Sealant for various installs

[saltyfish]

What is the sealant of choice to go in front of SS screws for bilge pump, float switch, scuppers, etc installs? I bought 5200 at WM, then on the way home realized those screws will eventually need to come back out, 5200 is said to be permanent.

thanks

Bryce

 

[DaleH]

5200 is no way permanent, specially when used on screws. It also is the sealant of choice for anything under the waterline or constantly exposed to water.

 

[Megabyte]

5200 contains a powerful adhesive.
If you think you might want to remove an item some day, 4200 is the same stuff without the adhesive.

 

[warthog5]

You don't see much 5200 around my place. When it comes to that it's 4200 Fast. I use it to install thruhull X-ducers. ZIt is made for "Below the waterline".

Normal 4200 & 5200 take a week to full cure. 4200 Fast is 24hrs.

I have been using some of the Attwood 7200. Can buy the toothpaste tube at WalMart a lot cheaper. I use to buy my 4200 Fast there. Then they did away with all the 3M products.

 

[saltyfish]

thanks for replies.

 

[Jpeg]

Here is another Idea. Drill a larger hole, say 5/16" for the screw. Then fill the hole with fast cure epoxy glue and allow it to set fully. Then drill a pilot hole for the screw in the epoxy and install your part. The idea is to seal the wood with epoxy. I also add a dab of silicone for extra measure before I put the screw in. I saw this once on a TV show about boat maintenance.

 

[jeffnick]

If you only want a temporary seal use 4200. Personally, for anything on my boat that requires bedding, I use 5200. I don't want to keep water out temporarily, I want to keep it out permanently, whether it's a fasteners or thru-hull.

As far as cure time, if 5200 takes a week to cure, so what...it seals on application, if you're looking for quick glue, you might consider epoxy.

Yes, but I used 5200 on a cleat, and when I removed that cleat, the 5200 took some gelcoat with it. Well duh, that's exactly why I use it.

 

[Sully]

Yes, but I used 5200 on a cleat, and when I removed that cleat, the 5200 took some gelcoat with it. Well duh, that's exactly why I use it.

Now thats "Red" ! lolol

 

[sparky]

Here is another Idea. Drill a larger hole, say 5/16" for the screw. Then fill the hole with fast cure epoxy glue and allow it to set fully. Then drill a pilot hole for the screw in the epoxy and install your part. The idea is to seal the wood with epoxy. I also add a dab of silicone for extra measure before I put the screw in. I saw this once on a TV show about boat maintenance.

Silicone sucks if you EVER want to paint or cover the area with any coating... the silicone gets into everything, and is basically non-removable.

4200, Life Caulk, or SikaFlex for something removable, 5200 for non removable. 5200's bond with gelcoat is stronger than gelcoat to fiberglass.

 

[Jpeg]

I know what you mean about silicone and the problems it causes if ever you need to refinish the area. The point I wanted to make was to isolate and seal off the wood. By making a plug of epoxy, and then having the screw set in this plug the wood is sealed off completely. Anytime I expose a wood core I seal the wood with epoxy to protect it.

 

[saltyfish]

great input, thanks.

Bryce

 

[jeffnick]

There's a new thought on bedding...butyl tape. It stays sticky and pliable but offers no mechanical bond like 5200. I got mine here:

http://www.pbase.com/mainecruising/butyl_tape

I used it to seal a rebuilt boat window and couldn't be happier. In this instance I believe the tape can tolerate more flex than 5200 and still maintain the seal.

 

[warthog5]

I've never used that, but the product that comes to mind is 3M's Strip Calk to rebed windows


http://3mcollision.com/3m-strip-calk-08578-black.html

 

[sparky]

I've never used that, but the product that comes to mind is 3M's Strip Calk to rebed windows


http://3mcollision.com/3m-strip-calk-08578-black.html

Butyl tape works great. We use it on the DSG windows when we have to mess with them at all. It also works well under cleats and other bedded hardware. It will always be soft, and always seal so long as you have fasteners doing the actual mechanical bond. Unlike 5200, if the object flexes, the joint won't crack or open up, and will always be waterproof.

There's really a few things that are being talked about:
1. Mechanical adhesives for sealing and bonding (5200, 4200) (Non-penetrating attachment of objects to hull or other parts)
2. Core sealing/Through-hull sealing (epoxy, thickened epoxy, other resins) (Transducer installs, through-hull fittings, any penetration into the fiberglass or cored hull components)
3. Fastener sealing (Overdrill/epoxy/redrill, 5200, sika-flex, silicone, Life Caulk) (Screws into hull or wood, etc)
4. Mechanically fastened long joint sealing (Butyl tape, rope caulk, etc) (Windows, door frames, portlights, cleats, etc)

Many projects actually involve several of these in one.
For example, if you wanted to install a new cleat to the gunwale, you'd need to address #2, #3, and #4. Depending on how you planned on doing it, you could complete any number of steps. You might want to overdrill/epoxy fill/redrill the holes for the cleat bolts, use Sika Flex on the bolt holes through the epoxy, and use Butyl tape under the cleat itself to prevent water from getting into the holes. OR, you could just drill holes, pack them with 5200, and fasten the cleat down. What's better? That's a topic for much discussion and arm-waving. There are a lot of factors to consider, that's for sure.