Board #3 - I like! - w/ balsa rails and some questions

General Discussion
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After countless hours reading Swaylocks I decided to try to make a surfboard. Then another then another. So far I’d say when I’m in the right mood, making boards is great fun and really eye-opening to say the least. My 1st board I made with a friend and it was an underglassed stringerless EPS that went OK but buckled and broke under my feet once I started to push it hard. My second had balsa rails on EPS and despite a big glassing mistake and a bad design decision it still goes great and fast in softer stuff and coming off the bottom I feel like it’s catapulting me up the face. A big appeal of making boards was trying different construction methods I read about here and, I hope, getting great rides from the boards. I still do from that one.

For board #3 I again made an EPS shortboard with balsa rails and despite countless things to improve on I’m very happy with it. It’s good in steeper waves and still launches me out of bottom (and some top) turns – handling it took some getting used to but the speed through turns is addictive. I’ve been having a blast with it and really feel when I lean into a bigger turn I get more speed out of it than with any other board I’ve had. Anyways I thought I’d post what pics I have of the build. The finished board is 6’3"x19 1/4" by 2 1/8", if I recall.

I cut out rocker/foil templates and carefully got them identical and smooth. Here I am lining them

up on both sides of the 1 pound/cubic foot EPS I got from a building foam place:

The hotwire cutter I made was cheap and works well. Scrap wood, nichrome wire off ebay, assorted cheap parts. I think the spring works better in line because when the wire was wrapping around a corner to get to the spring it could get stuck and not stay taut.

I also spliced in an old extension cord so I can just plug it into the old (ebay cheap) variac and not feel like I’m gonna zap myself.

Ande here it is all cut out (rocker/foil. I hotwired the outline afterward)

BTW, I also brushed a little canola oil onto the masking tape around the edges of the template. I really didn’t want to snag the wire on the template (had a less than ideal experience on board #2 that I didn’t want to repeat).

No pics of hotwiring the planshape but here’s the tool. The wire runs through a bit of metal tube held in the wood frame, and the tubewas long enough to protect the template from the wire but not long enough to scratch the foam the template was lying on:

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I have to say, hotwiring just feels cool.

At this point I had the foam “blank” foiled rockered and outlined. I had already left it narrower than the intended finished product to account for the thickness of the balsa I was going to glue on. So next I traced the rail of the hotwired foam onto a long piece of paper. The balsa I got was in 4x48 inch strips, so I glued them together so they could accommodate the traced form, stacked them and cut them.:

So now I have long strips of balsa that pretty much match up with the sides of the foam blank. To glue them on I put the hotwired foam face down on the hotwiring offcut from DECK SIDE, then brush epoxy on the foam and balsa and stick them on.

I used the deck-side offcut this time because for my board #2 I used the bottom-side offcut, and despite my best cutting efforts the matchup was not perfect. In that case it meant that where it was off a little the balsa did not reach to flush with the foam, and I had to do a ton of filling it in afterward with foaming glue or epoxy-qcell, etc. Pain and not as good as having balsa there! So now for board #3 I used the deck-side offcut as a rocker bed because if the balsa is not perfectly flush with the foam there, no problem – it’ll be chopped off in the rail bands anywho. The balsa went a little past the foam on the bottom side and was easy to plane flush when shaping.

So I epoxied the balsa strips onto the foam and clamped them on with a vacuum bag. Overkill, I know, but it’s a cool toy and works nicely, and after my ebay vacuum pump deal, probably as cheap as a few good big clamps. Also, I really like air pressure. A pic:

Altogether the rails were between 9/16 and 3/4" thick (thicker with one extra strip from 5" from tail to about 45" from tail), in layers 3/16" thick.

They started a little stiff but the epoxy I brushed on made them supple enough to bend pretty well in the bag.

The way I went about it worked well enough. Tracing the shape, cutting and gluing wasn’t too bad, but supergluing the 4"x48"x3/16" strips into longer strips was very time-consuming.

QUESTION: Has anyone tried steaming full-length balsa railstrips then bending them to the blank? I’m envisioning getting some long strips from somewhere like specializedbalsa.com, then steaming some 1/2"xrail-length strips in a capped PVC pipe for a few hours, then taking those and putting them in a vacuum bag with the hotwired foam and using the force on the bag to get the wood to conform to both the rocker and the rail line (probably bottom-side offcut rocker bed). Possible? Any experiences? Then once bent and dry, epoxy each wood strip to the foam and vacuum clamp on till the epoxy cures.

Anyway I have to go at the moment and put up the rest of the pics later. Of course advice and questions and pointing out my mistakes is encouraged. Once again, Swaylocks has been fascinating to me and allowed me to make this board, which is working great for me, so a big thank you to all and I hope these pics and the next ones I put up are at least amusing to you all.

