Swaylocks Inspired SUP #2 by Uncle D

A wise but younger man shared these words of wisdom to me: “I don’t know SH*T but I’m having fun experimenting!” I adopted these words as my new war cries as I ventured into my next surf related project.

The beginning of this year, Manoa and I were looking at all the left over 1# EPS foam we had from our fishing surfboard project. We made a few short board blanks and had enough to make two 12’3” Clark style blanks. My blank was the first of the longboard blanks we glued up. We got some 1” thick balsa wood that we recycled from a crate that carried balsa blanks from Ecuador. Manoa being skilled in woodworks piece together and milled a beautiful balsa stringer. Using pipe clamps and Elmers’ PU glue we glued up the blank. We learned most of these things from Swaylocks. The blank sat at my house wrapped in plastic sheets for nearly seven months.

After reading CarveNalu’s threads on SUPs and completing my first balsa skinned SUP and paddles, it was time to build number two SUP. I wanted something that was still full volume for a SUP beginner to easily stand on. I turned to the dependable Charlie Wong to shape this creation. I told him to get the deck flat, ease up on the tail and nose rocker, make the rails thick and boxy and make the bottom flat to vee in the tail.

After seeing the blank we made, Charlie said that it needed lots of cleaning up. He pointed out the flaws of the blank (i.e. gaps between the stringer and foam, unevenness, etc.) but said that he could shape those flaws out. He even gave suggestions on gluing up the next blank like lining up the stringer with the deck because it was easier to shape the unevenness of the bottom because of the convex curve, or align the blank from the center and work your way to the ends using bicycle tubes to hold the blank together during glue up. Charlie shaped a pretty decent board considering the blank he was working with. I then added balsa inserts in the fin plug and box areas. I also installed a wooden tail block. The dimensions came out 12’3” x 20” x 28” x18” x 4”. I wanted it at least 4.5” thick but we got what the blank yielded.

The board is a cross between a first generation SUP and a glorified longboard. I am not to sure if I can stand up and paddle on it but I know I can knee and prone paddle it. It’s going to work just fine for my daughters or a lighter person as a SUP. It also would be the perfect crowd control board as a prone paddler out at Pops Waikiki. (Watch out boys, here I come!)

1#EPS is such ugly foam when compared to the Clark stuff I am use to. I knew the blank needed sealing with all the pours and gaps in between the stringer and foam. I read most of the threads on sealing EPS and the debates on creating a good bond. One description that caught my attention was comparing sealing the blank with old fashion foam staining. Bells and whistles went off in my head. I can do this. I abandon my original plan to seal with spackle and decided to use a mixture of epoxy, Q-Cel and pigment. My goal was to seal and color in one step.

I did the deck with yellow and it came out pretty good. I started doing the bottom using the same method and I asked myself if I could do an acid splash seal job. I mixed red and yellow batches of epoxy/Q-Cel sealer and went at it. It came out pretty good. The trick was to squeegee as much off the board as possible. The sealer even helped fill in those gaps between the stringer and foam. I let the sealer sit over night and sanded it down using 120 grit sanding screen. I later sealed the tail block and stringer with clear epoxy. I really think this method has the potential to create some really beautiful boards. It will need more experimentation and perfecting.

I needed some art work to blend in the deck with the bottom. I wanted to hire CarveNalu’s daughter to do the work but I could not match the salary her current employer was paying her and she was booked solid for the next few months because of her Dad’s latest commercial venture. I even asked my own daughters but they wanted no part of it because work was involved. So, I turned to my own inner-child to create the colorful squiggly lines using Posca and Zig pens. Boy that was fun.

I glassed the board with 7.5 and 6 oz. on the bottom and the same on the deck plus a 6.oz deck patch. I used Fiberglass Hawaii (FGH) 2 to 1 clear epoxy. I noticed some gassing where I cut into the foam on the deck on the lap line. I monitored this and pressed down the gassing area until the epoxy started to harden. I hot-coated and glossed the board with epoxy plus FGH epoxy surfacing agent also.

