EPS board construction

In the "Don't call me late for dinner lightest board challenge" James and I decided to try building boards out of 1 pound density foam. There are some significant challenges with this (such as attempting to shape it is much like trying to sand a wet noodle ). That aside, the construction itself is rather interesting.

One of the issues with EPS that POLYU doesn't share is that the board must be sealed prior to laminating. I'm stealing a page from sfoam's website (makers of eps blanks):

EPS blanks must be sealed properly before laminating. Resins without micro-balloons added, will soak deep into EPS foam, making it difficult to properly wet out laminating cloths. This means you can use much more resin than
is necessary. This creates a heavy board, trapped air and pinholes; and loses the advantage of a lighter blank.

Although there are other methods of sealing EPS blanks, sFoam™ recommends using the "aviation" method of sealing structural foam.

Mix one part (by volume) micro-balloons and one part (by volume) epoxy resin/hardener. Squeegee this mixture over each side in turn, be sure to use a minimal amount to make a dry coating (try making a final hard pass with the
squeegee). Make a final hard pass over the stringer when you finish the sealing, to remove the sealer from the stringer.

Let side cure, repeat on other side.

Use a "cake frosting" consistency of epoxy/micro-balloons to fill in any pukas or dents left in the blank ( this can be done before the initial sealer is fully cured. )

When both sides have been done and cured, dampen a clean cloth with de - natured alcohol and wipe the blank. Then lightly sand the blank with 100-150 grit sandpaper and laminate.

Using the micro-balloon mixture keeps the epoxy from migrating too deep into the foam, yet insures a total epoxy-to-epoxy bond with the laminate and a strong bond to the foam.

Folks like Dave Vernor and Mike Walker the folks at Walzer seem to guard their sealant formulas with their lives! I just used TAP Plastic Microballoons and epoxy mixed as above.

My secret ingredients

I used a slow hardner because the current ambient temperature in the area is 102 degrees! Dennis made me a cool rocker table, but it's not quite ready for use. Hopefully once we get vacuum in place, I'll have the rocker table. So in lieu of the rocker table, I used an old board flipped upside down and covered in a polyethelene garbage bag. Epoxy won't stick to a 100% polyethelene bag, so that is technically a release film.

Notice the gap at the nose rocker.

I used masking tape to hold the nose down to the "mold" at the nose and then also at the tail. The 1 pound foam bends easily. My "hope" is that with the sealing coat the board will hold this rocker (keep your fingers crossed! )

Rocker set and sealing coat on and curing.

James working on his entry, we mixed up 6 oz, by volume, of epoxy and microballoons. The mixture is applied to the entire surface and spread THIN with a squeege. After the entire surface has been covered and the board is cured, we can remove it from the "mold".

Nice looking stick. What kind of cloth are you going to use? And don't you have to have a vent plug for EPS blanks? I thought I read that over at swaylocks.com

Hey Matt,

Thanks for the compliment. EPS doesn't require a vent. For example the current Inland Surfer boards have a minimal EPS core with wood laminated on the top and bottom. Surftech boards are another good example of boards with an EPS coare and no vent.

There is some general confusion over two types of foam EPS (Expanded Poly Styrene) and XPS (Extruded Poly Styrene). I won't go into the details of the manufacturing process, but XPS is correctly referred to as Styrofoam. Whereas coffee cups or coolers should actually be referred to as beaded EPS foam.

While XPS can be used in the manufacture of boards, there is a tendency of that material to "outgas" over time and a resultant delamination. This is the foam that typically requires some type of venting. I do believe that it was common for shapers to put pinholes in the decking to allow the gas to escape

Realistically, this board is being shaped ridiculously light, and has an expected life cycle of 5 minutes (just need to survive the challenge).

I used 1 pound density foam...it's almost impossible to shape. When you pick it up, it flexes...it seems to have the same torsional resistance as a large piece of cardboard. So, I'm planning on laminating it with Graphite (Carbon Fiber), if I can find it and afford it! I need some additional stiffness which the Graphite and Epoxy lamination will afford, but I still am hoping that I can it will win the lightest board challenge. We'll see.

