2nd Board build - 7'3" retro pintail, fin suggestions?

Hi there everyone, so I’m officially off and away on my second board build and I’m really stoked on it. I’m looking to make a 7’3"ish retro pintail. Actually, something very similar to this shape posted recently: https://www.swaylocks.com/user/reset/115351/1628262236/PA8IzMbYrANmjxY1usYYI9NSP0Yx2B6SLT8UPwxreHM 

I’ll update with pics soon but so far it’s still a rough and very fat and wobbly and misproportioned homemade blank. I did the “cut rockered strips and laminate together” method to build the blank from some 3" EPS construction foam (that I scored for free!) so levelling and squaring up the blank is a bit of work, but it’s getting there. 

Anyhow, my main question is about fins. I was thinking that I’ll go with a single fin. I might make it myself and glass on, or maybe I’ll do a single fin box. Any suggestions on if I should do single fin or something else for this type of board? Also, I know there are TONS of different single fin shapes, but I don’t know anything about them. Anyone able to point me to a resource where I can learn about what different fin shapes do, or why to choose certain shapes over others? Or if it matters at all? Or even some templates would be nice! 

Here’s a photo of an outline I put made in boardcad:

 

Advice on shape would also be much appreciated. Thanks in advance for any help you can give!!

  •  I did the "cut rockered strips and laminate together" method 
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Good choice, IMO.    That’s how I would have done it if using those materials.    We have a regular (Barry Snyder) who has built a ton of blanks using this method.  One of his variations involves cutting the template a couple inches narrower and then glue another 1+" wide strip around perimeter for the rails to net the finished template.   One reason is that finishing the rails is a lot harder when there are a lot of seams to cut through.

https://www.barrysnyderdesigns.com/dissect-series.html

 

With your shape I’d recommend playing with the control points for the curve a bit.   Maybe fatten the nose width a touch to smooth out the curve forward of the wide point.  Just a little rounder would do it, 1/4" might be too much.   

Same with your tail, maybe bring the 12" width a touch or perhaps fatten the curve in the tail block a little.  Not by much, but just a little.      

Your rocker needs work.   The middle is too flat and the ends are too abrupt.    You can download a blank image and crop it and flip it to get just the rocker, and then use the “load background” image to load it into your CAD software, then just follow that line with your design.    Don’t forget to adjust your deckline, too. “Deck rocker” is just as much a thing as bottom rocker.    I was talking trash about the 73A rocker in another thread but for your project I think it would work pretty good.  

Thanks so much for your reply! You are actually the one who recommended the method I used when I was first on here asking questions about my first board build so thank you :slight_smile: It suited me well so I figured I’d go again. 

I agree with your suggestions on the shape, but I got antsy and started cutting so I might do the snyder idea and cut an extra inch off to put strip around the rails. Working the rails and glue joints was a nightmare on my first board and ended up making the glassing extra difficult too so I’m seriously considering it. Though because of the width of foam I have significantly less joints on this build. 

As for the rocker… Yes I know I need to work more on it. I honestly dont know what type of rocker I should put into this type of board, I’m building it mostly out of aesthetic, I like the way this shape looks, but I also want it to surf decently as well. I kinda figured the rocker was not great but I’d work it in on the board as I shape. 

Any suggestion you have for what type of fin/fins I’d put on this? I plan to make them myself out of some very old cabinet wood I found. 

Here are some photos of where I’m at so far. The profile shots I tried to take as level with the board as possible so that you can see what the actual shape of the deck and bottom are looking like. Right now I havent put any concave or anything into it, I’m still just working on flattening the deck and bottom.Thoughts?

The old Yater single fin of the 70’s was pretty much a staple back in the day with this type of board.  Usually 7" and not over 8".  That fin was a little to erect for my surfing style in those days and I opted for more overall curve.  What we commonly call a “California Rake”.  True Ames and Rainbow both make versions.  Rainbow also has a fin called the “Azul”.   Same rake with a wider base.  This raked style of fin wil put you onto round-house cutbacks and redirection like you previously only imagined in your surf dreams.

When bulding your own blank you want to actively plan for your rocker before you even start cutting slabs.   For a singlefin design like this a good baseline would be 1.5" - 2" at the end of the tail and ~4" or more at the tip of the nose.   Pics can be deceptive so it’s hard to tell what the existing curve is like on the bottom or what it will take to get to a usable curve.   From this angle it appears that there’s a big flat spot behind the wide point, but maybe the curve isn’t showing well in the pic.   

 

Here’s a link to the current US Blanks page for the 7-3A which gives the measurements for the stock rocker.  If you can lay your blank on a flat and level floor you can get reasonably close to seeing what your existing rocker measurements are at the tips and how much material you need to take off the bottom in order to add more lift.   

     https://usblanks.com/catalog/fish-eggs/73a/

The stock rocker for the 7-3A has a nose rocker of 5+“.   I doubt you’ll get that out of what you have, but you might be able to get 4” and that’ll be enough to get by in most conditions.    Not heaving Hawaiian conditions, but sufficient for most mainland spots.   

