Making Wooden Keels

I know there’s alot in the archive on this, but it’s all in bits and pieces and I’m trying to get a procedure down in writing before making our keels tonight. I’m going to use some scrap ply we have laying around, and they will have a 9" base, 5 1/2" tall, with no rake. Rooster has helped a little already, but what do you think of this process:

  • Get a completely flat surface to work on.

  • Draw template on wood and cut profile.

  • Use orbital or block to get desired foil.

  • Tape off one entire side of keel and lay on flat surface.

  • Layup 2 or 3 layers of 8oz. glass on top of keel with Lam resin, making sure to get all air bubbles out.

  • When dry, cut excess glass from around profile.

  • Tape other side and do the same procedure…

  • Fine sand to liking…

Then when glassing them on, just use rope and/or patches around the base and hotcoat on, correct?

Thanks for any tips or suggestions…

I am doing a similar project and i read that the master of the wood fin Tom Jenson uses one layer of 6oz on each side to seal the wood and he also creates a bead of resin on the leading edge so they can be foiled easier and then glasses on with fin rope and football shaped patches like normal glassons. He also mentions sealing them with milled fiber adative like the FCS filler and just smearing it on with his gloves and then once sealed glassing on like normal. He also makes a point to seal the bottom of the fin.

Tenover,

And when you laminate the fins make sure you work on a piece of glass or board covered with wax paper otherwise you will laminate them to the flat surface.

Yup, for sure! Another question…Once the wood is cut and foiled, and you’re ready to lay up one side, does it matter how oversized the glass is? Should it be cut pretty even with the fin or does it not matter. and also, does the bead you’re talking about take care where the two sides of glass would meet in the middle? Where in SD are you?

You’ve seen longboard fins and fish retro fins made of wood, there is a 1/4 inch bead of clear resin/glass around the fin. That’s solid rope saturated with resin…looks cool and retro.

Most guys I know who make wood fins like to seal the fin itself BEFORE any glassing. They brush on a coat of lam or vinylester resin on the wood, let set, sand lightly if needed, and then lam. Something to do with lam coats don’t breathe, and the ply is not permeable from one side thru the different layers, to the other side. A seal coat, given normal one our set time, can breathe little air holes, and have time to seal itself up before gelling.

Tenover:

Are you making a layup fin of wood and glass layers? Sounds like there is some static in the flow chart going on here. This is just my take on the process and it might not apply to your project.

If you are laying up fins made primarily from multiple layers of cloth laminated together (maybe with some colored layers of cloth or thin wood) then the flat suface is good. You are trying to laminate 30+ layers of cloth together and keep it flat. If you are using wood as your primary core then it is more of a process of shaping the already flat stock. I use some cheap spring clamps to hold my fin stock down on a work bench or cross rail on my shaping stand. Side lights can help here just as if you are working on foam.

If you are looking for a plywood fin (birch is good, but you can use most any kind) then you are going to take a piece of 3/8" ply and cutout your template, true up your outline on the pair and get to work on the foils. At this stage, squared edges, you might consider the bead of glass rope. It will be a lot better edge and way easier to glass later. (air bubbles at the apex of the foiled edge where the two cloth layers meet). Cleanlines posted a great tip, try to cut a routed V or groove in the squared edge to improve the surface you are laying the cloth rope into. I use my smaller Porter-Cable variable speed sander/polisher with a 3’ disc to start my foil. You might start with 36 grit and work it down to 80 grit or so. I like to seal with lam resin (epoxy is my medium now and that works even better). I set them on my marks with a hot bead of of glue stick, some hot resin or 5 min epoxy depending on your tastes. After that it’s the same old same old glassed on fin routine. Fin rope, couple of layers of 6 oz. cloth, hotcoat then sanding and finish coat if you like. Making your own fins is an art unto itself, one of the most important aspects of the board building process. I never discard a design until I’ve explored all avenues of the fin position, template various surf conditions. Good luck, let’s see some of the pictures.

Tom S.

Thanks tomas-

That’s what I was looking for. We are making “old-school” keel fins for our fish out of ply. I made them out of 3/8" and they’re looking good so far. you’re definitely right about it being “an art unto itself”!

You know, back in the 70’s we’d make a ton of keel fins all at once. If you are doing some numbers and have access to a good table saw and can make some accurate, basic jigs, you can cut the entire piece of stock into a foil before outlining any fins. For example, you can take a 48" long piece that is 9" wide and run it through the saw ON EDGE, to get a bevel (tilt the blade a few degress). This bevel runs the entire 48" with a bevel face of about 4". Flip the stock and run another bevel to comlete the rear edge rough foil. We used to belt sand some curve to eliminate the facet-ness? of the bevel. With the rear edge of a four-foot long piece already foiled, it was a piece of cake to bandsaw the outlines and use a 36 grit 5" wheel to make the leading edges then finish with an 80 grit belt. (Don’t want it too fine so the resin will have some tooth to hold). In recent years we make a slurry of lam resin and milled fiber and smear it on using rubber gloves. We then focus on only a slight bead when the fin actually gets glassed onto the board. Good Luck.

Re: Clear glass bead around skeg

David platt – Thursday, 6 November 2003, at 10:01 p.m.

I’ve done a few timber fins with clear beads for old longboards I have restored.I cut out the blank,hotcoat one side with lam resin and glass that side with about 1/2 to 3/4" of glass hanging over the edge of the fin.When it has cured turn the fin over and you have a mould to lay your fin rovings into.David.

This is one of the fins mentioned in the above post.platty

Thanks platty- That looks really nice.

all my fins are made of wood as well …

you want a piece of laminex or some other really shiny surface to work on …and some mold release agent as well ,makes the job way easier,

i use two different techniques,one for centres and the other for sides…they all get done together tho …i usally run between 6 and 9 sets of thrusters …once your doing more than 27 fins at once time becomes an issue …

first stage is simple cut and foil timber (i use 9mm ply),if you leave your leading edge a little fuller itll help for glassing later…

then i line up all my centre fins on the shiny laminex surface and cut 2 layers of 6oz which i lay on the laminex next to the centre fins …i mix some res and glass the the two layers on the laminex ,then pick up the wet cloth and lay it on the centre fins that way you can keep the glass off the table coz the glass only just makes it to the leading edge, spans a gap of about 1.5 cm then onto the next fin ,…

then the area where i picked up the wet cloth from i wet a little more ,covering more area ,then place all my side fins flat side down…i usually stick em down in setts so they look like boomerrangs lined up the fins are base to base…

while the resin is drying i cut my glass rope and two large patches of 6oz,when its tacky enough so the fins dont move ,do the next brew ,wet out rope and lay it along leading edge then the tacky spots between the fins come in real handy coz when i put the glass on it sticks down real firm…wet everything out and work the bubbles out with my finger along leading edge like when your setting fins on a board…once that sets ,hot coat both the row of centres and sides,

when its dry a few hours later get a scraper and lift all the side fins in one sheet.off the laminex, then run a sander over the flat side and glass 2 more layers of 6 oz on ,just like you were laminating a board with a sqeegee,…

now your centre fins have a layer of glass one one side ,you can lift em up turn over and put glass rope on leading edges and then the last 2 layers of 6oz and work out bubbles like side fins …then hot coat…

when all the glassing is done you have a whole sheet of perfectly glassed fins …

now you just cut em out with a jigsaw and clean up the foils ,ready for the board…

regards

BERT

eventually when i get a camera i will post a series of shots that shows the sequence i just explained…