Open Cell Foam for Cockpit Cushions

Bull City

Bull City
6,943
2,592
North Carolina
In 2015, I had some new cockpit cushions made for TONIC. They have open cell foam. The top and sides of the covers are Sunbrella, and the bottom is mesh. They have been fine until now. I store them on the V-berth, and I've noticed a flaky yellowish powder on the berth cushions lately. While vacuuming the cabin today, I noticed that this stuff is coming from the cockpit cushions. The foam surface has become brittle and is flaking and coming through the mesh.

These cushions get light use, and are stored in the cabin. Maybe it's reaction to heat or cold? Any how...

The solution is some new foam cut to size. It's easy to slide it into the covers. I like the idea of open cell foam. What should I get? Is there a chemical type that doesn't get brittle?

Thanks.

B.C.
 

Zonker

Super Anarchist
9,291
5,223
Canada
There are open cell foams designed to get wet. They dry very fast via drainage.


 

toddster

Super Anarchist
4,182
965
The Gorge
Sounds like decaying polyurethane. Even a bit of exposure to direct sunlight will turn the surface to powder quite quickly. But in the end, it's biodegradable.
 

colemj

New member
8
8
We have 2yr old cockpit cushions that have DriFast foam - a specialty foam designed to allow water to pass straight through and for use outdoors. They started shedding dust after a year. They have never been wet. All open cell foam cushions I've seen on other boats also start shedding dust in time.
 

Bull City

Bull City
6,943
2,592
North Carolina
We have 2yr old cockpit cushions that have DriFast foam - a specialty foam designed to allow water to pass straight through and for use outdoors. They started shedding dust after a year. They have never been wet. All open cell foam cushions I've seen on other boats also start shedding dust in time.
Interesting. Maybe I was lucky. Mine took 7 years to shed.
 

Zonker

Super Anarchist
9,291
5,223
Canada
Our first boat had cockpit cushions that were lawn chair furniture style. Open mesh top and bottom and I assume a type of flow thru foam. Lasted years, just got thinner and thinner. Don't recall any shedding. Kept them out of the sun mostly except on passages.
 

DDW

Super Anarchist
6,317
1,012
Reticulated foam. Sailrite sells it. The cells are intentionally burst so that water drains through very easily.

That said, I've personally liked the vinyl covered closed cell cushions (like CC Cushions). No water absorption, and easy to clean. Current set looks barely used after 12 years.
 

slug zitski

Super Anarchist
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worldwide
My generously endowed and somewhat beat up old sit bones and hips prefer the stiffness and resilience of closed cell foam, or something like a high density memory foam. Comfort is a question in this discussion.
Hard to define comfort

You certainly can’t sleep on high density foam

I find that the ergonomic defect of many boats is that the height of the seating and lack of a foot rest causes butt fatigue on firm foam ... particularly when heeled
 

CaptainAhab

Anarchist
813
211
South Australia
You need to go full race mode. CoreCell makes non absorbent high load cushions. You can carve personalized details into it as well. If you like stiffer cushions, skin them with glass before adding the cover.
 

Bull City

Bull City
6,943
2,592
North Carolina
If you walk and work on the cockpit cushions they must be firm for traction and security

I’ve always used closed cell foam

I'm wondering if I should go with closed cell foam.

Is it more durable, i.e. not likely to get brittle and shed? As to getting wet, we mostly daysail and pick our weather. The cushions usually only get wet when (a) we're anchored somewhere and swimming, or (b) we take a rare splash of spray. Does closed cell absorb a lot of water in those circumstances? Would it take long to dry? Again, the covers are Sunbrella, and the bottom is mesh.

Forgive my stupidity on this stuff. I've never had cockpit cushions before. Thanks.
 

slug zitski

Super Anarchist
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909
worldwide
I'm wondering if I should go with closed cell foam.

Is it more durable, i.e. not likely to get brittle and shed? As to getting wet, we mostly daysail and pick our weather. The cushions usually only get wet when (a) we're anchored somewhere and swimming, or (b) we take a rare splash of spray. Does closed cell absorb a lot of water in those circumstances? Would it take long to dry? Again, the covers are Sunbrella, and the bottom is mesh.

Forgive my stupidity on this stuff. I've never had cockpit cushions before. Thanks.
I don’t know the brand or density but I have had closed cell cushion last 20 years

as far as I know they pretty much last forever

the closed cell appears to absorb zero water

you should ask the canvas maker for type, brand recommendations
 

Bull City

Bull City
6,943
2,592
North Carolina
I've gone around 'n' around on this. I think I'm going to go with firm open cell from Sailrite. The existing foam was fine for several years, but I don't think it was firm. If it gets brittle and sheds in 7 years, so be it. I'll be 80+ and probably won't notice or care.

Now, how to cut it? I'll be using 2" foam. The cushions are roughly 16" X 66" with some curves. The front edge is pretty straight; the back has a gentle curve. A serrated knife might work on the those edges, and the ends but probably not on the corners. I have a jig saw and the blades are definitely long enough. Would it work with a blade designed for wood? I have also seen these "hot wire" cutters that plug in.

Thanks in advance for any suggestions.
 

yoyo

Anarchist
724
291
You can cut the foam with an electric kitchen carving knife. I think sailrite and youtube have videos doing it that way. That worked for me using regular foam, open cell foam and memory foam (mattress topper).
 

Bull City

Bull City
6,943
2,592
North Carolina
You can cut the foam with an electric kitchen carving knife. I think sailrite and youtube have videos doing it that way. That worked for me using regular foam, open cell foam and memory foam (mattress topper).
Thank you. They're not very expensive, which is nice.

 
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