Hollow wooden surfboard

[Cub]

Hi all
At school I am taking part in a surfboard making club, now I am making a hollow surfboard (basic ply frame/skeleton then veneer over top and around edge). I have made the basic frame and am up to the stage of placing the veneer on top. I just wanted to know would it be smart to put marine foam inside the surfboard, for accoustical reasons (to reduce the noise of splashing water under neath and if in the event of a break would provide some support) ?
Thanks for any advice :2tsup:
David

[pugwash]

I think solid foam inside would make the structure stronger. Also, if by chance you get a leak, your board won't sink!

[Cub]

Hi
Thanks Pugwash for your speedy reply, I found a place in Australia that has marine suited foam, would I just get the liquid/expanding type and spray it in and have a bit of scrap ply on top and bottom to keep it flush and then remove excess once it has set?
Thanks again for your advice
David

[whitewood]

Cub,
I sell a lot of Paulownia to hollow surfboard builders and have talked to most of them about their boards. I have never heard of any of them putting foam inside the board. Some attach the strips for the skin to a sheet of glass/epoxy to make a single section and the 'glue this to the frame. The outside is then glass/epoxy and this provides the strength and waterproofing needed. The big thing is to have a drain plug to control air expansion and contraction within the board. Some guys even have the drain plug as a release valve to maintain an even pressure within the board.

Having said that I can see no reason for not putting foam inside the board if that is what you want to do. It will add some weight but the final decision is yours.

Whitewood

[Cub]

Cub,
I sell a lot of Paulownia to hollow surfboard builders and have talked to most of them about their boards. I have never heard of any of them putting foam inside the board. Some attach the strips for the skin to a sheet of glass/epoxy to make a single section and the 'glue this to the frame. The outside is then glass/epoxy and this provides the strength and waterproofing needed. The big thing is to have a drain plug to control air expansion and contraction within the board. Some guys even have the drain plug as a release valve to maintain an even pressure within the board.

Having said that I can see no reason for not putting foam inside the board if that is what you want to do. It will add some weight but the final decision is yours.

Whitewood


Hi
I really like the idea of a drain plug hope you don't mind me borrowing that. :)
We will be fibreglassing it in the end but I just thought the foam being dense would provide support for the veneer on top which is about 6-7mm thick. Should I bother? I'm perfectly fine going the extra mile if it gives me a stronger board.
Thanks again all for the ideas.
David

[whitewood]

Hi
I really like the idea of a drain plug hope you don't mind me borrowing that. :)
We will be fibreglassing it in the end but I just thought the foam being dense would provide support for the veneer on top which is about 6-7mm thick. Should I bother? I'm perfectly fine going the extra mile if it gives me a stronger board.
Thanks again all for the ideas.
David
__________________
If I can do it, you can do it :2tsup:

David
I believe it is absolutely essential you put a drain plug in the board. If not to drain water but allow you to stabilise air pressure within the board. As the board goes from hot sun to cold water the air pressure changes a lot. If the board is sealed completely at construction time in a cool shed then as soon as it is in the hot sun the air inside expands and can open up seams thus causing leaks.

Most of the Paulownia I sell for hollow boards is 6 mm thick. This thickness is my recommendation. Some guys have used 4.5 mm and extra epoxy which i believe defeats the weight saving as epoxy weighs more than Paulownia. The part I can't advise you about is the spacing of the internal frames to support the skin. In my mind the strength of a board comes from within and depends on the method used by the designer to build the frame. This is way outside my expertise so I won't comment other than to say I don't believe any 2 hollow surfboards are built exactly the same. There are some basic concepts but each builder appears to put his own ideas into the finished board.

Whitewood

[AlexS]

While the foam would certainly add strength, it probably isn't necessary if you use 6mm ply or paulownia. However, it could cause problems by retaining water. IMHO, you'd be better off leaving it hollow and including the drain plug.

[malb]

I agree with AlexS about foam. To be totally waterproof, it is fairly heavy, anything less than than totally waterproof will absorb and retain water, becoming increasingly heavier as it absorbs more water.

Also make sure that every rib and stringer in the frame has moderate sized half moon notches so that water can run to the drain plug when the board is stood near vertically for drainage. You definitely need the drain plug to allow air pressure inside to equalise with that outside. The board will be subject to fairly extreme temp changes in use, causing expansion/contraction of the internal air. (on car roof on a 40deg day into water at about 15 deg). Leave the bung in the drain but loosened about a turn or so to release the seal, close just before enterining water, and remove to drain when leaving water and return to one turn loose position.

