Aloha nui, i been building Oc-1 here in Argentina fo the past 2 years, using Poliester resin, stone age hand layups with a final weith of 35pounders.....and some times a bit more, the deal is, even though Epoxy-carbon fibers and foam core technilogies are very, very expensive here, i feel like making a prototype.
what you recomend? i was thinking building myself one with Epoxy resin and regular fiberglass layup for this first time, no carbon fibers, cause of its cost.
any help would be more than welcome since its gonna help improve a bit more our canoes, and finally our FUN in the waters.
mahalo in advance,
Aloha from Argentina.
Mariano.
Submitted by marianolarghi on Wed, 04/14/2010 - 2:24am
Aloha Mariano,
You can contact Vicente Dors, in Porto Alegre, Brazil (It´s not near but not so far anyway)
He is a rowing boat buider but he made a very nice OC-1 for me
He also teaches how to work with vacum bag
Here his web site http://www.vicentedors.com/
See ya,
#1 Wed, 04/14/2010 - 5:19am
Mariano,
Are you building with molds ?
Can you get any kind of foam or balsa for core material ???
What weight fiberglass are you using ??
35 pounds fully rigged ?
Without changing anything but your construction techniques and layup schedule your solid glass / polyester boats should be less than 30 pounds.
aloha,
pog
#2 Wed, 04/14/2010 - 9:17am
I remember the old days, when us guys would furnish the resin to make sure it was fresh and not the old stuff when time came to make our skis. It may not be economical, but there is big difference in the finished product.
#3 Wed, 04/14/2010 - 10:15am
Epoxys much better now but even sitting inside, the moisture can start to effect them if they sit around unused.
Hardeners worse IMO.
aloha,
pog
#4 Wed, 04/14/2010 - 12:05pm
yep i use mold, i been using gelcoat, then one super thing layer that here is called "velo de superficie", then a 4oz, then a 2mm coremat and last a 6oz. with the reinforcements on seats, iakos inserts and footwells, plus the stringer from iako to iako, only the hull is around 35 to 40 pounder....very very good training boats.....i do this in polyester resin with HAND LAYUP......of course comparing to what you guyz are doing or using, this is STONE AGE....but consider there was no market here for STATE OF THE ART, since is very, i mean very much expensive.
now 2 years went by, and i have a few dollars extra to spend on my own canoe, i fugure, eh, why dont venture myself into Epoxy and some other technilogies.......thats why i been asking for you Kokua...any suggestions on layups will be more than welcome, dont forget im not into vacumm bag still yet...
well thats it for now, mahalo for your time and generosity, i guess all the canoe builders might be cranking boats left and right for molo solo, but maybe a few minutes could make a big difference in our boats here, specially weight wise....and at the end of the day.....FUN WISE!!
ALOHA FROM ARGENTINA GANGE!
#5 Wed, 04/14/2010 - 2:40pm
O.K. cool ....
Are you spraying in the gelcoat ???
Don't worry too much about the Carbon for now ...
I would skip that "velo de superficie" ply entirely AND most importantly ...
Get some 1mm coremat ... The 2mm is killing you.
aloha,
pog
#6 Wed, 04/14/2010 - 2:47pm
It's time to invest in a vacuum pump. Ebay to the help.
There is also a company that refurbishes pumps - price for a $ 2500 pump is about $ 1200, including shipping you may get it for $ 1500 ?
I received it with USPS, they do services up to 70 pounds - it was surprisingly cheap.
I agree with Onno - having limited experience myself - I hand-laid-up my first boat, weight 25 lbs without ama.
I am just about to finish another attempt, this time with carbon/glass and coremat, vacuum bagged; much better.
Because it is a prototype I did not focus on light weight, but I will end up between 23 and 25 lbs and could have saved about 2.5 lbs.
Too much weight means too much resin obviously and that means less quality of the layup - of course, you all know that.
