Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 25-02-2021, 06:34   #1
Registered User

Join Date: Jan 2018
Boat: 50ft Custom Fast Catamaran
Posts: 4,881
Window Saga. New Thread. Small Question.

I have my new poly carbonate windows floating in a frame. It’s working pretty well. I’m having just a bit of a problem.

This is the really good poly carbonate. The stuff I had from the beginning. Only in this geographic location do I have this problem and only in the morning as there is a really quick 50 degree change in the temperature of the polycarbonate. And this is what has torn the windows apart time and time again with Dow 795.

At night, it’s about 50į here. Maybe 60. Something like that. Very soon at 9 AM, surface of the poly carbonate heats up to probably 110į. But the inside of the windows is still cold. 50 or 60į. The temperature differential creates more expansion on the exterior of the poly carbonate than on the interior. This causes it to curve and bow out. It does this while it is also expanding more than a quarter of an inch in all directions from the heat.

Once the temperature differential goes away and the entire polycarbonate sheet is 110į, everything is good. It settles back down.

I have solved the expansion issues by floating the windows in frames. You can see the frames on the bottom and top of the windows in this picture. However, in areas where the windows meet each other, where there is a vertical gap between the two windows, I have yet to figure out how to hold that down. Because they want to bow out instead of squeeze up and down into the frames you see in these pics as they are supposed to.

How can I hold the middle of the windows down, in a vertical sense, so that the windows get taller and shorter as they expand and contract, instead of bowing out?
Attached Thumbnails
Click image for larger version

Name:	099E9761-36EF-492F-9FD8-789959EDD517.jpg
Views:	168
Size:	401.8 KB
ID:	233297  
__________________
Epoxy can kill me like a kid smelling peanuts across the lunch room. Even the freshly machined dust from cured epoxy. Please donít suggest using it.
Chotu is online now   Reply With Quote
Old 25-02-2021, 07:22   #2
Registered User

Join Date: Jan 2018
Boat: 50ft Custom Fast Catamaran
Posts: 4,881
Re: Window Saga. New Thread. Small Question.

I thought I would post another picture from inside to make it more clear. See? It is rising up off of the supports. There is nothing holding them in place yet. But I want to make the right move. I donít want to do something wrong. So I thought I would get some opinions on how to best hold these down.
Attached Thumbnails
Click image for larger version

Name:	0B42FDC3-1828-4F7E-960D-3D311DA9483E.jpeg
Views:	130
Size:	390.4 KB
ID:	233298  
__________________
Epoxy can kill me like a kid smelling peanuts across the lunch room. Even the freshly machined dust from cured epoxy. Please donít suggest using it.
Chotu is online now   Reply With Quote
Old 25-02-2021, 08:55   #3
Registered User

Join Date: Sep 2020
Location: Ventura, California
Boat: Toes in the surfline and eyes on tomorrow's horizon
Posts: 314
Images: 11
Re: Window Saga. New Thread. Small Question.

Commercial boat manufacturers don't seem to have the problems with their windows that you're having and their windows are equally as big or sometimes larger than yours.

It's possible that it's your windows which are the problem here and not the way you're trying to attach them.
Rob_P is offline   Reply With Quote
Old 25-02-2021, 09:31   #4
Registered User

Join Date: Jan 2018
Boat: 50ft Custom Fast Catamaran
Posts: 4,881
Re: Window Saga. New Thread. Small Question.

Quote:
Originally Posted by Rob_P View Post
Commercial boat manufacturers don't seem to have the problems with their windows that you're having and their windows are equally as big or sometimes larger than yours.

It's possible that it's your windows which are the problem here and not the way you're trying to attach them.
That’s because they are using glass. This is poly carbonate. I want to use it because it weighs significantly less. I’m looking for ideas on how to capture it. Not how to change materials, please.

Basically, what I have come up with so far, is 1) some sort of H shape channel to go between them, held by the adhesive Thais holding the J channel

2) stuff a bunch of 795 under them, but that won’t work because it will peel it, or

3) put a screw in the middle of each one. But that won’t work either. Because they need to expand and contract.
__________________
Epoxy can kill me like a kid smelling peanuts across the lunch room. Even the freshly machined dust from cured epoxy. Please donít suggest using it.
Chotu is online now   Reply With Quote
Old 25-02-2021, 09:35   #5
Registered User

Join Date: Jan 2018
Boat: 50ft Custom Fast Catamaran
Posts: 4,881
Re: Window Saga. New Thread. Small Question.

And I should add the entire rest of the boat is fine. Only this part which receives the morning sunshine facing east has trouble. I never ran into this before because I didn’t use a dock.

The increase from 50 or 60į to 110į in the sun it’s a lot in an hour or so
__________________
Epoxy can kill me like a kid smelling peanuts across the lunch room. Even the freshly machined dust from cured epoxy. Please donít suggest using it.
Chotu is online now   Reply With Quote
Old 25-02-2021, 13:23   #6
Registered User

Join Date: Jan 2018
Boat: 50ft Custom Fast Catamaran
Posts: 4,881
Re: Window Saga. New Thread. Small Question.

And now that the interior and exterior temperatures are closer, they settled right back down.
Attached Thumbnails
Click image for larger version

Name:	3F673B78-945E-4100-AD52-DE227B0AF518.jpeg
Views:	86
Size:	292.8 KB
ID:	233319  
__________________
Epoxy can kill me like a kid smelling peanuts across the lunch room. Even the freshly machined dust from cured epoxy. Please donít suggest using it.
Chotu is online now   Reply With Quote
Old 25-02-2021, 13:47   #7
Registered User
 
Narfi's Avatar

Join Date: Sep 2020
Location: Bush Alaska
Boat: Bateau FS17
Posts: 123
Re: Window Saga. New Thread. Small Question.

