I tried looking through the forum, but couldn’t find a post like this, so here goes:
I am thinking of making a solid wood board out of doug fir and a cedar “stringer”.
I plan to buy dimensional lumber 2" x 6" x 10’ for the doug fir and a 1" x 6" x 10’ for the cedar.
I am going to use my current 9’6" square tail as a template, and match the rocker and widths, cutting out the boards individually on a band saw or with a scroll saw.
I then plan to drill as large of holes as possible in a randomly staggered pattern on the internal pieces to alleviate some of the weight.
Next I’ll glue and clamp the whole thing up, including the fin, which will be shaped along with the board.
Plane and shape to the same as my pattern board.
Then varnish or glass the thing as seems most appropriate.
Is this a ludicrous plan? I haven’t seen a board constructed like this, the closest have been reproductions of old Hawaiian boards. I know it will be heavy…
If the holes aren’t all connected, you’ll need a separate vent for each one. Otherwise, board gets hot, air expands, board pops apart.
It’ll probably, even drilled, still weigh about 70 lbs too. Ever try to carry 2x6’s on your shoulder? When I was a college football player, I could comfortably carry 6 8’ers. Your board will be (assuming 23" wide at center) made from 15.3333 pieces (maybe the .3333 is the cedar). Those are 10’ers, so its like carrying 18+ 8’ers. Say the template takes out 35% of the wood, the thickness & rocker another 35%, and the drilling another 10%…you’re still carrying the equivalent of 6.977 8’ 2x6’s.
If the holes aren't all connected, you'll need a separate vent for each one. Otherwise, board gets hot, air expands, board pops apart.
You should be able to remove considerably more mass using staggered (connected so there is even air/preasure flow) chambers than just drilling holes in the boards.
For visual insight into what the chamber might look like, look at http://www.hollowsurfboards.com/how_to.htm Paul Jensen’s site. This in not the same thing but amagine that each of your 2x4s look like the stringer. These chambers would be overlapping staggered chambers.
With this aproach you should get adequent strenght and remove greater than 50% of the wood. Maybe able to remove something between 60-80%.
If you’re worried about weight and if it’s just for show or even for that one-time ride to say you did, I’d just varnish it. If you do glass it, you need to go overkill on “sealing” it with several coats of brushed on resin (epoxy). Otherwise it will delam and you’ll get cloudy spots all over where the glass didn’t adhere to the wood.
Any reason why you want to shape the whole thing with fin glued in? Much harder (way much!) to shape with that fin in the way, not to mention you’ll probably bust it off turning the slab over and over to shape it. I’d leave it off until the end and glass it on as customary. If you varnish it instead of glassing, rout a slot (1/2" deep +/-) for the fin base after it’s all shaped and glue it in the slot.
You won’t get much color contrast with a cedar stringer in a doug fir board. I assume the stringer is for looks. If color distinction is an issue consider either using basswood (light contrast) or black walnut or some other dark wood. Don’t use balsa, as the very soft wood against your more dense fir will be a shaping problem you don’t need to mess with. As a percentage your stringer isn’t going to be a weight issue anyway.
Venting: I’ve made a several chambered balsa boards and never vented any of them with no problems. The balsa guru is Jim Phillips who states he never vents either. However, if you’re going to ride it, have it hanging out in the sand in the sun, leave it on your car rack outside, and treat it like a regular surfboard it’s a different story. Heat and especially ultra violet light will be a demon, so a vent would be the right thing, but a polly glass job will likely delam in abusive (normal surfing use) conditions. If it’s a rider you might really consider epoxy, but won’t get that super gloss look as many sanded coats of spar gloss varnish or polished polly will give.
Bottom line: To ride or not to ride? The old Waikiki redwoods were varnished and they rode them by day and dried them back out by night and just kept sanding and adding more varnish every few weeks until it got “broken in” when it ultimately just got ridden with no more fuss. For a purist, that rode hard and put away wet look doesn’t look to bad on a wood board. If it’s a showhorse gloss it out and keep it in the stall for looks. Go for it!
Enjoy the ride,
Richard
PS: Here’s a shot of a chambered board prior to glue up from my website:
PSS: Paul Jensen and Bert Berger have loads of experience with wood boards so maybe they’ll also chime in with advice on your venting issue. There’s stuff on this in the archives too.
Thought this might be helpful. Under the balsa wood section (in surfboards section) it scrolls through planks of balsa that are being preped to be made into a board. Looks like the have pencil lines marking off a chamber that will be routed out in the balsa planks before they are connected.
Hey, Thanks for all the good tips and links. That was more than I was hoping for.
If I come out with a reasonable finished product, I intend to ride it occasionally.
I thought gluing the fin in at the same time that I clamped the rest of the board would be stronger, but you’re right, it would be difficult to work that way, plus I could spend more time and make a more intricate fin.
I was thinking as I posted originally that I wouldn’t get much color contrast out of the woods that I mentioned. I will probably go to the lumber yard and look around, but I don’t think I’ll have much selection.
I live in a little town on the Oregon Coast, I was thinking it would be neat to make the board out of some indigenous trees…Western Red Cedar and Red Alder, maybe? There are several small mills in the area…
Thanks again for the input. If I commit to this thing I will be sure and post some pics.
By the way, I grew up in Houston, and spent lots of time down by Galveston. Hows the surfing?
I made a board with a hollow 5 1/4" wide RW stringer in 1964 for a friend, Terry Hall. Terry still has that board. There is no venting necessary if you cover with glass. I’d reconsider using Doug Fir. Just too much chance of delamination due to sap. But you probably knew that. Are you just looking for challenge? How about Basswood, with RW stringers for contrast,or Western Red Cedar? Or KD Redwood with Spruce or Basswood stringers for contrast. I’m assuming cost no object. KD anything is priced OUTRAGEOUSLY. I’d use Polyester and glass with two ounce cloth, hotcoat and gloss with no vent. Of course you would have to baby the board, but that would a small price to pay.
in that post RDM makes an interesting weight calculation based on shell thickness.
I have built a hollow one, using the directions in Jensen’s site. I glassed it with poly, the board has been used for about a year almost daily, and there are no delamination problems yet. Not bad for a 60 dlls board…If you wanna go cheap you can use poly too.
Haven’t started the pine board project due to lack of free time. All I can say is go for it, and then let us know how you go
Hi Stiffler Why not try an all cedar board? I’ve been packing doug fir and cedar for over 30 years .Cedar is half the weight. With fir you should use clear KD fir $$. It needs to be dry before you glue.If you try cedar . Theirs alot of small cedar mills on the Oregon coast to get clear. Or shop at one of the larger lumber yards. If you go with fir post so pictures. Gordon
Just had a look round your site, what beautiful work! Truly inspiring and I am very envious of your shaping “room”. One day when I have a little more understanding of the complexities of surfboard design and when I have a little more experience of building wood boards I will build a chambered balsa, hopefully it might turn out half as lovely as these.
