[Ned Knepp]

Okay, Bob, you gave me a good laugh.

I'll confess that I sweat it a bit every time and I spend more time masking then I do fixing. I did it this way because I couldn't think of any other way to do it and I just keep on doing what I did.

I'm not a professional repairman so it's not as if I do this all the time. I sometimes suspect that it's a waste of time since I often end up scraping it all down with a razor blade anyway.

Ned