Man thanks so much for the link, that is a great resource that I never even knew about! I guess my issue is that I just need to research more about rocker before I start. Im honestly not a very good surfer and this board will probably be used in max 6 foot surf (which is still fairly big for me) but I want it to work well. I planned for 3.6" at the tip of the nose and 1.3 at the tail and I cut the strips for the blank with lots to work with so I think I should be able to hit at least 1.5 at the tail and hopefully 4 at the nose. I’ve got a lot of foam on there, at the wide point it’s honestly probably over 4 inches still so I have room to work. My plan when cutting the strips was to leave myself a lot to work with because I knew I was gonna make mistakes. I’m pretty sure you’re right about the flat spot, but I think I can get to the 73A measurements, or close. Thanks so much man, you are a legend, I honestly love getting feedback from you.

Dude, thank you so much!!! I think this is exactly what I’m looking for. The Rainbow Azul looks awesome. I love the shape of the california rake, should that be around 7" as well? Thanks so much for pointing me in this direction

With the Azul you gain a little fin area with the wider base.  So I would think 7" is perfect for anyone of average or better than average ability.  Nothing over 8".  Gets to be too much fin for the board.  6" is doable if you like to drift the tail a bit.  Taking it a step farther;  small side bites and a 6" or 7" center fin.  

Yeah not bragging, but I completely “hosed” Jimmy Lewis and another guy on the shoulder at Ukemehame on a chin high day once.  Almost drowned them with that big fan of spray from a round house cut back.  The look on their faces was classic.  But their jaws dropped further when I laid it out so far that I was horizontal on my back.  The curl and whitewater caught my back and pushed me back upright and into a bottom turn.  From there I stepped forward for a little Miki climb and drop before I cleanly kicked out over the top.  Classic.  And All done on my favorite 9’4 with the side bites out and an 8" Rainbow “Rake”.  Cutback and Redirect compliments of Rainbow.  Lowel

Hope it all works out for you and you realize your “Surf Dreams”.  If I had another board shaped similar to yours I would rather have it in Polyurethane Foam.  Primarily just to have the extra pound or two and the ability to sink a board that sits lower in the water, the way Poly does.  I understand though your use of EPS.  You will have alot of fun on that shape.   And fun is what it is all about my brother.  Lowel

TRUTH. 

I’ve actually never shaped a poly board before, don’t know if I’ve ever actually ridden one to be honest. I would love to try shaping poly but the cost of shipping a blank to where I am is so ridiculously high that its honestly cheaper to actually buy a finished board. I have a lot of volume in this board and I’m thinking of thinning it down. I weigh about 220 and I’m not a very good surfer, but I want it to be fun and challenging so I’m thinking of taking it down a bit more than I originally planned. Thanks fo all your advice and help man, I really appreciate it. It’s so cool building a board like this and hearing the input of guys who rode the originals! Any thoughts on rails for this board? Thanks again man, can’t wait to get this board finished and out in the water!

So I put a couple hours of measuring, analysing and sanding the other day and I was indeed able to get 4" in the nose, which I’m happy about. I can “probably” get it to 1.5 in the tail, but right now I’ve got it at about 1.25. Honestly I feel like I’m not a good enough surfer to notice that difference, but I still want the board to work well, do you think I should try to get the tail to 1.5"? I think I can, it would just mean thinning it out a little more.

Forgot I had these.  For your viewing.  Based on your template I think you should leave a fair amount of volume in the stomach, chest area.  Beaked noses were common on these boards and they primaryily rode off the front foot.  Pressure on the front foot or a step forward increased speed thru sections and tubes.  Slight V thru the fin area and mostly flat bottom.  An updated bottom would be a concave thru to V in the fin area.  I never cared for a "Beaked " nose and considered them to be unnecessary.  The inability of a shaper to use a mini plane.  They have made a retro come back in recent years.  The old boards were primarily down railed.  Harder in the tail gradually turning to a 60/40 thru mid board.  The old ones were even down railed in the nose.  I don’t think that is necessary.  

A flatter rocker in the tail will make it faster down the line, aut also stiffer.   With that said, you’ve already got some curve in the rear quarter of your template so that adds some more control back in than when compared to if you had used a swallow or squashed tail block - other dimensions being equal those boards were really straight through the rear quarter.   

You want to be mindful in the tail to not go too thin.  It takes ~1.1/18 of thickness @ 4" from the tail block to fit a full depth finbox.  A little more would be better.    If it ends up being too thin you’ll have to glass your fin on.   Originally these boards were foiled pretty chunky, which at your stature and skill level would still be a good thing for you.    

SUPER cool dude!!! I’m planning on making the fin myself so I love seeing these! Also, I am ready to start shaping the rails as of yesterday so thanks for that as well! I’m still a bit confused by rail shaping and terms but a down rail basically means it has a sharp (ish?) edge on the bottom right? The example I found showed an 80/20 down rail and the bottom was a hard edge. As far as shaping rail bands go, I’ll go with the 60/40 through mid board like you suggested. How far up from the tail should I start moving away from the downrail into the 60/40? 

12 to 20" from the tail end. Use your own judgement.  16" or so is pretty normal.

That’s what I was thinking, thanks for the confirmation and all your help man. I’ll update with photos once the rails are done, the board is really coming together now, just wish I had more time to work on it.

So it’s getting to the point where I’m thinking of glassing this board (just working on rails now) and I thought I should ask what you learned boardsmiths would recommend for glass. I was thinking the standard 6 bottom and 6+4 deck, but thinking about it now I’m wondering if that will be strong enough seeing as I don’t have a stringer in this board. The glue joints were done with gorrilla glue but it is 7’3". Will be glassing with epoxy. Am I going too light doing 6 64?

Put Carbon tape down the middle top and bottom.  If you can get it.