#7 Wed, 04/14/2010 - 2:52pm
Mahalo Onno Paddle,i been told to use that "velo de superficie" to hide the weve from showing, then yes i spray da gelcoat and i was using 2mm cause no mo 1mm on this side, but today i found one company that brings something called ESPHERE-CORE and is 1mm, they told me this core when weted is way lighter and stronger than coremat....what uyou think?
mahalo for the help, and let you guys know how much lighter i went....
#8 Wed, 04/14/2010 - 3:18pm
If you're considering a vacuum pump, and don't plan on using it for production any old pump will do. Shouldn't run you more than $500 from an air conditioning supply store. Search for JB vacuum.
#9 Wed, 04/14/2010 - 8:59pm
Mahalo nui Keizo, the question is, the vacumm baggin is only posible while using Epoxy, or i could use it while using Polyester to?
have you heard of something called ESPHERE-CORE? cause i cannot get 1mm coremat, and the 2mm available here is making my boats to heavy for sure. so this ESPHERE-CORE is 1mm and i been told by the sales person is lighetr and stronger than coremat....
mahalo once again for all your Kokua
cangratulations on your boats, the look Cherry and Fast!!!
and good race if you are crossing!!
Aloha from Argentina,
Mariano.
#10 Thu, 04/15/2010 - 1:55am
Many variations ... Which one are you considering ?
http://www.spheretex.com/
aloha,
pog
#11 Thu, 04/15/2010 - 2:10am
honestly, i just heard of it yesterday, by the sales person of this company that imports this kine technilogies.
i will call him up, right now, and let you know.
mahalo for being there!
#12 Thu, 04/15/2010 - 2:55am
right there Onno, THE ONE IS CALLED "spherecore sp" 1mm
the guy is talking miracles about it compare to coremat, always working twith polyester sitl yet!
what you think
should i go for it on this one
and next....i invest on a Pump, and jump into the next REALM??
mahalo once again for your time!
#13 Thu, 04/15/2010 - 3:10am
Mariano, I think that the gel-time with polyester is kind of short for vacuum lay up.
I use a mix of a slow hardener and a regular hardener to extend the working time for epoxy resin to about 40 min.
With that mix you (I) need three people to lay up a boat with four layers. We did it with two people, got nervous half way and used too much resin for the final layer.
The resin pooled and pulled the sides of the part together while heating up and curing. It was correctable, but still.
Coremat is probably not the 'best' material, compared to divinicell etc., but is is very workable in a smaller setting.
We wet out the core mat, hang it on a line, do the fist layer(s) - after pre-wetting on the bench -, then take the coremat and apply it, then add the final inner layer dry, wet it out and apply the vacuum.
To distribute the vacuum evenly we have a central pvc pipe with holes cut into it every 1 1/2 foot. The holes are covered with breather material and peel ply. This way you get sufficient vacuum at bow and stern, too.
Vacuum is much more satisfying - that alone is worth the cost in my opinion - ; the same is true for epoxy and even for carbon - even though carbon is more difficult to apply. I am not sure a full carbon layup is necessary or even the best - it certainly is the stiffest. Kevlar is most break and puncture resistant, but quite difficult to repair, and, also more difficult to wet out, I heard.
Regarding layup/stiffness do a google book search: under kayak stiffness and carbon layup you can find an article that compares different layup schedules for a K1 - I posted the article here about two weeks ago.
The essence: carbon is stiffest, but with a carbon flange around the seam line you do very well, too. Stringers did not get good results, surprisingly. They are more for flotation, I guess.
"For every year lived, a man has to build a foot length of boat" ( some old English quote )
#14 Fri, 04/16/2010 - 7:47am
I would say the guy is pulling your leg ...
One might say to him ... same shit, different bag.
....... at least its 1mm ....
Different coremats in DO have slightly varied characteristics such as higher compression, better drapability or slightly stiffer parts yeilded but then these also end up being a little heavier even with the same process.
