oc-1 layup

down here (Argentina) i am building the firsts oc-1, handglassed regular fiberglass, no vacummbag system yet, so the question is: to be on 40 pounds or less (18kg) hull and 6 pounds ama, what layup you recomend ???
your Kokua is highly apreciated!!!
aloha nui!

Submitted by marianolarghi on Mon, 11/12/2007 - 1:52pm

Mariano, i double checked my info for you as i said i would to be sure it's a good option for you.

As weight is not a huge issue here, you could first put down your gelcoat followed by a very light chopped strand fabric (to prevent weave bleed through the gelcoat, some of the strand fabrics can be peeled (split) in two) then either a 4 or 6oz weave, then your coremat (what ever brand is available there 2mm ?) and then a 6 oz weave inner. Coremat should saturate fine without vacuum pressure, just double check the difficult areas.

I would suggest you do a few test panels first to see what you're happy with, you can then weigh the samples and calculate the approx weight based on the surface area of the OC1. Obviously you will need to reinforce the seat and iako areas.

Let's know how you go.

Cheers Rambo

#1 Mon, 11/12/2007 - 2:29pm

mahalo Rambo, i knew i could count with you, any other feedbacks are more than welcome, as soon as i get them in da water i send you pics, i have plenty of the plug and molds, but i guess its better to see'em in action,


#2 Mon, 11/12/2007 - 2:46pm

Mariano, what plugs and molds do you have, designs? ... PM if you want to keep private.

Cheers Rambo

#3 Mon, 11/12/2007 - 2:56pm

i shaped the plug, is my own desing, according to what i liked of a viper exel i used to own back in late 90', then the hurricane and wave blade really blew my mind, so judging from what i see in pics now its something betwen a peagasus and a wai nui

if you want pics i send them 2 you.

#4 Mon, 11/12/2007 - 3:55pm

You certainly picked some cool canoes to get inspiration from.

Good luck, hope it works for you first time.

Cheers Rambo

#5 Mon, 11/12/2007 - 4:42pm

Very cool. Any chance of posting some pics? I for one would love to see what youre doing. Hows the outrigger scene in Argentina? Rambos pretty much spot on. Youve got plenty of weight to work with so you may want to add another layer of glass in the middle section of the hull and seat area. Also do some buildups around the iako tubes and rudder. They take quite a bit o' stress. You know about the internal stringer, right? Finally, dont cap the boat with polyester. Your bond is only as good as your adhesive, of which poly is poor. Use epoxy for that step.

#6 Mon, 11/12/2007 - 8:16pm

If epoxy cost is a problem in Argentina, vinyl-ester resin would be a cheaper and safer option and be stronger bond than polyester.

Cheers Rambo

#7 Mon, 11/12/2007 - 11:01pm

once again, mahalo for your Kokua Rambo,
Aloha Aqua, the scene down here its pretty much like a Keiki that just pow using dippers and making the first steps.
i lived in Haleiwa for 7 years and paddled for Manu o ke Kai canoe club, it changed my life for the better, in my dreams i always envisioned bringing outrigger to my country, Ronald Williams helped me to bring KAI O ' PUA (first oc-6 in argentina), wich is the mother of MANA OHANA, OHANA O KE KAI and this sunday we are celebrating the blessing ceremony of WAHINE ILIKEA and NALU PA'INA. with the first 2 canoes we founded Manu o ke kai Argentina, then Nicolas, one of the first paddlers to stick around made his move and founded Ohana o ke Kai Canoe club, this gave us 3 canoe races!!!! before was "match race" hahahha, and imagine our happiness cause this summer we will have 5 canoes in the line up!!!
paralel to this i started reaserching about oc-1 model, i wanted to shape my own design for many reasons, well 2 years went by, 3d autocad, Rhino, routers, shaping, re-shaping, glassing, sanding, sanding, did i mention sanding??polishing......molds.......and in less than i month we are gonna be able to paddle oc-1 aswell.
this is pretty much it, one stroke at a time.

Imua Manu!!
Imua Uncle Randy!!(my coach and inspiration)
Imua Solange!!(my ku'uipo and the reason this became reality)

#8 Tue, 11/13/2007 - 2:41am

ps: Aqua what is "internal stringer"

#9 Tue, 11/13/2007 - 2:44am

There is a vertical support structure inside the canoe. The foam stringer, typically Dow board, or some sort of XPS (extruded polystyrene) is cut to mimic the internal shape of the deck and hull. It fits between the foot wells and runs, at least, from iako tube to iako tube. ( imagine cutting a canoe precisely in half right down the center from top to bottom. The area inside the laminate is the exact shape to make the stringer....make sense??) It keeps the canoe from collapsing on itself. If you are going with polyester or vinylester, you will not be able to use these to bond the XPS or EPS. They will "melt" the stringer. Use epoxy, or use a sheet of urethane foam and glass each side with a layer of 6oz./poly/vinylester. It is, however, an integral part of the canoe. Good luck, post pics!!!!

#10 Tue, 11/13/2007 - 7:13am

The other benefit of a stringer (and this is compulsory in Australian made/imported canoes) if the canoe breaks up at sea, the damaged hull will support the paddler as a safety platform. 0.02cubic metres of foam (approx 2000mm x 50mm x 200mm ) and the 0.01cubic metre natural buoyancy of the hull materials will support a 100kg person, even full of water. This is a good safety feature, as well as extra stiffness for the canoe at very little added weight.

An easy way to attach the stringer to the hull and deck when joining the two halves after the seam adhesive has been applied, is to cut the foam stringer height slightly smaller than required and apply expandable liquid foam to the top edge, then clamp the two mold halves together. The foam will expand and take up the gap and bond to the underside of the deck and stick to almost anything. Obviously you adhere the stringer bottom edge to the hull first, usually with the seam adhesive.

