Drying and loose foam blocks

[sjh]

I'm in the early part of drying out the world's heaviest sunfish. It weighed in at around 235 a week or so ago. I put three 4" holes in for ventilation (1 in front of the mast step, 1 just behind the splashboard, and 1 near the old rudder deck plate) and to reattach the three loose foam blocks in the front. I still have to remove the waterlogged expanding foam that's no longer holding the front blocks, and I currently have the deck covered with black plastic bags and am using a small solar fan to draw out air.

Obviously losing 100 pounds in water and water vapor will take some time, so I have the following questions. Once I'm done removing the squishy expanding foam, would I be better off turning the boat over so it's hull up, covering the hull in black plastic, but having the ventilation holes on the bottom? This would presumably reduce the ventilation from convection, but it would help me not have to go cover up the holes every time it looks like rain. (I seem to recall seeing a drawing for somebody who created "funnels" out of plastic bags to keep the rain out, but I haven't been able to find them.)

The other question is, how dry do the styrofoam blocks have to be before I can "glue" them back in place using the 2-part expanding foam? I can tell they're heavy, but compared to the old expanding foam, which I can wring out, the blocks no longer seem to "squish."

Thanks.

 

[AJC6882]

the expansion foam holding the blocks in place shouldnt be squishy. it should be very stiff like wood. At least thats how mine is. im in the process of rebuilding my boat from the bottom up. because mine was actually filled with water. I drained it and it wieghed in at 245lbs! When i removed the deck from the hull the foam was totally saturated. and the expansion foam is saturated too but hard as wood. They probably ran out of two part foam at the manufacturer and used GreatStuff.

 

[DanB]

There’s a pretty good explaination of the foam saturation conundrum posted in the Sunfish Sailors library file ( http://groups.yahoo.com/group/sunfish_sailor ) One of the members has also posted a pictoral account of doing the reattachment that goes along with the Windline Sales instructions ( http://www.windline.net/project3.htm )

With a fan you are going to get circulation rightside up or upside down. If you are still interested, I remember seeing a photo of someone’s scoop setup in the Sunfish Sailors picture albums too.


how dry do the styrofoam blocks have to be before I can "glue" them back in place using the 2-part expanding foam?
You might give US Composites a call to find out ( http://www.uscomposites.com/foam.html )


They probably ran out of two part foam at the manufacturer and used GreatStuff.
Great Stuff, that’s funny, but I find it unlikely a boat manufacturer would resort to running to the store for lightweight home insulation foam where a boat is involved.

[US Composites says this in the FAQ]

Is this foam water resistant?
Yes, but with the following caveat. The foams that we sell are considered closed-cell, which means that each cell that makes up the foam structure is completely closed off from surrounding cells which prevents it from acting like a sponge. It is completely safe for this foam to be in contact with water for hours/days/weeks and even months with no adverse effects. However, it should never be submerged in contact with water permanently. Over a period of years the water contact can begin to soften the foam and cause it to lose its closed-cell status. This foam is designed primarily to be used as an insurance policy in case of damage/holes that could cause a vessel to lose buoyancy. Pinhole sized openings would essentially have no effect on the foam since the amount of exposure is so minimal but you should always make repairs as soon as possible to keep the foam effectiveness as good as possible. This will be the case with all after market closed-cell polyurethane foams and even manufacturer installed foams.

.

 

[AJC6882]

If the amf or vanguard or whoever manufactured the boat used the right expansion foam. then it should be as hard as balsawood even if it was fully saturated with water. There is no way he would be able to ring it out. They definally used the wrong expansion foam. Sunfish Boats built during the mid1980's to 1990's were built inconsistantly and the builders used improper materials and they had many many call backs and had to replace many boats.

 

[sjh]

Thanks for the info. Just to clarify, my Sunfish was built in 1964 and up until a few weeks ago the hull had at least a couple of gallons of water sitting in it for at least 6 months and maybe for a few years, so water could indeed be squeezed out of both the Styrofoam blocks and the expandable foam.

There's still obviously moisture in both the blocks and the foam, but much less. The first few days after I cut the holes and drained the standing water I would mop up about an inch of water that had drained out of the foams and settled in the inside keel areas. Now sections of the inside of the hull are noticeably dry. Ah, the wonders of solar power.

(Attached pictures show standing water in the keel area next to loose block, loose foam block resting against mast step, and easily removed expandable foam that is seeing the light of day for the first time in 44 years. Note that the Rotozip hole attachment makes great round holes in fiberglass.)

 

[Porpoise2]

"...Once I'm done removing the squishy expanding foam, would I be better off turning the boat over so it's hull up, covering the hull in black plastic, but having the ventilation holes on the bottom?

Hull "up" and black plastic sounds right. Drying needs heat and air movement.

I'd put the bow as high as possible where it will be in the sun most of the day, open all those ports, and use that solar-gained air movement to aid your fan. If you place the Sunfish bow against a tree, garage, or fence, I'd secure the bow handle to the object to prevent a wind gust from moving it.

 

[AJC6882]

After looking at your pictures the foam in your boat is much different looking than the one im restoring. Mine is a 62 sunfish. and the expansion foam is much more dense in appearance. i have some pictures on my camera. ill have to post them. the foam doesnt look to have been as puffy as yours.

 

[mike4947]

As to the "how dry?" question we don't begin to do any work until the boat weight is well under 150 pounds. Above that and you're fighting an amount of moisture coming out that we've found doesn't allow good bonding of foam to either the fiberglass or the foam blocks.

 

[OSU66]

I too have a very heavy boat and want to remove the foam. I need to take the top off to do that and it sounds like you have done that. Any suggestions as to what to watch out for.

OSU66

the expansion foam holding the blocks in place shouldnt be squishy. it should be very stiff like wood. At least thats how mine is. im in the process of rebuilding my boat from the bottom up. because mine was actually filled with water. I drained it and it wieghed in at 245lbs! When i removed the deck from the hull the foam was totally saturated. and the expansion foam is saturated too but hard as wood. They probably ran out of two part foam at the manufacturer and used GreatStuff.

 

[AJC6882]

I wish that I loaded the pictures up. I will in a couple days. but the main thing is that you need to start separating the deck by using a utility knife. I did the whole rear 1/3rd like that. Just get the blade in as far as you can between the deck and hull and work it back and forth separating the two. I worked from the rear starboard corner and to the front. then the far back and then port side. The front I used a different approach. I used a sharp stiff putty knife once I separated about 5 inches using the utlilty knife. All together it took about 45mins to do the whole separation. i have all the foam removed except for two blocks that travel under the cowling.

Ohhh! dont for get to support the boat when you begin to realign and clamp the deck back together. with out the deck fully attached the boat may twist a little.

I too have a very heavy boat and want to remove the foam. I need to take the top off to do that and it sounds like you have done that. Any suggestions as to what to watch out for.

OSU66

 

[OSU66]

thanks for the information. I removed the rail and separated the top from the hull using the method you suggested. It worked great and I have now removed the foam. What a difference in weight. We are going to put it back together today. Thanks

 

[mike4947]

Just remember the foam blocks are not there for floatation they are an integral part of the structure of the boat.

 

[AJC6882]

Yeah you must replace the foam. its a structural part of the boat! I'm gonna use extruded closed cell foam. its more rigid and easier to cut.