It worked! Taping it to the "mold" did create a bit of nose rocker in the board. However, the foam retained some memory, so I lost about 15% of the rocker. I think that I will put a wedge under the deck when I seal the top.

A "discovery" is that it is possible to shape a board WITHOUT using an EPS blank with a cut rocker and without having an actual rocker table.

One issue though, is that the sealing did add 3 ounces of weight, so with just one side sealed the board is up to 9 oz. I'm hopeful that a fully sealed board, without laminate will be a shade under 12 oz, or 3/4 pound. I think that I can laminate with and only add another 12 oz...sooo, I'm estimating that I can get the finished board down below 2 pounds.

Are you worried Ed, Roy and Billy?

I don't a strong idea of what I'm going to do yet, I think I'll pass on using anything from a salt and pepper shaker though.

Why worry? Here is the prototype that we are working on this week. Weighs less than 1 pound and it is too small to put a Calibrated sticker on it.

Top secret prototype

Roy, that looks remarkably like it's been photoshopped - is that possible?

Ed, the salt and pepper was JUST in case the board didn't hold shape, I was going to eat it. It has about the same consistency, strength and weight as a potato chip.

Fully sealed and lightly sanded, the blank is now 12 oz. I have done some calculations and opted away from the Graphite. I don't really expect that this board will be ridden more than the 5 min requirement, so...I located the lightest weight eglass that I could find...at 1.4 oz per sq yard. I'm hoping that it will be rideable with a single layer of glass top and bottom and that I can get it laminated at less than 6 more oz...for a combined total weight of 18 oz. I don't think tha I can get any lighter than that...won't beat the Pink Mohawk that Roy has...uummm, conjured up ;)

Hey Jeff, you should have seen the picture before i made it... we couldn't find a picture of a blank wake. It's actually a sequence shot from right after Kay fell !

Wow, 18 oz..our goal was under 4 pounds =| haha

ya u can BARELY see her rite behind um..her..

Here's the shape I just did. I plan on glassing it hopefully this week. I'm thinking of two layers of 6 oz glass for the bottom and two layers of 6 oz for the top. I need to take a pic of the wood fin I'm working on.

Matt does my memory serve, isn't that an old Clark blank? Are you actually shaping your own fin? Sick! I want to see the details on that, please.

Robbie, you are a virtuoso with photoshop. If I see Kayley busting 4 foot airs, I'm busting YOU!

I don't think I'm going to make my 18 oz goal. I went with .75 oz fiberglass vail and when cut that weighed a total of .5 oz. It doesn't offer much in the way of structurally rigidity, but it certainly is light!

However, I calculated that I would need 150 ml of epoxy to wet the vail out and THAT weighed in at a hefty 5 oz!!!!!! I also wound up have to mix up another 100 ml or so for the rails. So, my guess is that right now the board is in excess of my 18 oz total goal and I still have to laminate the bottom.

The pot I mixed in weighed 1.1 oz, so the epoxy by itself here is 5 oz. I think that if I was bagging, especially infusing, I could reduce this to no more than 150 ml, perhaps a little less.

Thats actually not photoshop..its much more basic =) and i never thought of doing that for kay ... good idea though! So how are we testing these boards ???

Yeah, it's an old blank. I've got two of them. They're from 1991 or so. Here are two templates I did. The template on the graph paper is 16 inches long and 3 inches high at its apex. The blue template is 15 inches in length and 2 1/4 at its apex. I am really not sure how these designs will work in relation to a conventional fin. I'm thinking about shaping a Home Depot blank and putting one of these on there to test them out so to speak. I really don't want to ruin my good blanks. I guess I could always "knock them off" and reglass some twin fins on there. But back to these, I'm thinking the one drawn on graph paper is going to be a single fin. The blue is a bit smaller and I've thought about making it a twin. I got the idea after reading about "are we really going finless" in an older wakeboard magazine. Their take was that these wakeboards really are not "finless" with these foils going down the rails. My son's little board has them. Anyway, we're taking my 7'2 McCoy Nuggett out tomorrow and throwing a turbo tunnel fin on it to see how it rides.

