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Re: Pocket Board (HF) Layup Question

Posted: Wed Jul 03, 2019 1:00 pm
by thewindego
Oh ya they are gold. That plastic I think is medium thickness painting drop sheet polyethylne.

I was hoping to see some details on how the race board mast area was done for the boards from downunder. Also some specs on size and actual weight.

Re: Pocket Board (HF) Layup Question

Posted: Wed Jul 03, 2019 1:23 pm
by downunder
Sorry guys,

This are the trade secrets from my mate. I cant reveal that, it wouldn't be right.

Trust me, they broke a number of boards before settling on the design that works.

And the worst thing is to break it after so much DIY effort.

This is why would recommend the solid wood board for 100kg rider. Splash a few layers of carbon around mast area and done. Cheap, robust and light enough.

think of carbon as 5 layers 180g/m2 is just over 1mm thickness. Not much to hold inserts on top of xps in place when s.it hit the fan...

Re: Pocket Board (HF) Layup Question

Posted: Wed Jul 03, 2019 2:20 pm
by jespin4845
i broke my first board that i made with H80 and carbon vacuum bagging it was only 12mm thick, right in front of the plate

on my second board after some research and found out 12mm is way too thin, this one is 25mm

as you can tell it has several strips of uni and 2x2 under the deck, probably 5 in total starting around the plate area in both sides, 2 covering the whole deck

my question is would i benefit from adding a layer of glass on top? i was also thinking of wrapping the rails in UNI carbon tape

would i benefit from this at all? i have probably 3 yards of carbon in this 34" x15.5" board

another thing i learned is not to ride it for a week as its still curing, not 24 hours :o

Re: Pocket Board (HF) Layup Question

Posted: Mon Jul 08, 2019 9:43 am
by hcohen2018
yeah a week time to cure is a good idea.
12mm is so thin man, I'm going now for 30mm with paulownia in the plate mount, just a 16x20cm (not a complete piece) with holes for the inserts, something like Pierrot showed here http://kitefoil.forumactif.org/t7787-no ... 2x45#64699

Re: Pocket Board (HF) Layup Question

Posted: Mon Jul 08, 2019 1:28 pm
by downunder
jespin4845 wrote:
Wed Jul 03, 2019 2:20 pm
i broke my first board that i made with H80 and carbon vacuum bagging it was only 12mm thick, right in front of the plate

on my second board after some research and found out 12mm is way too thin, this one is 25mm

as you can tell it has several strips of uni and 2x2 under the deck, probably 5 in total starting around the plate area in both sides, 2 covering the whole deck

my question is would i benefit from adding a layer of glass on top? i was also thinking of wrapping the rails in UNI carbon tape

would i benefit from this at all? i have probably 3 yards of carbon in this 34" x15.5" board

another thing i learned is not to ride it for a week as its still curing, not 24 hours :o!

Layer of glass no, layer or carbon yes. But, it is half wasted coz the stress riser is where it broke. So that area is a must, the rest not so.

Re: Pocket Board (HF) Layup Question

Posted: Thu Jul 11, 2019 9:16 pm
by jespin4845
so far so good....day 2, havent stomped ollies yet, but have grabbed it mid air and landed back with the kite...hopefully it holds, we will see

so much twitchier compared to a 10 lb wake skate...

Re: Pocket Board (HF) Layup Question

Posted: Sat Jul 13, 2019 1:19 pm
by hcohen2018
Can you post some pictures pn the build process?
Enjoy, loooks good

Re: Pocket Board (HF) Layup Question

Posted: Sat Jul 13, 2019 4:33 pm
by jespin4845
first couple of things i learned along the way, a vacuum pump isn't really necessary, vacuum storage bags work just as well, perhaps doesn't suck the resin out as good, but it does a damn good job. With the traditional vacuum pump i was getting leaks through the connector cause i bought the cheaper one and pulling -30 with the pump running continuously and having to baby sit it for 8 hours just in case it started a fire....with the vacuum storage bag i was able to get it down to -20 with a hand pump, and no leak...and the bag is resealable!!

so first i took to sheets of divinycell 1/2" and glued them together to get the rocker...gorilla glue and quickly put them in the storage bag and pump out the air...gorilla glue doesn't stick to the plastic bag and you do lose some rocker from spring back...

then draw out outline...cut with jigsaw and form rails with sand paper, divinycell is like a really soft wood, doesn't really work like foam at all

then cut out holes for insert with a hole saw...fill with epoxy and cabosil/microballons and let it cure...

Re: Pocket Board (HF) Layup Question

Posted: Sat Jul 13, 2019 4:38 pm
by jespin4845
then your ready to put as much carbon/fiberglass on each side as necessary, and pump out each side....

i started out small patches, then larger, then larger...i can't really comment on placement of carbon as I'm still learning, i don't know if i overbuilt this or not...i did do X with uni with a strip down the middle, several patches of 2x2 and one arranged in 45 degrees....also fiberglass on top and rail tape all around...it came out to 5 lbs when I've been told it should have been 4...maybe cause i put too much, or didn't suck enough resin, i don't know

i will be able to tell you if it will hold up to me going full gorilla on it as I'm going to hood river next week for three weeks

Re: Pocket Board (HF) Layup Question

Posted: Sat Jul 13, 2019 4:42 pm
by jespin4845
finally after both sides are done and wrinkles are sanded down your ready for the "hot/finish/sandable coat" microballons/cabosil mix to a runny paste then paintbrush it on.... let it cure then sand down with 150, followed by 400grit...and you can continue... even polish or paint...by why add unnecessary weight...

i put the t nuts on with the paste paint, with wax in them, after it cured i tapped them

they are on top of the carbon just being held on by the epoxy,...easily can be pushed out by force, but its basically what moses does with their boards,...the thought of drilling a perfect hole to get an interior insert baffles me...