Mar 16

Composite sandwich rail material trimming

As we mentioned in yesterday’s post, we build the rails up using 1/4″ thick pieces of Divinycell H80. The 1/4″ thick pieces bend fairly easily around complex and rather tight curves, whereas a 3/4″ thick piece would not. The down side is that we have to glue up 6 pieces of material and there is a fitting process for each layer. We’ll talk about that and show you what we are doing.

First here is a picture from yesterday showing the 3 layers of 1/4″ thick material.

wakesurf board rails 002

You can see it’s a fairly tight bend around the tail.

As no doubt you are quite aware, as we build up each successive layer, the lenth around the outline will increase. As you can see in the picture above, the first layer is a smaller diameter around the tail than is the third or outer most layer. In effect the innner most layer is actually a shorter length than the outer most layer.

We don’t have a scientific way that we do this, instead we simply wrap the layers over the outline and then mark them at the nose for cutting. When we do the second and third layers, we lay down the succeeding layers first, then mark the last one for trimming. The following picture gives you an idea. It’s really hard to see, but there is a mark at the end of the core on the rail material.

wakesurf projects 006

This last picture gives you an idea of the extra length of each piece. This will then give us a nose area that doesn’t overlap, but comes real close to touching individually. We’ll still insert a nose block of a slightly higher density material to prevent a disaster when the board eventually gets away and slams into the boat! But the gap after glue up will be minimal.

wakesurf projects 007

There you have the next step in the build process, the trimming and fitting of the rail material prior to glue up.

Thanks so much for following along, we really appreciate it.


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