Why don't builders use foam that doesn't absorb?

I've often wondered why there is a constant threat of floatation becoming waterlogged. Are there no products available that are "closed cell" and could repell water indefinitely?<br /><br />Just curious about this, and thought someone might know the answer.<br /><br />Thanks,<br /><br />Jinx

Re: Why don't builders use foam that doesn't absorb?

Many builders use closed cell foam, Jinx. It does not absorb water.<br /><br />Boston Whaler is one example.<br /><br />Most foaming kits (2 chemicals) make closed cell polyurethane foam.

Re: Why don't builders use foam that doesn't absorb?

Same reason they don't use all stainless fasteners and hinges and coat all wood with resin and seal all thru-hull fittings etc.etc.. $$.

Re: Why don't builders use foam that doesn't absorb?

And even Whalers can take on water over time given a chance. Water's a funny thing, as it ALWAYS wants to get where it isn't. Through osmosis, wicking, seapage, etc. it'll eventually find it's way through just about anything. Some materials hold off the ineveitable longer than others, but it seems to get through one way or another. Taking care of what you have is the best way to hold it off. If you drill a hole in the floor to mount a ski-tow or battery box, make sure you seal it up. If the gel-coat is cracked, seal it up. If you ding the hull getting it on the trailer, patch it. Invest in a good, automatic bilge pump and mount it where it'll get the most water out. Store the boat bow up with the drain plug out so anything in the hull will drain out. Give a peak under the floorboards now and then to make sure nothing is blocking any drainage holes or channels. A lot of that may seem like common sense, but common sense isn't always all that common. Give water an inch and it'll take a nautical mile...<br />- Scott

Re: Why don't builders use foam that doesn't absorb?

very well said ,CHINE..<br /><br />want to point out.. there's a false sense of security about sealing up around that 'battery box' screw mountin' holes.. <br /><br />especially with regular chalk an/or silicone..<br /><br />it really don't seal well for the most part..an sure don't seal well after year after year.. it'll come loose / debond, ware-off ,or get breached.. <br /><br />you really want to seal it very good an THEN seal it more ,very good.. <br /><br />the only sealmaker i trust is epoxy or 3-M 5200...

Re: Why don't builders use foam that doesn't absorb?

I agree with chinewalker...all boat foam will get saturated if submerged long enough. Open cell foam just does it faster and closed cell slower. Both are near impossible to wick dry while still in the boat. <br /><br />Boat mfgs use blown or poured in foam. The most water resistant closed cell is done under pressure...such as foam coolers (which can still get waterlogged if water sits in them long).