Bomar Hatch Lens Replacement

[sailingchiro]

I have 12 hatches and did not want to spend alot of money to replace lenses. The size of lens is 3/8" on my lewmars. My supply house had 3/8" scraps about 2' by 2'. Perfect. Each was about $25 apiece. I used a laminate trimmer with a trim bit for laminate counter tops. Used $1 spring clamps (six) to clamp old to new and took about 3-5 minutes to cut out new lens. I made a bunch of plastic chips. The 795 takes along time to set up. Could be several days but it stays pliable and easy to clean.
The first two lens, I took the time to mask off the frame in and out and was very precise. Took probably 2 hours each.
The last few lens, no masking what so ever and just used razor blade to trim excess 795. The non-precise lens look better and sealed better as the 795 oozed out as I pressed in the lens. Go figure. Each took less than 30 minutes. Basically I put 795 in frame, pressed in lens, then put in 795 in space between lens and frame and let dry (could be several days). Came back and use razor blade to trim excess. Easy as pie.
My old lenses were very easy to cut out because the 795 was still pliable. I left my edges unsanded to take sealant better. Lexan or acryllic. I don't know. Our hatches have covers on all the time, I didn't care. Some of mine are acryllic and some are Lexan. I can let you know which will craze first.

[sanibel sailor]

Beware 795 has limited shelf life, even unopened. Then gets slow to cure or no cure... it is a pain if that happens.

[dennismenace111]

How did you deal with the 795 oozing out on the inside. I replaced my lens a few months back and had a mess inside the boat where the sealant oozed out when I pushed tge lebs into the frame.

[sailingchiro]

It didn't ooze enough to drip. I found 795 is like 5200, the more you play with it, the more messy it gets. seal it up and let it dry, then trim after it dries. I found more is better inorder to have a nice straight cut flush with the frame and lens on outside and even with frame on inside.

[NSboatman]

Originally Posted by DougR

When I replaced the lens in my 24 inch Bomar, the lens that came out was about 1/8" lexan, and very scratched. I replaced it with either 3/16 or 1/4" acrylic, and that's plenty thick as the three aluminum cross bars provide support. If you use 1/4" or thicker a slight bevel on the edge works fine.

As mentioned, Dow Corning 795 is the stuff to use to seal the new lens. My installation is about 10 years old and still no leaks.

DougR

Thanks Doug - stripped the lenses out of my hatches tonight. they are original, and are 3/16" thick lexan.


I'm thinking i'll replace with 1/4" lexan. I like how tough it is... still debating the VHB vs DC795 approach... may try the VHB first to see how it goes, and if it looks good, go that way for all.



thx-

[Daniel Grant]

I have a Bomar on my Columbia. I ordered a replacement "glass" from them. I cleaned the aluminum frame with a metal prep, then primed and painted it. I then installed the new glass using the tube of adhesive they sent. It was a commercial GE-SSG2000 sealant and adhesive. This is used to seal windows on skyscrapers. When finished it looked new and it has been 6 years withoour a problem. I liked the GESSG2000 I used it when I replaced all the windows. It has also been 6 years and none have ever leaked a drop. It is not easily acquired. I had a glass place order it for me and also talked to GE directly and they sent me two tubes. Best sealant, adhesive I have ever used. The GESSG2999 I used was black. I do not know if it comes in any other color. It does not show anyway.

[sailcrazy]

A word of caution....we replaced the lens of our Lewmar hatches about 8 years ago. The last 5 years we've been in the Caribb, and left the boat up on the hard over the summer/hurricane season. And we neglected to cover the hatches. While we survived the hurricanes (IRMA, etc) without issue, the blowing sand/dirt/grit from the yard is like sandpaper to the hatches! We get light thru ours now, but that's about all-no visibility!

[thereefgeek]

We have the same hatches and completely restored them about 4 years ago: https://svrambleon.com/glazed-projects/

Hinge pins and all the dogging hardware pop out with a hammer and a punch, we had them sandblasted, and then I primed them with zinc phosphate and painted them with Interlux Perfection Plus. I got acrylic (NOT Lexan) from TAP Plastics and cut the lenses to fit. DOW 795 is about the only sealant that works. I tried SIKA twice and and they leaked.

