I have been busy on a special order for a 10’ chambered balsa longboard lately. I have posted the day to day progression on my pro FB page but then one of my fellow swaylockians asked me to post it here, too. So here it is.
I didn’t take any photos of the preparatory work (joint-planing the lumbers, thickness-planing, weighing each of them, slicing them in halves so as to put one on each side and get something well balanced in the end; The first photo shows the rocker being pre-shaped with the bandsaw, the second shows the pre-assembly of all rockered pieces.
(When pre-viewing the post, I noticed that the photos uploaded upside-down. Not the first time this happens. Bummer; Anybody knows how to get them straight?)
Edit: thanks to Huck, everything is back to normal!
Since I am not a band-saw champion, there were still many flaws in all pieces and I had to plane everything down before outlining. Yes, that’s Pete Casica’s modified Makita planer and it did a fine job.
Next step was to make a temporary assembly for shaping the blank so that it could be disassembled later in order to chamber; the idea is to get the blank as close as possible to finish, then chamber, then glue everything back together for good. This temporary assembly is done using thermo-melting glue in very tiny spots every foot or so. The glue sets so fast that it cannot really penetrate the wood; It’s strong enough to handle the blank for shaping but a few mallet strokes will easily separate the pieces when needed.
A few pieces had bad knots that looked like I would get in trouble with them later so I decided to take them out and replace them with a piece of “healthy” wood. Hard to find the same color and grain. Oh, well…
Currently glueing the chambered pieces together (one by one, since polyurethane glue is used and it starts foaming very quickly. Besides, having some time for fine-tuning the joint is not bad either.)
Hi Mc Ding, no, I had them made by a guy nearby who does a lot of metal working. Next time I will have them made thicker because those have a bad tendency to bend when you put a bit too much load on them.
Great work Balsa. I’ve yet to ever cut into Balsa. I could buy a Chambered Balsa Blank, but I think it just isn’t a true"handcrafted" Balsa board if you don’t pick the Balsa, bookend it, glue-up and chamber from start to finish yourself. I think you’ve done a great job of using a drill, router and jig saw combo to chamber. Very well done! Lowel
Actually, I started chambering with the jigsaw but forgot the idea after the very first piece as the blade had bent and my cuts were dangerously too deep on the outside; I had to patch one or two chambers with some leftover balsa as one side was about 1/2" thick while the other was less than 1/4". Went back to the good old drill press with square chisels, takes much longer but way safer and more precise.
All the guys I know who used pre-assembled hollow blanks went through the deck or bottom at one time or another during the shape process and had to patch the holes, so I am not too keen on trying those myself…
The tricky part with balsa is that it does not catch light as well as a white blank of foam. Flaws in the curves are much harder to spot. And, of course, as long as you use the planer everything goes fine but when you start using sand-paper, differences in density between the pieces make for bumps and holes very easily…
Not for the faint of heart, for sure, but the end result is still worth it.
You know I hadn’t thought about it recently, but I remember someone telling me he used a large Fornster(so) bit on a drill press to chamber a blank. The way Huck is doing his. Pete C once told me about some guys using an electric drill with a long bit like Electricians use and standing on the Balsa.
Balsa, I am loving this. I built a long one a while back and it definitely made me a better shaper. Foam is so easy to shape, but balsa will humble you for all the reasons you mention.
I made several mistakes on mine and would put it down for a while before getting the courage to continue. It took me 2 years to finish. I almost cut it in half in my anger one time. But I figured out a way to fix my big mistake and continued.
My mistake was cutting one rail side too deep with my Skil 100. I tripped over the cord and took a chunk out. I was able to smooth it out, and then with white glue I laminated thin planks of hobby shop balsa to the proper depth. I bagged them on using a cheap blow up beach mattress that was deflated and wrapped tightly with sheet plastic and then inflated to apply even pressure to the wide area. Worked beautifully. Blended nicely. You won’t need this trick because you are a pro, but maybe another rookie like me will need it.
And I too am loving my Cassica Makita. I use it more than my Skil when doing wood and other heavy cutting. My Cassica Bosch is my “go to” for foam.