3M Marine Adhesive Sealant 5200 - Permanent Bonding and Sealing for Boats and Marine Applications - Black - 3 Ounces

3M Marine 5200 is very much a marine industry standard -- for a reason. It does what it does very well, but don't order this unless you know exactly what that is. It's a "sealant" that takes a full 48 hours to cure... and once it does cure, congratulations, whatever you used it on better be something you want to stay put forever-ish.It's also a "use it or lose it" $20 tube. Open it -- and consider anything you leave in the tube as toast. You're not just going to stick a nail in the tip like it's RTV and use it later. It's also fussy about how you prep the mating surfaces. Acetone? Perfect. Alcohol? Congrats, it will never set. Never. READ THE LABEL.

I used this to seal under the stone around the periphery of my pool, and it worked great for that purpose. I liked that it was also sealed on the non tip end to prevent premature drying of the tube.

This adhesive is crazy. I wouldn't use it on anything you do not want to be PERMANENT. We replaced our propane fridge in the RV with a Residential fridge. I used this adhesive to glue metal L brackets to the top, and small Wood spacers on the bottom. It took forever to cure (7 days..) but it is NOT coming off. In retrospect, I think I should have bought the "fast cure" version.

I bought this to seal my swim deck ladder to the swim deck after making repairs. I have also used it when installing the bow roller. Works good, seals and bonds well.As stated by others, the tube is off a bit on size. The first time you use it, you may not notice. But if you are like me and save your tubes for future use, the next time, the tube will begin to torque to the side when squeezing out. I save my tubes by cleaning the tips and wrapping them in plastic wrap really good. Yes, it works, but it sometimes only slows the curing of the product. In this sealants case, it worked OK, but I did have to remove a few inches of sealant to get to the softer stuff. This sealant wants to cure, so keep that in mind. I have reused silicon years later wrapping them, but this sealant isn't going to last long for additional uses.I recommend this sealant and only this sealant for keeping the water out of your boat. Dont go the cheap way on this stuff. Do your research.

I'm using this to put a ceiling in a fiberglass top RV, and I needed a way to bond the wood supports to the ceiling and side of the van. I used this adhesive in combination with deck screws to hold the ceiling supports up to the roof, and the results were so good I used the adhesive by itself to put my supports on the side of the van. After a day, those were on pretty solid, but I'm letting them cure a full 7 days before building the van out further.I chose this adhesive because it has greater flexibility than epoxy which is an important consideration when you're banging down dirt roads in an RV. And while the contact patch I'm securing to the fiberglass is not all that great and the weight it will carry is minimal, I figure all other things being equal it was better to go with the more flexible option.I only used a small amount on the ceiling, and my side walls didn't go up for another week, so I put the tub in a plastic bag in order to keep the adhesive from setting. That worked like a champ, and I was able to save about 20 bucks by not having to toss the majority of the adhesive away.

Very good

I bought this for some through hull fittings on my jon boat. And to permanently fill some holes in the live wells (the guys before me cut speaker holes in each 40 gallon live well. I was able to glue a .080" piece of aluminum to the inside of the live well to block the holes. I used some duct tape to hold the plates in place while this set up, it has a surprisingly long set up time, it was still moldable even a couple hours later. This means two things, first it's able to flow into all the little cavities if you were using it to fill a fiberglass/wood hole, second it means you have to kind of watch it if you fill a holes that vertical (like I did) because you have to go back and make sure the adhesive hasn't run out of the hole. It's less viscous than a bathroom caulk but more viscous than a wood glue.It also says on the side of the bottle that you have to use the tube within 24 hours of opening the seal on the back. I want to let you know this just isn't true. If you actually seal the end with packing tape or one of those caps it will keep for easily a week or more if it's out of the sun and heat. I set up everything I wanted to use this for at the same time, glued everything, didn't use as much as I had expected. Came back a couple days later found something else and used it again. 2 weeks later found one more thing to use it for and it was still very usable. I don't know how long it would have kept but it made it through my project, and easily lasted 2 weeks if I resealed the tip of it each time (I didn't seal the back where the plunger goes.

Great product, I have used over 50... But, of little use if shipped without a nozzle. I ordered 2 mahogany and 3 white cartridges and received only one nozzle. Packaging was lousey. Just thrown in a box with a little craft paper. This is very expensive caulk and heavy. Both orders in one package (5 tubes) were loose and banging around. There is a place for the nozzle around the neck of the opening, there was just one loose amongst the tubes and craft paper.