[Cub]

Hi all
Thanks everyone for your advice, after thinking about what you all had to say I won't be filling the board with foam (phew decision made), but I will be incorporating a drain plug and a small passageway for water to migrate back to the drain plug. Thanks again everyone for your helpful input. If someone has anymore tips they would like to share go for it and share it.
Thanks again :2tsup:
David

[malb]

How is the internal frame configured? You will need multiple drainage channels to ensure that every cell in the framing is able to drain. A single drainage channel suggests no internal longitudinal framing between the rails, which I suspect means a broken board fairly early in it's life.

[whitewood]

How is the internal frame configured? You will need multiple drainage channels to ensure that every cell in the framing is able to drain. A single drainage channel suggests no internal longitudinal framing between the rails, which I suspect means a broken board fairly early in it's life.

I still don't hold the opinion that I have expertise in designing or building hollow surfboards. Malb is right about the drainage holes. Depending on the types of wood you have used in the construction it will be important to absolutely essential to get all moisture drained out of the board. Even moisture from the air can condense inside the board. You should not have to hold the board in 1 position for a lengthy time to allow any moisture/water to collect into 1 drain passage. Most builders remove excess timber from the frames with a keyhole saw so drainage is quick and dry air can circulate inside the board to complete the drying process.

On the question of a board breaking because it doesn't have a longitudinal framing may not be so black and white. Depending on the designer longitudinal strength can be built in through the rails, as done by Roy Stewart. I assume you have a design so you should follow it and you should not get into trouble.

I'm not too smart with computers so can't work out how to attach a copy of an email showing photos of a board constructed by a 15 year old with advice from his father. If your interested to see it send me an email and I'll forward it to you.

Whitewood

[Cub]

Hi
Well below is a drawing of my frame, I will take a photo when school gets back to show my frame clearly. (you may ned to click on it to make it bigger)

BTW whitewood to attach a photo the easiest way would be when your are in the section to write a message up the top where it says font etc theres a little paperclip click on that and there will be a popup and you just click on browse find your file or picture then lick upload, now once you have done that click anywhere in your text where you want your picture to be then go back to the paperclip and click on it, it should say manage attachments click on the image name and some words like ATTACH will apear in your text now your done, you can check in preview its where you want it to be.

Would it be best to just drill some holes in the centre of the frame pieces or should I notch a bit on the edge(bottm side) so there is a clear path for the water to escape?
Also does anyone know of some good drain plugs to use or would just someones off ebay be suitable?

Thanks for the help
David

167501

[malb]

Hi Cub,

From your sketch you are building a hollow swallowtail with a single stringer (longitudinal structural member).

Re info about a drain plug, we used to use an early version of this (http://www.ronstan.com/marine/product.asp?ProdNo=RF734). You want to place it as far into the nose as you can get it,near the junction of a rail and the central stringer. You would need a drainage notch in the stringer to allow drainage to flow to the off centre plug.

I have cobbled a sketch as a PDF file for a suggested layout for the drainage notches in the ribs (see link below). This shows a couple of notches near the centreline but clear of the stringer. These want to be in the order of 12mm wide by 6 mm deep, and placed on the ribs so that they fall behind the centreline of the plank, i.e well clear of the planking seams. The sketch also shows a couple of breather holes (10mm dia would be adequate) to allow air to enter cells while draining to prevent a vacuum developing. To minimise reduction of rib strength these should be placed accross the rib at about the horizontal centreline. There should also be similar hole in the stringer in the front bay near the drain plug.

It would pay to seal the end grain of the notches and breather holes to ensure that moisture cannot get into the timber. Epoxy would be suitable.

Hope this makes sense to you.

Mal

[springwater]

Just clarifying malb, you say to put the drain plug in the nose (of the board)? Like sunk into the deck or the bottom of the board? So it'd be best to rest/store the board nose to the ground?