Most recent weigh in, I'm up to 18.4 oz. That projects out to 24.8 oz with both sides laminated, significantly less than 2 pounds, but more than I had hoped. I think that an 18 oz board is doable. So I may have to try again.

That is an interest fin design, you'll have to let me know if the lenght vs depth change provides the same drive. I've wondered about how the longer base would affect the turning of the board.

Back to my resin issue. I don't have the vacuum bagging set up, but I think that I'll do that before the end of the season. In my situation, I had almost 10 times the amount of resin to fabric. My guess is that the board will be a bit brittle. Folks that have figured this stuff out, shoot for a resin to fabric ratio that is close to 60% (as opposed to my 1000% ratio .

Also, if you look at boards like the Calibrated telum with ABS rails, vacuum bagging allows the builder to create complex composite shapes. Dennis found an article that described Bert Burger's construction methodology. It's possible to build boards with rails constructed of a different material than the core and in so doing, change the riding characteristics of the board itself.

So for example, this project is constructed of very flimsy 1 pound density EPS, but no doubt the felx will be too significant to make a quality board. If we laminate d-cell to the rails, it will stiffen up the board, possibly creating a board with low weight and exceptional snap or rebound. "Possibly" being the operative word in that sentence.

Jeff
I was researching XPS last night and came across this one link. This one guy named Greg Loehr (who is originally from Central Florida and also a great shaper) is kind of at the forefront of EPS technology. Here is a link to the article I found. http://www.swaylocks.com/forum/gforum.cgi?do=post_view_flat;post=156225;page=2;sb =post_latest_reply;so=ASC;mh=25;

Take a look at this stuff. It called nida core. Some type of honey comb foam. http://www.nida-core.com/english/nidaprod_nidafoam3d.htm

Loehr is the man behind Resin Research Epoxy, he's definately the guru. I think that I have his Shaping EPS 101 DVD around the house somewhere.

I think I remember looking at that Nida stuff, but isn't it fairly narrow? The max width was something like a foot and less than 4 foot long? Maybe glue two pieces together. So many different materials out there, plus if you combine them...it seems the variations are endless.

The strongest, lightest, anything is probably a composite.

That's a great thread Matt, thanks for sharing that find. I think that Ed is right, the composite of different components is what the future will hold. I'm REALLY interested in 'bagging EPS and D cell, attempting to develop something that is exceptionally light, without being too fragile and yet has some incredible rebound or snap that also doesn't effect the board's ability to develop drive. Sheesh, in reviewing that list...it's no wonder industry hasn't jumped on that bandwagon!

I just glued some EPS blocks together with epoxy but I was surprised that foam soak resin so much. First I was thinikg about spraying foam with with some epoxy paint, but dont know about results. Thanks for ideas

(Message edited by hawaj on September 02, 2007)

Just for your consideration - awesome repair and construction resource
http://www.boardlady.com/index.htm

jeff you are insane! i wish i had that kinda time and knowledge to mess around

Hey Sean, I know - the obsession thing has it's advantages. Matt and I have been talking off-thread about some concepts. There are a few composite constructions around...if you think about it, the Inland Surfers are composite construction with the WoodLoc, the Calibrated with ABS rails are a form of composite. My bet is that Walzers have a similar composite construction.

To make it more insane, Matt and I were thinking about stealing a concept from Firewire...the boards would have 1 pound density EPS cores, and then Balsa rails/perimeter stringers and a balsa skin.

Interesting if I can get it to work.

Dang it that's my concept, but I'm 100% Balsa with a special skin.

you guys crack me up, ill leave the board building to you guys and then if its cool maybe ill buy one

That's a LOT of Balsa! Like model airplane construction? Balsa stringers/outline also? Planning on CA for the adhesive?

What will you use for skin? As a kid we used wet tissue and dope, then came those iron on films...I can't imagine any of those would standup to 180 pounds. Planning on a balsa skin also?

I'm thinking beyond our challenge, the current stringers on boards seem to allow torsion rail to rail, and I'm wondering if changing that to a more lengthwise orientation would provide more drive?

