Fin placement for a single fin mini - Now a build thread!

paulr · June 23, 2012, 11:34am

Oh, and before I forget, a teaser for chippy!

Flat stone slab with waxed paper.

About 45 layers of 6-oz saturated with white-pigmented epoxy.

And another flat stone slab on top (with waxed paper underneath) to compress overnight while the resin cures.

Hopefully this fin turns out like the picture in my head…

Cheers
Paul

chippy61 · June 23, 2012, 12:19pm

great stuff Paul !

I'll be keen to read / see how thin or otherwise the compressed fin will turn out ...

[any hint on how big the fin will be , Paul ? ....and hopefully , you'll be able to have two small one tabber side bites from the left over offcuts ??]

keep the thread going mate !

cheers !

ben

paulr · June 25, 2012, 12:00pm

A bit more progress to report…Sanded the hotcoat on the bottom.

And on the deck

I found the sanding a bit frustrating, because I paid a lot of attention to making sure the lam was as flat as possible, prepared the laps very well, and layed down the best hotcoat I’ve done. But the sanding really showed the little dips and bumps that I didn’t think were there. It’s nothing like fish-eyes or zits, but more just lots of shiney spots. When I sanded more to eliminate them, I’d touch the weave in spots. I actually found the soft pad with 100grit did the best job, but I’m going to have to go back and read the archives on sanding technique. And epoxy hotcoat technique. I’m gonna try WoodOgre’s technique for laying down the gloss with a foam roller to get it nice and thiiiin!

Hopefully I can get the gloss coat down during a couple of evenings this week…if I can get away with using epoxy in the dining room…

chippy61 · June 25, 2012, 12:06pm

.....and has the fin panel cured now ?

paulr · June 25, 2012, 12:14pm

And chippy, here’s how the fin panel came out. Once I trimmed off the dry cloth, it ended up about 12"x7".

This is the template that I’m thinking of using, basically a 9" dolphin style fin. I can’t remember where I got the template from, probably from a photo on the internet somewhere…

Or I could go with a 12" minimally foiled hatchet/pivot fin…haha…just testing the thickness. The panel is about 9mm thick, which is pretty close to a perfect fit. Once I foil and hotcoat, the base should be a perfect fit.

Cheers
Paul

paulr · June 25, 2012, 12:17pm

Forgot to mention I should get a couple of small stabilizers out of the panel too.

chippy61 · June 25, 2012, 1:04pm

YES !

well done !!!!

you'll probably be able to get FOUR one-tabbers out of the offcuts ....

...or two 3x3's at least !

paulr · June 28, 2012, 10:26am

I got ahead of myself in my earlier post. I can’t gloss coat the board yet, because I wanted to cap the fin boxes with 4oz. I know this isn’t really necessary, but given my amatuerish ProBox install, I’m a bit more comfortable with them capped. So I taped off the ProBoxes

And taped off the center box.

And cut my 4oz patches. I decided to use one big patch to cover each pair of ProBoxes to minimise sanding between them.

I lammed the patches.

Then when it had gelled, but was still a bit sticky, I hotcoated them.

The next night I taped off the leash plug.

And cut my 4oz patch.

And lammed and hotcoated it.

Since I had a bit of left over resin, I also glossed my homemade quads. Sorry chippy, I started making these fins before I had even contemplated this board, so I didn’t really take any photos of the early stages. But basically they’re just FCS FG7 templates, with the fin panel made from uncoloured epoxy and 6oz. After foiling and hotcoating, I sanded and spray painted black, and lightly sanded again before glossing. Just need to polish them up now. BTW these look like FCS bases, but they’re really ProBox bases, which you can see if you look closely. The pale bit is just where I had them hanging from the clothesline with masking tape when I was spray painting them.

Hopefully next week I can get time to sand the caps and gloss the board. And foil that center fin…

Cheers
Paul

Huck · June 28, 2012, 11:00am

great thread, very attractive board

MickD · June 28, 2012, 11:21am

Yep, looks great Paul, nice work!

Cheers,

Mick.

paulr · July 3, 2012, 11:37am

Thanks Huck and Mick!

I’ve made a bit more progress on this build. I glossed the deck using a foam roller. I found a thread on here with Wood Ogre explaining his technique to get a really thin layer of epoxy, so I thought I’d give it a go. I ended up using only about 75mL of epoxy for the deck, but I haven’t got the technique quite right as I did end up with quite a lot of microscopic air bubbles. Don’t think it will be too much of an issue though when I sand and polish.

The next day I sanded the 4oz finbox patches to blend the edges and open up the boxes.

Then I taped off for glossing.

And then I glossed the bottom.

