How sweet it is!
Ok…anyone…can I borrow some dinero so I can buy a printer cartrige…its too dry 
Bert
Nice board, you really have started something here! I am in the middle of making the moulds for my own finbox system, as an old windsurfer, I have gone for small ‘tuttle’ type bases with 1 nylon screw, threaded into the base through the deck. After seeing sab’s post about fins I have made 2 sets this week, one with 12mm Jelutong core (lightest timber in the workshop at present) and one 12mm A700 corecell, the latter with one layer of 300g uni carbon and 2 x 300g woven carbon weigh 98g for the set! probably too light, but have to start somewhere! Am gathering materials at present for the board to go with them.
BTW is your artwork on the foam or the glass?
Cheers
Mark
colour is on the foam on the bottom and glass on the deck …
theres no way those fins are to light performance wise , positive bouyancy in your fins cant be beaten …
they may be to light strength wise …
but i doubt it …
i used to make carbon fins in a small autoclave i had , 60 grams for the set …
i was gonna post a pic , but the upload icon didnt load on this page ?? weird …
regards
BERT
Hey Bert - for someone who is going to try a balsa veneer for the first time, what would you recommend as a thickness? Seems like thinner would be easier the first go-around but at what point do you lose the benefits of the wood skin?
thanks,
Keith
It sure helps to have the additional thickness when you’re sanding things smooth like the rails and other curves. 3/16" or 1/8" seems the thinnest I’d go based off my first experience at this. Granted we’re actually bending the balsa strips around the rail, so you get breakage here and there depending on the flexibility of the balsa. So patching and resanding is almost expected.
I’m been thinking like John Mellor about the single wide sheets but I can see how bending them in multiple directions would be tough.
I’ve been totally amazed at how well the vacuum and some strong taping can actually form the balsa into a complex curve. But I too have been contemplating a paper thin layer of koa, maple, or zebrawood over the top of a layer of divinycel.
Although the “feel” and flex wouldn’t be there you could get some real pretty and decently strong boards this way. I’d vacuum the veneer with a poly covering to try and get a final gloss to eliminate sanding.
Foam to fiberglass to divinylcel to paper thin veneer to gloss coat as an experiment.
Bert,
Any comments? You probably tried this already.
My instructor told me that Home Depot has woven Bamboo sheeting that could be used as a deck patch or bottom panel as it’s very strong but not as flexible as balsa for the curves. Real pretty too (looks like Hawaiian Lauhala mat)if you check out his website you can see for yourself…
Bert
Paul Jensen and the hollow board folks seem to use cork for the rails intead of bending the wood to form one. I noticed you cut your rails out of divinylcel while Sabs used multiple balsa strips. Ever cut the entire rail from cork and then vacumm the top and bottom balsa to the cork rail?
Hi Silverback
Sorry I didnt get back to you earlier,Ive had my yacht out of the water for antifouling etc ,I tell ya surboard building is a lot easier
Right the stringers. I draw the shape first so that i can pre cut the stringers to the exact shape then shape the deck foam down to the stringer
This means that yes i trace the stringer on to the balsa strips,because the timber has to curve in around the board as well as follow thr rocker shape the rocker curve is better cut than bent from the timber
No I held the stringers on with clamp blocks,I think baging it is ok just try it dry first
Mike
Hi Jong
With the red beech board I used cherry stringers then eps foam to form the rail shape then the veneer,the bottom first going up the rail curve 10mm,this edge was then sanded to a feathered edge then two more strips each with feathered edgers ,then the deck was laid over the top and the whole lot sanded smooth
On the balsa board I used thiner cherry stringers then laid three layers of 5mm balsa on to them
mike
hey keith…
as far as thickness anything goes …
depending on your methods and how much you sand off to get your final shape …
ive used from 1mm to 9mm and all those boards are still in use …
going thinner or thicker both have advantages and disadvantages , 1/8th is a safe start …
there will be certain problems that everyone will encounter going down the sandwich road , those problems have made most of the other explorers give up and go back to standard construction …
pinholes, venting, delamination and shear failure …
all these problems are perfectly solvable …you may not have the patience to go through a series of boards before you get the bugs out …
the thicker wood you use the less chance you will encounter those problems …
but then theres a performance trade off , the thinner you get the wood the better , but you get into the problem zone …
so while im not trying to steer people away from sandwich , its more a case of be prepared to deal with a little pain here and there , and if your concerned about finance and doing things on the cheap , then that could be an issue as well …
oneula !! one of the biggest problems with putting different layers together without glass between them is getting an even spread of resin or glue , it can actually end up lighter to use a fabric between every layer , because you can wet out the fabric seperatly with the bare minimum of resin without letting resin soak into each laminate or being spread unevenly , which can lead to stiff zones or delams …
not having a layer of glass on the outside is asking for trouble , let alone just a cover of polyester resin …
if you want to make a board quick and easy , forget a sandwich board…the set up you described with foam ,glass, pvc ,wood then resin , i have done that combo , i never even surfed it , it was to heavy before i even finished it , without glass your resin just disappears into your laminates …
if you dont mind a little extra work and a few extra dollars for something light and strong that will out perform any conventional board then a vac board is for you …
with this construction you cant afford to take short cuts …
i just realised , what i said ??
