This may be the wrong place for this, but here it goes. I am interested in trying a backplate setup. What all is needed? How do you attach weight?
Dave
I went through this when I was considering a BP/W setup. It all seemed very confusing to me.
You need a backplate. It can be aluminum or steel. If you select aluminum it will tend to be 6 pounds, give or take, lighter. I dive with a steel plate and a 7mm wetsuit. If I use a steel plate and steel tank with a single tank adaptor and a 3mm wetsuit I sink like a rock. So for me, steel plate for cold water diving. Aluminum plate for tropical water diving.
You need a harness. There are two types. The hogarthian harness (named after Bill Hogarth Main). Have a look at
Threading a Backplate System - YouTube for a video on threading a harness. You can buy the webbing and all the parts separately but generally you get a kit with the webbing and all the parts you'll need. The other type of harness are called 'deluxe' harness. The hogarthian harness is one piece webbing. The 'deluxe' harness has buckles which make it easier to adjust and get in and out of. For example, if I'm rescuing you and you wear a hogarthian harness, I'd cut it off with a z-knife. If you are wearing a 'deluxe' harness, I'd just unclip the buckles just like a jacket style BCD. Some people don't use a crotch strap. I'd recommend buying a kit with a crotch strap. If you don't like it, don't use it.
You need a wing. If you are diving with a single tank then a wing with 20 to 30 pounds of lift is sufficient. You want a wing designed for a single tank. The wings for double tank configurations are wider and don't work well with single tanks. Some wings are made with thicker bladders, tougher outer shell. Some you can change the bladder by unzipping the shell. Some are sewn in and need to go back to the manufacturer to get fixed.
Some wings have ridges and slots for tank straps (cam straps). With them you don't need a single tank adaptor (STA). However, I find a STA is more stable and your tank does not shift around at all. Whether or not you want a STA depends on the wing you buy. If it says it has a built in STA then you don't need one. I use a STA.
Finally, you need a set of straps to hold the tank to the backplate and some wing nuts plus lock washers to hold everything together.
If you look at my setup, I have a steel tank. On the steel tank I have a STA held on with two straps. The STA has two bolts. The wing has two holes which the STA bolts go through. Next the backplate has two holes which the STA bolts go through. If I didn't have the STA I would have just two bolts to hold everything together. So now the layers are the tank, the STA, the wing, the backplate. I put wing nuts and lock washers on the bolts and tighten them.
I wear my weights on a weight belt. You can get pockets which go on the harness. Some pockets are fixed. Some have a quick release.