Opinions on major balsaboard repair needed

Hi everyone,

I broke my 9.1 casar moreira balsaboard while surfing at wenningstedt on sylt/germany.

Now i wanna repair it with keeping as much of the original beauty as possible.

I’ve come to two options so far:

  • Get new balsa and replace the whole chunk with new wood. Than i would have just a thin visible glueline along the break but a big area of slightly different coloured look.

  • Use the original balsa as a kind of veneer. In this options i would have thicker visible gluelines cause i lost some wood along the edges by breakage that i have to replace. On the other hand I can keep the look on the area.

In both options i would use the hollow core as a kind of mortice in wich I fit a tongue forming a strong connection between board and replaced piece. As the board is pretty heavy anyways, losing that bit of hollow core will not make that much difference in performance.

I’m happy to get opinions or even differnet solutions on that…

Thanks in advance,


and here some pictures of the desaster:

According to the photos, here’s what I would do:

  • Glue the nose piece back in place

  • Then route out regularly shaped holes where irregular pieces of wood are missing

  • Then shape new pieces as close to those holes as possible and glue them in

  • Re-glass, hotcoat, sand, gloss, more sanding, polish, buff.

Of course, the repair will be noticeable, but very clean.

Given the nature of the damage, the method offered by Balsa, is the only sensible answer, IMO. Don’t rush the process. Do lots of ‘‘dry fitting’’ before you go to the glueing stage. Then proceed as Balsa indicated. Good luck.

Wow, thanks for the very quick answer!!!

How would you glue the nosepiece back into place?? Would you use a fitted tongue glued into the hollow core on the board. Or would you just glue the broken out piece back into place as it is??? I’m just afraid that just glueing it back in won’t give it much strenght…



Glueing it back won’t bring much strength, but the double layer of cloth (minimum) laminated around the whole broken area will.

Listen to the masters here, consult with those you know (especially those of us who run the workshop!) and this will be fine!! We have the technology and ability and enthusiasm and I want to try it out after it’s done!!

Cheers Paul!!

I go along with balsa and Thrailkill on this one.

I’ve actually done a repair at least this extensive, although not as difficult as what I see here.

I had a chambered balsa board explode/implode on an airplane flying from San Diego back to Florida a few years ago.

Don’t worry about strength in the glue up. Use tape (wide masking) to hold it in place as it dries and use Gorilla glue since it will fill in the gaps. You just need to have it hold together long enough to reshape if needed and reglass.

Strip all the old glass off and do a complete reglass.

This is a good opportunity to tighten up the shape if there’s something you didn’t like about it the first time.

Actually there is another option here too. Reshape into a fish (this is a solid board?). Sell the finished fish for enough to get more balsa and make another board.

Sorry, just read the part about hollow core. It doesn’t look hollow from the photo.

Have fun

Im not a wood board Guru

but I do know that a glue joint on balsa is way stronger than the balsa itself

do as the others have said and reglass the whole thing

As has been said, the glassing over the repair will give it the real strength, plus your glue joints will most definitely be stronger than the balsa was originally. I wouldn’t add any tongues or tenons or anything, it’s just about impossible to get the alignment right with such things, kinda like dowelling a broken foam board: the dowels or tenons or whatever have to be perfect or else so loose that the glue and filler get to be a problem.

Instead, do do a lot of dry fitting with the pieces you have, as Bill mentioned, and do it with your clamps set up so you’re all set to clamp it up in a way that has everything as flush and nicely fitted as possible. Try different clamp setups, a block here and there , mebbe even a block plus shims to get it all just right. Take your time, work it through

I’d be a little careful with Gorilla Glue, as it can expand ( gap filling properties) and throw things out of alignment, especially when you have so much area to glue. A good wood glue like Titebond might be a better choice for this particular repair: use lots of it laid on heavy and let it seep out under clamp pressure. Better some dribbles to scrape than a starved glue joint.

Also, balsa wood does funny things when it gets wet. I’d try to get it as dry as possible without resorting to hair dryers on high heat, etc, that can tend to warp things and mess up your fit. From the looks of things, everything came out of the water immediately: good. If there’s a little salt residue, I might very, very carefully clean it off and again I might not- it might not be worth it, introducing more water.

If you have any missing wood that shows, as Balsa said, rout it out and lay in new. Don’t do it freehand, make jigs and such to keep your router exactly where it needs to be. If you make the ends of your new pieces a bit uneven, kinda like they do veneer repairs on furniture, it’ll show less. If you have a router with collars and such for pattern work or a top piloted bit you can use your pattern and your jig together- let me sketch it:

That wasn’t much of a sketch, but shoot for rounded contours, no smaller than the diameter of your router collar or top pilot bearing.

Hope that’s of some use - good luck



many thanks for all the quick and good replies. You’ve all been a big help! According to you, glueing the piece back in, filling the gaps and then glass it seems to be the best solution. So i’ll probably go for that.

But first I gonna have a chat with “the masters here”. See what you think, Richard!


I meant the masters on Swaylocks not at Milford!!


see you later.

Paul, that board looks like a stunner, I’d be gutted. Fear not though, you are in very good hands…

Like what they said!!!

You can make 2 or 3 holes in the middle of the wood and you could put tube (or massisse) carbon to make a good point of strenght.

I make this in aeromdels sailplanes wings foam, covered with carbon.

These airplanes are for DS soaring and they are 4 Kg weight, and they reach oftenly more than 25 G´s.

In the joint there is some joint´s “putty” that you can misture with residuos wood of the color that you need, and then make the finish that was spoked.

First of all, I am not a “wood worker”, 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 wouldn’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: “How do I repair the damage made by the clamps?”

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 (you’ll need one for each side). Square on the outside, exact curve of the board on the inside. And make sure it’s thick enough to handle the rocker. But don’t over tighten the clamp or you’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 won’t need that much glue. Refit. Use 2” 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 doesn’t really matter. It will not come apart. If you use too much glue, you will be cleaning up glue and if it’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 doesn’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 it’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. Don’t oversand. It’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 doesn’t take much sanding to get some balsa dust. If you don’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. I’ve done two or three. I’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 won’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, “I wonder what’s under that”?

In the words of Charlie Keller (rip 1934-1996), one of the first East Coast surfboard builders, “You ain’t buildin’ a piano”.

I know it´s not the same…

but give a look in the repair issue…


hey again. the board has been in the water around pembrokeshire a lot the last two years… i did as recommended here. striped the glass off on the area, cleaned up the jointline, used foaming pu glue and held everything in place with tape. reglassed it and it looks good.


big thanks again!!!