[malb]

I am going back about 50 years when my dad built my sister an 11ft ply plank. This beast had laminated softwood rails, nose and tailpiece, with 3/16 ply skins rebated into the softwood surround, two 1/2 in stringers and ribs about every 8 inches. Drain was in the nose on the deck. After use, pop the plug pick up the tail and walk forward, raising the tail till vertical. any seepage runs out as you the tail. Once flow stops, walk backwards to lower the tail, and loosely refit the plug, but don't seal the O ring. This allows the interrnal air pressure to vary with exernal pressure.

I took this board over about 2 years after it was built and used it daily for 12 years before replacing it with foam/glass board. In that time it developed one crack due to cousins running along it on dry ground. Till then it was watertight.

Drain needs to be on deck in nose as this is where it has least immersion and causes least drag when on a wave. Keep it as flush as possible.

[springwater]

Thanks for that malb. Going by cubs sketch he's after a board that's going to be loose as a long neck goose as in a fish tail twinny. As I see it that's a good option considering the weight diff between "modern" construction methods and wood boards. As I see it, the wood board is an aesthetic choice, a good one at that and perhaps a reaction against the "modern" style of surfing which is a bit spinny flip floppy for me :-:)

[Cub]

Hi
Sorry if my drawing was not as detailed as I hoped, around the nose and the back there will be some ply going horizontally in the frame to add some ridgidity, and the stringers going around will have some small block to hold the rails, I drew another diagram so please find it attached. Thanks malb for detailing where abouts the drain is.
Thanks everyone
David
167876

[whitewood]

Cub

Thanks for the instructions about loading photos. I just tried this morning, without success. Haven't got the time to try again. I'm better at attaching photos to emails. One attachment is a complete email with the photos attached.
I'll repeat the offer again if your interested to see what a 15 year old can do with help from his father.

Whitewood

[Cub]

Hi whitewood,
Thanks for the offer just sent you a pm then with my email,
Thanks
David

[Cub]

Hi everyone
As suggested I have included some images of the frame so far, now if you are going to ask where are the sie rails well the little attachment blocks were being glued while I took this photo and hope to include a photo of it next week or so, Thanks everyone
David
BTW if the images seem of incredibly poor quality it's becuase I took them on my phone.
168511

168512

168513

[Luddite]

Cub,

Looks like you are on the right track mate.

I have made a number of hollow wooden surfboards (HWS) and am just in the middle of making another one for my daughter....a 5'10 fish with a batwing tail. I have also been on a week long course with a pioneer of HWS by the name of Paul Jensen. Paul was one of the first guys to create a system whereby just about anybody with some basic woodworking tools and some rudementary skills can create a beautiful and functional surfboard.

Have a look at Paul's website:

http://http://www.hollowsurfboards.com

There are a number of really good sites on the web, have a look also at the Tree to Sea web site. Rich Blundell is studying in Australia at the moment and he runs boards building courses, perhaps you could save your cash and get along to his (or one of Paul's) course.

Tree to Sea has a great forum, the people on there are really helpful. Just tell them something about yourself and they will help, guaranteed.

Tree to Sea Wooden Surfboard Builders Forum - Index page (http://www.grainsurf.com/forum/)

If all else fails, happy to answer any questions and assist as best I can. Just send me a pm and I will come back to you.

Oh, and one last thing. If you, or any of the other guys who are making boards want to buy some Paulownia, you should contact the poster on this thread called Whitewood. He has supplied me and his product is excellent and is a great bloke to deal with.......support those who run an honest business.

Good luck,

Anthony

[Luddite]

T As I see it, the wood board is an aesthetic choice, a good one at that and perhaps a reaction against the "modern" style of surfing which is a bit spinny flip floppy for me :-:)

Mate, that comment made me laugh.....I say stuff like that and my kids tell me it is because I am too "old school". My oldest bloke told me it would be embarassing to ride on a timber board....only old men ride them.

Long live the old schoolers.

Anthony

[springwater]

:2tsup:Onya Cub and to those lending a hand. It'd be a good thing to achieve making one's own board, very satisfying let alone surfing it. I've gotter do one or two before too long. One thing though Cub, one thing that I'd think would be almost essential for the construction method you're using is a flat surface to register to, seems like that table in your pics is a good one but hard to tell.