An aluminum H channel secured to the frame?
A composite H channel?

Over sized holes and large area decorative washers? (I don't think it would look as good here though ;/ )

That is a lot of expansion.... Do your upper and lower frames offer enough room?
Narfi is online now   Reply With Quote
Old 25-02-2021, 13:56   #8
Registered User
 
Narfi's Avatar

Join Date: Sep 2020
Location: Bush Alaska
Boat: Bateau FS17
Posts: 123
Re: Window Saga. New Thread. Small Question.

Knowing the expansion, you could control where it goes with slotted holes and screws around the parameter.....

At minimum size the screws are in the outer edge of their slots, when it expands to its max, the screws are at the inner edge of the slot and going each way guides it to prevent expansion from all going to one edge or corner as well as guiding it back to its happy place when done...... seems you will need some sort of VERY flexible and resilient sealant if you have any hope of keeping it sealed though.
Narfi is online now   Reply With Quote
Old 25-02-2021, 14:26   #9
Registered User

Join Date: Nov 2015
Location: Currently in Michigan
Posts: 259
Re: Window Saga. New Thread. Small Question.

You should use the channel to control all edges. It looks like you have plenty of structure to attach the channel to on the vertical seams. you might just need to trim a tiny bit of material off the edges of the panes to make enough space.


Maybe next time you could get a groove CNC routed into the surface of the glazing to hold a PTFE O-ring with some squeeze preload, which could seal on the channel you provide, it would then be more leak tight, even with the expansion. As far as I know all O ring material can be obtained as continuous lengths.
Westcliffe01 is offline   Reply With Quote
Old 25-02-2021, 14:26   #10
Registered User

Join Date: Jun 2019
Location: Rochester, NY
Boat: Chris Craft Catalina 381
Posts: 1,946
Re: Window Saga. New Thread. Small Question.

I agree, channel on all 4 edges is the answer.
rslifkin is online now   Reply With Quote
Old 25-02-2021, 14:28   #11
Registered User

Join Date: Jan 2018
Boat: 50ft Custom Fast Catamaran
Posts: 4,881
Re: Window Saga. New Thread. Small Question.

Quote:
Originally Posted by Narfi View Post
Knowing the expansion, you could control where it goes with slotted holes and screws around the parameter.....

At minimum size the screws are in the outer edge of their slots, when it expands to its max, the screws are at the inner edge of the slot and going each way guides it to prevent expansion from all going to one edge or corner as well as guiding it back to its happy place when done...... seems you will need some sort of VERY flexible and resilient sealant if you have any hope of keeping it sealed though.

Thatís a thought I never had. Thatís a good one. I like the H channel a little better, because it will look nicer, but it would be possible to have slots and screws. I never even thought of that.

They donít leak now, because the rain just goes over the top frame, down the window and off the boat.

When itís raining, the damn sun that causes them to lift is gone and they are cool so they lay flat and no water gets in.
__________________
Epoxy can kill me like a kid smelling peanuts across the lunch room. Even the freshly machined dust from cured epoxy. Please donít suggest using it.
Chotu is online now   Reply With Quote
Old 25-02-2021, 14:33   #12
Registered User

Join Date: Jan 2018
Boat: 50ft Custom Fast Catamaran
Posts: 4,881
Re: Window Saga. New Thread. Small Question.

OK. I guess the channel wins out. Maybe I can try with the H channel.

Then on the very end just use the normal J channel that I have.

I think this is going to work. And it’s nice to have not even half the weight of glass.
__________________
Epoxy can kill me like a kid smelling peanuts across the lunch room. Even the freshly machined dust from cured epoxy. Please donít suggest using it.
Chotu is online now   Reply With Quote
Old 25-02-2021, 14:54   #13
Registered User

Join Date: Nov 2015
Location: Currently in Michigan
Posts: 259
Re: Window Saga. New Thread. Small Question.

Did the supplier not offer white for the edge masking ? That black trim tremendously increases the heat stress.
Westcliffe01 is offline   Reply With Quote
Old 25-02-2021, 15:09   #14
Registered User

Join Date: Jan 2018
Boat: 50ft Custom Fast Catamaran
Posts: 4,881
Re: Window Saga. New Thread. Small Question.

Quote:
Originally Posted by Westcliffe01 View Post
Did the supplier not offer white for the edge masking ? That black trim tremendously increases the heat stress.
There is no supplier. I did everything.

I realize Black increases the heat stress tremendously. But also, I have a look to a accomplish.
__________________
Epoxy can kill me like a kid smelling peanuts across the lunch room. Even the freshly machined dust from cured epoxy. Please donít suggest using it.
Chotu is online now   Reply With Quote
Old 25-02-2021, 15:14   #15
Registered User

Join Date: Jun 2019
Location: Rochester, NY
Boat: Chris Craft Catalina 381
Posts: 1,946
Re: Window Saga. New Thread. Small Question.

There's always the half-joking worst case answer to reducing the heat stress: Some kind of fan setup to blow a bunch of air across the windows to cool them when a significant heat differential is detected. I wouldn't actually recommend doing this, but it might work...
rslifkin is online now   Reply With Quote
Reply

Tags
wind

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Huge fonts in Options window and Chart Panel Options window scud OpenCPN 2 27-03-2019 04:06
Saga 409 dinghy davits question a22dphd Monohull Sailboats 6 01-03-2016 20:25
Any New Developments In The Bounty Saga? GaryMayo The Sailor's Confessional 17 24-10-2013 09:41
Window screen to cover a sliding window sdowney717 Construction, Maintenance & Refit 2 14-11-2012 06:59

Advertise Here


All times are GMT -7. The time now is 07:09.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.