Aluminium frames, changing to plexiglass

[Garethh]

I have bought a dawncraft cruiser 30ft, the windows are the original aluminium sliding ones but a few of the originals windows are broken and wanted to replace them with plexiglass, was was gonna buy some sheets and cut them my self, I was wondering 3 things

1) is cutting them myself a good idea and thickness of plexiglass?

2) how would I go about putting them in?

3) how do I seal them?

I'm very new to all this and would really appreciate the help.

Edited August 2, 2023 by Garethh

[GUMPY]

Why not use proper glass, any half decent glass merchant will be able to cut them from a template and send them off to be toughened.

Plexiglass/Acrylic will scratch and or discolour. 

[Tony Brooks]

25 minutes ago, Garethh said:

I have bought a dawncraft cruiser 30ft, the windows are the original aluminium sliding ones but a few of the originals windows are broken and wanted to replace them with plexiglass, was was gonna buy some sheets and cut them my self, I was wondering 3 things

1) is cutting them myself a good idea and thickness of plexiglass?

2) how would I go about putting them in?

3) how do I seal them?

I'm very new to all this and would really appreciate the help.

 

1. Doable with a fine jigsaw for curves and care, but you need to keep the cutting face cool. maybe spray with water or direct an airline blowgun onto it.

 

The thickness is governed by the size of the channel in the frame, but you need to allow for the rubber sheet that is often used to seal the glass into the frame.

 

2. Not sure what you mean, the sliders into the frames or the frames into the boat.

 

3. Glass to frame, usually sealed by rubber strip over the glass and down each side & pushed into the frame.

 

Frame to cabin side closed cell neoprene gasket or the mastic strip sold for the job.

[Garethh]

40 minutes ago, GUMPY said:

Why not use proper glass, any half decent glass merchant will be able to cut them from a template and send them off to be toughened.

Plexiglass/Acrylic will scratch and or discolour. 

Sum child's where throwing stones at the boats and broke the windows, so I thought plexiglass would be better as they can't be broken.

20 minutes ago, Tony Brooks said:

 

1. Doable with a fine jigsaw for curves and care, but you need to keep the cutting face cool. maybe spray with water or direct an airline blowgun onto it.

 

The thickness is governed by the size of the channel in the frame, but you need to allow for the rubber sheet that is often used to seal the glass into the frame.

 

2. Not sure what you mean, the sliders into the frames or the frames into the boat.

 

3. Glass to frame, usually sealed by rubber strip over the glass and down each side & pushed into the frame.

 

Frame to cabin side closed cell neoprene gasket or the mastic strip sold for the job.

Thank you for the reply very appreciated Where would I get the rubber seals from, I bought the boat and it has non, so I just presumed I could slide the new plexiglass into place but it seems a bit more complicated than that, do I need any special tools for the job?

[Tony Brooks]

2 hours ago, Garethh said:

Sum child's where throwing stones at the boats and broke the windows, so I thought plexiglass would be better as they can't be broken.

Thank you for the reply very appreciated Where would I get the rubber seals from, I bought the boat and it has non, so I just presumed I could slide the new plexiglass into place but it seems a bit more complicated than that, do I need any special tools for the job?

 

You have not been specific enough to be sure, but I suspect that you are talking about the sliding windows. These might not be in an aluminium frame, they might just be sheets of glass sliding in the frame that is fixed to the boat. Do you have a frame that slides in the main window fame. If not, you might be right in that you can just fit new "glass" but it might need the man frame splitting, so you can fit the new "glass". How about a photo showing the setup.

 

My answers are for generic aluminium famed boat windows, so it is not specific to your boat. Please look at other Dawncrafts or your other widows to see the seals.

 

Typically, you need to split the sliding frame, if you look carefully you will normally see a pair of small screws and the cut ends of the frame. There might be two such joins. You undo the screws and very carefully pull the joint apart, but on no account distort the frame. If the "glass" is not in a frame, you may have to remove the main window frame and split it to get the "glass" in.

 

If the glass is not framed, then the outer "lip" on the channel it slides in would either be lower than the inner one or have holes drilled in it so any water building up in the Chanel can drain way.

 

I am sure Seals Plus Direct will supply the rubber strip once you know the dimensions.

[BEngo]

An alternative to plexiglass/perspex/acrylic/ poly methyl methacrylate would be polycarbonate sheet. Aka Makrolon and other names. It's a lot tougher than acrylic (they make riot shields with it) so will be much more yoh proof than Perspex. There are places on line that will cut to a template.  Acrylic crazes with age, polycarbonate yellows.

If the frame grooves are wide enough, look into toughened glass.  All decent glaziers can get glass toughened, but the minimum thickness is 4 mm AFAIK.

 

[Jess--]

For getting perspex & similar sheets cut ask around to find someone locally who has a laser cutter, most of the commercial ones can cut it with a cleaner / more accurate cut than you ever could by hand (and a hell of a lot quicker).

[koukouvagia]

 

I used this firm to cut polycarbonate windows.  It might be worth asking if they'll cut to a template supplied by you. https://www.cutplasticsheeting.co.uk

I originally used acrylic sheets - a big mistake, they crazed in sunlight.

 

 

[PeterF]

Seals Direct sell a lot of different seals, I have used them but not for boat window seals. https://www.sealsdirect.co.uk/

[Tony Brooks]

A further point as you have not clarified exactly your sliding window design. If it is glass sliding in the main window frame, then often it slides in what I can best describe as a flocked rubber channel. That is a rubber U section pushed into the frame with the inside faces covered in fur.

[Garethh]

On 04/08/2023 at 08:39, Tony Brooks said:

A further point as you have not clarified exactly your sliding window design. If it is glass sliding in the main window frame, then often it slides in what I can best describe as a flocked rubber channel. That is a rubber U section pushed into the frame with the inside faces covered in fur.

Sorry late reply, yeah there the sliding glass in aluminum frames, I think I'm gonna try drill out the pop rivets, as it the only way I can see to get the old glass out and new in, still not sure what material tio use for new windows.

[Mad Harold]

10 hours ago, Garethh said:

Sorry late reply, yeah there the sliding glass in aluminum frames, I think I'm gonna try drill out the pop rivets, as it the only way I can see to get the old glass out and new in, still not sure what material tio use for new windows.

I think the pop rivets are fastening the frame to the cabin.

To replace the glass you will need to dismantle the frames.They are usually held together with steel corner pieces tapped to take a small screw.

They will be corroded so will need drilling out, if they are cross head that's ok, but if slotted they are a sod!

On re-assembly I made new corner pieces from ally and used small self tappers with the point ground off, because it will crack the glass/plastic  if it prodrudes very far.

Polycarbonate is quite cheap, but if you want unbreakable, use Macrolan or it's also called Lexan.