Another Foam Question!

[Jamepc]

I did a search and found some useful foam information, but I have a few more questions relative to an '85 17' Chris Craft Scorpion Bowrider:<br />The pump stopped working at one time and the boat filled with water to about half way up the stringers. I know the stringers got soaked but what happens to the foam?<br />Does the foam hold water? <br />Does it dry out or will it stay wet?<br />Is it true that usually only the back portion of the hull is foam packed? Or is it foamed all the way to the bow?<br />Thanks!<br />James

 

[JasonJ]

Re: Another Foam Question!

If it had water for a short time, there should have been minimal or even no water absorbtion. Its when it is exposed to considerable water constantly for long periods that you have to be concerned. It is hard to say how it is foamed, every boat is different.

 

[Link]

Re: Another Foam Question!

Hey James<br />----------------------------------------------<br />Does the foam hold water? <br />Does it dry out or will it stay wet?<br />----------------------------------------------<br /><br />Yes it can hold water but it has to exposed a long time with no way to dry out. As long as there is air circulation and is in a dry place it will dry.<br /><br />-----------------------------------------------<br />Is it true that usually only the back portion of the hull is foam packed? Or is it foamed all the way to the bow?<br />-----------------------------------------------<br />Boats 20ft and under are designed to float level if swamped. So how much foam and where it is depends on the design of the boat<br />There is a web site where you can look that up. I will look for it.<br />The worst part of foam soaking up water and not drying out is that with fiberglass, water can rot the glass over a long period of time.<br />Thier are a lot of people here that can better answer in detail your questions and I'm sure they will.<br /><br />Link

 

[CTD]

Re: Another Foam Question!

My 87 Chris Craft was foamed full length. Jason is right it takes a lot of time for the foam to absorb water. If you really want to know if it is wet use a hole saw and drill some holes, pick out the foam and check it. If ok put foam back and plywood plug you took out and glass it back in.

 

[18rabbit]

Re: Another Foam Question!

Just a quick update on my current foam project. Maybe it will be useful to your foam project too, jamespc.<br /><br />I posted a query here about foam a few weeks ago and received excellent replies. Thanks to everyone!!! Since then I have had an opportunity to speak to the project manage at the boatyard (that built/builds the boats) about replacing the foam in the keel. He mentioned foam that is used to take up space (like floatation foam) can and should be covered with a thin layer of fiberglass. This acts like a barrier to keep water out of the foam and you should never have to replace it again. That is the spec for my boat. It may not be the spec for yours but you might be able to lay a few glass sheets over your foam and seal it up. If you do, try to anticipate where and how the water will flow to get past the foam and into the bilge.

 

[walleyehed]

Re: Another Foam Question!

Epoxy resin only here, please.......polyester resin will dissolve your floatation in a very, very short period of time.........If you are using anything simular to polystyrene type foam.

 

[CCrew]

Re: Another Foam Question!

"polyester resin will dissolve your floatation"<br /><br />Not according to US Composites: " Once fully cured this foam can be laminated over with any type of polyester, epoxy or vinyl ester resin without melting"<br /><br />-Roger

 

[walleyehed]

Re: Another Foam Question!

If you are using anything simular to polystyrene type foam.<br /> You missed this part........Make sure the foam is 100% cured before attempting to glass over, or you will have nothing left but a shell.

 

[BillP]

Re: Another Foam Question!

PolyURETHANE foam is the type that will not melt with polyester resin.

 

[walleyehed]

Re: Another Foam Question!

BillP, thank you.....you said what I was trying to say.