First of all, I am not a â€œwood workerâ€, cabinet builder, trim carpenter, etc. My only wood working experience has come from vintage string musical instruments and balsa wood surf boards.
Due to the delicate nature of this project I would approach this repair the same way I would an old Martin Ukulele. In other words, I wouldnâ€™t have a clamp within 10 feet of it.
If you try to clamp it, your next question you post on here may very well may be: â€œHow do I repair the damage made by the clamps?â€
Everything may fit together very nicely when dry. You may even get clamps and shims to seem like they are going to work. When dry. But everything changes when you add glue, which, when wet, is a lubricant. As soon as you start turning the clamps handles, everything will start to move. Why? Because you are dealing with multiple curves. Even if you try to clamp using rubber bands (made from inner tubes) they will slip off (because of the out side curve). Same with a strap clamp.
You could build a clamping jig (youâ€™ll need one for each side). Square on the outside, exact curve of the board on the inside. And make sure itâ€™s thick enough to handle the rocker. But donâ€™t over tighten the clamp or youâ€™ll be re-outlining the entire board and reshaping to get rid of the distortion.
But why would you go to all that trouble? You could build a whole new board in the amount of time it would take to do that.
First: Get everything dry fit. Then take it apart carefully.
Add a little bit of glue. You wonâ€™t need that much glue. Refit. Use 2â€ tape and tape it all together real good. Use lots of tape. If you use Gorilla Glue, as I said above, it will fill in the internal gaps and, believe me it will not push anything out of alignment. That is if you use enough tape. Wrap the tape completely around the entire board several times. Nothing is going anywhere if you do this.
The strength of the glue joint is a total none issue. The only reason for the glue is to hold it together long enough to get some glass on it. You could spot glue it with a little Titebond too. It doesnâ€™t really matter. It will not come apart. If you use too much glue, you will be cleaning up glue and if itâ€™s on raw exterior wood, you will be sanding it off down to raw wood. Something you do not want to have to do. Because then you will be reshaping more than you need to.
For the patches: I have done this dozens of times. Make the patch first. Take some raw wood and make the patch. I like what I call football shapes. Make any shape you want, it doesnâ€™t matter, just keep it simple. Lay the patch on top, draw an outline (lightly use a ball point pen not a pencil) and cut the hole out. This works better than cutting the hole and trying to make a patch to fit it. I use a box cutter to cut the hole. It takes about two minutes to do it. Balsa is soft. Using a router for a delicate job like this would be overkill. If you make the plug in a slight wedge shape, as you push it in it will get tighter. You can glue it if you want but itâ€™s not even necessary if the fit is tight. The resin will fill it in anyway. Shape to fit using a small wood plane. I use the Artu planer with a fresh blade. Sand lightly with sixty grit. Donâ€™t oversand. Itâ€™s hard to tell if you will even need any patches at all. If most of the wood is there you may be able to get by with just some fill. You can make your own filler with balsa dust and a little white glue if the hole isn’t too big. It doesnâ€™t take much sanding to get some balsa dust. If you donâ€™t have any scrap balsa for the plug or to make dust, you can get some sheets from your local hobby store.
The big question I think is: To reglass or not reglass? Stripping the glass off a balsa board may not be that big of a deal. Iâ€™ve done two or three. Iâ€™ve had some where, once the glass is started, it comes off in big sheets. Others were not so easy. The hardest part to get off is the double wrap on the rails. You may be doing a bit of reshaping and cleaning up the rails
This is a rider, right? Not a wall hanger. You will have an interesting story to tell about the repair. The deck part will have wax and you wonâ€™t be able to see most of it anyway. If you want to hide it, you could also put a Hawaiian print fabric band, or even a pigment stripe to cover the repair. When I worked at G&S back in the late sixties early seventies, a group of us from the factory would be sitting on the wall at PB Drive after a session and some kid would walk by with a board with a pigment stripe on it and someone would say, â€œI wonder whatâ€™s under thatâ€?
In the words of Charlie Keller (rip 1934-1996), one of the first East Coast surfboard builders, â€œYou ainâ€™t buildinâ€™ a pianoâ€.