For light weight Ama's you could use 4oz fabric or even smaller, try a prototype first.

Cheers Rambo

#11 Tue, 11/13/2007 - 10:52am

Hey Rambo, Good stuff. I also dig your video work. Very inspiring. Im gonna work on some vid cams mounted to the OC6 this next season. Do you build boats? Ive found that the expanding urethane is adequate for adhering to the deck but I like to attach the foam stringer to the hull with laminates. Reason being is the urethane will expand and shrink causing void impressions in the hull. The deck has enough radius and build ups for seat deck and iakos in the laminate to eliminate this. although it may not matter for a heavy hand lam. Also by laminating into place you "seal" the bottom of the stringer where, if there is any, water may collect but not saturate the foam. Just some thoughts.

#12 Tue, 11/13/2007 - 2:44pm

Aqua, i did suggest seam adhesive (usually thickened resin ) for the bottom of the stringer in my post above for those very reasons you stated. Thanks for the Kudos on the Vids, i enjoy making them immensely and in fact now that our OC6 season has started, will also be doing OC6 vids as well. I am not a "boat builder", but i have built Oc1's before. This one below 12 years ago was all 2mm marine plywood and glassed on the inside only. It was constructed in the "cut pattern sew together and fold" construction method. And then of course there's the infamous Hurricane rebuild that most of the forum have already seen. http://rambos-locker.blogspot.com/2007/04/repairing-hurricane.html

Check out the cool foot pedals in the 2nd photo ...hahaa ... it was eventually sold too a guy who stripped the deck and used it as an AMA for a cabin cruiser contraption pictured below.

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#13 Tue, 11/13/2007 - 4:00pm

i dont know if i am spelling it right but DIVINICEL is the type of foam i once saw as used to this internal stringer, is compatible with polyester, super light and stiff. is light green colour, you know this one?
tonight i will post a few pics of the hull and ama so you can check'em out.
about the weight of the hull, 18kg, is it posible to make {em lighter?? acording to all the reinforsements, layups, seams, etc, etc, i couldn´t calculate a lighter number.
i know that with "state of the art", epoxy,keblar,carbon, vacummbag you can end up with 14kg or evenless. how ever here is so expensive only a few could afford, and plus even if reg fiberglass is heavier, they may handle better through the years of abuse...........right???(iam planing to have a few at the canoe site for the gange to start with)
the seam is another vital issue, my idea is a 2cm lap all around both, bottom and deck, there is a glue from SICA "291", you apply with a cocking gun, then clamp'em, welded for ever.
any feedbacks on this one?

mahalo for being there!

#14 Wed, 11/14/2007 - 1:50am

the ama..........

#15 Wed, 11/14/2007 - 4:09am

cockpit to nose.........

#16 Wed, 11/14/2007 - 4:16am

front iako to okole.......

#17 Wed, 11/14/2007 - 4:25am

her name is KA NALU NUI.

#18 Wed, 11/14/2007 - 4:30am

marianolarghi your canoe is beautiful. Good job. As for the PVC foam (divinicel) you speak of, what thickness will you use? It is very expensive stuff as Im sure you know, You will need a stringer 1" thick. Im guessing you are using somethin much thinner so put a layer of 4 or 6 oz glass on both sides. You can use polyester. Most builders use whats called a shoe box seam to join deck to hull. Ill explain how. Forgive me if you already know. After you have laid up hull and deck molds, remove the deck mold, leaving the plug in the hull. Wax the flange on the hull mold and 4-6 inches up the deck of the plug all around the canoe. Do a lay up like the deck mold, covering the hull flange and 3 inches up the boat. This is your flange mold. This can be a little thinner than the mold thickness. After its cured, remove it and pull the plug from the hull mold. Trim the ragged edge from the deck mold to 1 1/2-2" above the seam line. Sand the inside surface....the surface that was against the plug, not the surface that meets with the hull mold.....place it back on the hull mold and add strips of glass to it all around its circumferance till you have added 1/8th thickness. You may want to go 3/16th on the ends. When this cures, gel coat, sand and polish. Now when you do your hull laminate it will be inset 1/8th inch at the seam and extend upward 11/2-2" into the deck mold. Besure you sand both surfaces of the shoebox seam before capping deck to hull. Good luck.

#19 Wed, 11/14/2007 - 3:47pm

right on Aqua, iam glad you liked, and even more that you are sharing your knowhow, as i said before, its get isolated down here and to have this type of Kokua really makes a big difference, mahalo nui.
ps: how is your neck problem? you ever contacted DABOSS?

#20 Wed, 11/14/2007 - 4:25pm

my apologies for being such a bad drawer.......is this what you talking about???

#21 Thu, 11/15/2007 - 8:19am

Mariano, Looks like you have it under control. The masking tape you have on the plug in the last photo looks to be in the perfect position for the split. The stern deck may be fiddly to remove, it's hard to see with the dark photo at the stern.

Cheers Rambo

#22 Thu, 11/15/2007 - 12:12pm

Thats pretty much it. Ill try to post better drawings with laminate explanations. It looks like you understand the concept for the most part. Have you started the molds yet?

#23 Thu, 11/15/2007 - 12:47pm

molds are pow allready, if god keep blessing her, this weekend i will be working on the seam set up, hopefully i get one ready under the christmass tree........the 25th of december early morning run!!!!
mahalo for your kokua gange!!

#24 Thu, 11/15/2007 - 2:11pm

Merry Christmas

#25 Thu, 11/15/2007 - 4:51pm

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