because ive covered so much ground , i can look back and evaluate whats a short cut and whats not … so i should be careful that im not quick to cut down ideas …
sometimes it just takes a slightly different approach or another way of thinking , and you end up making something work that others had written off as a bad idea …
hey john!!!
has something changed ???
cant attach photos anymore???
regards
BERT
Yeah Bert I know what you mean now…just got my shipment of Balsa skin 1/16" and its really soft…like paper board…need thicker sheets…thanks for the very critical tips…
laminex or formica is made from paper …
its just a matter of how you treat it …
regards
BERT
o yea , i almost forgot …
i heard a comment that came from the mouth of australias surftech rep , this is a secondhand comment , but the story is that surftech have recently had the fortune of discovering some new contruction procedures and in the near future will be able to offer custom sandwich boards …
looks like someone sees value in building custom sandwich boards , but the reality is a local producer will always be a in stronger position for the same sale …that is if there is any local producers???
has something changed ???
cant attach photos anymore???
Bert -
I’m not sure what happened on that. I think Mike removed that feature. You can still post photos but now must link to an outside URL where image is stored. If you store your image on one of the image sharing websites, you can enter the URL for the image after clicking on that “mountain” icon above your message.
I guess too many photos were taking up a lot of file space. That, and every time a long thread with lots of photos was being viewed, it burdened the system as it loaded.
Some of the photo threads were very informative - like yours. Some were getting to be almost spam-like.
Hey Bert
Sorry for my rudimentary attempt here but it’s my first attempt at making any surfboard let alone a vacuum bag balsa lammed one… As you can see the vacuum sucked the balsa around some nasty curves. Even the bottom concaves were maintained, if you saw one of these boards in person you’d realize how awful these can be to glass let alone wood lam. Surfgear’s teaching me alotand I owe him so much for helping make this christmas present for my brother come true in just a couple of weeks.
Top pic after most of the tape was removed. Obviously this is before sanding and patching. good sanding is the key so you don’t go through the 1/8" lam.
Bottom pic showing the top wrap to the bottom
Another project I’m trying to also finish. Pretty much a standard 6’0" performance shape in EPS
Thanks for your inspiration …
Hopefully the after pics will be available later this week.
As promised here’s the after pics.
Sorry but I’m in a rush and so the pics aren’t staged to get the best angles.
Want to thank sincerely Surfgear for helping me finish it off for me in time to give it away as a present tonight to my bro… It been raining cats and dogs this week even today.
Just want to emphasis that we started the board on Wed 12/8 and pretty much worked on it through the following monday when I had to go back to playing business exec.
The board is 1/8 strp balsa vacuumed on conventional foam, 2-1 epoxy 6oz bottom and 4ozx2 on deck with Redex fin plugs. I believe triple urethane spray sealed with surfco pro-tec fins and nose guards… Yet the board is about 1-3 pounds lighter than my HIC version and seems to have a very strong shell.
First attempt at making anything since 1971-1972 so I’m happy… Can’t wait for the next one after the holidays…
Sorry about the pics the angles make the curves and fins look funky…
Mele Kalikimaka and Ha’ouli Makahiki Hou!
“Ikaika la’au papa he’e nalu mai Pu’uloa”
Strong, wooden, surfboards from Pu’uloa (home of the O’ahu’s Shark God)
Found another nice article on vacuum bagging. I learn much more by seeing & by doing than by reading, so every different set of words I can read on a subject helps round out the picture…
Edit: oh yeah, the article:
I’ve made an EPS longboard blank with 3x 1/2" d-cell stringers, solid balsa rails & nose & tail blocks that’s about to go into the bag, as soon as my (on sale for $8.99) vacuum pump arrives from Harbor Freight. What’s getting bagged on are 3.5" x 3/16" balsa strips. Oneula, did you cut your own veneers or did you find a sheet? I cut my own, but I’m lucky enough to have a bandsaw in the garage. I did balsa rails before the veneer so it can sit on top of them and won’t crush into the EPS. Then, I’ll bend on thinner balsa sticks to actutally shape for the rails, like Paul’s. With the 2" wide balsa at the widest & thickest point on the board, I’ll be able to shape all-balsa just like foam for the rails, but I got to glue on most of the balsa in straight sticks.
Good catch Benny nice article.
