Window Mounting

[Bob S]

I read the article in building tips about window mounting and I have a question. When mounting from the outside it says to make sure the glass has a ceramic border that protects the Sika 296 from UV. What to do if the existing glass has no such border, can it be retrofitted and where do you source the material?

[CaptPatrick]

Bob,

Are you thinking of direct glazing your side windows?

When I refer to "Direct Glazing", I'm referring to the technique commonly seen on late model auto windshields. The glass has been waterjet CAD cut, glazed from the outside, and has no external frame. In that case, the flat black material on the inside perimeter of the glass is the ceramic coating.

For one off work and someone outside of that segment of the glass industry, there virtually is no source for the ceramic coating.

However, the Sikaflex black primer is fairly opaque if applied in 3 - 4 coats. You need the activator and primer at any rate and there is ample in the bottle to apply multiple coats of the primer.

The real problem is that to look right without an external frame, the glass has to be cut in a very tight tolerance to the opening. The edge of the glass and the edge of the opening define the width of the glazing compound. On a boat that width is about 1/4" and if there's much variation of the width of the compound, the finished appearance will be less than desirable...