Dive Rite ABS plastic Back Plate

[itemize]

I'm starting to work with my LDS on setting up my first set of doubles. My dealer is suggesting using the ABS back plate as the base because it feels warmer than the metal plates and won't suck the heat out of you. I'll be using the setup in the NJ area so staying warm is often a concern. I'm having trouble finding any threads discussing the plusses and minuses of using the plastic plate. Does anyone have any experience with this setup?

 

[cool_hardware52]

I'm starting to work with my LDS on setting up my first set of doubles. My dealer is suggesting using the ABS back plate as the base because it feels warmer than the metal plates and won't suck the heat out of you. I'll be using the setup in the NJ area so staying warm is often a concern. I'm having trouble finding any threads discussing the plusses and minuses of using the plastic plate. Does anyone have any experience with this setup?

Let me first say I have no bias against plastic back plates, I build both Stainless and a plastic/stainless hybrid.

Unless the stainless plate is in contact with your skin the material the plate is made of should have no effect on the heat transfer rate.

If you wearing an exposure suit, (my guess is you are in NJ) any plate, plastic or other wise will quickly assume the temperature of the water. Heat transfer is a function of the insulation value of the Exposure suit and the temperature differential between the inside (you) and the outside, the water or the plate.

Plate material selection is really a matter of weighting. With doubles you may find a 5-6 lb SS plate too heavy. That's when a lighter AL or plastic plate can be an advantage.


Regards,




Tobin

 

[The Chairman]

Tobin's Kydex/Stainless steel hybrid absolutely ROCKS. I need to get the right bolts to try it with my doubles... but with my single steels, it works way well. But then I don't need any additional weight even with a drysuit.

 

[Bob3]

Yah, the thermal conduction story is a big stretch.
If you want to just make your own plate, plastic sheeting is pretty reasonably priced.

 

[ShakaZulu]

I'm starting to work with my LDS on setting up my first set of
doubles. My dealer is suggesting using the ABS back plate as the base because it feels warmer than the metal plates and won't suck the heat out of you. I'll be using the setup in the NJ area so staying warm is often a concern. I'm having trouble finding any threads discussing the plusses and minuses of using the plastic plate. Does anyone have any experience with this setup?

That was funny, thanks for the laugh........are you diving wet/dry, single/doubles???

 

[itemize]

That was funny, thanks for the laugh........are you diving wet/dry, single/doubles???

Dry. The setup will be for doubles. In the store he held the abs plate and the aluminum plate against my back. Even tho they were the same ambient temperature, I could instantly feel that the aluminum plate felt cold.

 

[ShakaZulu]

Dry. The setup will be for doubles. In the store he held the abs plate and the aluminum plate against my back. Even tho they were the same ambient temperature, I could instantly feel that the aluminum plate felt cold.

That may be the case, but with your thermal protection, you won't feel it. If that was the case, you will feel the water temp too, and then your drysuit is not doing it's job. The determining factor has to be the weight. Determine how much weight you need for the doubles, and then decide.

 

[cool_hardware52]

Dry. The setup will be for doubles. In the store he held the abs plate and the aluminum plate against my back. Even tho they were the same ambient temperature, I could instantly feel that the aluminum plate felt cold.

The answer here is the specific heat of the two materials. All metals will have much higher specific heat than ABS. Specific heat is a measure of how much energy you have to add to or subtract from something to change it's temperature. Your skin is ~98, lets say the ambient was 72, so there is a 26 degree differential. To raise the temperature of the aluminum plate 26 degress requires much more energy than the ABS. With NO insulation between your skin and the plates you detect this difference as the al plate being colder.

When your diving, i.e. surrounded by water, both the water and ANY plate will be at the same temperature.

Try this little test:

Fill a bucket with water, place a plastic spoon and a SS spoon in it. Let them acheive the same temp. Reach in and grab each one wearing your neoprene gloves. Which one feels colder?

Regards,



Tobin George

 

[The Chairman]

The thermal conductance of air (a gas) and water (a liquid) are incredibly dissimilar. Water is far closer to the conductance of Al or SS than air. Putting a BP on your naked (or close to naked) back would make it appear to be a much larger heat sink than a plastic plate. Unfortunately, your body will be immersed in water which is also a huge thermal sink. Any thermal protection that would protect from water, would also protect you from the Al or SS backplate. Since water would surround the entire back plate, it would not insulate you adequately from it.

I hope that this was a genuine error on your LDS's part based on flawed understanding of thermodynamics and not an attempt to sell something based merely on profit.

 

[OneBrightGator]

1. Find a new LDS.

2. Buy an AL or SS plate, whichever you need for proper weighting, from new LDS.

3. Dive.

4. Enjoy.