Gluing in flush mount windows?

[pods8]

Anyone know anything about gluing in windows?

In my foam core hardwall pop-up camper design I might want a few thin fixed pane windows in the overlapping section, which would lend itself better to a flush mount. I was wondering about building in a recess and then just ordering tempered window glass (or maybe uvex or something like that) and gluing them in (windshield adhesive?). Anyone have experience? What about doing a double pane version by gluing a window in from each side with maybe a couple weep holes for condensation issues?

 

[southpier]

anytime there are dissimilar materials, there is a variable coefficient of expansion. glass isn't going to respond kindly to the forces exerted by the panels moving, so will need to be isolated. rubber gasket may be the key.

these folks have a number of profiles: https://secure.steelerubber.com/

 

[pods8]

If there is proper adhesive to glue tempered glass into metal automobile frames (they often don't use rubber gaskets these days) why wouldn't the same be applicable to a fiberglass structure which expands less than metal?

 

[LukeH]

If there is proper adhesive to glue tempered glass into metal automobile frames (they often don't use rubber gaskets these days) why wouldn't the same be applicable to a fiberglass structure which expands less than metal?

+1
After all, the principal component of gfrp is, um, glass.
Windscreen glue is amazing stuff; it's so strong it actually allows designers to use the rigidity of the windscreen to stiffen up the superstructure (insider info here).

Now for the bad bits: if you machine or rout a recess the thickness of your pane of glass, you'll probably go through the skin and be in the foam. So you could recess further and lay some mat & resin to give an airtight receiver.
Also most foams don't like uv so better to line your opening with gfrp and gelcoat.
Like your idea of doing double glazing, but there I can see potential issues (all fixable):
If you make a system that breaths then you risk letting humidity into the gap. That will leave traces you can't reach to clean.
If you seal it, you could put in a couple of those aluminium rails that glass cutter professionals use to assemble double glazing. They contain silica dessicant, which would solve your humidity issue, but then there's the altitude issue!
The pressure differences you could encounter MIGHT be enough to fragilise your assembly.
KTC Windows do it with sealed double glazing, but at 1000euros a window better to sort something out yourself.
They use laminated glass and security film, I would suggest using the same.

Or, to go back to the system with a breather, you could channel the breather through a little dessicator filter.
IMHO the completely flush mounted glass will look very elegant; it's quite fashionable these days, the big MPVs use that style.
BUT are you sure you want a window that you can't open? One thing you need in a small camper is ventilation, and windows are a good way to air the interior.

If you're talking about windows in the exterior part of the lifting roof, then they only have to be flush on the inside. With the previously mentioned recess you could mount a seitz (or copy) window without the interior cassettes. That would have no protrusions towards the interior. Ok it's not going to look nearly as cool as a flush exterior, but it would open.

These are just my analyses of the potential issues you might be faced with; please don't get angry with me, I didn't knock the idea, I actually quite like it.

 

[pods8]

No anger at all LukeH, I'm posting here to discuss the idea, constructive criticism is what its all about.

For starters the recess for the glass would be put into the foam prior to hand laying up the glass and painting the camper (actually the core in the window frame area may be wood as well but that has little effect since it will all be glassed and finished the same way). After all that is when I'd want to glue in the glass.

I'll need to research the desiccant rails, I'm not familiar with them.

Bear in mind I'm not trying to do all windows like this, I will most definitely have opening windows elsewhere. There are a few areas where something like this might be nice depending on what configuration I pursue (single overlapping hardwall or double overlapping hardwall pop up).

One option I just thought of while reading your response would be to glue in the exterior window and then make a flush fit removable frame for the interior portion. That would allow taking that interior window out to clean things periodically if required. The interior wouldn't need to be moisture tight (if fact it would be better if not) like the exterior...

One of my big questions is has anyone glued in windows before? Can you just mask of the glass and camper exterior and fill the gap flush with adhesive (similar to caulking) and then peel off the tape, potentially needing to scribe the interface line with a razor first?

 

[LukeH]

I watched a carglass technician replace my windscreen recently.
He just pumped tons of adhesive onto the overlapping surfaces, then squished the screen on so lots came out at the edges. Then he scraped around with a spoon-like tool and cleaned up with acetone.
It reminded me of when I stuck on the hand wash basin at home, except he cleaned around the edges much better than I could.
I guess masking tape could help, cos the glue is really very very sticky; but he didn't use it.

HTH
Luke