SurfGear(Charlie) buys his balsa strips in bulk (100 strips?) from a model airplane wholesaler on the mainland.
I guess the model airplane guys have been doing this balsa vacuum stuff for years building their wings.
Buying in bulk means that its not all AAA graded stuff so you have to search for the most flexible strips for the rails and the stiffer pieces for the center. I think they are 4"x48"x3/16". He also has that woven Bamboo sheeting 4’x8’.
After watching Sprout I’m intrigued by this Paulownia wood. There’s a US Supplier but I think you have to buy a tree or something…
http://www.paulowniasupply.com/index.htm
The other thing I’m starting to understand is the use of perimeter stringers or solid balsa rails like what Sabs shows here but I’m perplexed on how you get the balsa to flex and bend both horizontally and vertically at the same time to wrap the rockered shape. Seems like if you cut the rocker profile from a sheet of 1/2 thick balsa like what Bert did with the Divinycel for this experiment, them you could wrap them to the rails and epoxy/vac them to a thinned EPS blank. This pic from his 93’ board kind of says alot to me about how far Bert’s ahead of everyone…
Looks like bert’s got a wood Hydroepic design using light EPS foam as the flexible insulator in place of air.
Building the shell seems to be the key and having a high float, flexible but structurally firmer core is what the above
picture is telling me.
Seems like if you could build the wood shell using this design from Hydroepic which almost like a stringed instrument top/bottom and epoxy vacuum adhere that to the foam you could “tune” flex, float, and strength together using some natural materials. The shape of course would be fundamental no question…
Been also “toying” around with lamming a thin sheet of wood horizontally in-between two 1.5" sheets of white homedepot EPS and doing the rails in the 2" blue XPS cut like how Bert did with the divinylcel.
I don’t know there’s so many options but it seems like its coming down to this concoction:
EPS Foam
Solid wood Perimeter Rails
Balsa Shell with possibly Bamboo or Koa deck patches or bottoms.
Sealed Epoxy all the way
Finally I’ve been trying to extract and compile all of Bert’s stuff and anything on vacuum, epoxy or wood into a Word document that I can print, read offline, and refer to when you’re in the shop. Kind of makes me wonder why no one has bothered to spend the hours to do so for the rest of Sways. While its idealistic that part of the adventure is discovery but plowing through the archives is both time consuming and frustrating. Seems like some adventurous spoirit could index and group the stuff on this site to make it aside from the crazy personalities, a true encyclopia of board building.
Hi Ben,
What blade works best for the balsa?
Also see for vacuum building:
Also look at some guitar builder sites to learn about bending wood with a pipe and propane torch.
hey guys …
benny , that article you found has some useful information in it …
all things youll learn as you go type of stuff …
oneula , the model airplane guys have no idea about vacumn bagging …
they still use the rib and frame method …
i had a guy a number of years back who built light aircraft , who basically freaked when he saw the potential of building small wings with the method i use …
he was an engineer and couldnt believe someone hadnt thought of it already , let alone a lowly surfboard factory …
at the time they were still using the frame method for there light aircraft …
one of my employees ended up working for the same company and worked at setting up there tooling systems for doing vac bagged components and shells …
oneula has been doing some clever detective work and made some very logical deductions …
well done , surely after all that hard work you wouldnt want everyone else to have access to the information in one easy package do you???
i was reading an old post a while back while searching the archives for something else …
i saw what i had written , and thought o no that shouldnt be there , but it was to late to edit , but then i figured out , that it would take one motivated searcher to piece the whole puzzle together , i still keep a handful of secrets closely guarded , but i did let one slip on the old swaylocks …
long before anyone really knew what i was talking about …
it was interesting , coz holly and greg loehr were onto me straight away …as for everyone else it went straight over there heads …phew!!!
the quality of the wood used to be an issue for me in the past , when i was using the same technique as surfgear …but with a pretreatment system i use now , you can get the lightest balsa to the point where you struggle to get a jigsaw blade through it …
you just gota get a little forceful with the wood and it will do what you want …
hows this , i have been trying to get some paulownia for a few years now . so hard to track what i want , my balsa supplier said he could get some but then it fell through , hes in the eastern states im in the west , he said he heard it comes from west oz but he didnt know where ???
heres the best part , all the paulownia in oz comes from a supplier , with every bit of machinery needed , sanding thicknessers , 8 head profilers , horizontal bandsaws , you name it …
just 15 minutes drive from here … and amazingly its run by a guy i used to go to school with …
so you should be seeing a paulownia version soon …
i was checking out the factory a few weeks back , there was wood stacked 3 stories high , at first glance , it seems paulownia will deliver a board similar to western red cedar , for weight and strength …
nice work as well oneula on your first vac bag board … the outline freaked me a bit , is it one of those crowded line up designs ???
sure looks different , but still has everything it needs in the right place …
regards
BERT
Well…the easy ones first. To rip the balsa I use a bandsaw with really big teeth. Its a 5/8" wide blade with 5 teeth/inch. In rip cutting, you want to clear dust, fast. To contrast, if I’m cutting hardwood or curves, I use a 1/4" blade with 10 tpi and If I’m cutting metal or fiberglass (like for fins) I use a 3/8" blade with 18 tpi.
