Classic "D" Fin Fiberglass Bead

Hey Guys!

Continuing with my ongoing fascination with the Bing era, I shaped my own Nuuhiwa noserider today.   It’s your basic 9’8"Y US Blank with all the wrong rocker, but I was anxious to give this board a try so I went with a stock blank.  It does have the traditional high density blue foam stringer, so that’s a plus…but it’s still a modern blank to my dismay.  

My question tonight is how to achieve the heavy fiberglass bead around the classic “D” fin.  Here’s one of Bings:

 

I have some nice very thin 12" x 12" sheets of ply from Woodcraft and I’m thinking of laminating 15-20 sheets of pigment dyed cloth in between.  The traditional red Nuuhiwa fin has a section of black fiberglass sandwiched in the middle, so I thought I would blend an older style of Bing’s “D” fin with a tip of the hat to the hachet Nuuhiwa…

Anyone familar with laminating this traditional fin?

Thanks!

 

Hey Thomas, excellent looking restorations on your site man!  Great screenwork and graphics too.  You got some real talent there.

For that bead, you might want to pick up some glass roving (greenlight has it, but you might find it at a marine supply in town), lay it around the perimeter of your fin between lamination layers to build up the bulk. 

You can also cast that bead on with some resin and a small amount of milled fiber.  Foil your wood, sandwich between two sheets of stiff plastic cut about 3/4" larger all around and edges pinched and sealed with duct tape.  Some spring clamps along the center of the fin to position it and keep the plastic 'envelope' from balloning when you cast the resin.   Once it's set, trim the resulting bead to finish size, clean up and blend the foil, then glass.  

I'm sure there are other ways to get this done, but those two have worked for me in the past.

Hope that helps.  Good Luck! 

Personally, I wouldn’t put a D fin a Nuuhiwa replica if that’s what you’re aiming for.

   Howzit Sammy, I have to agree with you about a D fin on the Board since I am pretty sure they didn't come with D fins, by the time those boards came out D fins were not on any boards. I remember a friend who had one and the fin was what we called Donkey Dick fins. Aloha,Kokua

 

Yes. The D fin was pretty much obsolete by the mid 60s. As rail and bottom curves became more refined, it was in conjunction with fins having less surface area.

I think a replica of the Nuuhiwa style fin done in wood with a nice bead would look great, and be more functional. I recall seeing just such a fin somewhere on the 'net.

D fins are not fins....they're rudders.

Also,

I personally like 1/8 to 1/4 hardwood for wood fins. specially dem longboard fins.  Cut your little sticks and squares out on the table saw....glue them together in the little checkerboard or stripe...or checker/stripe pattern, and glue together with brown resin glue, or alphic elmers wood glue.  Now you have a fin panel. run the panel through the surface planer, drum sander, or your belt sander smooth to about 1/4 in thick. and cut out the fin.  Shape & foil to no more than 1/4 in thick fin.  finished fin should be covered with thinned out lam resin and left to dry, this fills in the little pukas and air holes, plus seals the wood from gasing and doing wierd things when you glass.  Cover both sides in 4 oz glass 3 times, let the cloth cover the fin by at least 3 inches all the way around, use a pretty heavy coat on resin so you dont get bubbles, let this dry and cut out your finished fin shape with the bead in place. Now finish covering the fin in 6 oz cloth with another 3 layers+

 

Dat's my way of doing it?

Tommyrocket,

Check the archives for a thread by Austin..I can't remember the name..maybe "Building D-Fins". He doesnt use extra cloth or fin rope. He builds resin up in individual layers( with extra styrene i think) until it is built up to the desired thickness. Very clean and mega clear.

Bob

Thanks Guys,  I have an orginal Bing- Nuuhiwa fin template from 1968… I just spent a month restoring a Nuuhiwa and wanted to do something a little different.    

Today I decided to use Dewey’s Performer color scheme with Navy Blue rails and red competition stripes, so I’m now leaning towards a flex style fin instead.

This is one that I’m having some trouble locating…it’s made by the Fibre Glas Co.? 

Thanks so much for the nice words and all the info on glassing the skeg.   I’ll post some photos and let you know which method seems to work best for creating a thick clear bead around the foiled “D” fin as I still plan to stock the fin blanks for future boards.

