So a few months ago I was driving around school and I found I giant block of 1#/ft3 EPS foam next to a dumpster near the engineering department. Its about 7’ by 2’ by 3’ and judging by the slots cut into it I figure that it must have been some sort of packing material. Anyway I finally transported the foam down to NC and decided to give compsand a shot.
OK, heres the disclaimer: This is an experimental board. I just want to test out some new construction methods… please dont get on me if they are not ideal. With that said heres the plan- 6’6"x20" dimond tail with XPS rails and balsa wood deck with 4oz under and 6oz over.
I was able to cut two 6’x20"x5" blocks out of the larger block. Here’s a picture of one of them and a few of the left over scraps…
I should have used a hotwire to cut out the rocker. really, I should have. But I just got picked up a Hitachi P20 off craigslist (for $50!) and wanted to get some practice with it. Supid choice. It took 6 hours and over 2400 passes with the planer to get the rocker right. Really… 2400. I did the math. For the first hour I used proper techniqe and all but I was getting nowhere so I digressed to the cross cut method. I know, I know… its juju but I was getting impatient. Anyway heres what I came up with…
The next step is to attach the XPS rails. I picked up a huge sheet of 1/2" XPS insulation from Lowes for $13. I know there are some spray adhesives that work great with foam but I also read a thread somewhere that elmers white glue works too. I decided to go with elmers for convience sake. I roughed up the XPS with 100grit and glued it on. Heres the tail…
… and the first layer of the perimiter rails. I plan to do two layers to give it a 1" rail and lay the balsa over the EPS
Anyway thats all I’ve got for tonight. Please, offer comments, suggestions, and criticism. More to come tomorrow
I think the skins are 1/16" but im not 100% sure. I didnt buy the wood. I still havnt decided if im going to to wood on the bottom. I think 4oz, balsa, and 6oz would be a bit overkill for the bottom of a board thats not going to see waves over 3’.
Bag the skins skins before the next layer of rail you say. Ok. Makes sense. I just have to wait for this glue to dry. I think the humidity (we had storms last night) might be keeping to from hardening.
Yes, I will be using inserts for the fins. Im thinking 2# EPS.
I guess I should have taken some pics of me pulling the rocker out of the board but I was eager to get started. The block was pretty ugly looking so my first order of business was turning it into a true rectangle. I snapped a chalkline down the center of the block to give me a center line and used a right angle to trace out equal dimensions. I used a hand saw to cut out the rectangle and cleaned it up with the planer. Now that I had some good lines to go off marked the rocker measurements on the right and left side of the blank at 3" intervals and shaved the deck and bottom down to meet the rocker profile. LOTS and LOTS of planing. This method worked OK but the blank has a slight twist in the tail, took forever, and its murder shaping in a tent on a hot NC afternoon. Next time in using a hotwire. faster, easier, and it’ll give you a more accurate shape.
My questions-
To vent, or not to vent?
Balsa on top and bottom or just the deck?
Thruster or single fin? It would have made a great quad, but I just used my last quad set.
Here’s one I’m working on,xps rails and fin inserts.I used white gorilla glue to put it all together,cost me 6$ for enough glue to do more than 2 boards.The rail bands on the right are done,the ones on the left are marked to be cut.The bottom of the board is laying flat on the table.The blank is foiled,1/2" thick at the tail,1 3/4" center and 1/16" at the nose.It will have 3/32" balsa skins glassed 4oz-balsa-4oz top and bottom.Hot wire is a must for me,along with a japanese pull saw,and an xps sanding block with 60grit.
Super job Brian! Hope you don’t mind but I’ve got to tell Sways a little about you. Yankeesurfer just graduated from the Naval Academy and is soon off to serve as an officer in the US Marine Corps. We met when I supplied him with some eps blanks. He used my shop to shape and glass his first board. He is very talented and has been on his own after the first couple of boards. On his second board he tackled a checkerboard paint job which required quite a few hours of taping. He’s definitely not afraid of a challenge and qualifies in my book as a full blooded Swaylocker!
Dave- Thanks for your kind words. You have been a tremendous help to me over the past year and a half or so and I appreciate your generosity and mentorship.
Jesus- I though about gorilla glue but I was woried that the glue lines would be too difficult to sand through. Did you have any problems with it? Also, is the XPS OK for a fin box insert or should I use 2# EPS?
A storm blew my tent over last night and we got a decent little swell this morning so i havnt been able to work on the board. Maybe tonight.
Sorry about your tent,I’ve read here and also on other sites that xps is ok for fin/leash inserts and also rails.A thin bead of GGlue is all you need,Scuff the xps with 60 grit,brush a little h2o on the xps then apply the glue.I try to center my glue beads on the xps (because it foams alot) edge to avoid having to sand it,it sands out ok though and its nothing the skins can’t cover.
I’d really recommend a goretex vent, but if it’s just a board for yourself and you’re carefull with it, then you could be ok.
Make sure it is fully sealed, NO PINHOLES.
I find thats the mistake that gets made with these boards.
Probably because it’s amazing how the pinholes can propogate themselves all the way through the process and still be there even until the gloss coat! Its the air breathing out of the board that does it.
With 1# EPS i’d recommend doing wood skins on the top and bottom, it should actually turn out lighter.
Fibreglass on its own ends up being as much or more weight than a sandwich skin, as you have to add so much to get adequate strength.
I measured the width and found that it was almost 21" so ive decided not to but a second layer of XPS on the rails. I blended the rails down and heres the final product.
A toad hopped into the tent to inspect my work.
He peed on me. Who knew toads were such tough critics. I let him go but made a mental note to get him with the lawn mower next weekend.
I forgot to install the fin inserts but I’ll do that tomorrow in the morning. I remember reading somewhere that you dont need to seal the blank if your gunna vacbag but the foam still had some gashes so I speckled the bottom.
Jesus- Thanks for the advice. White Gorilla Glue sounds like the way to go. Elmers takes forever to dry and runs a bit. Its also a bitch to sand through.
KKsurf- I have a screw vent but I dont think im going to use it. The board is for personal use and I’ll take pretty good care of it (no hot cars, left in the sun, ect).
Thats 1# eps,I would vent it.PeteC has some good vents for sale and you can also make your own.I have a 1# eps bamboo skinned board and my vent is gortex,stays dry and I leave the board in the front seat of my truck with the windows up in florida summer heat.I have no leaks or delamns.I planned on making more than 1 board so I opted to make my own,they cost me a few dollars to make and are easy to install.I saw one board on here that had like an 1/8" hole drilled in the deck,when he surfed it he put a piece of tape over the hole,then removed it when out of the water.
very astute observation, the installation involves packing the lower half of the hole surrounding the plug with an epoxy putty and topping off with resin…this keeps it from flooding the bottom and sealing the vent, it also reduces the amount of stacked epoxy keeping exotherm to a minimum.
