Welcome abord. I have to admit that some of your early Longboard magazine ads helped get me motivated to shape balsa, so thanks!
Interesting question, and great-looking install. What did you use to glue the insert to to the box and surrounding wood? That could alleviate any leakagre from between the box and the underside of the insert… For the edges, the Git Rot could be good, or another penetrator/bond enhancer like G-4 (that’s what it’s sold as here in France anyway) followed by some reinforced epoxy? I suppose I’d be worried that straight resin over balsa is eventually going to take some little dings and scratches just from moving the fin, etc. and that these are going to eventually let water get into the unsealed wood…
For whatever that’s worth, I’ll be stewing over it…
Hey it was great meeting you at Three’s at Waikiki a few weeks back and share a few waves with you. Is your goal to to seal the wood covering the box? I would just cap the box with layers two of 4 oz. glass. Later do a fill coat and sand to blend it in. Use a Dremel tool to cut out the slot. I cap all my fin boxes so having epoxy or PE resin filling in the channel is not a problem as long as you don’t force the resin in the slot. We did this before the gloss coat. This is what we did with sailboards to strenghten the fin boxes.
That was a great day wasn’t it? It was nice sharing waves with you too.
If you’ll notice in the photos, we’ve already done all that. Board is completely glassed, the wood plate over the finbox was completely glassed over and the slot has been cut with a dremel. Now, wondering the best way to seal the raw wood (about 3/16") that is visible right where we cut the slot between the glass and the finbox.
Next time, if there is a next time, I may be inclined to cut the slot before we glass as you say and then wrap glass around the edge of the slot.
I used thick epoxy paste to glue in the box and with a fin installed made sure it was straight, since there was a little play, until it went off.
Then, I used Gorilla glue around the edges to keep it firm in the sides of the box and put the preshaped balsa plate on top. I know the Gorilla glue may take water (since it’s foam) but it’s no where close to being exposed. And I figured the fact that it expands would fill the gaps around the box to keep it from getting loose later.
“Git Rot” is very thin, the consistency of water and just as clear. It’s a two part epoxy. I figure that applying multiple coats and turning the board on it’s side it should penetrate the porous balsa at least 1/2". “Git Rot” effectively turns the wood to plastic.
Thanks for your kind words about the ads. You would have been better off if the ads had just lead you to buy a pair of shorts (like Uncle D did) than take up the dubious profession of shaping balsa boards. lol. But if you’re happy, I’m happy.
Well, I never did get a pair of trunks, but I did get a tahitian band tee as a gift that saw many, many washes. When it finally
go too bad to wear in public it became a “shaping shirt” and prolonged it’s life that way.
I did get a laugh out of your final paragraph, thanks. The wood boards have become by far my favorite aspect of shaping. In fact, they’re just about the only boards that I take orders for at present since I went back to school this year. A few for clients, and a few for good friends, and I’m very feeling pretty fortunate to be doing it.
If the Git Rot is penetrating 1/2", then I don’t see any issues. I had wondered about the gluing because we did skin covered boxes on a couple of balsa compsands a few years back, and the inner lamination protected the underside in those cases. I’m sure you’re fine with the Gorilla Glue.
What we had ended up doing to handle the exposed wood sides when we opened the box was a 45ish degree bevel that met the box opening and (in the best of cases) allowed the subsequent patch to meet the inner lamination and thus seal the wood. Time consuming, and you did have that little beveled lip, although with the 2mm skins that wasn’t a real issue. I haven’t seen one come back with a great-looking black stain, so I’m assuming it worked out long term.
"I used thick epoxy paste to glue the fin in the box and with a fin installed made sure it was straight, since there was a little play, until it went off.
Then, I used Gorilla glue around the edges to keep it firm in the sides of the box and put the preshaped balsa plate on top. I know the Gorilla glue may take water (since it’s foam) but it’s no where close to being exposed. And I figured the fact that it expands would fill the gaps around the box to keep it from getting loose later. "
—did I miss something?
why put in a finbox and cover it with balsa, cut it open and GLUE THE FIN IN???
I didn’t glue the fin in. Just the box. The fin is removeable. That’s the whole idea. I wanted a removeable fin but didn’t want the box to show. Look at the photos.
I’ve never put a finbox in a balsa board before. Just wanted to try something different.
A couple of customers were asking about a balsa travel board. This is a prototype.
Very nice. If you notice any surftec it is the same clean finish also( wood or painted epoxy). Most quality wind surfers have finished fin and mast boxes too. Every time I see one like you did I know it was a well planned build and the maker took the extra effort to make it nice. The down side is if done incorrectly the potential for water absorption is high. It looks as if you have it wired.
just something i seem to remember from a post awhile back, someone was saying about when you seal wood with epoxy the epoxy is soaking into the ‘gaps’ around the fibres or the softer part of the wood as it were and while it might appear sealed its actually just hiding all the little fbres like drinking straws. come to think of it it was probably on a compsand thread.
guess your edges might get bashed a bit putting a fin in and out. how about putting a bevel on like the previous poster said then a resin ‘edge’ where the bevel was so that you have a definate plastic edge.
Yes. It sounds like a good idea. I had thought of using Suncure in the tube so I have some fibers for strength but a couple of experts I’ve talked to don’t seem to think it’s necessary once the wood is saturated with the Git Rot.
Also, Git Rot is pretty shiny so I’m not sure if anything will actually stick to it.
Did a “reverse tech” 7’10" chambered balsa gun in '78 with high-density foam stringers, tailblock, and foam-and-glass fin, all glassed with epoxy. Unfortunately, the white foam stringers got contaminated with balsa dust and from any distance at all look like more balsa. Maybe a colored foam would look better, or spray or resin paint the stingers before glassing.
BTW, epoxy is definetly the way to go when glassing wood.
ive never heard of gitrot over here but sounds good, maybe worth doing an experiment.
you said you were originally looking for ways to do this for future boards, do you think the following would work? :
set the fin box in to the board as you have this time with the box lower than the surface, lay glass overlapping the bottom of the board… which dips into the hole and sits on the top face of your finbox, then take your balsa infill and squeeze it into the hole, this will squeeze the resin and cloth into the corners. then pull the cloth up through the centre hole and onto the surface. effectivly wrapping your balsa insert with glass.
I haven’t been on here in a while and then I ran into Uncle D at Threes in Hawaii (actually he almost ran into me as I was paddling for the shoulder to get out of his way) and we started talking and he got me stoked with the idea of coming back on Swaylocks.
Hey Surfindog,
The only problem I see with your suggestion is that the balsa piece needs to be shaped down to the level of the board after it has been glued in and the glue dried. This photo shows the piece after it has been shaved down and before glassing.
good point bill. i wish i had a drawing package on this comp so i could sketch what im about to suggest.
if the balsa had the glass pulled up from underneath and held vertically till it sets you could then slice the upstanding glass off and sand level as normal.