I’m lucky enough to be near a very good hardwood supplier (MacBeath in Berkeley) that usually has some decent balsa. For the deck strips, I found pieces almost 4" square by 6-7’ long. I picked through them for weight & color. I cut all this to 3/16" for both the flat surfaces & bending the rails.
For the solid rails, I bought 5/4" x 4" (minimum width - it comes random) sticks, about 3’ long. To get the rocker curve, I cut the scarf joints at about 85 degrees - for a compound joint of 170 not 180. Then 3 pieces lined up = 9’ along each side. Another layer on top of that and I had 2.5" of solid balsa on each side of the blank.
I then templated the blank to 1" less than final dimensions all the way around. I cut the outline through the foam at the ends & the balsa at the rails. I added solid balsa blocks to the ends, also at 1" inside final. I’m epoxying the deck & hull to this outline (with a layer of 6oz) and will cut flush. A flush-cutting router blade with a roller is perfect for this. Then, 4 layers of balsa will get bent around the rails. I again expect to have to cut angled scarf joints to accomodate the rocker. Then the rail pieces will get trimmed flush to the deck & hull and I’ll have a squared-off, rockered, thicknessed, templated blank.
The rails will have 1" thick plus the blocks at the ends - plenty of wood to radius them without shaping into any foam. The sides will have, at center/thick spot, a maximium of 3.5" of solid balsa between the bent outer rail layers and the straight inner layers so I can aggressively radius the rail into an egg so its not too blocky.
It’s getting a finbox, despite my internal objections. But its coming out so light & durable that it might make a good travel board. So far, I’m a little worried that the rocker came out too well - I was expecting more ‘relaxing’ of the materials over the couple weeks its taking to get into shape.
I’m taking photos so it will all make sense when I start to get the film back…
Thank so much, Bert, for pointing the way. And Oneula, your balsa work is just what it takes for me to see that a home-based guy can pull these off too…
Mahalo for the kind words Bert & Benny…
But I owe it all to Charlie(SurfgearHawaii) one of the most honest and sharing guys in the business I’ve ever run into.
Also the only shaper I ever ran into that actually delivered a finished product on time as promised…2 weeks.
As far as I’m concerned all the rest of the so called “names” just suck and pretty much have turned the rest of us off this industry so much that we’re looking at resolving the issue ourselves… by building our own, longer lasting solutions…
Just look at everyone here at sways… It’s an indication of how the general industry has abandoned it’s core group in favor of chasing the money. Gets yours then get out is where it’s at, maybe it’s always been that way…
Anyway Benny
I’m looking at buying those 1"x4"x48" Pawlounia samples and ripping them into 3/16"x4"x48" sheets to build a lam skin. I figure I can get 4 sheets from one block…
Can’t I just do this on a tablesaw?
Do I really need to use a bandsaw? (I have a small one)
I don’t like the idea of ripping on a band versus a table… I figure I lose 1/16"-1/8" per cut
Anyway I’m also looking at cutting out the boards rocker(like building a stringer) out of some 3/4"x6"x48" balsa glued up into 3/4"x6"x96" sheets and then vacuum epoxy these to the side of a semi fiinished blank I might need to do 2 of these per side to get 1.5" of width. strength and weight. Then vacuum Balsa/Pawlounia/Bamboo taped sheets to the top and bottom.
The key I guess is hotwire cutting the EPS to a very close tolerance blank and then accurately cutting off an inch off the profile to glue on the solid wood perimeter rails. Nose and Tail blocks would help out a great deal in eliminating too severe wood bending. Although Bert just said something else here that’s answered a question John and I have been pondering, and now we know the answer… From what I understand in a discussion I had from a furniture maker its water based and doesn’t affect epoxy adhesion… Definitely gonna give it a go with some harder woods we have here in Hawaii…
Bert,
that board I made is a new design Jeff Alexander is selling here in Hawaii. Looks weird and ther’s been alot of hype around it, but bottom line it gives this old fatso the speed I need to do just about anything I want, any where I want on a wave. The experience was so enlightening I wanted to turn my brother on to one for Christmas, just couldn’t afford the $700-$800 for poly 6’4" version from Jeff/HIC so I decided to make my own… Oh by the way Jeff took 6 months to deliver his not quite perfectly finished product. Charlie and I did ours in two weeks and I think ours will last a bit longer.
Thanks again to everyone… so much mana’o (knowledge) on this one thread.