Cleaning and re-installing ports

[cantstopnow]

I have searched for the answer to this because I know that this has been discussed before somewhere but I am still posting the question for clarity.

I have removed the starboard fixed port to repair the leaking problem. Removal and disassembly went smoothy. The window was bedded in the frame with what looks like a black butyl rubber. I am going to try mineral spirits to clean off the black stuff. Any advice?





I am not sure what was used to seal the frame into the openings, It could be silicone. What is the recommended regiment to clean prior to re-installing and the best product product for the new seal?

[cantstopnow]

replying to my own post... Polysulphide sealant for the frames and and deadlights?

[bhartley]

I just replaced the lexan in my Bomar hatch. For installing the lexan, a structural silcone sealant was recommended by the manufacturer. I used Dow Corning 995 (from McMaster Carr). The installation looks pretty close to the original and it sure doesn't leak! I used a razor blade to remove the bulk of the old sealant from the glass and a putty knife on the frame. Final cleanup on the frame was done with a Scotchbrite pad. The silicone product was only used to bed the glass in the frames and not the frames in the openings. I know silicone is evil, but I went with Pompanette's instructions in this one case.

[Hirilondë]

Definitely do NOT use polysulfide if the lights are plastic of any kind. Most manufacturers of polycarbonate and acrylics recommend silicone. But you will find that a few of us here are not big fans of that stuff. I have used polyurethanes with good results, and Sika now makes one specifically for glazing. Mine are done with Sikaflex 291-LOT and have stood up well.

[mitiempo]

I think the earlier poster meant Dow 795 (not 995). Both 795 and 739 are structural adhesives recommended for lexan and plexi. They are far removed in properties from the silicone you have probably seen or used before. They are used to attach glazing to highrises without fasteners as well as ports in Boeing planes among other uses. This is one case (maybe the only one!) where silicone should be used on a boat. But to attach the frame to the deck I would use either butyl or Sikaflex.

[bhartley]

Actually I did mean 995. That is what was recommended and that is what I used...

http://www.dowcorning.com/applications/ ... &Type=PROD

[mitiempo]

The 995 is listed as for metal and glass but is probably a good choice. The best recommendation I have received is for Dow 739 which is designed for plastics specifically. http://www2.dowcorning.com/DataFiles/09 ... 002241.pdf

[Hirilondë]

I have used Dow 795 and it works great. But just try to paint adjacent to your ports some time down the road and see if you feel it was worth using.

[cantstopnow]

Thank you very much for the responses. We got things cleaned up and I will get the sealants tomorrow and get it back together.

The aluminum frame has some corroded areas that I cleaned up and smoothed the best I could. I wonder if there is a source for replacement frames for this model?

The black sticky stuff (butyl rubber?) cleaned up easier than I expected with mineral spirits.

[cantstopnow]

Update:

I am sure that there is no quicker way to feel like a clumsy moron than when installing deadlights alone when pressed for time. Well it's done and the thunderstorms that followed showed no leaks.
I do have some clean up though...

[Rachel]

Moving right along! :)

Remember George?

His caption was "Drinking and caulking do not mix"