Polishing the gloss coat was something else. I sanded with 240, 320, 400 and 600 grits. I used FGH surfboard polish and attempted this for about two hour. I could not get the epoxy to luster like I can with PU/PE boards. It did come out slick and smooth but just not shinny enough for my taste. Perhaps I need to let the epoxy cure a bit more (I only let it cure for 16 hours), read a few more threads on polishing epoxy and try again later. Hey what the heck, I’ll just surf it and not worry about it.

I installed FCS side bites, 10.5” center fin box, two Chinook vents (one on each side of the stringer) and a leash loop hole through the deck. The fins are FCS GL side bites and a True Ames 9” cut away fin.

I really want to thank CarveNalu for the inspiration, Manoa for his help, generosity and expertise, Charlie Wong for his shaping mastery and letting me use his FCS/fin box jigs, etc; also the Swaylocks’ community for all the hints and ideas provided to make this project possible.






More pics:

Yes Hicksy, that’s your laminate! The Surfco Hawaii nose guard fits well.

Not quite shinny enough.

Balsa and readwood tail block. Acid splash/epoxy-Qcel sealing combination




Yowza! I think you’re onto something with that tinted sealing step. Nice idea! Who needs a paddle, I can think of a half-dozen places I’d love to take that baby surfing :slight_smile:

Uncle D,

That is BEE-U-TEE-FUL!!! Nice job! That is an awesome display of workmanship from someone who doesn’t know sh*t but has fun experimenting!!! Hahahaha!!! Seriously, if you can’t stand on it now, I’m willing to bet you will be standing on that baby soon… Those dimensions are perfect for your next or 2nd board… Just a matter of time… Great job Uncle!!! Lets get together one day and paddle or surf!

Aloha Benny:

I think the sealing and foam staining is a great way to make those ugly 1# EPS blanks look half way decent. I showed Maona the board and he said it looked like a PU blank instead of the 1# board we glued up together. I think I’ll try a cleaner cut line on the deck rail on the next EPS project. The yellow came out really even with the Q-Cel. Again the trick is to squeegy off the excess and later sand with the sanding screen.

Aloha CareNalu:

I rode the board yesterday as a prone paddler. It paddle really well but the waves were just about flat in town. Mahalo for your comments but there are a lot of flaws up close. I wanted to try different things on this board and experiment with the sealing/foam staining method. It works and I am stoked about it.



Mahalo UncleD for showing me your awesome new SUP. Great work…I cant wait for my SUP!


The cool thing about our friendship is that we feed off of each others’ energy. If it wasn’t for meeting you, this board would have not happen.

Plenty Mahalo,


Heu Uncle D, how much cabo sil did you add to the resin and pigment to do your color/sealer, any help for a newbie welcome

Aloha Joel12:

I am assuming you are referring to epoxy resin. This is a large board so I started with 8 oz of mixed epoxy and added pigment and mixed to the shade I desired. I slowly added Q-cel to get a creamy peanut butter consistency. I am estimating by volume, the Q-cell was about three times the amount of epoxy. The thickener that you use will influence the color of the board. Q-Cell made the color brighter / lighter. Make sure you squeegy the excess and sand lightly with sanding screen when dried. It will seal the board well and hide those ugly EPS beads. It will allow you to free lap and glass with clear epoxy and still end up with a colored board.

I hope this helps.


Thanks UncleD great info on the color and acid splash idea, I’ll post my pictures of the boards when done, this site is great for all the info it provides to anyone who needs to learn and we all can learn, been surfing since 1962 (age 7) , seen all the changes in board revolution, still seems to me those early sixties were some glorious times, no leases, heavy boards and lots’ of swimming after those wipeouts’, take care.

Hey dude, you are my age (class of 1973). I started surfing at 12 in 1967.

Good Luck,