Sealant for Plexiglass Hatches

[svcattales]

I'm replacing the plexiglass in a couple Lewmar overhead hatches and need suggestions on proper sealant. A friend tried silicone and the glass popped out because there is not enough adhesive in the silicone. Suspect their is some special stuff for this job. Any ideas?

[Talbot]

Lewmar quote a "silcone sealant" Sikaflex would be yoo aggressive and stop you ever being able to replace the plexi again. Personally I would use Wurth Adhesive Sealant, but dont know if it is available to you (made in germany) Not so aggressive as the sika, and remains useable for much longer in the tube, but is vastly superior to normal silicone

[irwinsailor]

I'm sorry to disagree with Talbot but Sika does make a sealant that would do the job. I called the rep 3 times for my window replacment and they will point you in the correct direction. I am very happy with the product and service.

[irwinsailor]

James town Distributers is the best place that I found to buy Sika flex products.

[Talbot]

Well aware that Sikaflex make a product suitable for this use, However it tends to seal too well, and the next time you have to re-new the perspex, it can be quite a job if you have used Sikaflex.

[irwinsailor]

The Sikaflex rep told me that any auto glass company can get the plexiglass out just as they would do a windshield. However I would be more concerned that the sealant was not strong enough than to strong.

[capt lar]

I still believe silicon is the correct answer. I have been confirming that same question since I have one to do myself. If you have adequate surface area, proper cleaning/prep, warm and dry, the silicon should bond no problem. I am just starting to work with sika-flex products, so I can not comment either way.

Larry

[irwinsailor]

You must be very careful with what you to bond plastic. Non of the 3M products were to be used on acrylic. I checked into Dow Corning products and again they were not to be used on plastic. Sika Flex (as far as I know) is the only system of products for bonding acrylic.

[svcattales]

Thanks for all the inputs. I talked to a guy from "Maritime Plastics" company in Annapolis. He highly recommended a GE product called Sil Pruf, SCS 2003. He said it is a silicone base with some polyurethane adhesive mixed in. This guy repairs lots of hatches and never had one come "unglued." Think I'll give it a try.

[Jentine]

This (January 2006) months issue of Sailing Magazine has an article detailing the method and materials required to change the acrylic lenses in hatches. The author's recommendation for sealing material is Sikaflex 295UV, Sika-cleaner 226, Sika-primer 209. He states: "There are several sealants that could be used, but I hav had the best results with Sikaflex 295-UV".
Were I to change the lenses in my hatches, I would go with the article. It is well thought out and finely detailed.

You can find the article at http://www.sailingmagazine.net/technique0106.html

[capt lar]

Jim - Good article. After reading, I am inclined to go with the 295 UV. Do yoy know if the cleaner and primer are anything special, or can we use products already on most of our shop shelves ?

Larry

[Jentine]

When the hatch lenses on my last vessel needed replacing, I replaced the whole boat.
Jim

[irwinsailor]

The cleaner is some type of alcohol, the primer is like a black paint that acts like acid. I have not run into anything like it. It etches the plastic.

[capt lar]

irwinsailor - I ordered all 3. The primer is the big $ and I assume it is formulated to bong with the 295. I figured the cleaner was no biggie, denatured would probobly be fine. I'll let all know when it arrives.
Jim - I came close with a Sabre this fall. Thought I should finish one boat before I bought another. Besides, the Sabre had more leaks than my Bristol.

Larry

[irwinsailor]

Larry, did you order from James town?