How to glass a window rebate into a panel?

Thanks for some helpful suggestions.
Mess inside the boat is a non issue at the moment as we're midway through replacing & reinforcing the keel floors.

I suspect I would need to make my own plate as the curvature on the cabin side is large enough that flat plates would stand proud in the middle.

 

If grinding (and painting) is not a problem then your first post procedure is eminently doable. Grind the edges of the existing laminate to a feathered edge, then make a (much larger) MDF mold, hot glue it to the outside and laminate the lip in one go. I would want at least 4-5mm thickness if you go solid glass. The end result should look like the lip was molded in from the start.
Good luck and post pictures.

 

Thanks.
I was was thinking to basically match the existing laminate of the coach roof on the lip, but exchanging a couple of the 600csm layers for 600 biax. Laminating from the inside & staggering the layers out.

After making the lip, if I still need some additional rigidity I can core around it later on. I'll be sure to post pics.

 

Why would anyone want to use acrylic when polycarbonate is so much friendlier to machine? Sorry, but I really hated trying to make window panels with acrylic. Yes, hardness is different. But curve cutting acrylic without shattering is a trick I've not learned.

If using the word acrylic is just as a generic reference; we need to remember others may read here.

 

I had planned to use Acrylic.
I generally don't cut it myself, I make up a template & my local plastic sheet supplier will cut it for me for almost less than the price of a new set of jigsaw blades.

Acrylic seems to resist UV and be more scratch resistant. I've seen people argue for both materials.

 

I don't find acrylic hard to cut at all,you need a metal cutting type jigsaw blade and the coarser types are better.Its best to use a professional jigsaw as the DIY level variety don't have the power or the pendulum cutting action by and large.Better yet is a bandsaw as it carries the dust away much more effectively.Polycarbonate is no harder to cut but it does have a couple of disadvantages in that it does scratch relatively easily and also moves a lot with thermal expansion.Any sealant has to be selected with this very much in mind.

 

Just to note, I would never free hand cut anything like this that I want to look good, I've got a professional level jigsaw, but over a long distance its very easy to wander ever so slightly from the line & then that's the whole piece ruined.
I'd make a template, perfect that, cut close to it & then use the router for the final trim.

 

Isn't it possible to apply the panel on the inside and then put trim and stop in place? Something like 12mm acrylic with a 12mm fiberglass trim epoxied and then another piece of fiberglass that acts as a stop screwed to the trim? Then the screw are inside and only support the glue cure.
And if this is the plan; I apologize. You could finish with uv resistant glazing.

I installed the aluminum trim ones in a new build and if they fail; this would be my redo...

 

@fallguy I'm a bit confused by your description.
You mean put the perspex on the inside of the cabin side?

 

Yeah, why not?

 

You could make an interior ring with the same material as the window and bond them with adhesive.
TAP Article: Best Glue For Plexiglass : TAP Plastics https://www.tapplastics.com/product_info/diy_articles/plexiglass_glue

 

Its not really the effect I'm going for.
It wouldn't be flush, but recessed, & the lip would catch & hold water due to the shape of the cabin side.

I'd rather go for bonded to the outside then inside if I went down those lines.

@gonzo Its a good idea, but I wonder if I'd run into trouble with the different expansion rates of fibreglass & acrylic, sika recommend a bead thickness of around 5mm for my windows due the size of them and I've seen plenty of acrylic windows damaged by fasteners over time due to the same thing.
Plus I think with glass & gelcoat, I'll be able to make it look pretty factory.

 

The main reason not to put the window in from inside is safety. By having it on the outside,any force applied pushes it into it's mounting surface and spreads the force over the whole of the mounting surface.By fitting it to the other side of the superstructure the situation changes so that any force applied is pushing it away from it's mounting surface and if fasteners are present,it concentrates the force at those fastening points.

The point about water gathering is a good one and that sort of thing leads to green stains developing in a surprisingly short time.

 

It seems the ideal is then to create the recess in the superstructure. Here, it seems unlikely this boat would encounter forces of the sea on the lite large enough to blow it in. I had always considered that for forward facing.

It just looks better to me for the extra glass to be inside.

What is the sikaflex recommendation?

Thanks @wet feet

 

My boat pre-dates RCD categories, but it would probably fall around C / B.

The North Sea & my local area can both get pretty nasty when they want to be, either way, I'd hope the window never has to take a wave, but if it does then I would like it to be strong.
Either way, I wouldn't go to that work for the acrylic on the inside, aside from the reasons mentioned above, I just wouldn't like the look of it, and really after the functionality of the thing, its my own personal boat, I like her to look good.

Link to the Sika guide:
https://usa.sika.com/content/dam/dms/us01/d/Bonding and Sealing Plastic Windows.pdf

Link appears to down right now.
Essentially you have to leave an expansion gap around the window which is filled with Sika & smoothed over & have a minimum bead thickness of sealant, both of these are determined by the longest edge of the window.