stringerless blank ...

…has anyone here shaped one ?

advice ?

pitfalls ?

glassing ?

… thanks in advance for any and all help !!

ben

[ps - attached is a shot of the blank. c 6’10 x 22" x 2 3/4" , at present …I’m wondering if that would be too flexy , at that length… if about a 6’4 would be less of a snap risk ?]

Hey CF,

I made this fish from(home depot 1lb) EPS, no stringer,used rail channels to stiffen it. Greg Loehr posted that after 6ft a board needs some sort of stringer or it will be prone to snapping. This board works great and is still in good shape after 6-9 months of use/abuse. I was told to glass heavy as well, 3x6oz deck and 2x6oz bottom, it has some weight to it but I like that in boards.Hope that helps…

A couple more pics…

Stringerless blanks… well, shoot, I gotta tell ya that the first blank I ever shaped (after reshaping a couple longboards) was mail ordered from Dave Sweet, he advertised in Surfer magazine. This was in '69 or so, I lived in Hilo.

The blank came in a box… stringerless (surprise) and utterly devoid of rocker (surprise). It was just a rectangular parallelopiped (now that I’m older I can write these things).

I made a 6’6" very light board. The blank acquired a twist in it, which I never completely removed. It was very responsive, and for the day, very light. It also collapsed under my back foot pretty quick, despite double 7.5 ounce glassing. Weak foam.

Still, it is interesting to think of doing it again, though I don’t think taking out the stringer is a winning idea. I think most of the strength of a board is in the glassing; I think snapped boards fail first on the compression side of the stressed board, when the glassing releases from the underlying blank. This compression failure is followed by the stringer failing, and the tension side snapping. More detail if you want it.

IF I got a rockerless chunk of EPS, XTR or whatever, I’d probably put a stringer in it for shaping purposes. It would probably flex too much to shape accurately otherwise. HOWEVER, after rough shaping I’d think of just going stringerless with (miltiple) glue lines.

thanks for your replies, guys !!

Oceans23, please tell me about your heavy glassing… how many layers top and bottom and what oz cloth you used ?

   cheers mate ! 



      'chip'

Hey chipfish61,

I used 3x6oz on the deck and 2x6oz on the bottom. Rail channels to stiffen it,goes well although a little corky.

wow… and would you mind telling me the dimensions, and especially the thickness , Oceans??

I’m guessing with five layers of cloth and the accompanying resin, it gained both weight and thickness compared to what looks thin and light in the ‘blank’ photo.

Is the colour a tint or a spray ?

Last question [for you, for now, anyway]…

Does it flex noticeably when you turn, or have all the layers of cloth made it a similar stiffness to a polyurethane blank, do you reckon ?

I’d be hoping for flex, but not so much that it will break after a few surfs or something !

Greg Loehr, if you’re out there… what are your thoughts , please, on say a 6’4 x 20" x 2 1 /2 " [when glassed] pintail single fin?

…WOULD just two layers 6oz top , and one layer 6oz bottom snap too easily ? [I’m thinking epoxy].

Anyone else who has done one with just a conventional polyurethane blank [minus stringer] , have you glassed it with epoxy or polyester resin ?

I’ve not used epoxy, but would consider giving it a go , if it meant I could get away with using less layers of cloth on this blank , yet still have good strength ?

I can see there COULD be some tradeoffs.

I guess what I am talking about here may not neccessarily be a very long lasting board, unfortunatey

…light, strong , flexible… possible ? or an oxymoron ?

How MUCH flex will be the tricky part , I’m guessing… and, will flex through turns be easy to handle ?

I think of George Greenough , and how he was saying his boards AND fin flexed, I wonder how that would go STANDING on a stringerless board ?

Sorry if this last bit has been a bit of a ramble...I guess I'm thinking aloud, trying to also invite feedback on what people here have found who may have experimented with flex plus lightweight equipment... Dale Salomonson [sp?] , I'm looking to you .... any others , too !! 



  Okay....thanks  in advance for your help ! 



