Re-start on topic: Questions concerning Backplates.

[tbone1004]

Stow that can light cord Tbone!

that isn't me buddy, that was just a picture I find through a quick google search. I think the blurb said there was 9 bottles in there, I think it was just to prove a point that you could carry 9 of them, showing no practical purpose at all. Support divers carrying that many bottles will often clip them together then onto the rear crotch strap D-ring and tow them in on a DPV. That picture was likely just for sh!ts and giggles.

 

[ScubaInChicago]

that isn't me buddy, that was just a picture I find through a quick google search. I think the blurb said there was 9 bottles in there, I think it was just to prove a point that you could carry 9 of them, showing no practical purpose at all. Support divers carrying that many bottles will often clip them together then onto the rear crotch strap D-ring and tow them in on a DPV. That picture was likely just for sh!ts and giggles.

Oh, and it's just a coincidence that the analysis tape says tbone?

 

[tbone1004]

deWit - Tekcamp 2013 – Day 4: Stage handling with Graham Blackmore & Rebreather trydive with Phil Grigg

That is the article. Never been to Tekcamp, I'm not Patrick deWit, I don't believe in wrist compasses or any dedicated UW compasses, and don't currently own a DUI suit, so yup, just a coinkydink! ;-)

 

[kwinter]

1.) I suggest not considering a 316 CRES material over 304 CRES. For our usage, they will behave identically. If you want to hand down your BP to your great grandson someday, a 316 CRES plate will look shinier than the 304.
Science: (Do not read if you are tired) 316 has a slightly higher yield strength and tensile strength but the two alloys have the same elastic modulus and density. We will not be using the materials to their yield point (if so, they would be bent, deformed or stressed to a permanent extent). (If you were in your high-rise condo and there was a power failure while in the elevator and wanted to pry the elevator door open using your BP...the 316 CRES backplate may provide some advantage.) 316 is used much in the marine industry for extended exposure environments but more so in the chemical, food and industrial process industries for containment of chemicals, food, dairy and corrosive materials at extended durations and elevated temperatures. Aluminum BP are also used so the additional strength advantage is not a factor. I am buying the stainless due to weight properties. If a plate happens to be 316, great but consider it stainless. Don't consider 316 over 304.

I wish I could find that photo I took after a one-week trip. I had 2 large bolt snaps side by side. Both brand new before the trip. One made of 304 stainless and the other was 316 SS. The amount of corrosion and rust on the 304 was clearly visible after a week of salt water diving. Now it is possible that the one I got was defective. And it also probably doesn't matter if there is some rust or corrosion on a backplate since there are no moving parts. But 316 marine grade stainless will definitely hold up better in salt water than 304. No contest.

 

[ams511]

Uh, well no.

First, I never said he needed a 35 lb wing.

Second, if you look at the chart I linked to they do list a Faber HP-100 at -15 full.

Third, I assumed that he is using something more reasonable like a Faber FX-100 which is about -9 negative, a Worthington X7 would be -10.

Fourth, you have many posts saying that a rig must float without a diver in it. So lets take a look at it again at the beginning of the dive.

Regulator -2
Tank Full -9
Weight -14 all on rig
Total -25

It is marginal that this rig would float without him in it. You are relying on the DR wing to have 25 lbs of lift and that his current BC is a few pounds positive. He would need to carry some weight on the belt. If he is using the Faber HP then we get.

Regulator -2
Tank Full -16
Weight -6 Steel backplate only, anything else on belt
Total -24

In theory we are positive but again we are assuming that the DR wing is at 25 lb. In this case it may be better to have an Al plate.

The OP also mentions he would like to carry a stage which would make either rig even more negative at the start of the dive.

My point is that he needs to pay attention to where he wants to carry his weight. What am I missing?

 

[eelnoraa]

Also be careful that many manufactures quote wing lift based on no tank attached. Once you attach a tank, worse case 8" tank, lift can drop significantly. I am not saying DR travel wing will behave like this, but do consider this as well.

My personal take is that between properly design wings at 25lb and 30lb, the additional profile or drag from that is minimal to negligible. I will definitely pick the 30lb. It is benefitial with out any drawback, apart from maybe cost.

 

[cool_hardware52]

Also be careful that many manufactures quote wing lift based on no tank attached. Once you attach a tank, worse case 8" tank, lift can drop significantly. I am not saying DR travel wing will behave like this, but do consider this as well.

My personal take is that between properly design wings at 25lb and 30lb, the additional profile or drag from that is minimal to negligible. I will definitely pick the 30lb. It is benefitial with out any drawback, apart from maybe cost.

For cold water there is essentially no difference between a 25 and a 30. It's when the same diver travels to warm water that having the smallest safe wing for cold is a benefit.


Tobin

---------- Post added March 30th, 2015 at 02:25 PM ----------

First, I never said he needed a 35 lb wing.

No, but the OP did. Apparently he wants to stay with Dive Gear Express and it appears his choices are a 25 or 35 lbs lift wing.


Tobin

 

[ScubaInChicago]

deWit - Tekcamp 2013 – Day 4: Stage handling with Graham Blackmore & Rebreather trydive with Phil Grigg

That is the article. Never been to Tekcamp, I'm not Patrick deWit, I don't believe in wrist compasses or any dedicated UW compasses, and don't currently own a DUI suit, so yup, just a coinkydink! ;-)

So you just dable in copyright infringement for $#! T's & giggles.

Copyright © 2015 deWit.

 

[ams511]

No, but the OP did. Apparently he wants to stay with Dive Gear Express and it appears his choices are a 25 or 35 lbs lift wing. Tobin

I am not sure why. While the $310 25 lb DGX special is a deal, it is also sold out. Once he moves to the Voyager wing your package deal is actually less expensive.

---------- Post added March 30th, 2015 at 02:06 PM ----------

Also be careful that many manufactures quote wing lift based on no tank attached. Once you attach a tank, worse case 8" tank, lift can drop significantly. I am not saying DR travel wing will behave like this, but do consider this as well.

I may be mistaken but I think Dive Rite downgraded the lift capacity of their wings a few years back. So hopefully the actual lift is as stated.

 

[walkonmars]

Thanks for the help.
With the DGX travel combo sold out, it looks like my choices are wider.
Under a worst case scenario, if I need to run an aluminum 80 I would need to plan for that.
To be honest, I wanted to go cheap and simple and figure out what I like and hate later. It happened with my BC and as I was starting to change my diving habits and simplify my routine. Harness set-ups are seemingly flexible after purchase but wings are not. The travel set-up at least gives me the option to have a travel wing if needed (I admit a dumb idea since I don't travel much for diving.). The DSS LCD30 is a 30# lift wing, right? I couldn't find lift spec on the website for some reason.