22 BHM window installation.

Joined
Apr 7, 2018
Posts
18
Likes
13
Age
31
Looking to get some thought/ constructive criticism.

I have my precut margaurd windows ready to install. I was going to 4200 with stainless screws and raised washers. first time doing this just seeing if anybody had any pointers. Thanks. 96EC07FD-A6AC-4BDA-8E57-5FFB27EC483B.jpeg
 

Genius

Captain
Joined
Feb 11, 2016
Posts
3,538
Likes
1,966
Location
Rhode Island
Hopefully Brooksie chimes in, the lexan authority. I think 4200 or silicone would be fine. Mine are clear silicone and don't leak, probably have been in for 8 years? Builder put them in with flat head screws, heads on the inside (I thought was strange). Used finish washers for the heads and large fender washers for the glass side. He trimmed the screw lengths off, but some were pretty sharp. It tore up some of my clothing as I passed along the side of the house. The sharp and protruding pieces had to be ground down to make it workable. I think heads on the outside make the most sense.
 

Genius

Captain
Joined
Feb 11, 2016
Posts
3,538
Likes
1,966
Location
Rhode Island
We use butyl tape. It’s a easier to clean up if you ever have to take the windows of and reinstall them.
I've used butyl tape for framed windows, and really like using it. How does it look with Lexan where you can see the tape below it? Also, how do you handle the bolt holes? any pictures? thanks
 

Eastporter

Captain
Joined
Sep 1, 2011
Posts
3,435
Likes
1,062
Location
MA
Boat Make
Sold- 20' Eastporter (Rebuilt 2011) 22' Pearson Ensign
marine silicone
 

Prdlobster

Senior Member
Joined
Dec 25, 2011
Posts
394
Likes
168
Location
Pt Judith RI
I've used butyl tape for framed windows, and really like using it. How does it look with Lexan where you can see the tape below it? Also, how do you handle the bolt holes? any pictures? thanks
I’ll be down on the boats later today and snap a few pics for you. We tighten up on the bolts after the first summer after the windows have been installed and trim the excess drool off after it expands a little in the heat. We always use black tape...maybe the white wouldn’t expand as much.
As far as the bolt holes go, all my boats are steel so it’s gonna be a different application then most guys on here. We just drill the holes in the steel a little bigger then the bolt so we can put the four coats of paint in the hole and still run the bolt through without chipping the paint. The holes on the windows themselves we keep pretty tight. We use all 316 SS hardware. For washers we use the ones that have the little rubber grommet attached to them on the outside to help seal. We dont put any silicone or anything like that when we pass the bolts through.
 

Genius

Captain
Joined
Feb 11, 2016
Posts
3,538
Likes
1,966
Location
Rhode Island
I’ll be down on the boats later today and snap a few pics for you. We tighten up on the bolts after the first summer after the windows have been installed and trim the excess drool off after it expands a little in the heat. We always use black tape...maybe the white wouldn’t expand as much.
As far as the bolt holes go, all my boats are steel so it’s gonna be a different application then most guys on here. We just drill the holes in the steel a little bigger then the bolt so we can put the four coats of paint in the hole and still run the bolt through without chipping the paint. The holes on the windows themselves we keep pretty tight. We use all 316 SS hardware. For washers we use the ones that have the little rubber grommet attached to them on the outside to help seal. We dont put any silicone or anything like that when we pass the bolts through.
Do you see any leaching from the black butyl tape? I've been told, and have used white to prevent this. Thx
 

Prdlobster

Senior Member
Joined
Dec 25, 2011
Posts
394
Likes
168
Location
Pt Judith RI
Do you see any leaching from the black butyl tape? I've been told, and have used white to prevent this. Thx
yes after a while it does leach. It does clean up with light coat of WD-40 or brake clean on a rag. Not sure how that would effect fiberglass
 

Brooksie

Captain
Joined
Mar 25, 2013
Posts
1,377
Likes
512
Location
Cape Cod
Boat Make
Bruno-Stillman 35
I have had good luck using the Lexan silicone sold at Home Depot and it's inexpensive or black 100% silicone. I would not use 42/5200 as it may damage the Lexan. Drill oversize for the screws to allow for difference in thermal expansion between Lexan and material you are mounting to. Pan head screws are fine no washers needed really... Flatheads could wedge the Lexan, it won't crack like Plexi but it will give you a strange effect when you look through with polarized glasses. Make a trial fit, mark and cut the masking paper, mark the cabin for masking in and out. I use silicone dots, they come on a sheet peel & stick, the smallest ones I can find, and I apply them all around to keep from squeezing out all the caulking/sealant when the screws are snugged down. Butyl tape would be OK too,not a big fan b/c it ie the "gift that keeps on giving" squeezing out months after.
Check the date on the black silicone b/c it is not a fast mover and can be outdated,
 

Genius

Captain
Joined
Feb 11, 2016
Posts
3,538
Likes
1,966
Location
Rhode Island
I have had good luck using the Lexan silicone sold at Home Depot and it's inexpensive or black 100% silicone. I would not use 42/5200 as it may damage the Lexan. Drill oversize for the screws to allow for difference in thermal expansion between Lexan and material you are mounting to. Pan head screws are fine no washers needed really... Flatheads could wedge the Lexan, it won't crack like Plexi but it will give you a strange effect when you look through with polarized glasses. Make a trial fit, mark and cut the masking paper, mark the cabin for masking in and out. I use silicone dots, they come on a sheet peel & stick, the smallest ones I can find, and I apply them all around to keep from squeezing out all the caulking/sealant when the screws are snugged down. Butyl tape would be OK too,not a big fan b/c it ie the "gift that keeps on giving" squeezing out months after.
Check the date on the black silicone b/c it is not a fast mover and can be outdated,
good point about the damage from 4200/5200. How do you keep the air bubbles out of the silicone when you tighten the hardware? Any tricks.
 

Brooksie

Captain
Joined
Mar 25, 2013
Posts
1,377
Likes
512
Location
Cape Cod
Boat Make
Bruno-Stillman 35
Never had that problem. Once I get everything masked off holes drilled, trial fit, I am not shy with the silicone so I get complete squeeze out in and out. Then walk away. Next day cut excess away with razor and pull masking. I hate silicone but it is the cprrect stuff for Lexan.
 

Carl Berg

New Member
Joined
Jul 7, 2018
Posts
5
Likes
0
Age
28
Through-bolting with button head socket bolts and crown nuts on the back looks pretty clean
 
Top Bottom