         "chip"

Hey CF,

Sure, it is 6’2" x17.5" x 21.5" x 17 “x 3” , foiled to the ends nose and tail were around 2-1/2" to 2-3/4" thick, I am pretty big so I wanted a lot of float…and I got it. No noticeable flex, could be the glass schedule,could be the channels. I used 1lb home depot EPS and(glue line in pic…) glued up two 2" pieces,then planed in my rocker and shaped it. I did an acrylic spray tint on the foam, acrylic paint thinned with future and sprayed on thin. I definitely don’t think it will snap, I think the weak foam(1lb) will eventually fail(read get crushed…) causing a delam situation…we will see. So far it is a great board, snappy and quick,I have been abusing it just to see what happens(something I would not do to a board I bought…) and to see how the materials hold up.What type of foam is your blank? Density? Any more Q’s, fire away…have fun…

W-E-L-L-L , it’s funny you should ask ‘ocey’, because I was wondering today if this ‘packing blank’ may BE polystyrene…

Would the way to tell be just cutting a piece off it… it feels and looks like a ‘normal’ polyurethane, but then…I’ve never SEEN a polystyrene blank !! [are they always really thin like yours ?]

Because my blank is about 2 3/4" thick , I assumed it was normal polyurethane, just with no stringer. [Also, is polystyrene ever a different colour… yours LOOKS the same to me ?? ]

I wonder how much stronger the epoxy will make it… talking to a guy on the design forum at ‘surfer’ who is just starting to use it, he seems really happy with it.

There ARE places here in perth which have epoxy…I just need to learn stuff… “blue liquid”… “bert” … can you help me , please ?

I’m guessing if I just glass "normally " , after a coupla grindy ‘scarbs’ days the board may be no longer…

So , “occy”, you glued up two 2" thick pieces, then planed them down to 3" thickness, is that what you’re saying ?

And , the “glass glue up” you mentioned… do you mean like a coloured resin stringer, to get your template even from, or what ?

Sorry for sounding clueless, I was just a bit confused what you meant, that’s all.

The EPS you used… is that the insulation sheeting I’ve read about here before ?

If it comes as thick as 2" , or even 3" in australia [I don’t KNOW…], would it really need to be thicker than that, in order to have nose and tail rocker ‘shapeable’ into the ‘blank’ ?

I AM intrigued, but for now, I’ve got this freebie blank to figure anyway !!

I’m figuring I’ll cut, and spray, then glass an offcut, wait a few days, and observe !! [obviously, if it WAS polystyrene, I wouldn’t have to wait THAT long for a ‘result’!!!]

          .... this could be FUN !!! [ I sure HOPE so !] 



                    "chip"   [ben] 

[ps - one part of me REALLY wants to make a thin 5’10 - 6’ “stubbie” single fin , with only one layer 4oz top and bottom… another part * of me thinks that would be one $300aus wave! ]

*probably the 'sensible ’ part of me [?!]

pps- I’m 5’10 and 145 and 43yo … how big [tall] are you oceans ? [did you find you needed any extra back foot area patch , by the way ?]

…thanks heaps for your help mate , by the way !

I make a 7’6" tri out of the pink insulation foam. No stringer. Glassed with 2x6+1x4 on the deck and 2x6 bottom (if memory serves). I put a carbon fiber strip into the deck - flat, under the glass, to help stiffen it. Can’t tell if that is working or not. It feels fine when ridden, but does flex a little under load. does not feel weak.

See the ‘Pink XPS’ thread in the archives.

The rail-channel/‘power rod’ thing seems to be a good idea. I may try that in the future - or a sandwich stringer between layers of foam horizontally.

EJ

Quote:

I make a 7’6" tri out of the pink insulation foam. No stringer. Glassed with 2x6+1x4 on the deck and 2x6 bottom (if memory serves). I put a carbon fiber strip into the deck - flat, under the glass, to help stiffen it. Can’t tell if that is working or not. It feels fine when ridden, but does flex a little under load. does not feel weak.

See the ‘Pink XPS’ thread in the archives.

The rail-channel/‘power rod’ thing seems to be a good idea. I may try that in the future - or a sandwich stringer between layers of foam horizontally.

EJ

…THANKS for that , Eric !

it may be in that thread [I’ll look for it soon]… how long and where did you place the carbon fibre ?

…I remember Rusty used to put them in the rails at one stage, another guy here puts two strips in…one each side of the stringer.

Please tell me… what is the flex like, do you feel any kind of extra thrust coming OUT of cutbacks and bottom turrns, for example ?

Can you feel it flex when you’re , say , trimming - or in the tube ? THESE are the things I’d be curious to see/feel if there WAS a noticeable difference in the feeling / ride of the board.

