How To Build A Spoon

Man O' War · Post by **Man O' War** » Fri May 06, 2005 3:11 am

Wax -- Thank you. The genie's out of the bottle. This is what ksusa is so good at.

Flex -- Nice pics. That's the kind of stuff that going to help. Paul Gross, there's a guy who knew how to build spoons. I pray he never sees this thread. lol

DrStrange · Post by **DrStrange** » Fri May 06, 2005 11:47 am

Great play by play manuel! Hopefully many will download and save this as a base to work from.

Man O' War · Post by **Man O' War** » Fri May 06, 2005 12:40 pm

DR -- I second your hope. This little thread will be a success if it helps get a couple hundred guys out in the water on spoons. What--that's not impossible. Just imagine spoonists starting to rip from Noosa to Biarritz to G-Land to Laniakea to Bolsa... oh that's right, there's no kneeriders in Bolsa... But what an impact on surfing, not to mention, Fun.

Since we're on the subject of progress, I'd say everybody's about talked out. I think the next phase will be visual and slower: as boards are made and tested, we'll have more and more pics and video. What will move this forward is proof.

For example, that little sequence of RW on MTB's board, as short as it was, was kind of a show-stopper, and it was backed by the comments of the judges. Even the two b & w Greenough bottom turn shots posted by Flexman, as old as they are, were amazing (about which I just received this email comment from Flexman: "Part of why I posted them was to show two similar bottom turns using the same equipment, one with George leaning hard on the inside rail and pulling on the outside rail, while the other pic shows only leaning, no pulling or grip on the outside rail.")

To borrow Greenough language, I think "Stage II" is already starting--it's about getting in the water and documenting.

You first, Dr Strange... You're in the Red Triangle but try not to think about it.

AM_Glass · Post by **AM_Glass** » Fri May 06, 2005 2:43 pm

First, thank you for your descriptive, mind reading (just what I wanted) post. Now onto the questions...

I was under the impression that the first flex spoons were made by working the deck of a full foam spoon down until there was no foam left. Kinda like, "this board goes ok, maybe it would be better with less foam." This made me think that that is how to make a flex spoon, shape a board with the end result in mind, heavily glass the bottom, then work almost all the foam off the deck.

Am I mistaken in the history of the flex spoon? What are the reasons to use the pour foam route?

Another question, I don't quite get why the spray can lacker is used. Is it only for graphics or is it contributing structurally?

P.S. I'm almost afraid to add to this discussion for fear that the conversation will drift from the original (very important to me) subject.

Marky V · Post by **Marky V** » Fri May 06, 2005 2:59 pm

mow
why use a clark blank at all? Get a block of eps and hotwire your required rocker into it.
Laminate with epoxy resin!
Must be a better way?
Mark

Man O' War · Post by **Man O' War** » Fri May 06, 2005 6:05 pm

Glass -- I'm glad it was helpful. I expect to see shots of you soon on your spoon at Middle Peak.

Yes, the classic way of making a spoon is to glass the bottom of the blank, flip it, and grind or scoop out all the deck foam except the rails. That's how I made my first one many moons ago. You can do it that way, it works. I didn't, for two reasons: (1) I learned that hand-pour high density foam in the rails is much stronger than regular surfboard blank foam, and therefore more responsive in the flex mode and less vulnerable to breakage; and (2) I realized that by doing it this way I could save the entire blank and either re-use it as a mold or reshape and glass it as a foam board. I saw some wisdom in that. I am going to use it to make a couple more spoons, and then I can still get a conventional board out of it.

The spray lacquer issue is an embarrassment. I'm sorry you brought it up but... What you're supposed to do if you're serious about speed is wet n dry the bottom and deck-side rails with 400 grit to get the optimum hydrodynamic surface. I didn't do that because wet n drying your board also opaques it a bit. I'm in love with that translucent deck, so I said, forget it. I did fine sand everything but then just sprayed it with the lacquer because it looked beautiful. The surface isn't as drag free as it should be, but I'm at the age where I'm not so worried about fractions of a second. Scott, do you still want the board?