This shot is for Stingray, who said, and I quote “you can’t even do a basic fin box install”. I think it came up pretty good in the end, even if the installation didn’t go as smoothly as I’d have liked.

And this shot is for Chippy. I’ve decided on a 9.5" template, which is now ready to cut out…maybe later in the week I’ll get to it. The perspective in this photo is a bit odd, because the base isn’t really that big relative to the height, it’s a fairly standard dolphin template.

Anyhoo, maybe some fin updates later in the week.

Cheers
Paul

paulr · July 14, 2012, 10:41am

Ok, so fin updates to report:

I cut the fin out with the jigsaw and a carbide bit.

Then I set up the belt sander on my workbench / shaping racks with a couple of clamps and trued up the outline, taking it back to the line.

The final result after cleaning up the outline.

Then I drew a centerline around the fin, so that I had a guide to work to while foiling the fin to make sure the foil came out symmetrical.

Then I drew bands on the fin on both sides to guide my foiling.

I did the foiling with my orbital sander and 6" disc with medium pad and 80 grit paper. This shot is part-way through the foiling.

The foiling completed.

Even though in the above pic, the fin looks ok, up close there were a bunch of pin-holes where the cloth wasn’t completely wet out in spots. So I mixed up some white pigmented resin with a bit of West System 411 microsphere blend to make a paste for fairing out to fill the pin holes. This shot is after squidgeeing the paste, but before sanding.

When cured, I sanded to 120 grit, and then used white pigmented resin to gloss coat.

Then I sanded and attempted to polish. I’m hopeless at polishing, but at least the fin came out smooth and nice!

paulr · July 14, 2012, 10:56am

So in the last pic of my above post, you might have noticed the board in the background. While I was making dust sanding the fin, I sanded the gloss coat of the board and attempted to polish. This has been my best board yet, being the first one that I could start sanding the gloss with 320 grit (earlier boards I had to start from 120). That said, there’s still plenty of cosmetic blemishes on this one when you look closely. But I’m slowly improving…The gloss I dry sanded at 320, then wet sanded with 400, 600, 800, 1000, 1200, and 1500. Then I tried the polishing compound, which brought out the shine a little bit more, but it’s certainly not polished. But it’s good enough for board #006 - I just want to get it wet now!

paulr · July 14, 2012, 11:12am

So that completes the build of the Mini-Franken-Simmons! Some pics of the finished product:

I’m going to look forward playing around with fin options on this one. The five-fin “Too Much Fin” option probably won’t spin out, but I don’t think I’ll try it like this…

Of course, it can also be set up as a quad:

So all up, it finished up at 5’2" x 21" x 2 7/8" and 37L, made from three scrap offcuts of EPS, some scraps of bamboo veneer, and some 6oz cloth and Kinetix epoxy I already had in the shed. The only things I had to buy specifically for this board were the fin boxes, and some pigment. Not too bad at all, I think.

fins · July 14, 2012, 11:47am

VERY nice , Paul !

...and the offcuts ?

could you get a couple of bonzer runners-sized fins from them ? or M.R. TX or GS type templates ? ....don't let THEM go to waste eh , mate ?

cheers !

ben

[yes , username change , on friday 13th ...the 'chip' names have been done to death since 2004 !]

and , as I went to post this , THIS came up ??? [A bit rude , I thought ? ].....

"

We are sorry, but the spam filter on this site decided that your submission could be spam. Please fill in the CAPTCHA below to get your submission accepted. "

fins · July 14, 2012, 12:07pm

how did you measure and drill the holes , too, by the way , on the single fin ?

and any reason for the screw going in the BACK of the fin , rather than the front ? [with the screw at the front , you can move your back fin further BACK , always a good thing , especially if you ever want to play with base cutaway , thruster setup positionings of the [different] back fin[s, you will need / want to try , over time ?! [hopefully , anyway ] ...just remember , I HAVE FINS for you , you know ...just say when !

I can't wait to read a RIDE report next , Paul ! [hint , hint] ...PHOTOS , please ?!

cheers mate !

ben

paulr · July 15, 2012, 11:12am

Hey Ben!

Don’t worry, I haven’t trashed the offcuts. I will definitely be able to get a couple of bonzer-style runners out of them, and probably a couple of one-tabbers. But I’m a bit over epoxy/fibreglass dust at the moment, so I think I’ll let them sit for a little while. To drill the holes, I first made a balsa template which I test-fitted to the box to get the hole positions spot on. Then I transfered the hole locations to the real fin base. I couldn’t figure out how to drill the screw hole on my drill press, so I just did it with the cordless drill. Both holes I started with a 2mm bit and made sure I got it centered and straight. Then I embiggened it with a 3mm, 4mm and finally 5mm bits. Naturally, I left the base a touch oversized and then sanded it down to fit right.