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QUESTION: Has anyone tried steaming full-length balsa railstrips then bending them to the blank? I’m envisioning getting some long strips from somewhere like specializedbalsa.com, then steaming some 1/2"xrail-length strips in a capped PVC pipe for a few hours, then taking those and putting them in a vacuum bag with the hotwired foam and using the force on the bag to get the wood to conform to both the rocker and the rail line (probably bottom-side offcut rocker bed). Possible? Any experiences? Then once bent and dry, epoxy each wood strip to the foam and vacuum clamp on till the epoxy cures.

I would advise against that. It seems like a labor intensive process I have made lots and lots of compsand style airplane wings, never made a compsand surfboard. What I do to make the leading edge, which can be laminated around curve like a surfboard rail is to first start with a sheet of 1/16" balsa. No need to wet it or steem it or amonia, whatever. It is thin enough to bend. This will be the first layer that will be attached to the foam. Use tightbond wood glue or epoxy spread thin and eavenly across the whole length of the wood and the rail. guestamate the wood to be about 1/4" thicker than the rail. It is easiest to do this step with a few short pieces. This first layer produces a buffer zone for the foam because CA glue (which will be used later) will attack foam. Use masking tape at short and regular intervals to attach the balsa to the foam. when the glue dries, remove the tape and trim the wood flush with the top and bottom of the board. Each additional lamination can be either 1/8" or 3/16" balsa sheet. 1/4" is a bit on the thick side for bending. Try to use contest grade balsa, it is the lightest and easiest to bend. Use medium viscocity CA (cyanoacrylate) glue to to apply each additional lamination. Be sure to stagger all the seams (not necessary if you can find full length wood). Apply the glue slowly in a zig zag pattern across the rail while immediatly following it with the wood. One hand on the glue bottle and the other pressing the wood down as you progress from front to back or vice versa. After the desired rail thickness is achieved, the rail can be carved, planed and sanded to shape. This method is quick and produces good results.

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Sweet! D-Rock!

looks good from here

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OK some more narrative/murky pictures. The vacuum-bagging of the rails onto the foam worked out pretty well. I also, after the epoxy cured, gorilla-glued on some balsa strips to make a noseblock and a tail block.

As you can kind of see, the balsa strips conformed to the outline curves pretty well. Also, I used a lot of epoxy in some places and it took some rocker-bed foam away with it. All was planed off in the shaping anyway (deck side).

Well, I don’t have too many pictures of the shaping. I did a little bit of evening up the wood with the foam and neatening up the nose and tail blocks. I also sanded the ~40" strip I had on the outside edge of the rails, making the rails from tail to midsection thicker by 3/16", to fade it more gradually into the rail.

Then I did the railbands etc. It certainly went better and quicker than my first two boards. I had drawings of cross sections that I drew tangent lines to, which told me how to mark my rail bands, etc. The best tool for taking away rail wood was a hand plane, and for the 1# the micro-bladed surform was good. So, I was constantly swithcing between handplane and surform to cut the same railband, as each rail band straddled some wood and some foam.

QUESTION: How do you shape an area that is part wood and part foam, without ripping the foam or going mindblowingly slow on the wood? ie, if you are shaping a 1" wide rail band, over 1/2" of balsa and 1/2" of lightweight EPS, any recommendations on shaping a nice flat even rail band in this situation? Is this what those electrical power planers are for?

Another QUESTION: Any tips on getting more sharp angles (when desired) for the planshape outline, when the rails are wood? In this case, I had envisioned more pronounced hips in the tail, but bending and gluing the balsa on led to some quite smoothed-out hips.

I guess I could have sanded the below hip would down, then the above-hip wood, to try to make for a sharper angle at the hip… right? I wonder how much rail wood I’d take off that way.

Anyway overall I tried to go for fairly thin rails and a gently dome deck (max thickness 2 1/8"). Tried to keep the tail thin, thinking of flex and springback, but did measure to make sure the Probox boxes would fit (no problem).

I filled all of the big foam tear-outs with a mixture of epoxy and corn starch. To seal I just used spackle and a little bottled water – much easier.

Here’s moments before glassing (I preinstalled leash cup and vent):

QUESTION: How do the more experienced folk finish their balsa rails, or any balsa materials, before glassing? I found the balsa reasonably smooth after I used low-grit sandpaper to blend the rail bands. But,when I tried to get them even smoother by using high-grit stuff before glassing, I felt like they actually got a little worse – more wood fibers sticking out, not very smooth, etc.