So, to answer your question, the lacquer contributes nothing structurally except some unwanted weight, but it does contribute visually, and for a shallow person, that's enough.

DrStrange · Post by **DrStrange** » Fri May 06, 2005 6:23 pm

You're in the Red Triangle but try not to think about it.

I very much remember swimming a spoon around in HI and thinking, "Hmmm, I feel just like bait."

Your Chum,
Dr Strange

DrStrange · Post by **DrStrange** » Fri May 06, 2005 6:25 pm

You're in the Red Triangle but try not to think about it.

I very much remember swimming a spoon around in HI and thinking, "Hmmm, I feel just like bait."

Your Chum,
Dr Strange

DrStrange · Post by **DrStrange** » Fri May 06, 2005 7:23 pm

Looking for prefab fin and found this on Swaylock's...Paul Gross on TrueAmes Greenough 4a fin:

...The Greenough 4A was a fin template I took directly off of a pre-Bob Duncan Wilderness (circa 1969) which is owned by Ray Maloney. The fin is 100% a “Wilderness/Greenough” design. I simply copied it and revived it. I had nothing to do with the design of that fin, nor am I claiming that I did. However… The original 9.75” Wilderness fin on Ray’s board was fairly thick in the base. In the mid-90’s, Spencer Kellogg and I made a number of prototypes from this fin outline and found that the template only worked if it was made from a 1/2" thick panel. The 3/8" panel fins tracked so severely, they were even hard to paddle comfortably. (1/8" might seem like a minor increase in thickness, but it is a full 33% thicker than 3/8". Obviously, this a tremendous difference in release.) I sent the 9.75” Wilderness fin template to Chuck Ames, and asked for some fins made of 1/2" thick panels. He made them up, and they were serviceable. The foils were a little funky, but this is to be expected in a production situation. So far, so good. Eventually, True Ames began to offer the Wilderness 9.75” fin in his catalog, touted as the “Greenough 4A,” but they were only available out of 3/8” thick panels. This thickness was used for cost reasons, which is to be expected, but the 9.75” Greenough 4A fin design DOES NOT WORK out of a thin panel. By any measure, THE STOCK TRUE AMES GREENOUGH 4A IS NOT A GOOD FIN...the stock Wilderness/Greenough 4A is a dog. If you want to try the performance of the “Wilderness/G4A” as it was intended, buy a stock True Ames version, sand the finish off of it, lay up 7 layers of 6 oz cloth on each side, refoil it into a flex fin, and you will have a ½” thick 9.75” Wilderness fin… and it will rip.

Ther ya have it

Man O' War · Post by **Man O' War** » Fri May 06, 2005 8:55 pm

MV -- Can you go into detail? What's a block of eps, and what do they go for? What do you mean by hotwire in the rocker? Why use epoxy resin, and what's the difference in cost? Sounds like you have experiences to share.

Does the eps block have a stringer? If not, that's going to rule out a lot of us who lack expertise and the proper tools. The comforting thing about using the Clark blank is that the shape is already so close to what you're doing.

Thanks for your input.

----------------

"Chum"? Very good, Dr. S...

Glad you found the Paul Gross take. Important for those thinking of using the IV-A. Also made me feel better about my particular fin (5/8 base) and all the sweat it wrung out of me.

DrStrange · Post by **DrStrange** » Sat May 07, 2005 6:22 am

re: pourable foam---bonds to itself well in multiple pours. Think this would work?

Instead of using the cut blank as a mold (thinking in terms of having NOT flat top of spoon due to laminating glass pyramid in place first) tape inner margin of rails with wide masking tape and pull up "outer" edge of tape to make shallow well. Pour small amount of foam using that to catch. Once set, use the foam and maybe more tape to do another band of foam. Work way up rails in that way ending pour much closer to end product as well as being able to do the process over uneven surface...

Man O' War · Post by **Man O' War** » Sat May 07, 2005 10:18 am

Dr -- In that case, think about Flexman's tried and true cardboard dam method. Build retaining walls by bending and taping cardboard squares into place. I believe the foam doesn't even stick to it, and the price is right.

