Overhead hatch replacement F36

[mike cunningham]

Instead of paying $450 for a hatch glass replacement I got the cut glass for $50 sealant for $15 and new gasket for $32 after a little elbow grease I had new glass installed and looking great. The Dow sealant is bulletproof by the way so long as you are very careful to keep your surfaces clean.

Mike , I just wonder what kind of caulk have you used ? 'Dow' what is it exactly ? I have some sort of small relevant project going on over this winter. I try to fix my main hatch which has dark acrylic sliding 'lid' with teak trim / handle attached to it. Teak peace wobbles on the sliding lid . ( Teak has a small groove where acrylic lid goes into and join is secured with 4 small screws and some sort of caulking or glue, acrylic cracked around screw wholes and wood trim wobbles now.) I am trying to think what kind of glue / caulk to use to join wood with acrylic ... and all those $80 per 10 oz. special brand name acrylic primers do not look very appealing so far..
Thank you.

Sorry about not being more specific during original post, I was away from the house and didn't have access to the material. I just went out and got a cylinder of the stuff from the garage. It is Dow Corning 795 Silicone building sealant. I have been told this is the stuff used to seal exterior glass on commercial buildings among other things. It is also what is used by "select plastics" which is the outfit who will replace the glass for you if you send the the hatch cover. I have the black color but I believe it is also available in white. You can easily go online and investigate its properties but it has been superb so far in keeping my hatches watertight. I did the job about 3 years ago now. It is very messy to use. Need to be super cautious mask anything you want to protect. It clearly does an excellent job bonding acrylic to aluminum (my hatch material) I expect it would work for teak as well but you would need to do your due diligence on that.

[rds]

Thanks for the detail info. Friend of mine tried to replace acrylic lens in his hatches some time ago. His previous several attempts were not so successful, acrylic kept poping up out of metal frames . I don't recall all the details but he told me that eventually he ended up using Sikaflex 295 UV caulk with very expensive primer, Sika primer 209D (something like $80-90 per small 5-7 oz. bottle), specifically formulated to bond acrylic, he also waited for month or so for the joint to achieve the full strength... sort of very expensive and prolonged method but perhaps reliable one. Alternatives like Weld-On and Dow seem to be attractive in my case.
Mike , what sort of surface preparation have you done (like sanding , priming , e.t.c ) before sticking acrylic to aluminum ? acrylic staying in place 3 + years seems to be encouraging result !
Erik, yes, the drawing you posted is exactly what king of joint i have to deal with. I did some quick research and discovered that Weld-on #45 or #10 is formulated to bond acrylic with wood. ( you used Wend-on #40 , do you think , is any difference ? ) . My light concern here is that the groove in my case wider then the thickness of acrylic, probably implying some flexibility of the joint . also wood expands / contracts depending on humidity and acrylic - depending of temperature. this Weld-on , is it acting like a caulk as well , allowing some flexibility ? or do I have to make dry tight (without any wobbling ) joint between wood and acrylic before applying weld-on ?

[bad]

I picked the Weld On 40 because it is clear which was important for my application. It is a hard glue, but I don't think it would have problems holding things together. BTW, I think the acrylic will move more than the teak.

Consider giving the manufacture a call. They were very helpful and sent me a free sample because it was not locally available.

Good luck'!

Erik

[RonR]

I used DOW 795 building adhesive on my current boat, after learning that it was used to seal windows on skyscrapers. It has held up well and has shown great adhesion for 10+ years. I had to buy a case back then, some of the tubes are still very useable after all those years. I would definitely use it again. I have had it pull away in small areas from teak, where there was a lot of expansion and contraction. I think surface preparation is the key there.

http://www.amazon.com/Dow-Corning-Silic ... B000NY76MI
http://www.dowcorning.com/applications/ ... px?R=264EN

Ron