What glassing schedule is used for balsa surfboards?
With the higher density/compressive strength of balsa, I am guessing the glassing schedule is lighter than for PU/EPS.
Really depends on the shape, the quality of the wood, the resin, and the intended use.
I’ve gone 4+4/4 s-cloth and epoxy with great results for boards that will get ridden a lot. Tried a lot of other things, too - standard poly glass schedules, standard epoxy, 4+2/4 epoxy, strictly 2oz… but the above schedule seems to do the trick for me well on both midlengths and longboards.
By the way, expoxy hotcoat as well as lam. If it’s me doing the glassing, I’ll do an epoxy gloss as well, especially if I’ll only finish it at 1000. But the Enthropy Super Sap will take a nice polish with a bit of work. My glassing buddy hates epoxy gloss and will always try to get me to do poly gloss coats… it can work if preppred right, but I still prefer an all-epoxy glassing. I no longer do poly lamination over wood.
It depends…
For hollow wood, i use a rib distance of 15cm, roughly 6", and I use 6mm balsa for the deck, 4 mm for bottom as lihtweight option.
If I glass the inside of deck and bottom too, a 3-4oz cloth for the outside is all I need, inside even a 2oz cloth is enough. Usually I use a thin veneer on the top deck, but even without, one layer of 160gr/m2 is enough, (it is somewhat around 4.5-5 oz/sqy.
But as said it depends on the wood too, use a fair amount of resin, more than normaly, because it sucks into the wood and makes it harder. Another thick gel- or hoatcoat is applied too.
Following this route, I get a real hard deck, and never faced dents in the knee or foot area.
Thanks gentlemen.
I am considering a solid balsa core for a couple of body boards.
Do you have any recommendations for a source of balsa blanks?
Solid core bodyboards, you can go with single 4oz with no worries in my opinion.
With the low rocker profile, why not just get balsa stock lumber and have at it? Frost lumber in San Diego is a good source for that. Tons of info in the archives on glue-ups, cutting outlines, etc. If you’re going to chamber, read up. Takes time and is a hassle, but well worth it depending on the wood.
At one point, I had a stock of aviation balsa from just after the war. The best of it was so light that chambering wasn’t needed, or even considered. For a bodyboard, if you get nice wood, no need I would think.
For pre-glued blanks… I honestly don’t know a source for bodyboards. I have a great one for surfboard blanks, but here in Europe and they’re not exporting to the States yet.
I can get balsa planks from a hobby/architectural modeling supplier, Glue-up should not be a problem. They have a grade that is fairly uniform and light, but pricey.
Just looking for more potential sources that might be a little less expensive. Have to do a little XPS and EPS prototyping first…
Yes 4 oz. on a solid bodyboard is fine. If it were a surfboard you would most likely want to go with something more traditional like a 6/4 Deck and a 6oz Bottom. On a surfboard that is intended for use and prone to foot traffic a 6/4/6 will be more durable. Wall hanger surfboards get 4 oz.
Stumbled across this Fiberglass Hawaii video after watching one of the videos Greenlight posted in another thread.
Dick Brewer Balsa Surfboard Lamination.
More than strengh i want a good waterproof skin on wood even more balsa that drink water a lot. So as what was said above use more resin, with a fluid long resin, let wood drink resin, and do a gel coat over then pinholes war at finish stage. s glass can be a good choice because of higher abraded strengh. As a repair man i see lot of wood water problems but on other hand my most durable boards have wood skins…
Neat video.
I hadn’t mentioned the filler coat - but that’s a must. Since we work with epoxy, it naturally has time to settle into the wood and really fill the little gaps and pores. The difference in the amount of bubbles in the lam is incredible.
I like the Fiberglass Hawaii instructional videos. They cut to the chase and offer a good idea of how to do whatever it is they’re demonstrating. In this one especially the viewer gets a good look at Brewer rails. The offset stringers really set off the contours.