MV -- That's OK, no need to explain. Here's why people say, "I want my MTB":

EPS = expanded poly-styrene (foam)
(Typically used for insulation in home construction)

Obtainable in rectangular sheets/blocks at Home Depot and similar stores. Substantially cheaper than Clark foam per cubic ft, but you probably will have to bond a couple of sheets together to get enough thickness.

This foam doesn't shape with tools (e.g. surform, sandpaper, etc.) as easily as does Clark urethane foam. The most common way to obtain the desired the rocker (i.e. lots of foam removal) is to make up a "hot wire". This is a stainless steel (or better, but more expensive, nichrome wire) stretched across the opening of a "U" shaped support (wire insulated from the support). The two ends of the wire are connected to a low voltage power supply and the current flowing through the wire heats it.

Typically a pair of rocker templates are fastened to each side of the "blank" and the hot wire is dragged over the pair of templates at a fairly slow speed. When it is in contact with the foam, it melts it, forming a slit (or "cut") that leaves one side of the cut with the rocker curvature; the other side with the inverse of the rocker. Too hot and the cut becomes ragged; too cool and the wire cuts slowly and with some resistance to motion. The latter tends to put an arc in the wire as the center struggles to keep up, resulting in a rocker that varies between the center of the cut and the edges. A pair of (half) outline templates can be used in a similar manner to precisely cut the outline (but most people saw the outline).

Epoxy resin is required because EPS is poly-styrene plastic. Styrene is the solvent in polyester resin and hence will also dissolve your EPS blank into a gooey mess. In the beginning, people tried applying a protective coating to the shaped EPS, then using polyester resin--but rarely with satisfactory results.

The EPS blank costs less, epoxy resin costs a lot more. I don't know how the combined costs of blank and resin compare.

The EPS sheets do not have a stringer, but tend to be more rigid than comparable urethane foam.

There is lots of information on comparisons of EPS/epoxy vs Urethane/polyester resin (PU/PE) construction, and how to use EPS/epoxy and build a hot-wire cutter on Swaylocks web site (and other hot-wire descriptions/construct/usage obtainable from a Google search).

Hope this helps some.

mtb

Marky V · Post by **Marky V** » Sat May 07, 2005 2:26 pm

Thanks mtb, that is a pretty concise explanation.
Epoxy resin may be more expensive, burt has so many advantages over polyester, with the boards that I have been building I use so much less resin that the cost is comparible. With a flex spoon in mind, the resin tends to be more flexible, but will not fatigue anywhere near as quickly as poly, also bonds much better to any material than poly. With the different hardeners available you also have much longer working times. In the US you guys should contact Greg Leuhr from Resin Research (I beleive he is in Florida), he has forgotten more about epoxy than anyone else will ever know! The great thing about polystyrene is that you can hotwire any shape you like into it once set up (minimal cost), the last block that I bought was 8'x4'x2', enough for 6 boards and cost £40.00, less than 1 603c blank!!
MOW if you are interested, there is loads of stuff on swaylocks about eps /epoxy.
I am totally into this spoon thread, and my next board will be a hopefully a super flexible concave deck eps /balsa skin board, almost certainly with a greenough inspired single fin.
You have done great work with your boards and with the information that you have so kindly shared with us, but with so many exciting and flexible new materials around us, and so much experience, I think it is time to take it to a new dimension.
Cheers
Mark

DrStrange · Post by **DrStrange** » Sat May 07, 2005 3:46 pm

Many comments about epoxy resin. Is improved flex and memory w/ regular fiberglass or only w/ carbon fiber? Why using less resin MarkyV? Does it saturate cloth with less volume of liquid or is the less resin when used on EPS foam and that foam soaks less resin?

If using the blank as a mold (covered w/ foil) and removing it could even use regular foam if need be since it never touches the resin...

Man O' War · Post by **Man O' War** » Sat May 07, 2005 4:28 pm

Mark -- Definitely take it to a new dimension, and take us along. When you're ready to build your board, start a thread. Give us the play-by-play, with pics, if possible. You're breaking new ground. "Point and go."