The removable fin systems we all know and use are modern precision systems designed for mass production. But I am wondering if anyone has ever encountered a handcrafted solution for a home-made removable fin. I am thinking along the lines of a keyed mortis and tenon, but any info on this subject would be appreciated.
So how does it work ? Does the fin go all the way thru the board like a Tuttle box ?
I dont know what a tuttle box is, but that’s what I envision (will look it up).
Or more angled thru the fin ?
The fin would be a bit longer but not by much so weights not going to be an issue.
like this
the fin would slide into a slot
the wedge would lock it in place
reinforce as desired
you could even attach a leash to the top tab
For what sort of board ?
If you are thinking of the cedar slab board Huck, how about a sliding dovetail set up? A dovetail dado with the fin tang having the matching “pin” side. Then another dovetail Dutchman to slide in behind the fin in the dado. The Dutchman can be kept in place with a dowel or push pin. Water intrusion of course would have to be eliminated. ps. I promise I’m not stalking you.
Seeing how unnecessarily complex fin systems are now, my mind went straight to a new fin system using a simpler thru-board slot with a simple twist locking cap on the deck.
The thru board slot would create a really stable hold on the fin.
I always enjoy the creative process.
You’re doing an old skool board. I think it’ll look better with a period-correct fin, glassed in place. I’d rout a slot and glass a full-length tang in so you won’t have to rely on a fillet to keep the fin on. You’d be burying an inch or two of the fin into the blank itself.
A straight glass on with a half dozen layers of fiberglass would be cool, too.
thanx guys lots of cool ideas here, I’m with Bret in loving the creative process. For a long time I’ve thought that a simple homemade removable fin system should be possible, and the keyed mortise / tenon is one idea I’ve had in my mind.
An older board-maker that I know showed me a system he’d been using for a long time where he’d make a timber box with a timber fin. There was a very fine tolerance so the fin only just fitted into the box. Before inserting the fin a strip of paper was folded over the base. When the board got wet, the paper would swell and the fin would be locked in
George Downing, perhaps? That is the exact description of the removable fin system he devised, in the early 1950’s, in Hawaii.
I always liked the screw from the deck idea.
So for modern fins an 8 mm rectangular slot with a mid level shelf and two screw holes.
Glass thru the board for stability, trim the deck.
Slot the fin in and screw from the deck. It could be made to fit any base shape because it’s not about the base.
Or even an 1/2 inch slot box for the fin base and two round tubes for the screws from the deck down to the box.
Downing comes to mind…
There are a few here who would remember a forum member named Mike Sabs. From Oz or New Zealand, I think.
Somewhere between 12 and 15 years ago he posted a thread about this very thing. He had a rather simple home-made system that actually allowed for adjusting the toe-in. I’ve tried many time to dig it up to no avail, and I just don’t remember enough of it to be useful.