If you're worried about UV, maybe look into some Welcome to Outland Boat Hatch Covers | Outland Hatch Covers

https://www.youtube.com/watch?v=u24aq3KROUI&t=147s

[WSMFP]

Originally Posted by CarlF

Call Hatchmasters. They've done thousands. Not much more expensive than doing it yourself but it gets done right the first time.

https://hatchmasters.com

Also, their views on Acrylic vs Polycarbonate (Lexan)

https://hatchmasters.com/tonys-blog/

I called them for a quote and they are 400 each for my smaller bomars and 500 each for the larger ones. That's to replace lens and gasket. With an 8 week backlog right now.

[SuW]

Originally Posted by Daniel Grant

...I cleaned the aluminum frame with a metal prep, then primed and painted it. I then installed the new glass using the tube of adhesive they sent. It was a commercial GE-SSG2000 sealant and adhesive. This is used to seal windows on skyscrapers. When finished it looked new and it has been 6 years withoour a problem.

Yes, we used this GE sealant to seal a new Lexan window in a Bomar hatch. (That was after using the 795 sealant which failed within a year).
Because the paint on the hatch surround was in bad condition we scraped, sand-blasted, prepped the aluminum and then painted with 2-part primer and epoxy. It took a long time. It looks like new 5 years or more later.

[Jack Buck]

I have a very similar hatch and we removed carefully and were able to get out without too much trouble. We then took to a local plastics company and they made a new lens from Polycarbonate. We used a special adhesive/sealant to apply. Worked great so far..

[wingssail]

A problem we have encountered is failure of the sealing compound in hot climates. We have very large hatches (31"x31") and I believe that the acrylic plastic expands and contracts enough to break the seal. At any case they often leak within a few months. We've used a variety of sealants, including Dow products and Sika 295, same results. We've used cleaners and primers. We used butyl tape which melted in the heat and dripped into the cabin, quite messy.

My latest theory is that I need to install the new lens when it is very cold, say below 60 degrees (that is cold for Mexico). The lens will not contract any further but it will expand in the heat of summer. I think the sealant will hold up better under compression than tension. At any rate we're trying it this winter.


AND, I am interested in the 3M VHB tape.

[Manateeman]

Hi. There is a lot of good advice here if you wish to replace the “lense”.
I purchased 4, 24” Bomar Ocean hatches. Before we could even finish building, we had serious problems. These are extruded frames...unsuitable for serious offshore cruising. Avoid extruded frame hatches.
You are so fortunate to have the far, far stronger cast hatches.
We contacted Bomar. One year had past. We were told any warranty was expired. Period. In 50 years of building yachts, I have never experienced this complete rejection of what we felt was a legimate claim. The sealing gasket shrunk as it was only attached by superglue. We filled the “vent” slots with 5200. Still leaks like a sieve and we had yet to go to sea. LOL.
Our temporary fix. Replace the “lense” with aluminum which is TIG welded with support bars . The final solution for true offshore. Fabricate our own TIG welded aluminum hatches based on proven designs.
Boatbuilders will not often admit mistakes but purchasing Bomar Offshore extruded hatches was my $4000 error. Pure dangerous junk. Seriously dangerous.
kindest regards from an old school builder...Mark

[SabreME]

A different perspective, but I used Hatchmasters after considering the cost of supplies, complexity of this job, and the fact that I wanted them to be water tight. They were not inexpensive, but they came back completely overhauled and with gleaming new lenses. I would highly recommend Hatchmasters if you are looking to outsource this one.

[David Mathis]

My 1997 43' Wellcraft Portofino has Bomar hatches of about the same size. A few years ago, due to salt stains, hazing, a corner lifting, etc. I decided to replace the lenses. The old ones came out with little effort. Bomar ho longer has replacements, or didn't then. I replaced them with 3/8" dark acrylic cut by a local glass company. After unsuccessfully trying a couple different silicone sealers to seat them, I called Bomar for a recommendation. The sealer they recommended worked fine. Using painter's tape on the lens and the metal hatch before applying the sealer stopped a potential mess from sealer oozing from the space when pressed into place. That was several years ago and they're still in place with no leaks. To further reduce the sun cooking the inside of the boat, hatch covers were made from Sunbrella. I highly recommend these.