As for the screw hole at the rear of the fin, when I was decided to place it fore or aft, I made up a cardboard mock-up to see how the fin would sit in the box, and where it would be relative to my rear foot. I’m not real keen of having the fin protrude beyond the back of the board, just in case my foot slips on a late takeoff, so I decided to put the screw at the back. As it is, if I put it all the way at the back of the box, it still protrudes a little beyond the tail of the board.

I’m keen to get a feel for it as a single, then I’ll speak to you about other fins! Definitely excited to ride this board!

Cheers
Paul

paulr · July 15, 2012, 11:37am

So a little bit of a ride report…I’ll start with a disclaimer: I’ve never ridden a single fin before, so my assessment of the board is biased by this fact. I’m used turning a board off the fins, ie leaning over, looking where I want to go, and have the board come around. I realise that on a single I have to turn it off the rails, so it’s going to take a bit of practice to ride it “right”.

I’ve now had two sessions on this board, both in weak, chest high beach breaks. At 37L, it definitely paddles easily, and duckdive likes a bodyboard - I can push it deeper than my standard shorty! For the first session, the tide was too high and the lack of decent banks at my local beachbreak made for fat and sluggish waves. Every so often, a bigger (head-high) set would come through, but they were usually “straight-handers”, ie closeouts. So I didn’t have a decent wall to turn the board on. However, I quickly figured out that my muscle-memory means of bottom turning doesn’t really work on a short single, and I had to really be conscious of my bottom turn and push it around on the rails. I did a couple of decent top turns that felt nice, smooth and floaty, like the board had a style of its own. And I did get one deep closeout barrel on one of the bigger ones, completely unmakeable, but cool nonetheless!

The second session was around the same size, with a bit more shape, but howling offshore that made it real hard getting into waves. Another frustrating session, but got a few on my backhand, including some reo’s and a floater. It’s definitely very stable. My bottom turn on my backhand was much better, but then it alway is better on my backhand, 'cos I tend to go straighter down the face, then really lay it over on rail and push it around. I tend to get lazy on my frontside and just angle across the face on the takeoff. Had some good runners in this session, but not conducive to turns, and I basically just had to race the breaking wave (did I mention the board is fast!). The single is definitely solid on a steep face, plenty of bite and no slippage at all, even with the whitewater explosion.

So not much really to report, just getting a feel for it at this stage. I can’t even make a call as to whether I need to move the fin yet. I really need to get it out in decent conditions where I have a wall to play on with a few turns. The banks around here are rubbish though, and I’m not going to take it out at (super crowded) Winkipop until I get it wired, so I just have to be patient until I get better conditions…

Cheers
Paul

paulr · July 16, 2012, 4:31am

Better conditions arose sooner than I expected…a new swell filled in overnight and I woke to a very straight 4-5ft swell with light offshores. Rather than Winkipop/Bells Beach, I decided to go out a lesser known (but still well known) Surf Coast point break reef nearby. This reef doesn’t pick up as much swell, but at least I had it to myself for 90 minutes with 3ft (head-high) sets and long clean walls. The perfect test track for a single fin!

With a bigger wave face, I found bottom turning much easier, drawing it out and pushing it around on rail. The top turns were just so floaty and smooth, and I managed some reasonably tight cutbacks too. The most unexpected aspect is the amount of hold that the single fin has on a steep wave face. I could ride up high through some steep fast sections and the board just held tight. Even when I had the lip explode next to me, the fin didn’t disengage like can happen on the thruster/quad. I guess this comes from the extra depth in the fin. So basically just lots of long waves with turns and gliding, and the occasional floater, really getting a feel for how the single rides. I’m really enjoying how smooth and flowing it is. If it doesn’t improve my surfing style, then nothing will!

I can’t say for sure just yet how I will adjust the fin. I remember my first quad, where right from the first wave, the fins just didn’t feel right, and so I had to adjust them until I found the right configuration/position. But with this board, the fin size/placement certainly doesn’t feel wrong. I don’t know if it’s “right”, as I’m still adjusting to how a single-fin rides, but there was nothing about this session that made me question the fin. I think I’ll give it a couple more sessions as-is, then mark the current position, and try a little forward and a little back, just to see the difference. I can’t accept that I got the fin spot on with the first attempt, but who knows, maybe I just got lucky!

And sorry Ben, no photos of the session, I was the only one in the water, and when I got back to the car on the cliff top, I forgot to take some lineup shots.

Cheers
Paul

paulr · July 16, 2012, 4:57am

Hey Ben, I just came across these photos from this morning at Winki. Pretty much the conditions I was out in, except the reef I was on was a touch smaller. Images aren’t mine, they come from Aquabumps (http://www.aquabumps.com/2012/07/16/torquay/)