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board 3, open for advices

Posted: Sat Jun 29, 2013 10:13 pm
by mattthieu
here is the third board, light wood bord !

it's 2 plys 1/8 baltic plus one little piece ( third ) on top for the inserts not to show thought the top ( inserts are .375 , to hight.).

it's more or less 142 x 46 little rocker little concave.

hollow insodes ( see board 4 ). glued with urethane under vac !

one 6 oz glas top and bottom, wraped rails ( pain in th.......), last time i do that on sharp rails even with vac.

carbon x colored glass tapes for the looks.

BUT something went terribly wrong as i switched from west system ( wich it expensive ) to miapoxy ( wich is not expensive ). i went for the slow hardener, and, it's been 2 fulls days ( 48 hours ) 25 celcuis average ( 30 days ) and the resin is still soft ( sticky ) on the edges ( center and most of the board is cool, the rails and adges are soft ) ?????????????????

triyed to sand this shit today, BIG BIG PAIN somewhere !!! got the most soft thing away.

comments ?

i'm desperate, going to sand all this and get a hot coat over it, ride it and let it be !!!!

top
20130625233 [800x600].jpg
bottom under vac
20130627233 [800x600].jpg

Re: board 3, open for advices

Posted: Sat Jun 29, 2013 10:14 pm
by mattthieu
i realized that all the areas that where under the peel ply are the places where the resin is still soft, could it be the peel ply caused that ?

Re: board 3, open for advices

Posted: Sun Jun 30, 2013 12:35 pm
by zfennell
perhaps bad epoxy
perhaps poorly mixed
perhaps cure time has been undersestimated


IMO
dont sand anything yet
leave it clamped to your rocker table

examine you mixing cup to see if that epoxy has cured
compare with epoxy in bag.

if the epoxy is/was well mixed and some has cured then it is most likely a function of time and temperature before the rest cures....

use heat gun, hair dryer, oven to see if elevated temperature will complete cure
try on a small sample from the bag.

-bill

Re: board 3, open for advices

Posted: Sun Jun 30, 2013 1:36 pm
by Johnny Rotten
95%of cure issues are due to poor mixing or poor measuring of epoxy.

If your ratio was close(ish) but off enough to keep it from final gel,try hitting it with High temps as zfennel suggested, it can often times correct small mistakes.

I usually have to do this when I mix up really small portions of epoxy to hot coat home made surf fins.
in those quantities (7mL) it's really easy to screw up the ratio. and my scale is useless at this resolution

I use those 500W halogen "work lamps" on the fins.

the heat distribution will be screwed up on a board but if it stays clamped to the table, you shouldn't warp it. and it will at least show you if the board will cure.

Re: board 3, open for advices

Posted: Sun Jun 30, 2013 1:51 pm
by mattthieu
thanks guys, will try the heat thing ( will do it with a little heater i use to heat my shead in winter ) or just let the board stay in my car for a sunny day ! héhé

it's not clamped, it's just baged layups, the shape comes from gluing the 2 payers of ply together !

Re: board 3, open for advices

Posted: Mon Jul 01, 2013 1:20 pm
by zfennell
mattthieu wrote:.......

it's not clamped, it's just baged layups, the shape comes from gluing the 2 payers of ply together !
matthieu.

i think johnney R and I were both assuming that you've been using a rocker table ( either bagged or clamped ) to control the board's rocker and/or concave.

if the epoxy has not fully cured it will allow the various layers of plywood to return to their original shape -flat.
or maybe twisted if only certain areas reached full cure.

so even if you've been using the bag to clamp the plys to some desired shape,
you should leave the board on the rocker table to hold that shape until you get the epoxy to reach full cure.

save all your mixing cups. they a good indicator of how the cure process is going.
full strength can be days after the intial cure period.

yes/no?

Re: board 3, open for advices

Posted: Mon Jul 01, 2013 1:51 pm
by mattthieu
got that !

just have to wait, i dont like waiting ! héhé !

thanks guys !

Re: board 3, open for advices

Posted: Mon Jul 01, 2013 6:32 pm
by Bille
mattthieu wrote:here is the third board, light wood bord !

it's 2 plys 1/8 baltic plus ...

...
WOW Dude -- your profile says : ( Kiting since: 2012 ) , and Your already
on your third board build !!

Sounds like You found what I would consider , a GREAT way to channel your
energy !!! Ya Think ??

Bille

Re: board 3, open for advices

Posted: Mon Jul 01, 2013 7:36 pm
by plummet
Unfortunately if it hasn't gone off by now it wont. You miss mixed your epoxy.

Unfortunately you need to wipe and grind it off.

measure your west system by weight with an electric scale. make sure you don't get it wrong.

don't lower yourself to cheaper resins your board will only be as strong as the cheap stuff.

Re: board 3, open for advices

Posted: Mon Jul 01, 2013 8:18 pm
by mattthieu
the thing is, west system ALWAYS get's cure clean and fast !

it's the new MIAPOXY that causses problemmes !

going to the call the store tomorow that's not possible to mix badly few times in a row !

someone know that brand ?