[quote="$1"] I'm hoping I won't need this information anytime soon, but since I'm worried about a couple of areas of delamination on the underside of one rail on a handshaped epoxy longboard, I will ask. Doc, are you suggesting introducing a little fresh water at the nose and pulling that water through the length of the board to flush out the salt? It's hard for me to imagine intentionally introducing water under the skin, but then again I've never even used a vac pump. Thanks. [/quote]
Hi Glenn,
Well, yes, I am suggesting that, though ideally not all down the length of the board. But, salt water will be intruding into the foam in a kind of concentric way from the spot where it made its way in in the first place. Drawing , say, the water in through the original leak will just clean out the path between the leak and wherever you're drawing the vaccum. So if you're not up for making more holes in the thing and you happen to have a vent in the nose, well, there ya go.
Now, old-style polyurethane foams were not terribly permeable. Pour water on it, it'd maybe go into a few of the open bubbles on the surface, but go no further in. But styrene foams vary a lot, some act like the old-style foam and some would make pretty good water filters. The earlier Patagonias were like that, for instance. Those latter are also the ones that take on a lot of water fast and gain considerable weight.
And if water flows through 'em fairly easily, so will air. You should be able to draw air through the length of the board with no ill effects.
And if you pull water through it, it should flush out the salt nicely. Probably do at least as good a job as, say, opening up said board around the spot the salt water came in and rinsing it, then reglassing and filling and all that fun and games. You might want to use distilled water for this,
And for those delams - you could use a vaccum pump to pull resin through the delams and pull them down some at the same time. .
hope that's of use
doc...