Closed Cell Buoyancy Foam Test

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Reid
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Closed Cell Buoyancy Foam Test

Post by Reid »

Hello Everyone,

In the interest of science (and also to appease Cape Man :wink: ) I have started a little test on our 2 part Closed Cell Buoyancy Foam (2lb. density). This topic has come up routinely on the Forum so I guess we are long overdue for a test to set the record straight. If a closed cell foam is cut, would it absorb water or would the closely knit cell structure prevent it from absorbing water? Does cutting Buoyancy Foam, as we do when we trim it to fit under our decks and soles, open the cells and allow for the entire piece to take on water?
Cape Man has hypothesized that the amount of water absorbed between two pieces of Buoyancy Foam, one that has not been cut and one that has been cut, will be minimal due to the cell structure of the foam.

The test: I made two identical blocks of Buoyancy Foam. Each one consisted of equal parts A and B (8 mL of each). The foam was allowed to set up with a screw and string in the middle. This was done to allow weight to be attached later on. Once cured, I trimmed the top off one block of foam. Both pieces of foam were then weighed. Weight was then attached to both foam blocks and both blocks were then submerged in a 5 gallon bucket of water. I will leave them submerged for one week, pull them out, and weigh them again. The difference in weight (if any) will show how much water was absorbed. Here are some pictures for your viewing pleasure!

Please feel free to let me know what you think the outcome will be.

-Reid

Start Date: December 15, 2021
Temperature: 78 F
Starting weights: Cut piece = 20 grams, Non Cut piece = 24 grams
Finish Date: December 22, 2021
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fallguy1000
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Re: Closed Cell Buoyancy Foam Test

Post by fallguy1000 »

Sometimes they use inks for the tests as well.
My boat build is here -------->

viewtopic.php?f=12&t=62495

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Jaysen
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Re: Closed Cell Buoyancy Foam Test

Post by Jaysen »

fallguy1000 wrote: Wed Dec 15, 2021 3:57 pm Sometimes they use inks for the tests as well.
Drop a little blue or red food color in the water. That will show how far the water penetrated.

It would also be interesting to cut along the string to see how much penetration happened along that inclusion.
My already completed 'Lil Bit'. A Martens Goosen V12 set up to sail me to the fishing holes.
Currently working on making a Helms 24 our coastal cruiser.
“Mark Twain/Samuel Clemens” wrote:Eat a live frog first thing in the morning and nothing worse will happen to you the rest of the day.
Jaysen wrote: Mon Apr 29, 2019 3:44 pm I tried to say something but God thought I was wrong and filled my mouth with saltwater. I kept my pie hole shut after that.

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Re: Closed Cell Buoyancy Foam Test

Post by fallguy1000 »

My transom steps were setup, by me, as a wet sump. But I realized this area will contact water and constantly be condensating. Also, I can't reach the bottom of it. So, come spring, I am ordering some. I know it needs to be 70 or so to apply.
My boat build is here -------->

viewtopic.php?f=12&t=62495

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cape man
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Re: Closed Cell Buoyancy Foam Test

Post by cape man »

Thank you Reid! What a nice Xmas present for all of us! :lol:
The world always seems brighter when you've just made something that wasn't there before - Neil Gaiman

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Re: Closed Cell Buoyancy Foam Test

Post by Reid »

Jaysen wrote: Wed Dec 15, 2021 4:56 pm
fallguy1000 wrote: Wed Dec 15, 2021 3:57 pm Sometimes they use inks for the tests as well.
Drop a little blue or red food color in the water. That will show how far the water penetrated.

It would also be interesting to cut along the string to see how much penetration happened along that inclusion.
Jaysen,

I will see what I can do with the food coloring.
Also, I wouldn't think that the string/screw will have any effect on water intrusion. The reason I say this is because the foam was allowed to set up around the string/screw so technically the cells should be "closed" still. I guess a way to relate this to boat building is when we install chase tubes under a sole and then pour foam around them.
I guess we will have to wait and see.
-Reid
Someone asked me, if I were stranded on a desert island what book would I bring... "How to Build a Boat."
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Re: Closed Cell Buoyancy Foam Test

Post by Reid »

cape man wrote: Thu Dec 16, 2021 5:41 am Thank you Reid! What a nice Xmas present for all of us! :lol:
Tis the season!!!
Someone asked me, if I were stranded on a desert island what book would I bring... "How to Build a Boat."
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Re: Closed Cell Buoyancy Foam Test

Post by Jaysen »

I don't disagree. But since we are doing the test we can now semi-empirically prove it. I say "semi-empirically" only because someone will eventually point out that we didn't use lab standards to officially measure.

I think the line may show some capillary seepage. I would expect the same from anything that is encapsulated (chase tubes, bulkheads, etc). It will be interesting to see how far that seepage extends along the surface of the item as well as into the foam.
Reid wrote: Thu Dec 16, 2021 8:51 am
Jaysen wrote: Wed Dec 15, 2021 4:56 pm
fallguy1000 wrote: Wed Dec 15, 2021 3:57 pm Sometimes they use inks for the tests as well.
Drop a little blue or red food color in the water. That will show how far the water penetrated.

It would also be interesting to cut along the string to see how much penetration happened along that inclusion.
Jaysen,

I will see what I can do with the food coloring.
Also, I wouldn't think that the string/screw will have any effect on water intrusion. The reason I say this is because the foam was allowed to set up around the string/screw so technically the cells should be "closed" still. I guess a way to relate this to boat building is when we install chase tubes under a sole and then pour foam around them.
I guess we will have to wait and see.
-Reid
My already completed 'Lil Bit'. A Martens Goosen V12 set up to sail me to the fishing holes.
Currently working on making a Helms 24 our coastal cruiser.
“Mark Twain/Samuel Clemens” wrote:Eat a live frog first thing in the morning and nothing worse will happen to you the rest of the day.
Jaysen wrote: Mon Apr 29, 2019 3:44 pm I tried to say something but God thought I was wrong and filled my mouth with saltwater. I kept my pie hole shut after that.

Reid
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Re: Closed Cell Buoyancy Foam Test

Post by Reid »

Update on the test... Looks the same as I left it yesterday.
IMG_6815.jpg
Someone asked me, if I were stranded on a desert island what book would I bring... "How to Build a Boat."
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OrangeQuest
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Re: Closed Cell Buoyancy Foam Test

Post by OrangeQuest »

Shouldn't we get a proper scientific update with a whole weather forecast of the bucket? Like Temp, barometric pressure, and humidity? :roll:

:lol: :lol: :lol:
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