The picture only shows the lateral stringers, not the longitudinal ones. The gross weight, before cutting is on the order of 35 Oz. I expect the balsa weight to be under two pounds. Pound for pound balsa is one of the strongest natural materials available. Use aircraft construction techniques to reduce weight and maintain strength.

Most of the design is shown. I need to rework my design for the longitudinal stringers. The strength of the design is longitudinal, i.e. front to back, not as much side to side. Also note I’ve got two pairs of 12 inch by 8 inch foot pads (not shown for clarity) made from ¼ inch balsa. Of one pair, one section is on the top of the board and the other is on the bottom of the board.

I’ve ordered my balsa, should be in by the weekend. I’ll buy a few sheets tonight for early testing.

The first layer of the outer skin is 1/16 x 4 x 48 balsa. I’ll put sanding sealer on the outer layer to reduce paint absorption. Then I’ll paint the entire outside of the board. I’ll wrap that with a polymer sheet for tensile strength.

That’s basically a 4 inch by 4 inch grid. Running the full length front to back there will also be 1/16 by 1/8 stringers on 1 inch centers. Also I'll add 3/8ths triangular sticks along the longitudinal stringers, kind of making them I-beams. The 1/16 by 1/18 stringers will help support the 1/16 skin, the I-beam will as well.

Do you think the 1/16" skin will support the 180 pound load on 4 inch centers?

Hey Matt,

I just got off the phone with Grant from Foamez.com. He's telling me that the 1 pound eps foam is exceptionally gassy and they don't even like to sell it...suggested 1.5 pound density. I'd also guess this is why some of the manufacturers are so secretive about their sealing.

Anyway, those folks from foamez are great to work with.

I have no idea how much weight the overall structure will support, isn't this why we're taking on this challenge?

Where the foot pads are there's over 5/8" of balsa. That's 1 1/16 skin, a 1/4 pad, 1/2 inch supporting structure, 1/4 running surface pad and 1/16 bottom skin. Elsewhere there's just 1/16th of balsa over the frame.

Actually, I thought it was so the winners could say: nah nah nah nah nah!

I'm interesting the the 1/16 inch skin selection. I'm looking at a composite that would have this structure:

Glass
Balsa skin
Glass
Eps Core
Glass
Balsa Skin
Glass

What I'm more interested in is the memory or flex return. If such a structure can produce a greater snap, I think the resultant board would be substantially more lively...if it just flexes without the snap, it's a total slug.

I've read about the distance between the skins offering some incredible increases in strength, but I can't get a handle on the flex and return...what I'd like to achieve is "some" flex, but MORE importantly, the memory or return has to be incredibly quick and strong.

Visually a cross section of the composite would look like this: Does it make you think of crayons?

Here is the composite site of all composite sites. http://www.compsand.com/

yo jeff, the fire wires are cool i agree, but there is all this hype around the boards, and im on my second one right now, and i have to say, they work well, but its not worth the time and effort ( or the money). pluss i already broke one completly in half my 4th time riding it.

Johnny, how did you break it? Holy crap man, you must have been ripping hard. When are you coming north man, you're wasting the whole summer!

I still like the idea of the composite construction, and I'll probably fiddle with it, just to see if I can manage different flex patterns...I've made so many piles of junk in the past, another one wouldn't deter me.

I really want to learn how to vacuum bag and I think that has potential in regular construction, just in resin minimization.

Maybe I can sell a specialty line of "crap" boards

I just finished cleaning up the longitudinal stringers. Here's a fresh concept. Skin, foot pads and a profile are shown.

It's absolutely gorgeous Ed! I did however calculate that it will take you 3.75612 years to cut and affix all the gussets

You'll have to post pictures of the build sequence for us. I'm looking forward to it.

Ya, I'm worried about build time, October 5-6-7 looks pretty close. Some of the stringers are identical. When I drill and cut them I’ll pin them together so I’ll make two to three a time. Jac said that there are places that will laser cut balsa for models. I wonder who does that and what the cost is.