I must disagree with the idea of using a lot of resin to create a bead. The original idea behind a halo on a wood fin was for protection more than cosmetics. A bead that’s made from a big batch of resin will shatter easily. Defeats the whole idea, IMO. Clarity is desirable, but at what cost in durability?  I feel the right way to do a bead is multiple layers of glass and fin rope.

Just a suggestion…

What about a tinted bead? I think it would look real nice if done right. From what I’ve seen of your work, I’m sure you’re more than capable.

I fart in the general direction of "rope" if you have to buy it.  Anyone who is competent to build a fin or a board has more than enough scrap glass laying about to pull apart, lay the threads parallel, put on the gloves, and saturate the strands in some lightly catalyzed resin.  Smooth it onto the leading edge of the fin after the fin is glassed to the board. 

Don't try put on too much at once or it tends to sag off.

Don't try put on too much at once or it may be hard to eliminate bubbles.

Not too wet, not too dry.  Light catalyst will give you time to find the right saturation level.

Rough shape each length of rope when the resin has cured sufficiently,  using your Surform. 

Then saturate, squeeze gently and lay another length on.  It builds pretty quickly.

If you're using UV cure, and it's a sunny day, the halo will be in place in under two hours. 

ALTERNATIVELY, get your wood to thickness and before you foil, lay the fin blank flat on some plastic and build a "dam" around the edges, which you fill with resin.  This method avoids bubbles and makes a beautiful clear halo (if you resin dries transparent) but if only resin is used for the halo, it will be weak.  Don't try to split rocks with it.  When the halo is built and foiled in, you can add a layer or several of glass around it and foil that in. 

Hint.... setting resin off too fast can make it discolor. 

Hint v2, a little tiny bit of tint or pigment in the halo resin will make a nice effect.

    Howzit Honolulu, o to fiberglass HI and buy a sq ft of roving glass and just pull the strands as you need them, it will last you for years for maybe $5. Aloha,Kokua

Hey Kokua...  frugal MacDougal doesn't buy anything he already has... in this instance, a large grocery bag of 6 oz. scraps willo supply more material for patching, fins and whatever, than I'll ever use.  Growing all the time. 

I used strands from woven roving before, they seem to be a good deal coarser than those from 6 oz. cloth and didn't wet out as nicely, nor did they go as transparent.  Maybe that was something particular to my method, or another unknown.  Anyway, it's taking apart scrap offcuts for me!

The day FH sells just a square foot of anything will be news to me.  I think woven roving comes in standard roll widths, 38 and 54 inches, so the minimum would be a foot long 38 wide or over three square feet.  Well I needed something to do anyway; and WR does come apart more easily than lighter cloth.

Simplest way to do the structural bead (not the clear resin kind) is in the glass-on process. Wet some extra strands of rope, roving, whatever; and when you layup the glass patches that run up the sides of the fin, leave them ''open'' at the front and rear of fin. Insert the wet ropes front  and rear, ''close'' the patches. Rope will stay in place surprisingly well, but may need a little tending. Don't let it slip down side of fin. The more ''forming'' you can do right as it gels the better. Razor blade off excess a few minutes later, final trueing in sand job. Old school.

Here’s photos and descriptions of how I did my first fin with clear halo.  Perhaps not the pro way to do it, but it turned out pretty nice. This was a fin box fin, and I learned the technique for doing that part here.

http://www.grainsurf.com/forum/viewtopic.php?f=11&t=570&p=14864#p14864

Mike’s got it down. That’s the best and easiest way, IMO.

Try layin up a clear fin panel 1/8" thick , then laminate yer wood on each side - then more clear to get your thickness...............cut out fin........foil fin ........and .......BOONGO !  halo  slowly becomes exposed when you fiol the fin.......with thinner leading edge-wider trailing edge and structural integrity (bonus)...works for me

Nice tech kayu.  I've seen something similar on commercial fins using a piece of veneer on each side of a foiled fin and glossed over, but the execution was horrible. Sounds like your method would produce an infinitely nicer product.

Has anybody out there tried something similar with some high-end lexan or clear polycarbonate?     

Tried 3mm clear acrylic sheet......can snap at base !

Here is one I just completed. 

 

I do not use any fiber in my beads.  After they are shaped they are less than 1/8" of resin.  After I glass three layers of 6oz on both sides, hotcoat and sand them we then glass them on with 3 layers of 6 again.  After all of this I have never seen one crack or shatter.  Hope that helps.

Austin