Hello Everyone,
In the interest of science (and also to appease Cape Man ) 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
Closed Cell Buoyancy Foam Test
Closed Cell Buoyancy Foam Test
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Re: Closed Cell Buoyancy Foam Test
Sometimes they use inks for the tests as well.
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Re: Closed Cell Buoyancy Foam Test
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.
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Re: Closed Cell Buoyancy Foam Test
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.
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Re: Closed Cell Buoyancy Foam Test
Thank you Reid! What a nice Xmas present for all of us!
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Re: Closed Cell Buoyancy Foam Test
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
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Re: Closed Cell Buoyancy Foam Test
Tis the season!!!
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Re: Closed Cell Buoyancy Foam Test
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.
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 amJaysen,
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
Re: Closed Cell Buoyancy Foam Test
Update on the test... Looks the same as I left it yesterday.
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Re: Closed Cell Buoyancy Foam Test
Shouldn't we get a proper scientific update with a whole weather forecast of the bucket? Like Temp, barometric pressure, and humidity?
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