tinted laminate to edge of balsa sheeting

General Discussion
1

I have a kite surfboard core that is Divinycell with balsa sheeting on the deck. Normally

wouldn’t put balsa over diviny but I ran my first machining sequence .100" too deep on

this board so I decided to skin it with some balsa. pictures of the core:

The bottom will be epoxy 4+2 with some resin tint splash randomness. And I’ll wrap that

up the rail and hopefully cut it right at the edge of the balsa. Then laminate the top clear.

I’m using RR epoxy and have pretty good laminating skills. I use slow hardener, F and heat

the resin to 90-95F.

What are my chances of pulling off a clean line at the edge of the balsa? I’m planning on

sealing the balsa with resin first to prevent weeping when I do the bottom. The bottom

and rails will be bogged with resin/balloons. What is the best tape and taping technique?

I’ve got a pretty steady hand with a razor but I’m sweating making the cut just the same.

Any ideas before I dive in?

Thanks,

Hein

2

Hein, i think you have lots of software access? why not try making your outline/pinline and cutting a vynil mask on a cutter plotter…

3

That’s a good idea. Although I’ll probably just tape off the edge of

the wood by hand. Will a vinyl tape work better? I think I’m worried

about tinted resin getting onto the wood and then having difficulty

making the cut along whatever mask I use. Maybe it will be easier

than I think. Just never tried anything like this before.

4

that’s a great looking board…I’m glad you’re not hiding the balsa :slight_smile:

Is your rail the same thickness all the way around? If so, since you’re sealing first, you could probably just run a wider piece of tape over the balsa-d-cell joint, and then use a scribing knife to cut the tape to the same smooth outline as the balsa. You probably know what I’m talking about - like an exacto poked through an adjustable right-angle instead of a pencil… Then you pull the tape that was outside the cutline and you end up with a nice line at the balsa.

Then I usually use red rosin paper to mask off the deck, and tape down the edges pretty close to my original cutlap line. The epoxy doesn’t go through the rosin paper, and it sticks to 233+ tape better than plastics do, when it gets a little wet.

Use s cloth for your deck lamination, or the freelaps will be visible over the tinted resin on the bottom.

5

Thanks for the tips, Benny. I think I can tape

off the edge of the balsa with out too much trouble.

I can always do it over and over until it’s right.

Is there any advantage to cutting the tape instead

of just laying it along the edge? Hadn’t heard of

a scribing knife. But the balsa doesn’t parallel the

rails anyway. Sweet kiteboard! Especially the handle;

(which I make for NSI.)

I’m more worried about cutting the laminate after

it cures a while. I plan on bogging the bottom and

rails and letting that turn tacky before laminating

the bottom. The bog should seal up the tape line pretty

well, I hope.

Guess I’ll have to post pictures no matter what happens.

6

Those are great handles - I love anything that trusts the builder to drill the holes himself (especially if my inserts are not perfectly measured!). :slight_smile:

Sorry about the scriber. I’ll put up some photos of my super high-tech version.

Even if your balsa isn’t an even distance from the apex of the rail all the way around, it might be the easiest way anyway. Depends a bit on how dark your tints are on the bottom & whether they would hide balsa or not…

Btw, I’m a reader on yahoo boardbuilding but haven’t had anything to contribute to the kiteboard stuff there yet - but I read your posts more carefully than any others. Its great to see you over here…

7

This one needed some pin lines, pin lines can look good.

Not too hard to do.

Seal wood and press the tape down with hard plastic.

Cut laps before it is fully baked.

Ian

8

Greetings and thanks for all the help in getting these done. I do a lot of reading here and that has

helped me tremendously.

I taped off the balsa and ran a squeegee along the edge to press down the tape. Then bogged the tape line with RR and micro balloons as the thick paste. Then bogged the bottom with a thinner mixture, let it tack and laminated. When it partially cured I cut along the tape line. I actually had better luck bending up the excess laminate and forming a crease at the tape line and then running a razor blade along that.

I sanded the lap but ended up cutting through to the white bog (should of tinted that too) so I touched it up with a paint marker. Looks OK from a distance. Probably should have done a resin pin line. All that taping, curing, sanding. -Not sure if I have the patience for that. -would look nicer, though.

The other board is the same shape with a resin splash. I’ll get a picture of the bottom of the balsa skinned one when I get the fins in it. I filled and laminated over the Pro Boxes so I need to make a slot, dig out the foam I stuffed in there, and then use a small laminate trimmer to cut the laminate flush with the edge of the box. Anyone know where I can get a solid carbide 1/8 dia bit to do that? It needs to have a bearing or bushing at the end to run along the wall of the box. I used some high speed steel ones I had but they got dull really fast. Ended up trimming by hand with an Exacto.

These boards are for surfing with kite power.

-Hein

9

Wow, those look fantastic! Proboxes look so good too. Are you experimenting with cant angles or do you have a favorite setup?

10

How thick are those? I bet a good grom could rip on them paddeling in.

11

Benny, Nothing slips by your critical eye. I like that. Fins are subjective and certainly riding with kite power changes what feels right. My toe angles are less and I actually run more toe on the rears. I’ve had good luck running more splay on the rears too. I have an idea that the front fins help keep the outside of the rear on the leaward side attached better but who knows. That fin creates a lot of drag when it cavitates while you’re edging which you inevitably do when using a kite. I’ve also tried some FCS longboard side bites in combination with the PC-3s. Not sure I like them in the back but haven’t tried them in the front.

I’d really like to try some of Larry’s fins. I basically use a small kite to tow onto the wave or swell and then try to surf like a dedicated surfer while I hold my kite at arms length. -not hooked to it. People tell me it looks good and it sure feels that way too. I’ve made a number of shitty boards but feel like this design holds a good bottom turn and is snappy too. I love going fast behind the kite and laying into a nice long carve down a swell or in smooth water. Just as much as I like letting my kite float down wind while I make turns on a wave. I’ve been riding this shape all summer and so I decided to build a few for friends. I’ll probably have to keep the top one for myself though. I had it out in some nice NW coast conditions yesterday.

-Hein

12

Makes sense… when you’re riding powered & edging upwind, those rear fins are probably closer to vertical in the water the more you edge the board, so they’re presenting the most surface area as you bank it over. And you’re probably heavy on the back foot to keep the nose up and the kite full of air…

But when you park the kite and ride the wave, the board’s less on edge and you’re probably more on the front foot. So you’re turning around the front fins at a flatter angle. Good stuff, Hein, I see it now.

Big boards = small kites = faster responsiveness.

Where’s Great White North…he’s got to see this. I think he’s working on a kite-powered surf quad right now too…