Anywho I glassed it 6S+4x6S+6+4. I think the S-glass outer layers were worth it – I don’t have any heal dents after dozen+ sessions, some in real overhead waves, some in chest-head hotdog waves. I did have some sand-throughs, though that’s my fault, and I’ve had some pinholes to cut out and fix, and i don’t know if that’s from bad glassing (not smooth enough along the lap edges, etc) or also due to my use (whether my feet or the wave lip hitting it).

I made this a quad, as I like how other quads I have hold speed through turns and can turn from a high line. Also, since this one is NOT a quasi-fish, but is for hold on steeper waves, I wanted to see how the quad would work on waves types I’ve only ridden thrusters in.

The pictures are making my computer a bit slow so I’m going to try to post these then show a little about glassing and fins in a reply.

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I marked fin placement dots before glassing and measured 4 or 5 times – precise stuff, fins!

I was really obsessing about fin placement, and now I don’t even remember all the numbers… I think I put the back fins at 5.5", front at 11". Front were toed 1/4", rear 1/8". The front fins were 1.2" from the rail (and the finbox hole is slightly in the rail balsa), while the rear fins were, I think, 1 15/16" from the rail.

Idon’t have too many picture of the glassing, as my hands were busy. I felt it went well over all, no huge drama. I found that I liked about a 4:1 ratio of fast:slow hardener with the resin research 2020. I had the temperature pretty high and wasn’t fast enough to work with just fast hardener.

Laminated the bottom at night and deck the next morning.

Since I had the gram scale out anywho, I can tell you that the lamination process added almost exactly 2000 grams to the board. (6+4x6+6+4, plus four patches in finbox areas). Certainly the glassing went better than with my first boards (don’t ask), and it came out feeling nice and solid. I actually wonder whether I could have gotten away with a bit less glass on the deck side.

Not too many pictures of fin-routing, hotcoating, sanding, etc. The Proboxes went in nicely – finished product:

QUESTION: Has anyone else had problems with routing the Probox jigs by mistake?

My board #2 I had a lot of problems, and on this one I had less, but it was still a problem. Robin from Probox gave me plenty of advice and help, but I still saw at least a little red powder in each hole, and noticed at least mild nicks on each jig. I’m sure that the problem has to do with me being a novice router, having a cheapo Harbor freight router, me being an idiot, and/or not having glassed well enough, but I really want to know EXACTLY what I’ve done wrong.

Regardless, the fin boxes are solid in the board and I’ve had a great time adjusting. The board works in the waves I intended it for, but my first guess for best fins was actually pretty far off…

Anyway here is the board before its maiden voyage:

Notice all the junks that has accumulated in my apartment after shaping and glassing… (a big thanks to my very patient wife. The picture was 6 weeks ago; we’ve gotten it cleaned up since then).

These pictures are after I fixed a sand-through or two (slowest speed on the sander is my friend.)

I think the pictures show that the weave is quite visible on the wood rails. Why? I’m thinking maybe I should have done a cheater coat on the deck-side of the rails before hotcoating - might that have helped?

I could also make sure to coat the entire rail when basting my laps before hotcoating the bottom.

Well, there’s board #3 for you. It does take off on steep drops and hold in steep waves, as I had hoped, and goes vertical when I make it – I’m happy. One less excuse for not going when a big meaty one comes my way.

A moderate to big bottom turn or a big (for me) top turn that I really lean into, and the board seems to rocket me out of the turn. Took some getting used to.

The nose flips up pretty dramatically in the last 15 inches, and I should have made it more gradual along the last 2 feet or so – occasionally it is awkward in cutbacks.

I thought the H2 fins I like as all-arounders would be good for this board, but in fact I like a more standard foil (I have Pro-teck fins on now and really like them). Trailers are just the standard whitish fcs trailers, I think they’re like 3.75 inches deep.

I found the board holds well with 6 degree cant front, 4 rear, though there might be conditions where I’d try 0 degree rear.

Best news for me is I recently found that when I cat the front fins 8 degrees, it’s great for smaller or flatter waves. The board has a lot more glide to it with that setup, and overall I’m finding it can be a really good board for not-heavy stomach to shoulder high waves. Easier to get down the line speed like this, really loose, but maybe not so easy to do tight or nearly vertical turns. Also on some set waves I’ve found it didn’t have the hold I needed.

So I’m carrying an extra pair of Probox inserts stuffed into my wetsuit if I don’t know what I’ll find wave wise.

Fin suggestions of course are very welcome.

Still despite all the mistakes here and there (and the 2 pinhole/dings I’m currently fixing) I’m very happy with this board --THANK YOU to all the advice I’ve gotten from this site. I did not have any clue how a surfboard was made before I started reading here.

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profile shot:

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As far as your probox routing issue, you have to make sure your router bit is at the exact length called for. You can find this info on the paperwork that came with the install kit or on their website. The blade of the bit shouldn’t be high enough to cut into the jig, just the bearing.