Sunday, February 26, 2012

So on my last post I said that I would give details on what went wrong on the last top mast. This is the end of it. Not sure what caused this. Keep in mind that there were plenty of times that it was wet and still in that aluminum tube on hot sunny days and it took two years for this stress to show. Clearly the wood is separating form all epoxy joints.
I did try to shave it down and glass it to try to save it. That did not help it was a nice end of season temporary fix but not a long term one.
My second epoxy failure was on the rudder box. My fix for this is to double up on ply wood rather than the popular strips shown here. I had enough left over plywood material from the original build to make a second box again. I care fully made two more skins then got some high quality 4mm ply at the local Low's then care glued them over size then cut the final shape after glue set. More pics of that are on the way. My second attempt at a strong box is on its way I will continue to keep the updates coming.
Here is my final fix for the top mast. Yes that is just PVC 2" as i said on the last post just shaved the .040 thousands off with a chisel shown below.
Here is the end view. Make note that I made the PVC a 1/16" longer that the wood material. For the reason and purpose of enough room to finish off the end grain with a good coat of thickened epoxy then a second coat of regular epoxy. My home made epoxy is simple mix a regular batch of epoxy then use left over sanding dust from sanding all that cedar and use that to thicken it up right in. Then let it dry fully cured out. Second coat is just regular epoxy.
Here is how I shave .040 off the outside diameter of the PVC. If you think that .040 is a lot it is not. I carefully shaved .020 each side and was careful to keep it's circumference accurate. PVC is a easy material to work with it does require a little patience, tlc and stinks when you shave it like this.

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