Portlite sealing

I have a small leak in one of my Lewmar portlites and have removed it to reseal it. I am very reluctant to remove the two small screws, separate the frame and remove the glass and gasket, I fear I will not be able to get humpty dumpty back together again. Much to my surprise, I was able to remove both the inside and outside gaskets, I had thought the gasket was like a single channel not two parts. Looking at the tight corner section, is is clear that the gasket was not the seal but rather a thin layer of probably Dow Corning 795 that glued the gasket in place, was the seal, and obviously it failed in lots of places.

I know the Catalina folks sell a refurb kit (!$100) with new gasket, Dow 795 and 3M4000 sealants but again, I fear taking the frame apart. I have ordered some black Dow 795 and my plan is to do away with the gasket entirely and just fill the entire space with 795 using one of those neat "tools" and masking tape to get a nice finished bevel. After looking at the deep channel where the 795 would go, I probably can fill a lot of that space with something to take up uncritical volume and still have at least 1/4 inch of glass for a sealing surface. In that way, if I ever have to remove the 795, there would not be so much to remove.

Also, I have read that once a silicone sealing is used, the surface is "poisoned" so that no other sealant will adhere, hence my idea of using the 795 in place of the 3M4000, I will still use the 4000 to seal the frame to the cabin side. Maybe this is not true for non porous surfaces, I would rather use 4000 rather than silicone, I question the adhesive properties of silicone, sure it is a great gasket material, but I think 4000 is a better adhesive.

Just as insurance, I looked at getting a new Lewmar portlite of the same tapered shape as a backup. I did find what looks like the same shape from Lewmar but only in a opening version, does anyone know if a fixed version is available. This portlite is really strange, the rectangular portion is not "straight" but rather tapers from about 7 1/2 inches to 7 inches, I guess for aesthetic reasons. Plus there are 4 versions of this window, two for the starboard and two for the port sides, so it is not possible to purchase one backup portlite for all the positions, bummer.

Would like to hear what the mavens out there think.

Hello Herbert,

My condolences! ...Having replaced all the glass in my E32 MkII ports, I can honestly say - This is NOT an easy project! ...I ended up spending a lot of time in the confessional booth - and I'm NOT even Catholic!!

The smaller standard sized ports went fairly well but, as you noted, the elongated shape makes it a real pain to get the seal and glass or Lucite to close up tightly again. I ended up making a two part jig (top & bottom half) surrounding the window frame. The jig was square to the world and allowed me to clamp the two aluminum pieces back to gather without them wanting to squirt out. (I have photos of it all but not available to me at the moment so created a simple drawing for you to review.)

I also have a name for a dealer who makes the window seal material and it was a better price than what Catalina charges. That too is not available to me at the moment as I'm out of town for awhile. Let me know if you want this info later and I will send it.

This allowed me to clamp the narrowed and elongated end with equal pressure to compress the window seal and glass back into the frame halves.

Hope this is of value to you and good luck!
Fair Winds
-kerry

HerbertFriedman said:

[snip]
Also, I have read that once a silicone sealing is used, the surface is "poisoned" so that no other sealant will adhere, hence my idea of using the 795 in place of the 3M4000, I will still use the 4000 to seal the frame to the cabin side. Maybe this is not true for non porous surfaces, I would rather use 4000 rather than silicone, I question the adhesive properties of silicone, sure it is a great gasket material, but I think 4000 is a better adhesive.

[snip]

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I've never had a good time with silicone. Stuff is terrible. Silicone wont even stick to silicone. No place for it on a boat. Try your best to get the surface free of the stuff. Solvents, mechanical sanding etc. Good luck. Would be interested to know how you fare.

Emerald said:

I've never had a good time with silicone. Stuff is terrible. Silicone wont even stick to silicone. No place for it on a boat. Try your best to get the surface free of the stuff. Solvents, mechanical sanding etc. Good luck. Would be interested to know how you fare.

Click to expand...

For sure! Nasty stuff! ...Doesn't stick where you want it to and sticks superbly where you need to clean it off of! (Not to mention I end up wearing more of it than what I put it on.)

I didn't use any silicon when redoing my ports. I bought brand new OEM rubber seals and they (so far) are doing great. I have one small corner leak to work on but think I can seal it fairly easily as soon as the cover comes off the boat this spring. (We just finished that project just as haul-out began.)

boy, now I am really am confused. The Catalina refurb kit contains not only new gaskets but Dow Corning 795 as the sealant for those gaskets. I am not sure how Catalina recommends to use the 795 in sealing the gaskets. Do they just say to coat the gaskets with 795 before inserting, or applying a bead of 795 at the interface between the glass and the aluminum channel, the stuffing the gaskets in place?? But in any case, they do recommend 795. Plus looking at the Dow Corning site, 795 is the recommended sealing for industrial jobs. But it is a silicone RTV (room temperature vulcanizing) product.

Your difficulty in replacing the glass once the frame is separated convinces me that going that route is dangerous. But after removing the gaskets without separating the frame and looking at the sealing surfaces, I dont know why one has to remove the glass at all. Unless they want you to lay in a bead of 795 in the channel and then insert the glass. The gaskets can be stuffed back in without separating the frame.

What do you all think about my plan to skip the gaskets altogether and just apply a thick bead of black caulk without the gaskets, just as one would do with a normal glass installation. In this method, I could use 795 or 3M4000.

IIRC, the instructions from Catalina say to put a bead of 795 in the aluminum channel and another bead inside the gasket. Four hands being required. This seemed like a really bad idea to me, so I just used a tiny bit of silicone grease to lube up the outside of the gasket (Dow high vacuum grease, which I had on hand.) And added the 795 to my shop inventory. I figured if that didn't work, I could always re-do it their way. So far, it seems good.

OK, that confirms my guess at the use of the 795 sealant. I was able to remove both gaskets without removing the frame but the outer gasket is pretty shot. I am still very reluctant to loosen the frame in view of all the negative comments about getting it back together. So again, what do you think about my idea of eliminating the gasket altogether and just using a thick bead of 795, or whatever, in place of the gasket?

HerbertFriedman said:

OK, that confirms my guess at the use of the 795 sealant. I was able to remove both gaskets without removing the frame but the outer gasket is pretty shot. I am still very reluctant to loosen the frame in view of all the negative comments about getting it back together. So again, what do you think about my idea of eliminating the gasket altogether and just using a thick bead of 795, or whatever, in place of the gasket?

Click to expand...

Please don't get scared off or discouraged about your project. It IS do-able with a lot of patience and effort.

I tried doing mine without any silicons and just the OEM factory rubber seal between the glass and aluminum. I did find a water based clear sealant similar to silicon at the local hardware and applied just a dab where the two end of the rubber seal came together - but that was all.

BTW - When we put our completed frames back into the cabin trunk, we bedded them with white butyl rubber. We bought it at an RV supply store in rolls.

It was placed on the inside of the aluminum frame, heated slightly with a heat gun and one of us pushed on the window frame while the other inside the cabin tightened the framing.

The cleanup was ever so easy compared to anything else and - so far - NO LEAKS!

(Not the best photo of the ports - but see attached)