Would it make sense to design the board, for this limited purpose, as a twin tip? Such that the nose and tail were identical, then it would seem to me that the cross ribs would only require three unique shapes, rather than what "appears" to be 6 unique shapes.

Manufacturing the ribs seems to me to be the bottleneck. OR you could simply recognize the futility of your efforts and secede from the challenge.

Ed - I'm excited to see how that turns out. Would be really cool!

There are several sites that show a similar design - some of these boards are beautiful.
http://www.hollowsurfboards.com/

One idea instead of foot pads is a thin layer of surf wax... I don't really like it on my boat, but for this purpose it might give you a few ounce edge...

I'll consider a twin tip design, sounds like a good idea. If I was able to slap together "Recycle This!!" and not recognize the futility of that effort, how could I possibly see the futility of this one?

The foot pads are more structural than performance i.e not for. traction. This board will probably not have any traction as that would add weight.

haha! jeff and ed man i really think its awesome how you guys just want to progess the sport and are trying to find new ways of building boards to do so. your the only people i know of who are willing to experiment which is one thing that i love to do but dont have the cash it takes to go forth with. keep up the good work. ill get up north when i start selling some boards of my own so i can pay for gas. im on a tight budget at the moment.

You need to get busy and sell Johnny, we expect to see you up this way soon!

I think that I am mostly stealing ideas from other folks.

If you think about it, the inland surfer boards with the wood loc is a composite sandwich structure: foam/wood/glass. Calibrated uses a foam core like Divinylcell and the ABS rails. I think that the Walzer's are a similar construction, only with some light density foam.

Walzer's and Calibrated's are vacuum bagged. There isn't any reason you couldn't do that with a normal surfboard rather than a typical wet layup. The one thing that is missing on the Walzer's and Calibrated's are bottom contours. Not missing, the boards just aren't designed with a bottom contour. They are basically flat, conforming to the shape of a rocker table.

However you could also press in a concave. Just so long as the material you used to shape a concave was a greater density than the foam core, it should press into the bottom of the core when it is under pressure of the vacuum. Learning new methodolgies or maybe UNLEARNING the old isn't easy.

I have read that with Vacuum Bagging it's possible to reduce resin use to 1:1 (resin weight : fabric weight), from typical wet hand layups that are in the 6:1 range. Not only does this reduce weight, but it makes the final board less brittle, I believe.

The Inland Folks are fairly innovative too, with the Epoxy Infusion. Theoretically that is supposed to reduce resin to fabric ratios below 1:1. I couldn't devise a way to make that work without scoring the underlying foam pretty heavily to get the epoxy to flow between the balsa sheeting/glass and foam. For the minimal weight savings it would afford my "design" I thought it best to skip it.

Anyway...lots of innovation out there, I wonder if we'll see production boards that are principally bagged rather than hand laminated.

OR

Built up balsa like Ed's Those would be a true stick, stick

A few weeks back I saw one of Larry Mann's (Trickboardz) new prototypes up close. I didn't ask him, but I would guess it was vacuum bagged and had a serious bottom concave.

If Larry entered the contest I'd think he'd have us all beat. That thing was ridiculously small and light.

the new surftech ones are bagged. although im not really a fan of randys technology... at all, but i do believe the placebos are bagged. i could be mistaken but im pretty sure they put a vacume on thoes bad boys

I just ordered my fins. I thoght about making my own fin like that template I posted earlier. I am going to do that, but not on my clark blanks. I ordered a fin type called speeedfins. The fin boxes look pretty easy to install as well. Once I get the fins, I'm going to glass the board.

All Calibrated boards are pressed using a thermal pneumatic epoxy process. No bags here, yet. Our new surfs (Matang) may go that way once we get it dialed. We are currently working with a windsurf company to get the bugs worked out. I'll let you guys know what developes.

Thermal Pneumatic? Hot air?

First step on my quest for vacuum bagging a board is this adjustable rocker table. Dennis is going to weld a million hex nuts on some angle iron for me to replace the eye's at the bottom on the base.

