So did you let that wakesurfers theory digested some? I think we rile some people and that’s good if it’s motivational, for others they just like being mad, probably not enough to do. Anyway, we aren’t going to talk about that today, today’s post takes us back to our wakesurfers rocker bed. You’ll remember that we glued the convex to the rocker bed and then also sealed that top surface of the rocker bed to give us a little extra compression resistance and a uniform surface to laminate to. Now in the next step, we laminate a layer of plain old 4 oz eglass. This will give us a few benefits. One is that it reinforces the surface of the rocker bed so that when we use it under vacuum there is less tendency to imprint the wakesurf board INTO the underlying foam. When we are assembling our composite sandwich wakesurf boards, there is extreme pressure on every part of the wakesurfs during the cure cycle. That can sometimes cause the project to dent the surface of the rocker bed, just like a heel dent.
Even with lamination we’ll still get some denting, but this way we can minimize it. After about 30 or so cycles, the rocker bed will have lost it’s usefullness unless we fix the indentations, otherwise it creates a concave on the board that is deeper than specification. There really isn’t anything special about this process, we lay out a section of eglass that is slightly wider than the surface of the rocker bed and trim the length. Next we cut the corners to allow the fabric to lay flat. Once that is done it’s time to start laminating! In this picture, we’ve already laminated the surface of the rocker bed, but still need to wet out the sides and you can see the fabric sort of proud.
You can vaguely make out the changes to the bottom structure, but it’s really hard to distinguish on that picture. One thing that we should point out and this is just something we’ve learned from the school of hard knocks. When we laminate the free standing billets of foam like that, actually even just the sealing process, it cause the underlying foam to curl upward in the direction of the rocker cut. We try not to embed anything in the bottom to prevent the curling, instead, sort of match the rocker and the project boards so the natural curl is allowed to happen.
OK OK OK we had to do this, because it reminds us of some folks, hopefully they’ll get those conditions checked into! Actually this is just a small bucket of epoxy already mixed up. We are using a cold temperature cure epoxy itended for industrial purposes and it’s relatively cheap. It’s more than adequate for our purposes here. Now we use epoxy for this, because of the underlying EPS foam of the rocker bed. Other resins, such as polyester contain styrene that would melt the EPS. NOT what we want!
The last part of the lamination process is to sort of lap the edges down to the vertical sides. It’s a little hard to get the epoxy to flow adequately enough over the edges to squeegee them down, so we always reserve a little of the resin and then pour that along the sides and squeegee the fabric down. If you look closely, you can see the 2 inch or so overlap on the sides.
After that was done, we tucked it into the shop to cure overnight, hopefully it will cure nicely by tomorrow evening and we can start working on wakesurfers soon!