Blank shaping first steps

Hello dudes, i’ve finally found the polyurethan for my first board, i need some help with the shapin’ procedure, cause i was reading

surfboard_design_and_construction 1977 but i’ve some doubts

I’ve now cutted the blank in two halfs and prepared the central stringer to be glued in with epoxy like in the sketch attached, how you do suggest me to cut out the rocker now?

Is it better to do the outlines (rails) before or after the rocker?

Thanks for you help, as soon as my digiCam comes back i’ll post some pics also of my first wooden fins :slight_smile:


…well i see that you go for a custom blank…now better you made a rocker template, when you do that then mark the rocker on the foam and cut with a hotwire…(yeah also the pu can be cutted with that). then do the rails…

-yeah pretty rude my explanation , but its a start…

isn’t hotwire cutting on PU toxic? (I don’t really know)

Yes it is. But outdoors in a breeze or with a fan is ok. Its not cyanide-toxic, more like burning hydrocarbons-toxic.

I didn’ t think to HotWire, that’s good :slight_smile: no dust, fast and accurate…gotta look for a tranformer.

Thank you guys, hope to have time tomorrow to cut it, i’ll try to keep this thread updated with the process.

Cheers Flavio

look in the “search for” box above. Lots of post in the past about making hot-wire systems. From what I have read, I think you want to hot-wire before installing the stringer. But if you already installed it just make sure your hot wire guides are alined with your stringer.

As i promised i’ll try to keep this thread updated, no reason to open an other thread every time.

I’ve just finished my first wooden fin set (see attachment) Pine plywood with epoxy and 2 plys 4Oz diagonal each side, Fcs compatible… some bubbles, next time i’ll try vacuum bagging.

I’ve also begun workin’ on the custom blank, cutted out a rough rocker line (i’ll post a pic later) and in a couple of days i plan to glue the two halfs with stringer between them.

Any suggestion C&C is really appreciated :wink:

Cheers flavio

Ok so these are the first pics:

Cutted the block in two and sanded the center part to keep it straight and at 90°

Prepared the center stringer and the .5" plywood guidelines to cut out rough

Cutted out upper and lower part with a hand saw, no hotwire cause i haven’t enough power to make the wire hot enough for polyurethane, next time il try polystyrene -Eps- so i’ll waste less material and get a better result with less work.

Next step is to glue with epoxy the blocks.

Yesterday i’ve glued with epoxy the two halves with the plywood stringer.

Here i am, today i’ve rough cutted the foam block, and started to pre-shape it.

I’ve some problems, the biggest one is that i’ve glued a stringer witch is bigger than the desired, i thought it was a good idea to oversize it so i could

easily have enough material later to learn to shape without the hassle of a too heavy material removal, but now that i’ve to sand it to the correct width, the problem is that when i pass a sanding block over it the foam gets grinded but the stringer is much harder than foam and so the result is that the foam is gettin thinner than the stringer, with a smothed step between foam and wood… hope it’s clear what i’m writing, how can i avoid this problem? how would you procede?

Here’s what i’ve done so far.

Cheers flavio

You’re going to have to cut the stringer with something sharper than sandpaper. A small hand plane, low angle block plane, even a rabbet plane would work well. The nice thing about a rabbet plane is the blade is right up at the front so you can see it as you go. Its harder to adjust, but once you get it right, its easy to use. The blade is also narrower than a block plane blade so you’ll get less foam. Put your plane at about a 30 degree angle to the stringer and cut with long smooth strokes.

Rabbet plane:

It also doesn’t hurt to put ‘sacrificial’ masking tape on the foam along both sides of the stringer.


I may have missed this earlier but, do you not have a power planer? If you don’t, a mid size hand planer will do the trick for the most of stringer on the deck and bottom. I have an old Stanley steel planer that is about 5" or 6" long, it’s heavy, sharp and it works great on those stubborn stringers, especially Tbands. Then I use a small, VERY SHARP, block plane for the nose rocker. Good luck!

Sr Pato

Doooh… how could i haven’t thought to this? ehehh thanks guys, i’ve my good old stanley hand-planer, unfortunately no power-planer, but i do remember that at the local spareshop there was a cheap one… uhm… usually chep equals low quality, so i guess i’ll continue with my hand-planer as soon as i decide to switch to a better electric one.

So here’s what i’ve done in 45minutes, uhm… quite hard, i think it will need an other couple of sessions of 1 hour each…and it’s only the bottom, the deck really frightens me… any suggestion?

Cheers flavio

Here i’m again… feel like a…@#] i simply cann’t resolve problems by myself… i’m sorry.

The problem is that i cann’t shape correctly the deck curvature, i’ve tryed with a small planer, a scraper i use for my instruments… but can’t obtain a smooth continuos curve. see attachment.

Cheers flavio


the problem is that when i pass a sanding block over it the foam gets grinded but the stringer is much harder than foam and so the result is that the foam is gettin thinner than the stringer, with a smothed step between foam and wood…

I had the same problem and someone suggested to run some masking tape from the tail to the nose along both sides of the stringer, hiding the foam around the stringer but leaving the wood exposed. That way when you sand, the foam doesn’t get touched.


That part of the deck is a bitch - you need a small spokeshave like the one in the attached photo. It works great in that inside curve of the deck. They don’t cost much and make it much easier.

Regarding a cheap power planer, cheap is OK for us amateurs - mine cost $40.00 with a 3 year warranty! They probably wouldn’t hold up for a pro but when you are only making a couple of boards they are fine.

Hi guys, thank you again for the valuable help… (hope it’s written correct…sounds strange)

In any case, i’ve almost solved out the nose deck side problem, i was goin’ overshaping it, but stopped just in time, used Shores’ method, a small sanding block with masking tape (the pic was taken just before i started, forgot to take one at the end, i’ll do it next time) now it’s time to cut out a more accurate rail outline, refinishing with a big surform and start adding some curves…

DMan the small spokeshave seems a better tool for the nose task, next time i’ll try it.

Just an other question, a design question, how thickness would you leave in the tail? now i’m about 1 1/2" but it looks huge, think i’ll reduce to 1" or is it too thin? i know a thicker tail gives better wave catching, but how thick is too thick?

Cheers :smiley: flavio

Flavian-san -

If you measure 1 foot up from end of tail, thickness might be about 1 1/2" - 1 3/4". Same with nose. At least those dimensions seem pretty standard on many shortboards.

Stanley tools makes a short curved surform that might help you get the stringer down inside your nose rocker… you could even attach just the blade to a piece of plywood…

Thank you John for the measures :slight_smile: i’m slowly progressing, hope to finish this board as soon as possible, i wanna try it!!

I’ve also learned a new lesson… always tight up very carefully the screw that keeps firm the blade… :frowning: se attachment, tomorrow i’ll fix it with some liquid PU.

Cheers Flavio

FLAV!------------You are incredible! The progress that you are making with minimal tools and knowledge blows my mind! You can fill that gouge with a little flour and resin, paint the blank before glassing and no one will even notice. Keep up the good work. McDing