Rocker in blank.....

by **Skim124** » Mon Sep 17, 2007 5:59 pm

Can you give me some tips to putting rocker in a foam blank that I am making? It is roughly 1/2" thick and will be used for a skimboard. It is going to have fiberglass cloth on both top and bottom. Should I just put the rocker in after the cloth or is there a way of bending it before?

**Sponsor**

by **essex sucks** » Mon Sep 17, 2007 6:01 pm

u use a plan too cut the rocker in then sand it smooth and then glass it

by **Skim124** » Mon Sep 17, 2007 6:54 pm

I used just a flat piece of foam.....is there a way of putting rocker in this?

by **essex sucks** » Mon Sep 17, 2007 7:08 pm

post a pic mate lets have a look

by **Skim124** » Mon Sep 17, 2007 7:14 pm

No problem. I will have to do this when I get home.....I know I am asking a lot of questions but I really want to get this right....

Also I used "sheathing" foam to make the blank and it seems to have shaped up really nice! If that helps anyone...

by **kitesurfer** » Tue Sep 18, 2007 7:07 am

Skim124 wrote:I used just a flat piece of foam.....is there a way of putting rocker in this?

2 ways i can think of.

1. Make your own stringer with the rocker in it you want. Cut your foam in 2 down the middle and glue the foam to the stringer.

2. Laminate the foam whilst you've got bend in it.

I'd go for option 1 myself.

KS

by **Skim124** » Tue Sep 18, 2007 1:48 pm

Here is the pictures of the foam board that I am using. I really would like to glass this first one with no stringer just to make things more simple. But I am starting to like the stringer idea more....

And just a side note has anyone heard if Sheathing foam works good for this?

by **tomcat360** » Tue Sep 18, 2007 2:29 pm

Sheathing foam is generally XPS, which is extruded polystryene. What they've been using for surfboards is EPS, which is expanded polystryene. XPS delams easier, and is in general not as good.

I don't know with epoxy on XPS....but you used to be able to glass the top, and when it sets it contracts, and it flexes it and givies it rocker.

by **Skim124** » Tue Sep 18, 2007 4:00 pm

O really? That would work great but I wonder if there is a way of making sure it gets the right amount. Maybe I will have to go the stringer.

The reason I went with sheathing foam instead of the EPS foam is that honestly the EPS foam seemed more like styrofoam and appeared that it would be really bad to sand. Is this just how it looks or was I looking at the wrong thing?

by **tomcat360** » Tue Sep 18, 2007 6:38 pm

Yeah, EPS is pretty nasty, doesn't sand too well, and you have to seal it with either a micro bubbles/epoxy mix, or some people use dry wall spackle. It tears, doesnt sand fast, etc. But you can do cool stuff with it. However structurally its better. And yes it does look like styrofoam, because it is :lol:

You could also make the board out of two thinner sheets, then put some glass between, and press them together with some weight on it while it sets. This would put some rocker in there like you would with a skateboard.

I would just put some string or tape connecting the tail and tip together with some tension on it, giving it some flex in the foam, then glass the bottom. Watch out for a twist though.

by **Skim124** » Tue Sep 18, 2007 7:07 pm

That is a good idea.....

I guess I will get to try my hand at some EPS foam since this place I contacted for price quotes just sent me about 6 sheets of foam that covered my entire door. haha.... At least I have room to screw up.

by **tomcat360** » Tue Sep 18, 2007 11:55 pm

If you are thinking of future projects you can glue up multiple thick pieces of XPS or EPS and then "hotwire" them, where you cut two rocker templates, clamp them to the side, and then run a "hotwire" which is pretty much what it sounds, a really hot wire, and that cuts right through and rides on top of the templates.

Kitey have you been doing any EPS/epoxy recently?

by **greg@hoodatsurfco** » Tue Sep 18, 2007 11:58 pm

why not just order a foam blank that is thick and ready for rocker to be shaped?? Unless you just have this and are trying to find something to do with it.. if so go with kitey's suggestion..

by **kitesurfer** » Wed Sep 19, 2007 7:18 am

tomcat360 wrote:If you are thinking of future projects you can glue up multiple thick pieces of XPS or EPS and then "hotwire" them, where you cut two rocker templates, clamp them to the side, and then run a "hotwire" which is pretty much what it sounds, a really hot wire, and that cuts right through and rides on top of the templates.

Kitey have you been doing any EPS/epoxy recently?

No eps yet tom, but i have been having a bit of a play around with different epoxies. SP115 and just got some resin research which i intend to use on my next kiteboard (6ft directional wave riding board).
Ive also got waiting to be done a 12ft paddle board blank which isn't quite thick enough as is so i will be laminating onto the deck an inch of core cell and then using epoxy to lay up. It's gonna be a beast. Heres the blank as is, only 3 3/4" thick which is not quite enough.

Sorry for the slight thread hijack scim.

KS

by **Skim124** » Wed Sep 19, 2007 1:03 pm

No problem kitesurfer....

So I arrived home last night to my 30 sheets of sample EPS Foam that measures 6' x 4' x 5/8"......haha I guess I will be pumping out some boards over the next few weeks.

by **kitesurfer** » Wed Sep 19, 2007 1:04 pm

30 sheets! :shock:

HAHAHAHAHAHAHA

Nice.

KS

by **^*^BATMAN^*^** » Wed Sep 19, 2007 1:17 pm

well, atleast you should be able to make one good one. Lots of trial and error available with 30 sheets.

by **Skim124** » Wed Sep 19, 2007 1:45 pm

Yea I would say so....but heres the kicker...it was delivered to my townhouse and I have family coming to stay with me on Friday for my brothers wedding this weekend....haha And were about to get about 4 days of rain so I have no idea where to put it....o well...I guess it isnt to bad of a spot to be in.

by **tomcat360** » Wed Sep 19, 2007 2:34 pm

Put some blocks under it then put a tarp over it? Never enough room is there, haha.

Kitey, I used RR on my most recent, stuff is pretty cool. Reasonably easy to work with.

by **Skim124** » Wed Sep 19, 2007 2:49 pm

Where is the best place to buy Resin Research? I was looking at that for my boards and it seems like a quality brand to go with.

Rocker in blank.....

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