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What do you use to seal everything up?

PostPosted: Tue Jan 27, 2015 5:55 pm
by Atomic77
Ok, so that was generic. What I"m actually getting at is, what do you use to seal things like, hatch doors, shore power outlet, outside shower box if you have one, roof fans, etc. I'm wondering if it's best to use butyl tape, silicone sealant or other varieties of sealants? Also, at this point I've refrained from putting any holes in the Filon, but I know when I add these items I will be forced to. I have taken extreme care to epoxy everything. Now what am I to do about the screw holes? These are some of the items I will need to seal up:

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Re: What do you use to seal everything up?

PostPosted: Tue Jan 27, 2015 7:03 pm
by 48Rob
Michael,

It is common practice to use putty tape to seal items that may need to be removed or replaced in the future.

Doors, windows, outlet covers, etc, can all be damaged and need to be replaced. Putty tape will allow for easy removal.
There are really good sealants in a tube these days that will never leak in 50, 100? Years, but getting the parts separated may not happen without a lot of damage.

If you use putty tape, trim the excess squeeze out and use an appropriate tube sealer to add a second layer of defense. It is also very wise, after getting the part installed, to remove a screw or two at a time and inject the same sealer into the screw hole.
Replace the screws and wipe off any excess. This will prevent water damage from water following the threads of the screws into the wood, which is very common.
I prefer the Polyurethane sealants over Silicone, as silicone is an air cure product that relies on very clean and very dry surfaces to "stick".
Polyurethanes are a "moisture" cure product, relying on moisure in the air, and or on/in the surfaces being sealed.
A screw into wood that is at 11%-20% moisture content will seal far better with Polyurethane than silicone.
As for Aluminum or plastic to Filon, Silicone may be a better choice. The Filon people should be able to suggest the most compatible product.

Rob

Re: What do you use to seal everything up?

PostPosted: Tue Jan 27, 2015 7:49 pm
by kayakdlk
Like Rob said for those items such as my fan, windows, hurricane hinges and moon roof that may need to be removed I used a butyl tape (or what looked like some from ebay). For the door drip rails I used a bead of clear RTV. I also used clear RTV in most of the screw holes (dipped the screws in the RTV tube) for the drip rails, galley and tongue box clasps, towel hooks, and lights. My door handles came with a rubber gasket so I didn't use anything else. My Shore power also came with a rubber gasket so I only used RTV in the screw holes so any water wouldn't seep in.

I pre drilled all holes and put it all together without any butyl tape or RTV and made sure everything fit, adjusted as needed and then took it back off and added the butyl tape and/or clear RTV. I got use to putting it together and taking it apart as I dry fit everything before painting and they checked again afterword. For the hurricane hinges, fenders and drip rails that had lots of screw I only used a few or every other one so I wouldn't wear out all of the holes or work them loose. Sometimes I used shorter screws for the same reason. During finally assembly I put all the full length screws in with RTV.

Your build is looking good

Dan

Re: What do you use to seal everything up?

PostPosted: Tue Jan 27, 2015 8:00 pm
by aggie79
Hi Michael,

In my build I used 3M 4200 for all items that, as Dan said, that I didn't think I'd have to remove - electrical inlet, trim, etc. It is rated for below waterline use. While it technically is "removable" I wouldn't want to try to remove anything bonded together by it. (I too epoxied the plywood around all openings. The 3M 4200 bonds to epoxy like crazy.)

I pretty much used the same technique for everything. First dry fit the piece including drilling hole and installing fasteners. I then put down a layer of painters tape at the edge of the piece on the exposed side of the skin. (This allowed for easier removal of the squeeze out.) I then applied a healthy bead of sealant and injected sealant into the screw holes. After sealant cured I removed the tape and squeeze out.

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I did use butyl tape around the windows (with a bead of sealant around the perimeter). As others said, butyl tape does not completely compress like a sealant would. I installed my windows, tightened the fasteners and waited a couple of weeks. I then re-tightened the fasteners, trimmed the squeeze out, and ran a bead of sealant around the cut edges.

Take care, Tom

Re: What do you use to seal everything up?

PostPosted: Wed Jan 28, 2015 11:54 am
by Sputterputz
3m 4200 for me. A product called geocell 2700 for my fenders just because it stays clear forever.

Re: What do you use to seal everything up?

PostPosted: Wed Jan 28, 2015 4:41 pm
by Atomic77
Ok Gentleman...all very good stuff. We use a lot of the 3M 5200 around the race shop. Never used the 4200 though. Must be a less permanent version. Thanks everyone for your input.

Re: What do you use to seal everything up?

PostPosted: Sat Jan 31, 2015 12:43 pm
by woodywrkng
Lexel caulk. http://www.sashco.com/products/lexel/

I used Lexel underneath and between items, such as were a gasket could be used. Where there would be an exposed bead, which was often on top of the item which had Lexel underneath it, I used type 230 siliconized acrylic caulk. My reasoning is that since the Lexel is tricky to make a nice bead, I didn't even try, and rather used the 230 caulk since you can make a beautiful bead with it. The 230 won't last as long, but could be removed and re-done in 15 years or so. Anyway, the Lexel is between surfaces, while the 230 is on top where you can see it, thus resulting in two barriers to water.