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Drying Wet Foam with Vacuum Pump

Posted: Wed Oct 31, 2018 1:36 pm
by Spc337
In the process of replacing my [OUTRAGE 22 boat's] fuel tank, I've install a drain tube from the fuel tank cavity to the rear live well or fish box.

When I pulled out the foam, it was damp. I can't say if the dampness is pervasive but since I have a few months before launching the boat again I'm thinking of drilling some holes near the transom to see what comes out.

When I replaced the brass drain tube in the rear fish box, the hull did drip then but I wrote that off as water that intruded due to the previously poorly installed tubes.

I'm thinking of rigging up a vacuum pump (like one for vacuum bag forms not a shopvac); has this been done? Is it worth trying?

Thanks

Re: Drying Wet Foam with Vacuum Pump

Posted: Wed Oct 31, 2018 2:01 pm
by jimh
In order to pull water out of wet foam with a vacuum pump, I think you will have to create some method to maintain a path for the water to flow outward. The method used in vacuum bagging may not be appropriate since it seems designed to NOT pull out liquid--the resin--from the form. My guess in answer to your question--will this work: the outcome likely depends on how you implement this technique. You could experiment with some already removed wet foam and develop the best method.

Re: Drying Wet Foam with Vacuum Pump

Posted: Wed Oct 31, 2018 5:23 pm
by dtmackey
I ran into this company years ago and wondered if their service worked as good as they claimed. Wet cores can are difficult dry dry out, but I believe some improvement can be made.

http://www.dryhull.com/

D-

Re: Drying Wet Foam with Vacuum Pump

Posted: Thu Nov 01, 2018 1:30 pm
by Spc337
dtmackey wrote:I ran into this company years ago and wondered if their service worked as good as they claimed. Wet cores can are difficult dry dry out, but I believe some improvement can be made.

http://www.dryhull.com/

D-


That's basically what I was thinking. Using a pump designed to run for long times without depending on the air flow for cooling (i.e. Shopvac). I would have thought it would have been better to locate any hull openings near the lowest point to leverage gravity in addition to the negative pressure.

I may give a local provider a call to see what it costs. I suspect it will be beyond reasonable for my 22' but who knows. I had also thought about using a dehumidifier under a tent to see what that could extract. Off course I'd never be sure if it was pulling from the ambient air vs the hull but probably a low less expensive than an boat yard so may be worth a try for a few days..