Exercise block as buoyancy floats ?

Has anybody used these kind of exercise blocks as buoyancy floats ? These can easily be cut to a shape desired and am sure one can easily make a hole to arm size or as required.

They are compressed foam blocks made of Polypropylene.

These seem to float nicely in a bucket of water and also don't seem to retain water. But don't know what pressure would do while diving ? 

Thanks for any help.

Here is a link  https://www.amazon.in/AmazonBasics-Set-Yoga-Blocks-Black/dp/B01FN7X7KE/ref=sr_1_5?keywords=exercise%2Bblocks&qid=1636531775&sr=8-5&th=1

Hi Diggy,

I have zero experience with the Amazon blocks, they look to me like some sort of styropor that is prone to crumble, when under mechanical stress. They also look expensive compared to a very affordable solution for buoyancy that I use for years: these are the floats that commercial fisherman use for their nets. They are of the closed cell foam type and can be cut to the desired size without soaking water and are available in very different sizes for little money (fishermen use hundreds, if not housands of them on one net, therefore they are a mass product). The standard floats tolerate similar depths as the expensive Stix floats. In addition special floats for deep sea fishing are also available that tolerate depths of many hundreds of meters and may be of interest for technical divers.

I buy them from a german factory (unfortunately their homepage is in german language only), but there will be more producers worldwide. See here an example for a standard float (The hole in the center needs to be widened and drilled to 25mm diameter (very easy to do with a long 25mm drill), then they can be put easily over the standard arms): https://engelnetze.com/schwimmer-t-680g-auftrieb-95x149mm-16mm-bohrung

Wolfgang

2 hours ago, Architeuthis said:

Hi Diggy,

I have zero experience with the Amazon blocks, they look to me like some sort of styropor that is prone to crumble, when under mechanical stress. They also look expensive compared to a very affordable solution for buoyancy that I use for years: these are the floats that commercial fisherman use for their nets. They are of the closed cell foam type and can be cut to the desired size without soaking water and are available in very different sizes for little money (fishermen use hundreds, if not housands of them on one net, therefore they are a mass product). The standard floats tolerate similar depths as the expensive Stix floats. In addition special floats for deep sea fishing are also available that tolerate depths of many hundreds of meters and may be of interest for technical divers.

I buy them from a german factory (unfortunately their homepage is in german language only), but there will be more producers worldwide. See here an example for a standard float (The hole in the center needs to be widened and drilled to 25mm diameter (very easy to do with a long 25mm drill), then they can be put easily over the standard arms): https://engelnetze.com/schwimmer-t-680g-auftrieb-95x149mm-16mm-bohrung

Wolfgang

 

Thanks, Wolfgang,

this is of great help. 

Diggy

Water pressure will collapse most foams. I have used and like Divinycell foam. Here is the blurb:

“Divinycell HCP - high performance PVC for subsea applications:

Divinycell HCP, a unique PVC formulation, is used from sea level to 700 meters depth and has an excellent track record in subsea applications for over 50 years.

This grade meets the demand for a high performance, low density buoyancy material with excellent characteristics. It is widely used in submarines, subsea buoyancy units, ROVs, diving bells and impact protection structures. As a result of its excellent hydraulic compressive properties and closed cell structure, it has very low buoyancy loss and water absorption under long-term loading conditions.

HCP stands for Hydraulic Crush Point and is defined as the point of pressure in Bar, where the material when subjected to an increasing pressure of 1-2 Bar/sec has lost 5% of its initial volume.

The design of subsea buoyancy applications is complex, and consideration must be given to the buoyancy loss and uplift requirements over the expected lifetime and service conditions, with respect to long and short term hydraulic compressive creep, water absorption and hydraulic fatigue.” 

I obtained mine as H100-PVC Foam  from 
Aircraft Spruce &  Specialty, POBox 4000, Corona CA 92878   it provides excellent flotation.

15 hours ago, Kraken de Mabini said:

Water pressure will collapse most foams. I have used and like Divinycell foam. Here is the blurb:

“Divinycell HCP - high performance PVC for subsea applications:

Divinycell HCP, a unique PVC formulation, is used from sea level to 700 meters depth and has an excellent track record in subsea applications for over 50 years.

This grade meets the demand for a high performance, low density buoyancy material with excellent characteristics. It is widely used in submarines, subsea buoyancy units, ROVs, diving bells and impact protection structures. As a result of its excellent hydraulic compressive properties and closed cell structure, it has very low buoyancy loss and water absorption under long-term loading conditions.

HCP stands for Hydraulic Crush Point and is defined as the point of pressure in Bar, where the material when subjected to an increasing pressure of 1-2 Bar/sec has lost 5% of its initial volume.

The design of subsea buoyancy applications is complex, and consideration must be given to the buoyancy loss and uplift requirements over the expected lifetime and service conditions, with respect to long and short term hydraulic compressive creep, water absorption and hydraulic fatigue.” 

I obtained mine as H100-PVC Foam  from 
Aircraft Spruce &  Specialty, POBox 4000, Corona CA 92878   it provides excellent flotation.

 

Thanks a ton. This is also most helpful.

I have gone and obtained a 1DX MK3 with Monitor etc etc. And need to get this behemoth completely neutral underwater.

Diggy