Building my first surfboard.

Hello everyone!


Been sometime crawling around all the content you have here. 

I am planning to build my first surfboard. It is going to be a 6’8’’ egg (more precisely this one ) and using a  4.5″ N / 2″ T rocker for it. 

So my main concern is this, I live in an island and there isnt much foam factories around, and ordering a blank is too expensive with all the fees for transport. 

The best I have is my ‘home depot’ type of thing here in the island. The only blanks they have are 15 kg/m3 density a little under 1lb/cuft and 20 kg/m3 density almost 1.3 lbs/cubft but this only comes in small rectangles of 1 m * 0.5 *  0.1

The only blank that has the lenghts necessary is  (2  * 1 * 0.04) is the 15 kg/m3. Im planning on stacking some 5 or 6 blanks to have the necessary foam to build the surfboard. My main concern is that the foam is brittle and it will turn out weak. Im planning on using stringer and glassing with 1 * 4 oz in the bottom and 3 * 4 oz in the deck. 

So… Do you think this will hold up? Will stacking up blanks make it horrible to try to sand it? I am not even that much concerned about weight, just dont want it to break in the first wave ahah. 


Thank you! 

RodAz , hi I am not sure that I understand your foam , I am presuming that it is  some kind polystyrofoam  , so yes use a tringer , you can use epoxy resin as the glue to glue the blank parts together that will make the blank stronger , after shaping get yourself some lighrweight spackle its probable called something else where you are but its used to fill small cracks in walls its not the thick heavy stuff , and spread it over the shaped blank , let it dry completly  at least 24 hours than sand smooth  , two reasons , it will be easyer to glass and it will stop the blank sucking in lots of resin  , do not use 1x3 of 4oz that too much difference , better 2x2 4 oz or 2x3 4oz good luck .

1lb eps is what we use for sandwich skin build. Without sandwich skin you need far more fiberglass than what you think if you don’t want a disposable board. 1lb is a soft and spongy foam. You need 2x6 bottom and 3x6 top. This is what is commonly use for monolithic lam on 1lb foam if you want some strengh. Stringer is not needed for final stiffness/strengh but can help while shaping to avoid overflex of foam, if you use one go with a light, thin one.

My foam is EPS, more specifically EPS60 which is that one that has lower density. Do you have an example of what is that lightweight spackle? Like a photo of the product, is that the microsphere stuff? Is it too expensive? And thanks, I am going to with that set up for lam. Maybe with higher oz.

Hello Mat, thanks a lot for the reply. I have been hearing about this sandwich construction, do you know where I can see an example?

Allright, so you believe with this lam setup the board will hold up? I am planning on using a stringer from plywood. Thin one, like 1 cm or 2 cm, depending on what they have available.

Do you think I will have problems when rough sanding it, or trying to make the rails? Will the foam just break apart? (EPS)

Also, do you think PU Glue not good approach to glue the foam blocks together? Epoxy better?

oops sorry about my spelling earlier but I was typing in the dark , yes you can use PU glue if you prefer , spackle is very cheap , you can get it at hardware , paint stores , very easy to use it will cover up some of your shaping boo boo,s  , follow lemats glassing advice he has a lot of experience with lightweight eps .

Hey gbzausa! Thank you a let for the info.

Allright, I will probably start today. Will try to keep this updated with info on how the project is going :smiley:


Rod , remember this first board is a learning experience , 1/ go slow when shaping if you remove too much foam you cant put it back , 2/ don’t get hung up on the weight , too light , too thin , two pieces ,  no fun , stronger thicker heavier  one piece = fun. some boards work better with a little weight , 3/  you will probably not be happy with the cosmetics of you finished first board no sweat many thing can be covered up or disguised using posca pens or paint , 4/ you are going to feel soooo good when you carry your first self built board down to the water 5/  bewar it can be addicting .  6/  dont forget to ask for advice on Sways befor you fuck something up we have all made mistakes . good luck .

For stringer thinner plywood you can find is enough, 3mm, 5 max, more is only weight and problems to work with. If you can find 3mm pvc extruded, like forex, is even better here. Or skip stringer and be care while shaping.

Whit so light foam you must use stronger stiffer skin. Sandwich ones are ultimate weight/stiffness ratio but cost more and are far more difficult to do right. Forget it fir first build, go with 2 and 3 layers of 6oz glass, each layers after each to have time to work clean. Seal foam first with spackle or epoxy slurry, let cured and sand before lam. Lam on flat clean surface is far easier.