TAKING OUT FOAM IN STINGER

[msteelman]

i have a 1981 aquasport 222. thinking about cutting tops off stingers taking out foam and glassing back over the tops. then getting 1/2 inch coosa board and glassing it too both sides and tops of stingers. What do yall think?

[222 newbie]

If the stringers are still bonded to hull, fine. Otherwise I would cut them out and replace them.

[RickK]

i have a 1981 aquasport 222. thinking about cutting tops off stingers taking out foam and glassing back over the tops. then getting 1/2 inch coosa board and glassing it too both sides and tops of stingers. What do yall think?

That's a good plan if the stringers are stuck good to the hull (as 222 said).  Here is a little reading for you for other ways to get it out
https://www.google.com/search?client=firefox-b-1&ei=PjO0WrbyL8LtzgKR976YCw&q=removing+foam+from+stringers+%2Bsite%3Aclassicaquasport.com%2Fsmf&oq=removing+foam+from+stringers+%2Bsite%3Aclassicaquasport.com%2Fsmf&gs_l=psy-ab.3...5824.14400.0.14970.29.29.0.0.0.0.122.2660.21j8.29.0....0...1c.1.64.psy-ab..0.0.0....0.2MXsPvNDHQg

[msteelman]

There still bonded to the hull! I’ve taken the foam out from the outside of the stingers that was supporting the inter hull and I’m going to put coosa stringers going from fiberglass stinger to outer hull!! I know their was foam in between the sides of Both hulls but I don’t see any need in put it back in, what do y’all think?

[mshugg]

I land on the side of putting the foam back in.  People tend to focus on the role of foam in adding flotation, but it also added to the structure of the boat.  The foam outside of the stringers under the sole added stiffness to the running surface.  The foam between the hullsides and liner provided a physical connection between that stiffened both.  It also serves to dampen that rattle that seems to be present in two piece boats.

[RickK]

I agree - the foam served the same purpose as what you want to add - short bulkheads from stringer to hull side - it was all connected and stiff.  That being said, I did not put any foam in the hull besides filling the stringers I made. I did the bulkheads.  I agree the foam did deaden the sound also.

[222 newbie]

I removed the factory pyramid stringers and fabricated my own with cross stringers to hull side. Then poured foam in the smaller areas and cut foam from blocks to fit larger areas. Then went on the new sole raised 4 inches. It not only deadened the boat noise but I believe it made the boat unsinkable in the process. Theory being, if there is foam there, water cannot occupy that area, hence, unsinkable.

[msteelman]

 but the foam absorbs water!!! is there a expandable foam out there that does does absorb water?

[msteelman]

does not absorb water?

[mshugg]

 There is no foam that won’t absorb water if it is exposed for a long enough time.  I think even Coosa has an absorption rate of 3% or so.  The trick is isolating the foam from source strength of water. 

The foam in stringers on my CCP were bone dry except for a section aft where the stringer had started to separate from the hull.  Why because the stringer was a sealed compartment -At least until it wasn’t. 

How do you plan on removing the foam between the hull sides and liner. Are you removing the liner?  That creates some opportunities for reengeneering things to keep the water away from the foam.  It also makes it possible to replace the stiffness of the foam without foam.  If you post some pictures of your rebuild, there may be some ideas here. 

Bottom line, it’s your boat,so you can pick your priorities.  I made the choice that strength and stiffness took precedence over the risk that the risk that 30 years in the future some water could make it into the foam.  I also took care to eliminate any pathway for water to get to the foam.

[msteelman]

pics

[msteelman]

pics

[RickK]

Apparently you are using your phone to take pics and you are holding the phone vertically.  This site (and most every other site) likes you to hold the phone with the camera to the left.
If you upload the pics to your gallery (see the email I sent you), you can rotate the pics and then paste the Image url (see the email I sent you)..

[mshugg]

Excellent work getting her stripped down.  I’m allways a little envious of people who have access to heavy equipment and enclosed shops for their project.

You have a lot of options depending on how original you plan to keep her.  If you’re reinstalling the liner, you can put foam back in or maybe you can glass stiffeners to your hull and liner. 

If you.re not reinstalling the liner, you can Core the sides with something like h80 divinycel or you can add stiffeners.  There are examples of both out there. 

[msteelman]

i don't really want to put foam back in because i took out over 250 pounds of water logged foam!! I do plan on putting liner back in and i think I'm going to running coosa stingers from original stingers to side of boat to support liner wheres foam was before! i am eventually going to flip the liner upside down and cut out the plywood that is supporting the floor and replace it with coosa also