It's not been leveled or adjusted yet, but this is basically what it will look like when it is complete:

The adjustment mechanism

This table has the adjustments on both side - MAJOR PITA to get leveled and adjusted (the process is: set the two extremes - nose and tail - and then "cinch" up the remaining 9 to the desired rocker).

However, it occurred to me that I could intentionally put a twist into the board. I'll probably do it UNintentionally too. We typically only ride one wake side, perhaps having a different rokcer on one side from the other (stop hooking the inside rail on 3's? ) would prove benefical...or NOT!

I was so busy busting your chops, Mike, I didn't catch the reference. The surfs? Matangs? Is that what Austin was riding at Nationals?

Awesome rocker table. I was just looking at those on a kiteboard building site. My fins and fin boxes should be here by the end of the week. Temps are dropping into the high 80's and a glassing I will a go.

How is your board coming along? I'm interested in how it turns out. Thanks for the compliment on the table, the base is still problematic. I need the angle iron with welded nuts to give it some rigidity - right now it's like stacked domino's if you even BREATH on one slat, they all topple over

Nice! Are you sure your an accountant, looks like the work of an engineer.

Oh, I didn't mean to indicate it was my concept. I stole the idea! Now THAT is the mark of a true accountant, far more efficient to STEAL an idea than create a new one.

It's coming along. I've just started shaping the outline of my other blank.

I had the need for some an odd shape foam that I couldn't find locally, so...I made some. It's 2 pound density PolyU. I made a simple wooden mold with an opening in the top to allow pouring the liquid in and then as the foam expanded, it exited the top.

This is a very simple structure, but similar in operation to the concrete molds that Clark foam used to make blanks.

Tremendous pressures built up inside the mold, even though I had a 9 square inch evacuation port at the top.

Mt. Foamy

Jeff that very cool that you are making your own foam -- but how it popped out like that is too funny. Reminds me of the classic "hot lava" home science experiment for kids. By the size of it you might be able to get two blanks from that.

Reminds me the the move 2001

Back to the EPS. I received two Marko stringerless EPS blanks. Interestingly enough the folks from foamez told me that the folks at Marko automatically cut all of their blanks in half and then glue them together with a stringer, or not.

Glue only stringer.

You'll draw the outline of your board on the skin of the blank. I like to do this drawing on the top of the blank. The "glue" stringer actually made my job easier. You want to make sure that your outline is properly centered left to right on the blank. As you're shaping, later on, you'll do frequent measurements to make sure that you are creating a symmetrical shape.

With your outlined drawn, you'll start cutting. I like to use a jigsaw with EPS, and a handsaw with PolyU. Cut outside the outline so that you can claen it up with other shaping tools. remember when using a jigsaw that if the deck is domed, you can't run the jigsaw pressed against it - the blade will be angled in toward the center. Just hold the jigsaw at an angle so that the cut is vertical.



(Message edited by surfdad on September 25, 2007)

All cut and ready for the next steps. This blanks is 1.7 pound denisty and is fairly thick. As cut it is 36.8 ounces. We'll see how light it is upon final shaping.

First pass at shaping the blank. I'm down to 28.1 oz.

Comparison to a PolyU scrap. The PolyU chunk is about 20 oz. My hope is that I can get this board laminated and under three pounds.

jeff whats with the hang up on the lightest board? i honestly dont like riding a super light board

IMO, lighter is more responsive and will, "I believe" allow more aggresive tricks.

For you, Sean, I have the perfect board, 60-70 pounds wet



(Message edited by surfdad on September 27, 2007)

Jeff your garage is looking a lot like mine. My wife went in there last night and said "what's all this dust everywhere"? I glassed on my fin last night. Going to do a hotcoat this afternoon. Let the board "cure" for about a week and then go out for a ride. I'll post a pic tonight when I get home from work. How is that marko foam? Me and a friend are taking a weekend surf trip over to Jacksonville and thought about picking up a few blanks from there.

Hey Matt,

Marko's foam is 100% virgin EPS (my understanding is that if it DOESN'T SAY 100% virgin, it contains some reground EPS) and the claimed denisty is spot on. I have found that some of the EPS manufacturer's claimed and actual density is off as much as 40%.

