site glass installation

[sfsailing]

Anyone out there have experience/advice about installing a site glass for viewing the rudder and keel? What type of material would be used? Lexan or laminated safty glass?
Thanks

[sfsailing]

I take it no one has ever put a site glass into see if kelp or other bad thing have stuck on the keel or rudder.

[yokebutt]

Now, this is going to be a bit embarrassing, but installing a sight glass is one of the few things I've never done on a boat. I was hoping that somebody with first-hand experience would give you exhaustive directions, but, if that's not going to happen, my first inclination would be to recommend a lexan window installed with 3M 5200, but as I said, don't actually have any first-hand experience myself.

Yokebutt.

[wet feet]

I worked on a boat which had such a window to view the prop so that the crew could be sure it was folded while racing. The recess had been moulded in by adding a disc to the surface of the hull mould and a piece of 6mm poycarbonate about 70mm diameter was bedded on butyl rubber mastic.The end result was never mentioned so on the basis that no news is good news it was judged to be a success.

[sfsailing]

Thanks wet feet, it is a place to start. Some how I think I will need to screw or bolt the plate in to give me a more secure feeling that it will not just pop out. I am just afraid to screwing or bolting unless doen very carefully will crack the lexan or plastic.

[wet feet]

The panel I mentioned in my earlier post was retained by three small bolts.My only reservation is that polycarbonate moves around quite a lot with temperature changes and the bolts may crack it,something I have seen with polycarbonate cabin windows.In use,there is only the force of gravity to resist and that is opposed by the water pressure on the outside of the hull.Good luck with the project.

[DGreenwood]

Start Here

http://www.diveweb.com/commdive/features/pvho.html
http://www.normas.com/ASME/pages/PVHO.html
http://www.psubs.org/designguide/wwindow.html

Good luck