I suppose, ideally, to be able to tell with any degree of “certainty”, I’d need two very similar outline, thickness, rocker boards to test ride, one of stringerless EPS and epoxy, and one ‘conventional’ polyurethane blank and ‘normal’ resin…

         ben

CF,

I am VERY happy with using epoxy,easy to mix/use. I use resin research epoxy(Greg Loehrs) and am glad I made the switch from poly. Very little fumes too. Yep,I glued up two 24" x 8’ x2" planks of the foam,used elmers wood glue for the glueing. Although if I did it again I would use epoxy resin after roughing it up for the glue up. Yes it was the insulation foam available at home depot /lowes type stores. My plank after glueing was 24" x 8’ x 4" thick, I would think you would need it somewhat thick to get the correct rocker out of it. If you look close at the profile pic above you can clearly see the glue line in relation to the rocker. I am 38years old , 6’2" and 220lbs, not much fat, my board floats me well and rides great. But like I said , a little corky at 3" thick. No tail patch ,with all that glass I did not figure I would need it. Hope that helps, have fun…

Sean W.

Ben,

The flex is there on turns, for examp. on a bottom turn I can feel it give a little. Not very lively flex unfortunately, my regular stringered boards are more responsive and feel more snappy. This is more forgiving, or passive, type of feeling. It feels like its conforming to the pressure of the turn a bit, which might allow for a tighter turn.

The CF is a one inch wide strip that runs from nose to tail down the center of the board. i think I’d need alot more CF in there to make it feel significantly different.

I think stringerless might work alot better on a fish. Short and wide like a classic fish would not be as affected by flex and wouldn’t be hurt by some extra glass/weight to increase strength.

One of these days I’ll post a pic of that XPS board.

EricJ

hey chip …i was going to respond yesterday but i ran out of time …

eric just confirmed the point i was going to make …

i was talking to len dibben about a week back…(over 40 years building boards)

we were discussing stringerless boards…

i said " i reckon stringerless boards are stronger, a stringer makes them break easier" i cringed as i awaited the rebuke , he agreed to my surprise…

he said when they used to build stringerless back in the sixties , they never snapped , they just went like dogs…

i fully agreed and said thats why polys need stringers not for strength but for performance , you need something to return the flex …some spring…

even tho me and len are at the extreme opposite ends of the scale when it comes to board design and contruction , we do agree on what works and what doesnt …

i dont think breaking will be your problem … it will be performance…

if you use nothing that will return the flex , then your safer to make it thicker so it wont flex as much …

regards

BERT

Hi again Eric!

I started reading SOME of that thread you mentioned, so far …

The options I’m thinking of, at the moment, are : -

a 6’4 - 6’6 single fin ,

5’10-6’ “stubbie” [ again, a single fin ]

or ,

another fish [but I’ve got 3 already, so probably NOT!!!]

Option 4 , for something REALLY out of the ordinary [for ME, at least!]

…a really thin thruster , slightly wider, with glass on fins.

I don’t know how well it really showed in the attachment in my first post, but I HAD drawn a rough outline on one side , of a rounded pin, about 6’2 to 6’4… around the same as my Bob Cooper single fin…[see attachment]

Okay … off to bed [it’s 1am saturday morning here in “w’ozzieland” …

zzzzzzzzz… chip…zzzzzzzzz

My board is a Tri(2+1) set up. FU box in center, Futures on the sides. I could easily use it as a single though.

Read what Bert has to say. If you don’t need a lot of ‘boing’ from the board a short, thick, single sounds doable. Maybe a knock-off of the McCoy Lazar-zap. Don’t seem to need flex there, but the bottom contours might be tough to copy…?

good night to you in wozzieland - Still Friday PM here in the US.

THANKS, Eric and Bert!

Well, it sounds like there’s a pretty good reason we don’t see stringerless boards around much anymore !

Although it may seem a waste of time / money to some and pointless in view of the information received, I STILL want to go ahead with making it fairly thin , perhaps with only one or a coupla 4oz layers on the deck, and with one 4oz bottom…

Why ? It may be a ‘mushy’ flex, but I’m interested to feel some flex…

[an aside: The boards I have made in the past have always ended up at least 2 1/2" thick with double 6oz decks, finbox thickness pods, 6oz bottoms [mostly flat bottoms].

IF ‘Multifins’ had made a thinner box, I’d definately have gone thinner already, with my boxed fin boards. I really like the option of boxes, ESPECIALLY on the singles I make… I’ve always loved being able to play around with different fin templates , materials, and placements !]

Bert, Eric, [Greg Loehr, if you’re there…]

I welcome your feedback on going say 2 3/8" [absolute MAX!] thickness [glassed]… with just 1 layer 4 or 6oz…epoxy only … Bad or okay idea, you reckon ?

I’m really wanting to hear from someone who has done this…what happened to the board over say six months/ or, years [IF it lasted a long time!].