Eckhart ... to bust your balls ... I can do ( layup ) a coremat boat by myself in a day.
aloha,
pog
#15 Fri, 04/16/2010 - 12:38am
exactly what i thought onno, but its true that is 1mm, and he said its properties are a bit closer to what i need weight wise, since this core "sucks"less resin than 2mm coremat.
im allready laminating a test panel
but on the meantime, getting usec to da idea i need to invest on a pump, and some lessons to handle epoxy an hi-tech materials, even though they are expensive, i might be able to get a decent boat for a decent cost.
mahalo nui eckhart, alevorin and onno to help with very usefull feedbacks.
#16 Fri, 04/16/2010 - 1:42am
Onno, that sounds pretty stressful;
how do you organize mixing your resin while laying up ?
#17 Fri, 04/16/2010 - 7:47am
Slow hardener and have everthing layed out, physically and mentally.
Mariano, you are using the grooved rollers ? If not, order some a couple of these and play around with them.
aloha,
pog
#18 Fri, 04/16/2010 - 9:24am
yep, i get those rollers......
got to work'em so the bugga no leave exesssss.
i cannot wait to see if i can reduce 15% to 20% off da weight by changing from 2mm coremat to 1mm spherecore sp..........16kg canoes are a big difference to 20kg canoes.........will see
next........vacumm-bag, foam core, doble carbon with epoxy!!!!
mahalo for your Kokua Onno!
#19 Fri, 04/16/2010 - 10:24am
what kind of gelcoat do you guys use? i heard polyester gelcoat is not working good with epoxy lay-ups and i saw many canoes, where the gel was peeling off. or is there any trick to make it work?
#20 Sun, 05/09/2010 - 1:30am
#21 Tue, 05/18/2010 - 1:06am
why did that text go so long to the right ?????
#22 Tue, 05/18/2010 - 1:07am
wow Latman, i could only imagine how many Labor that sanding, filling, sanding, primer, sanding topcoat would imply, meaning the cost, but once again, China labor should be viable...
mahalos for sharing though, is pretty reveling all the input you guys shared with me, im in the Stone age here building regular fiberglass-handlayup canoes, but eventually i will adventure myself into newer technics for sure.
aloha for now!!
#23 Tue, 05/18/2010 - 1:44am
If you do want to stick to polyester i would spray a thin gelcoat (thinner than materials spec) one layer of woven carbon160-200 gm/m2 ,then a layer of 1mm core (tigercore,coremat,spherecore etc) and another layer of woven carbon (if you buy the carbon wide enough you will be able to get both hull layers from 1 length of fabric) you could use carbon/kevlar mixed fabric instead or try glass fabric 1st to perfect your technique (its see through when wet), glass comes in E (regular) or S/R (stiffer) but remember pure kevlar is not as stiff as regular E glass and its a pain to cut with scissors or repair later (kevlar should be next to the Gelcoat)(kevlar also works better with Vinylester resin but best with Epoxy resin)
as for the weight of things CSM(chopped strand mat) uses way more resin than woven cloth fabrics but the finished laminate will be thicker and stiffer.
#24 Tue, 05/18/2010 - 4:40am
latman, do you thin gelcoat to spray it? i had problems to spray it, because its so thick. it took me about 2kg for a canoe. i think that is to much!
#25 Tue, 05/18/2010 - 5:19am
How long is your canoe ? 2kg Gelcoat may be right if it is long or there is a complex footwell ,or try for a bit less.(the painting is lighter but the labour expensive,and 2 pack is more toxic) The Company you buy Gelcoat from is already thinning it with Styrene liquid , we thin it a bit more (no more than 10% maybe) with acetone (as the acetone evaporates as you spray) but this is never recommended by the company. If it is too thin it will tripe (alligatoring there) but we lay up by infusion and it seems the vacuum pushing the fabric against the Mould/Gelcoat stops this a bit. some colours like white and light blue and light grey need leess Gelcoat for opaque coverage.
#26 Tue, 05/18/2010 - 5:53am
also our gelcoat guns use a 3.5 mm tip and need replacement every year
#27 Tue, 05/18/2010 - 5:56am
Ahha! So that's why, in the past, many Aussie skis were light sky blue in color? Less gelcoat, less weight?
#28 Tue, 05/18/2010 - 6:38am
#29 Tue, 05/18/2010 - 4:51pm