Best type of glass for under saltwater use??

[lightime]

I am building some small 316L stainless steel enclosures that will house cameras which will be semi-permanently used under saltwater. I will be using a 50mm diameter x 2mm thick lens but I am not sure what "type" of glass I should go with. I am looking at Borosilicate and Quartz but I am not sure which will be best or if there is another type I should look at.

Any ideas or suggestions are greatly appreciated.

Thanks in advance!

 

[wquiles]

How deep under water will the enclosure needs to withstand water pressure?

 

[lightime]

Up to max 10 feet...

How deep under water will the enclosure needs to withstand water pressure?

 

[wquiles]

That is not much pressure at all. In that case, almost any glass will do, and you don't have to go too thick either. I recommend that you read this link which talks about various types of glass that they sell, and that many here in the forums buy for our really intense hotwire mods. From those, it looks like the toughest glass they sell is Borofloat, although I don't know if they can cut you a piece at 50mm - they seem to sell/stock the most common 52.1mm size, which is what fits on a D/C Mag head.

Of course the other alternative is to use a plastic lens, since it would be far more resistant to being hit - it will not shatter like glass. Flashlightlens sells both glass and plastic lenses, but you can also order from many on-line suppliers like McMaster-Carr .

Will

 

[Justin Case]

Do you think that 316L is an appropriate choice for semi-permanent exposure to a salt water environment?

The low carbon certainly will help address grain boundary sensitization. But the alloy will still have issues with pitting corrosion, crevice corrosion, and stress corrosion (e.g., from any residual stresses from the welding that I assume you will use to make your enclosure). Is the water going to be flowing? If so, that might help.

I would suggest considering the duplex stainless steel 2205 for your application. Or at least use a high nitrogen 316L.

 

[McGizmo]

I assume that in the shallow water you have stated that you will need to deal with life growing on the camera's windows? If that is the case, you might pic the window material based on ease of cleaning it and perhaps abrasion resistance if the cameras are in a location where you can get calcium growth from barnacles or coral. I don't know if there are any clear ablative films or materials you could coat the windows with but I imagine that fouling could be the biggest issue you end up facing. Again, this is based on assumption that could be completely off base. I knew some boat owners who claimed that they got good anti-fouling service on their prop blades by applying a layer of anhydrous lanolin on them. I don't know if something like this would work on your camera window but it might be something to consider. You did ask for any ideas or comments!

 

[precisionworks]

Do you think that 316L is an appropriate choice for semi-permanent exposure to a salt water environment?

+1

Better materials would include Ti, NiAlBronze, or Monel ... if it has to be metallic. Many nonmetallics will give much better service than 316L while costing less than Ti. Ikelite has been using clear polycarbonate (Lexan) for more years than I can remember. Lexan is inexpensive relative to the nonreactive metals, easily formed, etc.