From Newsgroup: sci.physics

K need something an inch, inch and a half, at most 2" thick which by its
nature won't float or which will fill with water and not float, which I
can sit on in the bathtub so that it not longer hurts to sit on thard
surface.

I'd also like to know if so-called AI is acting stupid again:

When I google foam rubber that will sink
so called AI says

"Key Factors for Sinking Foam:

Closed-Cell Structure: This means air pockets are sealed, making it
less permeable to water and air than open-cell foam, but still
compressible."

Isn't this backwards? If the cells are closed, they remain filled with
air, and the foam will float. Right?

It also says "Dense Upholstery Foam: Look for ratings like "1.2 Density"
or "33 lb Compression" (ILD), as these provide support and are less
airy." Do these 2 things sound correct?

If the foam becomes totally waterlogged, will the specific gravity still
make it float, beucas it's maybe 98% water and 2% foam rubber and the
foam rubber is lighter than water? or will it stay at whatever depth
its place, stay on the bottom if it's placed there?

Since I lost weight, 270 to 200 on a 5'8" frame, I've lost a lot more
weight in my butt than I had originally gained there, so it's less
resilient than any time in my life before, and it hurts to sit in the
bathtub or on a hard chair, or even some padded chairs.

I miss taking a long pleasant bath. I tried a piece of foam that they
sell to sit on in football stadiums and it floats. I can trap it but it
tends to escape, it's pretty inconvenient, and ii would be better if it
were thicker.

i found things for sale that are pre-weighted, but they are all 4.3 to 5
inches high and meant for hottubs so that women won't get their hair
wet. My bathtub is already too shallow, so I don't want to lose that
even if I were not fat at all, I can't get my whole chest underwater.
I don't want to lose 4+ inches even more depth.

I need something an inch, inch and a half, at most 2" which by its
nature won't float or which will fill with water and not float, but is
softer than steel.

Any ideas, products or materials, or suggestions?
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From Newsgroup: sci.physics

You want open cell foam. Never rely on an LLM getting the facts right.

Most rubber formulations are slightly denser than water. However open
cell foam may retain sufficient air to reduce the average density to
less than that of water. If that turns out to be a problem try
attaching the foam to something such as a rubber anti-skid mat.

Have you considered using a folded up towel?
--
John Hasler
john@sugarbit.com
Dancing Horse Hill
Elmwood, WI USA
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From Newsgroup: sci.physics

In sci.physics, on Mon, 15 Dec 2025 23:05:09 -0600, John Hasler <john@sugarbit.com> wrote:

You want open cell foam. Never rely on an LLM getting the facts right.

Of course. So-called AI is worth no more than any random person's
comment and we know how often they are wrong, but I wanted another
opinion.

Most rubber formulations are slightly denser than water. However open
cell foam may retain sufficient air to reduce the average density to
less than that of water. If that turns out to be a problem try
attaching the foam to something such as a rubber anti-skid mat.

Have you considered using a folded up towel?

What a great idea! Not to take away from you and your truly great idea,
I did think of that a couple days later, and I tried it. it workded
fine. I took the towel out of the water before draining the tub, let it
drain on the side of the tub for a a half-day, then threw it over the
shower rod for another day. Took only a day and a half to dry and
doesn't seem dirty at all.

I've also put more towels on my desk chair, which doesn't get wet or
have to be dried. If I'd known the problems of losing weigh, I might
have been mmore successful in not gaining weight/
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