Ceramic Coating Over Gel Coat

Repair or modification of Boston Whaler boats, their engines, trailers, and gear
otter
Posts: 20
Joined: Wed Aug 26, 2020 10:16 am

Ceramic Coating Over Gel Coat

Postby otter » Mon Jun 06, 2022 2:27 pm

[Tell me your first-hand] experience of using a ceramic coating over gel coat resin.

The claimed benefits of a liquid ceramic coating are:
  • to make a superior covering for the hull,
  • to give lasting protection to the surface,
  • to last a couple of years, and
  • to make less work in the long run.

dtmackey
Posts: 759
Joined: Thu Sep 28, 2017 9:29 pm

Re: Ceramic Coating Over Gel Coat

Postby dtmackey » Mon Jun 06, 2022 3:16 pm

"Ceramic coating" means different things to different people. I started playing with ceramic coatings in 2021. The spray-on ceramic product is not the robust multi-season coating that you rub on and level with a microfiber. Real ceramic coatings cannot be sprayed since they are thicker (higher viscosity) and would clog, not to mention the costs are significantly higher: $1-per-ounce for the spray stuff and over $100-per-ounce for the true coating.

One of our boats is a 2000 Nordic Tug 32 with a dark green hull--one of the worst colors to keep looking new--but we love it since you don't see this color on every other boat. The boat was purchased new at the factory and has been boatyard maintained locally where they would compound and wax every spring. About 6 years ago [2016], they told us they would no longer buff the hull since it was faded badly and the before and after wasn't much different. They offered their Awlgrip painting services, but I wasn't ready to have it done.

The following year I bought a commercial buffer with 3M supplies and attacked the hull. I did a good job bringing it back over two full days. It looked good, but wasn't perfect. Last season I wet sanded the entire hull with 1500 followed by 3000 grit, then compounding (finer cut) and followed with a Turtle Wax Ceramic Spray. The hull looked great and the spray did a decent job and lasted longer than wax would and for $15 for a bottle, it did the tug and my Whaler.

This year I decided to try the real ceramic coating (after compounding) and purchased the 3M kit. I chose 3M because they are a chemical company with lots of R&D labs to design a top notch product, where as most cermamic coating companies are marketing companies rebranding someone else's material. I have a commerical account and can access the 3M material since it's not sold through retailers.

https://www.3m.com/3M/en_US/p/d/b5005168023/

Here's a pic of what the hull looked like at its worst.

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Here it is this year after buffing and ceramic coating.

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Last year I also did the Whaler hull and for a 1986 hull that has spent most of life outdoors it came back nice. I also used a Cerakote ceramic on the rubrail and this year I'm applying the 3M ceramic coating to the hull as well.

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After working with both products here is the most important thing I can share. If you are not able to or have time to get the hull back to perfection - then DO NOT use an ceramic coating as it will lock in any oxidate or lack of attention under the coating. You need to do a gelcoat correction and that can be a multi-process compounding or get extreme and wet sand if the finish requires it. You want the later steps to be with a fine polishing compound so it smooths the finish.

One note - a good ceramic coating should have almost no smell. Some companies ceramic coating has a solvent smell and the solvents are used to dillute the cermanic content so you do not get the same level of quality on the job.

Application of the ceramic, in both cases, is very easy - wipe on and level with a cloth.

D-