WINDOW REPLACING AND WHICH SEALER

kappykaplan · May 21, 2021

Dow 795 is great in this application.

kloudie1 · May 21, 2021

I am preparing to do that job on my H34 . I am going to use 3M VHB tape to bond the plexi to the fiberglass and Dow 795 around the perimeter after bonding. Good cleanup is a must and some surface roughing and a good wipe down to degrease/de-silicon is mandatory.

Hayden Watson · May 21, 2021

We just installed the first of 7 portlights with Dow 795 today. It is a smooth flowing silicone adhesive and easy to work with. We taped the boat and left the paper on the plexiglass and used a lounge depressor to sooth it out an create a nice cove.
One thing to note. It is a VERY SLOOOOOWWWWW CURING PRODUCT! at 77º and 50% RH it takes 3 hours to skin and curing time is 14-21 DAY!!! You do not reach maximum full adhesion until 14-21 days.

This is nice when you are applying the product because there is no rush to get the smooth-out and tape stripping done but then you need to wait!
BTW, if anyone is in my part of the country, I will have several tubes left over because I estimated that I would need to buy 5 tubes and got a case of 12 for only the cost of 6.

BigEasy · May 22, 2021

Hayden Watson said:
We just installed the first of 7 portlights with Dow 795 today. It is a VERY SLOOOOOWWWWW CURING PRODUCT! at 77º and 50% RH it takes 3 hours to skin and curing time is 14-21 DAY!!! You do not reach maximum full adhesion until 14-21 days.
This is nice when you are applying the product because there is no rush to get the smooth-out and tape stripping done but then you need to wait!

So, what's the best time to remove masking tape after smooth out?

Hayden Watson · May 23, 2021

BigEasy said:
So, what's the best time to remove masking tape after smooth out?

imediatly after smoothing out the surface. You do not want to wait until is skins over or it will tear.

AndyBC · May 23, 2021

twodzusfittings said:
My long smoked plexi glass windows on my O'day 30 CB are cracked and leaking. Nothing major, just enough to be very irritating. I think my local glass shop can provide me with the replacements if I supply him with a card board pattern. What is the best sealer to use. My last sealer was life caulk in black and was pretty useless. Also, apart from cleaning the cabin top and wiping the area with Acetone, is it a good idea to just scratch the surface area where sealant will be applied to help it bond? As always all responses are gratefully received.

Life Calk, as you discovered, is not the correct application for port lights. It's designed to bed deck hardware, thru-hull fittings, and underwater. Life Seal, which is a combination of silicone + polyurethane, is designed specifically for plastic port lights and what I have used to successfully seal my beckson opening port lights.

Hayden Watson · May 24, 2021

Yesterday I finished installing my fixed portlights in my 88 C30 which a "frameless" system. In the originals, the lens was held in place with screws around the perimeter but I used UHB tape and Dow 795. Here are some photos. The three vertical strips of white tape form a hinge to allow the lens to be properly aligned and then rotated up out of the way to strip the paper off the back and wipe down with alcohol before sticking to the tape.

nramsey · May 24, 2021

Check out the detailed instructions from "Main Sail", or "Marine How To" as Rod has named his business now.
Bullet proof step by step instructions. (with pictures

)

Gary Ryan · May 25, 2021

Just did my skylight windows as they were leaking. Used Dow 795. No more leaks.

Hayden Watson · May 25, 2021

nramsey said:
Check out the detailed instructions from "Main Sail", or "Marine How To" as Rod has named his business now.
Bullet proof step by step instructions. (with pictures )

I have seen his great and very detailed instructions on installing an opening port but nothing for installing the frameless glue in place fixed port like my C30 has. Can you provide a link or address?

Hayden Watson · May 25, 2021

Gary Ryan said:
Just did my skylight windows as they were leaking. Used Dow 795. No more leaks.

My V-berth hatch lens is the last one to do.

kappykaplan · May 25, 2021

Hayden Watson said:
Can you provide a link or address?

Try here: Marine How To - DIY for Boaters - Marine How To

nramsey · May 25, 2021

My mistake. It wasn't Rod Collins, it was Don Casey in Sail Magazine.
DIY: Replacing Fixed Portlights
This is the updated version without the pictures

.
I have a PDF of the original version.
Pay attention to the blackout paint type and procedure!

kloudie1 · May 25, 2021

Here is Allan's post on the forum : Hunter 34 Owner Modifications and Upgrades (sailboatowners.com)
and the SAIL article: DIY: Replacing Fixed Portlights - Sail Magazine
and youTube: How To Install Fixed Portlights - YouTube

Hayden Watson · May 25, 2021

I used Don Casey's article for the basis of my replacement but used a different slightly thinner VHB tape then the 4991 he called for because it only comes in light gray which causes the problem with shadowing he described. I covered all of the white with the black VHB x 1/2" wide and then infilled the radius corners with little bits to cover the exposed whiteness there. I then pinched the tip of the silicone tube down to a very narrow slit that allowed me to fill from the bottom of the void so that it got all the way down to the tape. A bright light from the outside confirmed not white showing through.
I used the dark smoke cast acrylic.

Hayden Watson · May 25, 2021

I also watched Boatworks today video and his anxiety on getting it located correctly when setting it onto the VHB was why I used the tape hinges. It made it so easy to place. Position the lens where you want it before pulling the backing film on the VHB. Mark reference lines horizontal and vertical on all edges. Apply several tape hinges to the top edge (I used 3m Preservation Tape which is great stuff to have on a boat) Hinge the lens up and pull the film and paper. swing it down into place, checking the reference lines before touching down.
The tape was plenty strong enough to put the small bend into the lens to match the cabin curve.

Hello Below · May 25, 2021

Hayden Watson said:
I used the dark smoke cast acrylic.

Hayden, I have to replace all my fixed frameless ports. I was surprised when you mentioned a 2 week plus curing time. But confirmed it on the product spec sheet. If I may ask, what was the thickness of the of your acrylic and ball park figure for the acrylic Thanks.

WINDOW REPLACING AND WHICH SEALER

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