BP/W setup - Galvanic corrosion and how to avoid it

[Diving Dubai]

That is crazy. It does look like the grommet more than the bolt, but rinse and disassembled would prevent any problems. Maybe paint the grommets to prevent direct metal to metal contact?

I pull my gear apart twice a year (when I reconfigure SS for Ali), and it's in the sea every other weekend. I do get a very minor bit of build up even soaking overnight.

Don't stress over it. If you're not using your gear for any length of time, then yes remove the wing and bolts from the plate for storage

I don't paint or coat my SS bolts and they're fine.

 

[-Moe]

That is crazy. It does look like the grommet more than the bolt, but rinse and disassembled would prevent any problems. Maybe paint the grommets to prevent direct metal to metal contact?

Well the good news is that xDeep uses plastic bolts made of polyacetal now according to a reply in that thread.

 

[Daniel M. Thomas]

I just read that xdeep now use plastic bolts rather than metal but they don't say where to get them from and i cannot find them anywhere online. I'd like to keep my rig bolted together and just give it a rinse off each time after use rather than unbolt it all. I have found some anodized aluminium m8 bolts and washers on ebay, i think i might try them.

I found a set of 'XS Scuba Highland delrin backplate nuts' to use too. Does anybody know if they are 1.25mm threads or 1.5mm threads normally used on BP/W setups? I'm presuming its 1.25mm.

Although it has left me I'm wondering why xdeep wouldn't just use aluminium bolts on an aluminium BP/STA setup, surely aluminum bolts will be strong enough.

 

[-Moe]

I just read that xdeep now use plastic bolts rather than metal but they don't say where to get them from and i cannot find them anywhere online..

In that FB thread xDeep states that they are German sourced and that "there's several different polyacetal compounds, some contain special inhibitors and stabilizers to prevent issues with chlorinated water or long term UV exposure". The issue being that standard polyacetal rapidly deteriorates with chlorine water exposure.

 

[Diver below 83]

I thought dgx sold the plastic bolts for plates.

 

[loosenit2]

I thought dgx sold the plastic bolts for plates.

the plastic sex bolts that dgx sells are for attaching the wing to the plate (which is really not necessary, just keeps it cleaner when tank not attached). I doubt they are strong enough to hold a STA to a backplate with a tank strapped to the STA.

 

[Couv]

Any ideas?

There are lots of good ideas posted before I even saw this thread. However, I do have a question as you have not yet purchased your gear. What wing will you be using? Are you sure if requires a STA? If you have not purchased a wing, consider one that requires no adapter. Use plastic/delrin bolts to hold it in place between tank changes. Eliminating the STA will save you a few $$ and a bit of weight during travel.

 

[KenGordon]

Hi divers.

I am in the process of building an aluminium Backplate rig with a primary use of travel diving. I have found an aluminium backplate and single tank adapter, but I'm having trouble finding a compatible bolt to attach the two together that won't cause Galvanic corrosion. Any ideas?

I am planning to buy:

Halcyon harness kit
OMS Aluminium backplate
Xdeep ultralight Single tank adapter

Open to the idea of buying different items to avoid this problem

Don’t worry about it, it is a non issue.

I have an aluminium backplate from Custom Divers which I use with one of their STAs and a little Apeks wing. It is bolted together with the usual wing nuts or with the Halcyon plastic wheeled nuts. Those are steel nuts in a plastic shell so you can do them up easily with fingers but the bit that is against your back is flat plastic. This avoids pain or damage to your back/suit.

I suggest buying the backplate and STA from one supplier to avoid embarrassing issues about holes lining up. Also be sure about what cylinders you will be using. I can’t use a 10l or fat 12l with my setup.

Go to a shop in person. DirDirect have a good range, Dorset, Devon, all the same really

 

[Daniel M. Thomas]

I have just today purchased a new aluminum backplate from Dirdirect, funny you should mention it!

 

[happy-diver]

https://www.industrialgaskets.com.au/bolt insulation - minlon top hat/flange and bolt insulation/page/shop/detail/offset/0?


https://www.industrialgaskets.com.au/uploaded/TOP HATS MINLON.pdf