TOP Sealants Comparison Table
1. The Best Semi-Permanent Flexible Adhesive Sealant for Boats and RVs [3M Marine]
![Open Semi-Permanent Flexible Adhesive Sealant for Boats and RVs [3M Marine] Semi-Permanent Flexible Adhesive Sealant for Boats and RVs [3M Marine] Picture](https://m.media-amazon.com/images/I/617ggkjWrhL._SL500_.jpg)
2. The Best Waterproof Sealing for Boats and RVs Above and Below the Waterline [3M Marine]
![Open Waterproof Sealing for Boats and RVs Above and Below the Waterline [3M Marine] Waterproof Sealing for Boats and RVs Above and Below the Waterline [3M Marine] Picture](https://m.media-amazon.com/images/I/81oTiIy60rL._AC_SL500_.jpg)
3. The Best Permanent Bonding and Sealing for Boats and RVs Above and Below the Waterline Waterproof Repair

Types of Sealants
Sealant in tubes or cartridges
Walk into any marine store you're likely as not to see a huge range of sealants, caulks, and mastics. But which one do you choose? I'm going to try and demystify the confusion surrounding all the different types of sealants and caulks there are out there. 100 years ago boatyard sealants were pretty much limited to white lead putty that were individual worker.
Now things are much more convenient. I'm going to walk you through the differences. With a few notable exceptions, these products come in tubes or cartridges and they're either polyurethane or polysulfide. Polyurethane is most known as an adhesive and for things like sticking a hull and deck together or attaching a keel to a sailboat, it's perfect.
Probably the most well-known one of those is 3M's 5200. Because of its adhesive properties, it's great for attaching things that are never going to be taken apart again. But quite often people will use it in the wrong place, and they'll use it for attaching a cleat to a deck. And that's OK at the time, but you're never going to get the thing apart in the future without destroying the boat. So for bedding things like cleats and things which we may have to take apart again in future, a much better bet is to use a polysulfide product. So just a recap:
A polyurethane is essentially an adhesive, and a polysulfide is a bedding compound. It's also worth remembering that some of the polysulfides will actually adhere underwater. If you're in any doubt, always read the label. Not all mastics and bedding compounds come in cartridges.
Dolphinite - is a particular favorite of mine. It never sets up and it's very economical because it comes in a can, you can scoop out how much you need, and then replace the lid. So this is a pint can. It also comes in quarts. It'll last for years, literally.
Sealant in butyl tape
Another option is butyl tape. This comes on a roll. You just peel off a section. It snaps off, and it's very malleable. You knead it to the shape you want, and it's perfect for fitting under deck fittings like cleats and winches and things like that. It never sets up, so if you have to remove it again at some future point it's perfect.
Sealants Statistics
- The most sealants come in tubes or cartridges.
- A 10.1 oz tube of sealant covers about 16 ft.
- Many people prefer to use marine sealants because they provide a strong, durable seal that can withstand extreme temperatures and weather conditions.
- Marine sealants are available in a variety of colors to match the boat's color scheme.
- Marine sealants are also good for RVs and other vehicles that are exposed to the elements.
- There are many different types of marine sealants, but the most popular type is polyurethane because it's a strong, durable sealant that can withstand extreme temperatures and weather conditions. It is also resistant to UV rays, so it won't fade or break down over time.
- Silicon sealants are also popular because they create a watertight seal that is flexible and can be used on a variety of surfaces.
- Acrylic sealants are another option that is less expensive than polyurethane and silicon, but it is not as durable or long lasting.