SS vs AL backplate

[rongoodman]

My warm water set-up is a SS plate and 30# wing, although 25# would be fine. I'm smaller than you, but with a 3mm suit in salt water and an Al80 I still add 8#. I would avoid anything like the HTS2 in favor of a simple one-piece harness--you'll save nearly $300, in addition to having much less clutter.

 

[cool_hardware52]

I think you'll need 4-8 lbs less for fresh water vs salt water. If you carry less than that in salt water w/ steel plate, you'll be a bit heavy in fresh water -- in the same suit: you'd likely need thicker, more buoyant suit in the lakes. I.e. more weight to cancel that out. Of course, being a few pounds overweight is no biggie anyway, but you might prefer that to be ditchable, just in case.

The other side is luggage weight: you can put the SS plate in your carry-on and drag it all the way to Caribbean -- assuming they don't start weighing cabin luggage, the way it's been going I'm surprised they haven't yet, -- but if you check it in, that can be 6 lbs of other stuff you're not taking.

The dry travel weight difference between the typical Stainless plate and lightweight plate is *NOT* 6 lbs. It's much closer to 3 lbs.

Tobin

 

[redacted]

The dry travel weight difference between the typical Stainless plate and lightweight plate is *NOT* 6 lbs. It's much closer to 3 lbs.

Tobin

That is about the weight of a liter of Captain Morgan. Costs about $15 in the US and $40+ on Cayman Brac.

 

[cool_hardware52]

That is about the weight of a liter of Captain Morgan. Costs about $15 in the US and $40+ on Cayman Brac.

Maybe, but I routinely encounter new divers and those considering a BP&W convinced a Stainless Back Plate is 10+ lbs and a lightweight (aluminum or kydex plate) weighs less than fly wings and will actually levitate out of the trunk of your car an onto the airplane by itself.

Having the actual facts, i.e. ~3 lbs difference in dry travel weight, allows them to make an informed choice.

Most divers that dive cold to moderately cold waters at home, and travel to warm locations to dive will be better served by a stainless plate, as long as they are using at least a 3mm suit and buoyant tanks while traveling.

They are after all traveling to *go diving*

Tobin

 

[beaverdivers]

I will be diving AL80s most if not all of the time. Most all my dives will be in warm water with board shorts and possibly a 3 mil rash guard

Most divers that dive cold to moderately cold waters at home, and travel to warm locations to dive will be better served by a stainless plate, as long as they are using at least a 3mm suit and buoyant tanks while traveling.

It sounds like a lightweight travel setup like the Litehawk would better suit your needs. Total weight is 6LBS, lift 30 LBs. Cost less.
Two streamlined weight pockets are included plus rear trim pockets.

 

[dmaziuk]

The dry travel weight difference between the typical Stainless plate and lightweight plate is *NOT* 6 lbs. It's much closer to 3 lbs.

I'm sure it's true: I guess I carried it over from "4-8 lbs" without thinking. Nevertheless, last trip I packed our checked-in bag to about 24.8 kg and with SS plate it would've been over the "official" 25 kg limit. Sometimes they let that slide...

 

[beaverdivers]

It seems like simple math. SS plate = 6 LBS. AL plate = 2 LBS. The difference = 4 LBS.

 

[redacted]

Or could it be that the SS plate is 5.7 lb and the Al plate is 2.3 lb and we are just dealing with round off errors. SS is about 2.9 times as dense as Al and I would bet the Al plate has to be thicker for strength.

 

[cool_hardware52]

It seems like simple math. SS plate = 6 LBS. AL plate = 2 LBS. The difference = 4 LBS.

Stainless is ~495 lbs per cubic ft and alum is almost exactly 1/3 as dense, or 165 lbs / cubic ft.

Stainless plates are typically 11 gauge or .115-.118" thick. Aluminum plates are typically 1/8 " or .125 Aluminum is commonly available in either gauge thicknesses or in fractions "plate" thickness. Stainless is much more commonly sold in gauge thicknesses.

A DSS medium SS plate is ~4.75lbs If .115" thick aluminum was used to make the exact same plate it would weigh 4.75/3 = 1.58 lbs for a delta of 4.75-1.58 = 3.17. With the added thickness typical of alum plates the al plate will weigh about 8% more than 1.58 or about 1.72 lbs for a delta of 3.03 lbs.

Keep in mind that the "6 lbs" I routinely use for a back plate includes the harness and it's stainless items, buckle, drings and triglides.

Tobin

 

[redacted]

Lesson for all: Try not to poke the engineer.