:) Thanks Luddite, yeah I was leaning on my age there, thought about it again watching Bells/Winki where the aerial thing wasn't so prevalent and the drawn out carves were the go. Still I'm very impressed with the contemporary maneuvers going on although I can't figure them out sometimes. Something would definitely give way if I attempted them now.:-:U

[whitewood]

That comment made me laugh Spring water
Quote:
Originally Posted by springwater http://cdn.woodworkforums.com/images/button2/viewpost.gif (http://www.woodworkforums.com/f251/hollow-wooden-surfboard-133680-post1306328/#post1306328)
T As I see it, the wood board is an aesthetic choice, a good one at that and perhaps a reaction against the "modern" style of surfing which is a bit spinny flip floppy for me :-:)

Mate, that comment made me laugh.....I say stuff like that and my kids tell me it is because I am too "old school". My oldest bloke told me it would be embarassing to ride on a timber board....only old men ride them.

Long live the old schoolers.

Anthony

Tell your kids that most of my timber goes to people in the 18 to 30 years old range. These the ones who have the skills to make boards without assistance from parents or teachers. I also sell timber to students to make alaia boards as part of the class work. Also I have one 'old' customer who copied his 'glass' board exactly and made an copy in paulownia that was the same weight. He feels it surfs even better than the original. There is nothing wrong with wooden surfboards.

Whitewood

[springwater]

:meg: Cub what's going on :whatonearth:

[Cub]

Hi all,
sorry about the late reply, i've been helping out with other people projects at school and have had very little time to work on my board, but i've finished the frame, applied the top and bottom ply and i've just put the first layer of cork around the edges :D
In regards to the cork, do i just trim it using my laminate trimmer or is it best to use a stanly knife? just don't want it ripping off is all.
cheers
http://i1130.photobucket.com/albums/m540/tigwelderg/woodwork/IMG_0593.jpg
http://i1130.photobucket.com/albums/m540/tigwelderg/woodwork/IMG_0550.jpg

[HOOKED.UP]

Hi Mate.
6mm marine ply, top and bottom of your frame will be heaps strong enough, especially if you epoxy coat and glass the outer edges.
The drain hole in you frame are call "limber holes" in boat building terms. They are there so water can flow to the lowest point in a boat and the removed. Pumped out.
In your case the water would drain from the drain plug.
Another suggestion I would make is to get 2 drain plugs.
There is a flush fitting version which uses a large screwdriver or special key to open it up.
You may need to buy this from oversea, I have not seen any in Aus for some years.
Put one of these unit at each end of your board and stand the board vertically. You are then aiding the natural flow of dry air through the board, while you are not using it.

Paul.

[Cub]

cheers, one of the teachers at my school who does a bit of surfing, has found a special plug that is for the ankle strap, which has a gortex layer/membrane in it so it allows ventilation and also acts as ankle strap point.
thanks everyone, i plan to glass the whole board later this year when i'm done

[Luddite]

Hello Cub,

Board is coming along nicely, well done.

You can buy a vent from this guy:

http://www.surfinggreen.com.au/store/hollow-wood-vented-brass-screw-new-model/

The web site is Surfing Green if that link doesn't work. Think carefully about having the vent and leash in one. If there is a failure in either the leash or the vent you are buggered.

Have a read of the comments and techniques the guys use on this link:

Tree to Sea Wooden Surfboard Builders Forum - View forum - Fins, Leashes and Vents (http://www.grainsurf.com/forum/viewforum.php?f=23)

I prefer to have the vent in the nose of the board, a leash set up at the tail of course.

Any questions, just let me know.

Good luck

[kamusur]

Apologies for my late inclusion to this forum (new member and poster) Cub.

Whitewood tell your son Laird has ridden a balsa gun that his stepdad Billy made at Jaws and other outside breaks.(oops he probably classifies Laird as old)

Listen to what Malb says as he is on the money.

Fwiw hope that anyone/everyone can make sense out of what few facts i have written below.
Cub you have been given some great advice and there have been some overlapping ideas and thoughts. Originally/historically surfboards were solid wood (heavy and not waterproof) tipping the scales at over 100 lbs when dry and not waterlogged then made hollow over frames (still wooden/timber) which resulted in lighter boards (most i have ever seen were built with bungs/water drainholes as insurance against any seam leakage,)and then they became varnshed/painted etc to waterproof the wood. Not until Bob Simmons made the 1st foam core (polyurethane foam) was fibreglass added to the outside to strengthen the soft inner core also these boards were even lighter still.Timber can be glassed over and hollow boards can be filled with foam even styrene foam, adding either polystyrene or polyurethane foam would only add a few ounces in total, but this is,not necessary at all just as removing foam to increase bouyancy also only results in the gain ability of the bouyant force to increase by those few ounces.
Any foam or core should be designed to increase compressive strength. Foams are bouyant mostly by way of all the air contained in and around the cell structures.

