You rarely see the term sealant on the shelf of the car cleaning section of the auto parts store, but stop over to a detailing supplier and you'll see a whole section of the webpage or store devoted to these products. In reality, most of what you find of the shelves of the auto parts store are sealants, they've been labelled at wax because that's what the average Joe is looking for. While waxes contain primarily natural ingredients and coatings are strictly synthetic, sealants represent the first step the industry took from wax toward coatings. Sealants are primarily synthetic, but may have some natural ingredients. These synthetics are generally a long change silozane molucules of Polydimethylsilozane (PDMS), they have a similar structure to long chain hydrocarbons with a backbone of alternating silicone and oxygen and methyl (CH3) groups off the backbone. . There may also be what are called 'reactive silicones'. These ingredients react with the PDMS and cross-link them together into a matrix. They may also provide bonding to the painted surface, normally this is an electrostatic or hydrogen bond, but some stronger bonds may exist depending on the formulation of the sealant.
Due to the cross-linking and bonding of sealants, they tend to last 4-6 months. They are quite hydrophobic and have what I describe as a sterile, high shine. They are the easiest protectant to apply. One can apply a sealant with a polisher and finishing/waxing pad and be done in a few minutes without breaking a sweat. They also wipe off with ease.
Because of the cross-linking chemical reaction, sealants do have a cure time. It's important to read the instructions to determine what the time is, it can vary from 8-12 hours normally. There are a few products that are nearly cured by the time you wipe them off.
Note that there are a variety of sealants with different application methods. Typically a sealant is applied, allowed to haze and wiped off. There are also Wipe-on wipe-off sealants that do not need to haze. Finally, there are wipe-on walk-away sealants that disappear as they are wiped on, that that point, you are done.
The durability and ease of use of sealants lend themselves to the novice DIYer on their daily driven vehicle. Some of my favorite sealants are listed below, it's important to note this is limited to traditional sealants, silica sealants will be addressed another time.
- Blackfire Wet Diamond All Finish Paint Protection
- Menzerna Powerlock
- Wolfgang Deep Gloss Paint Sealant
- Ultima Paint Guard Plus
- Blackfire Crystal Seal