Shinny top & dirty plexiglass on rocker table

[Danydan]

Slowly getting ready to add some more layers of fiberglass cloth to my first above mentioned first board... Based on feedback from foamnfiber, I will add a layer each side and use vinyl on top in order to get a better finish on top (glassy looking). Given that minimal amount of resin will be use, would it be all right to add the two layers in one step or should I do two different vacuum bagging process, one for the bottom and another for the top once the bottom as cured? Any ideas welcomed. Thanks.

Dany

[foam-n-fibre]

Are you planning to do the extra layer on the bottom using the rocker table again? I'm not sure, but suspect you might risk trapping air between the table and the already glassed bottom of the board, since there is no way for air to escape - you just have to hope it gets pulled out to the side.

Maybe someone has tried this and knows if it might work?

You could try using vinyl on both sides, fold it in half and seal it to make tape, then you can squeegee both sides (with vacuum also), and maybe once that is taken care of and smooth you could sit it on your table with some weights to make sure it does not lose any shape when curing - although I suspect it will hold its shape fine.

Peter

[Danydan]

Never thought of vinyl on both side!!! Sounds like a good idea and also a fairly rapid process which is good... The only thing is that how does the excess epoxy leave the board? Are you just using a minimal amout of epoxy and the very little excess epoxy gets trap by the vinyl outside the edge of the board? I thought of using breather around the edge to make sure that excess epoxy does not stay too close to the board (on the edge for example but at the same time I guess it would be fairly easy to remove by sanding). I will definitely try vinyl both side given that I just nees to add a layer of fiberglass each side but I am wondering if breather around the edge would be beneficial for the excess epoxy?

[tkettlepoint]

just pitching in here alittle .. get a sheet of MYLAR wax the it with a good floor wax ( the same way you do the plexi glass rocker table) once you are all done your lay up put that on top before you do you vacuum , no peelply no breather ( unless you want to do pull alittle around the edges like you said, I would put it ontop of the mylar at the edges to catch some of the resin). do you pull for the 24hrs and then peel the mylar off. will be perfect very close to foam-and-fibers way... Mylar can be reused ...

I little secret. after you wax the mylar you can paint it with kylon paint and it will stay on the epoxy for your finish as well... ( just make sure you wax the snot out of it before you paint it)

Terrie
www.jellyfishboards.com
"Chasing my dreams one letter at a time"

[foam-n-fibre]

Hi Terrie, that sounds like another possible option. Does the mylar conform to 3D curves without being under a lot of load? It's one thing to force plexiglass into a 3D curve on a rocker table, but another to try to get something not held in place tightly to take that shape. Also, are you referring to thin stuff like monofilm used for windsurfer sails, or much thicker and stiffer mylar?

Dany, if you did go with the vinyl on the outside, you'd have to use a squeegee to pull the resin out to the edges. Any scraps of fabric, some rope or perforated tubing would allow air and resin to be pulled away from the board. You will not find resin migrating back onto the board though, even without that.

Peter

[tkettlepoint]

peter this is the stuff I am talking about... I make stencil out of it for air brushing. http://www.amazon.com/Mylar-Stencil-Mat ... 0R32D2Y406

med or Heavy duty it will do some of the 3d curves depending on how sharp they are.. never tried the light stuff but It might pull into grab line on surfboard for the contours. All the RC guys use it to build their wings with vacuum... that is where I need it first.

6:45 in the vid is where he starts with the mylar.

terrie
www.jellyfishboards.com
"chasing my dreams one letter at a time"

[downunder]

Peter, everything is clear in your videos is just that for a newbie that never played with époxy and vacuum bagging before, it's a lot of info in a short period of time...

As promised, find attached pictures of my first board for which is based on my Cabrinha custom 135 (2010 if I am not mistaken but time goes by too fast for me to remember exactly which year exaclty is the model I have )...

If you look carefully, you will notice, on the bottom of it, that the fiberglass cloth is visible and I was wondering if it was because too little epoxy was used or because the plexiglass was not 100% smooth (the previous owner did at least a board with it and there was some residue that I didn't removed prior to vacuum bagging mine...). Any words of wisdom on this?!?

Also, there is some corecell that is visible on the bottom left along the rail but that's another story (as I cut my fiberglass cloth too close of the board and the corecell probably moved during the process and/or when I started to vacuum bag the board...)

Finally, the board is way too flex (like foam-n-fibre warned me...) and it is also surprisingly light (don't have a balance to weight it accurately but it is very light, way more than my Cabrinha Custom... I used T600 10.5 mm corecell, only tapered the tips to approx 6 mm and put 3 layers of e-glass on each side but it is quite flex in the middle of the board. What is the best way to get one more stiff??? Should I use Kevlar and/or more fiberglass cloth, a wood core, or anything else... Keep in mind, if you have any suggestion, that I am on a budget given the fact that I have access to fiberglass cloth and kevlar for free so number of layer doesn't matter even though total weight does matter... I honestly don't know what to do here...

P.S. I will let you know once I tried it on water but compared to my other Cabrinha boards (Custom, Rival and Caliber) I bought, it seems way too flex for kiteboading...

Dany

Ok,

I think the reason why is so flexy or wobbly board is this: You do not have an "I" beam:)

And to build it, watch this:

BROKITE 2012 part 2....how to build a kiteboard
BROKITE Building a Carbon Fiber Kiteboard, Part 3

There is no way you can fix this now, unfortunately. Myself doing boards with a proper perforated vac film/peel ply/breather. Yes, expensive, and trying to find an alternative too.


D.