Steve

P.S I have made many types of boards, surfskis, canoes dealt with polyesters and epoxies, timbers, plies and coldmolding so I extend an open welcome to any member to PM regarding any info that i can help anyone with.

[Cub]

Hi All
Apologies it's taking a little longer than i'd hope got caught up in another project building a pergola :doh: I've managed to finish all the layering and round it all over, i'm just finishing up the small details of the edging now.

Now i was thinking, it would look good if it had some vaneer strip of a lighter/darker wood, i can mill some strips down fine to about 1mm (ish) will this affect the fibreglassing and leave a raised section on the fibreglass or would a fibreglasser be able to make it all even no worries?

Anyone with a little insight with this is greatly apreciated

thanks and happy new year
David

[springwater]

I'm not a big fan of guilding the lilly. Embelishments and adornments are mostly trivial pursuits but can have their place. There will be a slight step when the fibreglass lays over the strip but with carefull (very) sanding you should be able to smooth it out. Where are you want to put the strips?

[springwater]

opps...and harppy newwy year!

[Cub]

Hi
Yeah thanks :)

was thinking that could happen, I'm not really experienced with fibreglass so bear with me, can a fibreglasser make the whole layering thicker? or double spray (Dual layering)?
Thanks
Dave

[springwater]

Hi
Yeah thanks :)

was thinking that could happen, I'm not really experienced with fibreglass so bear with me, can a fibreglasser make the whole layering thicker? or double spray (Dual layering)?
Thanks
Dave

Yep, fiberglass comes in a range of weights. As far as I know they still use imperial measurements. 8 and 6 ounce fiberglass used to be the norm but now 4 and 2 ounce is used more. You can use two layers of fiberglass if necessary, like on the deck where you would stand but be aware the thicker the fiberglass the more resin is needed and that all equals more weight. I'm pretty sure if you did some enquiries at a surfshop or on the net where there are some wooden surfboard builders you'll find someone willing to help, good luck and let us know how you get on.

[Cub]

Yep, fiberglass comes in a range of weights. As far as I know they still use imperial measurements. 8 and 6 ounce fiberglass used to be the norm but now 4 and 2 ounce is used more. You can use two layers of fiberglass if necessary, like on the deck where you would stand but be aware the thicker the fiberglass the more resin is needed and that all equals more weight. I'm pretty sure if you did some enquiries at a surfshop or on the net where there are some wooden surfboard builders you'll find someone willing to help, good luck and let us know how you get on.

Wow thanks Springwater, thats some handy advice. I will be sure to follow up on that and ask around. I'll put some pics up of the board progress in the coming days.
Thanks
Dave

[Cub]

Also does anyone know where I could buy some putty that has the appearence of cork, or somehting i can mix up/make that looks like it, because there are a few joints/ends I want to neaten up?

Thanks
David

[Cub]

Hi all,

sorry about being so late on my reply, I've been flat out.

Finnaly finished the board, and I must admit I am rather happy how it turned out, for a first attempt anyways.
I couldn't post any photo's recently due to the fact it was going to be showcased in this years Motorex and one of the terms was that the piece couldn't be publicly shared before the show. Hope you can all understand.

You're probably thinking how a board was in motorex, the guy who did the artwork asked me to put in the show to show off some of his work, amazing how a simple project can go so far isn't it :)

I thank you all for you advice and support, and hope to return the favour in some way or another along the line. :2tsup:

David


http://i1130.photobucket.com/albums/m540/tigwelderg/IMG_0893.jpg

http://i1130.photobucket.com/albums/m540/tigwelderg/IMG_0895.jpg

http://i1130.photobucket.com/albums/m540/tigwelderg/IMG_0901.jpg

[Charlie roth]

Looks good! :2tsup: Have you tried it out yet? or is it never to see water??

[Cub]

Thanks Mate :) only just in the pool to test all of the vents and plugs were properly sealed, don't think I'll be using this one, she's going straight to the pool room !