The glued stringer line is BS...I think they just messed up and didn't want to blow more foam blanks Also, I was originally looking for 1# density but couldn't find any pre-shaped blanks in that density. SSSSSSOOOOOO, I settled on 1.5#. These blanks arrived and were marked 1.7# which they are EXACTLY.

The foam is good, the management of the operation, not so much. I'd think if you saw a few blanks IN PERSON that met your requirements, you'd be happy with them.

In the future, if I want stringerless, I think I'll get billet and hot-wire the rocker and outline.

Can't wait to see your creation.

When you shape the EPS it doesn't turn to dust, it turns to chunks of beads. Also, it feels like it is electrostatically charged and sticks to everything - tools, the wall of the shop, every square inch of your person. You and your clothes will be ever so popular around the house. I plan to send a few oz to Ed S.

jeff i like a light board but i think too light does more bad than good, my carbon walzer is too light! my IS 4skim feels so much better, the little bit of added weight makes it smoother and overall ride better. i feel the 4skim is the perfect weight, its still light but doesnt feel like its gonna fly away on me

I'm not trying to suggest that you change your prefernces, just trying to sell you a surfdoor. I can make you a GREAT deal on it. I do believe that differing styles of riding tend to generate preferences in board size, shape and weight.

As you point out, you prefer moderate weight for a smooth ride. Also, as Roy and I were discussing the other day, many folks prefer a slightly heavier board when performing shuv's as it causes the board to rotate on axis, while a lighter board has a tendency to shoot outward.

My "hang up" with lightness as you referred to it (does that have a negative connotation, Sean? ) is more a focus on testing what can be achieved with lighter materials and construction methodologies. The board(s) that I am building aren't designed to be smooth, nor will they be used much for shuv's.

I believe that the amplitude of aerial tricks can be enhanced with lighter materials - a driving force in aircraft design. I believe that significantly more radical tricks can be performed with less swing weight and I also believe that for lighter weight riders, such as Judy W, Kayley G and Scott H, more manueverability can be achieved with lighter boards.

So I would suggest that your preferences are fine, but aren't a general standard...nor would I expect what I am attempting to achieve, would be either. Further, I would NOT agree with your generalization that "too light", as you define it, "does more bad than good".

It's just different, right?

to me it seems that slightly more weight would equal more drive? but im no expert

and jeff i would love to buy that door but im currently unemployed so i cant really jusitify such a lavish expense right now, hopefully it will still be available when i get a job

Sean, layaway? $5 will hold it indefinetly. I have to warn you though, I get inquires on that surfdoor everyday...mostly it's of the "are you crazy?" genre, but I'm sure it's close to being sold. If I were you, I'd tie it up today.

Personally, I don't think that an increase in board weight translates into an increase in drive. Realistically, the board itself is such a small component of the rider/board combination...changing the weight of the board +/- a pound probably doesn't have that much impact on drive.

I think that drive is mostly impacted by fins, shape and construction.

I do believe that once the board is out of the water, weight has a fairly significant impact. If you observe folks that are developing substantial air on a wakesurfer, it's only partially a function of drive or speed down-the-line. It's similar to skateboarding. The higher you can pull your legs up on an ollie, the greater the height of the air. However, I don't want to discount down the line speed, it's necessary.

Once in the air, manipulating the board is directly related to weight...well weight in relation to the riders strength. If we use a finger flip as an example, (ignoring the width and length of time in the air concerns) it would be easier to rotate a 2 ounce board vertically on it's horizontal axis than say...the surfdoor I believe it's Newtons first law of motion that states that a body at rest tends to stay at rest. It also states a body in motion tends to stay in motion, until acted upon by an opposing force. So...a lighter board would take less of an opposing force to manipulate in the air. When the rider is in the air, they don't have significant force generating capabilities. IF someone could get surfdoor into the air, attempting to rotate it would more than like cause the rider to be moved around in the air, too.

On the other hand...a lighter board could just turn out to be a lightweight piece of crap

jeff, i think that they put the glue stringer in the blaks so that its easier for you the shaper to get everything exactly even. with out it theres no referance point.