Also, pitfalls with glassing with epoxy ? Rail lap problems compared with polyester… or not?!

Any gelling problems ?..I’ve read some good stuff of yours in the archives Greg, just wondering if you do/did much polyurethane blank with epoxy [in the '70’s? was that the main available blank then, or were you using polystyrene blanks from the get go ? pardon my ignorance…]

Sorry if I ask a lot of questions , guys…I just like to get as much information available as possible from EXPERIENCED people before embarking on a new project , that’s all, in the hope that my “new project” will turn out well…

So, regarding possibly using 1 layer 4 or 6oz top and bottom, when glassing with epoxy, can I have some feedback from anyone who has actually DONE this, please ?

WOULD it be too fragile with ‘normal’ resin with that setup on my stringerless blank ?

Without a stringer will the board twist / lose what flex it has over a short period of time…like the 70’s fibreglass flexi skaties my mates rode, and the flexi fin on my Wilderness 1969 s-deck ?

Bert, bluejuice, any other ‘w’ozzies’ out there… are Sorenson’s and Kirkside the best epoxy suppliers in the perth metro area, you reckon ?

Any particular thing to ask / look out for ?

…can I use normal MEKP with epoxy, or not ?

 okay, thanks in advance for your help, guys ! 



       "chip"

Hey Chipfish, epoxy is a completely different animal… epoxy resins use hardeners instead of MEKP catalyst. Check out West System’s site for general epoxy info (including gel times) and dealer locations (sorry, I’m in Japan) http://www.westsystem.com/frames/tier2/productinfo/requestliterature.htm

I haven’t tried their product but I was thinking about trying their SB-112. Right now I’m using Greg Loehr’s RR2000 on EPS and PU. He sells fast and slow hardeners depending on how long you want to work with the glass. One advantage of epoxy is that it sets gradually whereas polyester really seems to kick fast once it starts to set. Also, when using epoxy, mix in small batches - there are a lot more tips like that in the West System guides. Good luck. If you use the SB-112, let me know how it goes. Cheers, Brennan

2-3/8" is thin - but does not seem too extreme (to me) for a shortboard. However, especially without a stringer, a single 4 lamination top and bottom is not going to give you a lot of strength. It may work for a while, but it’s likely to fail when stressed. Yes you’ll feel it flex, but likely only for a short while, then… it would ‘flex no more!’ (sorry)

Without a stringer and thin - I’d say go for at least 2x4 bottom and top (plus a patch). Lam carefully and you can make a light board - it will have some flex - which may be affected by where your feet are placed (You may be be able to flatten it out with a wider stance…?).

I think (help me hear folks…) If you put a dome in the deck - thin rails, thickness in the center - that shape of the glass/foam sandwich will add a bit of strength/stiffness over a moslty flat deck and bottom. I guess the kicker is how much dome can you expect to get in a 2-3/8" board…?

Epoxy can be very good to work with and, with care, can help you get a lighter board since you can use a little less resin. Greg Lohr’s Resin Research epoxy is very good stuff - don’t think you can get it in Au. yet though (Bert, Greg?). I’ve heard that the West System stuff works fine, but is more pricy - and less clear. Also - Forget MEKP if you are using epoxy - it’s not part of the process.

Build the ‘thang’ will ya!?

Eric J

Well, tonight , in my boredom, and because of a massive deck delam, I did ‘the chipper thang’ [bert, talk to Ross about this ! he knows my …er… habits], and stripped my 6’9 cordingley single.

Because of the deep bonzerish concave, both the fin and tail snapped off. I now have a partially shaped 5’9 x 18 x about 2 3/8 STRINGERED blank. A few holes to patch, some work to get it even, but…

if I’m going to do epoxy, I’ll give THIS one a go, methinks!

That way I’ll get my thin, non finboxed thruster - and also get to try epoxy on a board that won’t suffer from what sounds like ‘mushy’ flex to me. [Maybe I’ll just end up keeping the stringerless thicker, as suggested, and go with polyester and a layer or two of 6oz on that.]

So, would it be safe , as this one has a stringer, to use one layer 6oz top and bottom on this board, or should I still go with two layers to be on the safe and hopefully stronger side ?

Sorry if this has been a bit of to and froing and now change of plans. But I figure now I already have a thinnish and stringered blank to work on , I may as well give epoxy a go. I’ll ring around tomorrow to find out about what ‘stuff’ to get, and how much $ it will be.

Any further help, info, things to watch for in glassing with epoxy for the first time, would be much appreciated.  Thanks! 



           ben