A possible far superior coating/paint for boats.

Dec 8, 2025
16
Oday 27 Tuscaloosa
I've commented here about my odd ideas and using new materials to lower cost and hopefully much more rapid, better and cheaper, revitalization of older fiberglass boats. I think it likely the newer Polyaspartic resins could be a huge advance. Here's a link to a guy who used these to coat the cockpit in a commercial fishing boat. Seems to have held up well.


These coating seem to have all the ideal properties needed for coating and are far superior, it seems, for boats. They are more waterproof than epoxy, they are more elastic and they had very, very good UV protection qualities. I guess the only deficit is they have less tensile strength but they are not weak. Right now the big use base is garage floors, auto show room floors, aircraft hangers, etc. My understanding is that large showrooms and hangers have very positive results over time. They can be food safe so might be a great alternative for water tank coatings. From an AI,

"...polyaspartic coatings are known for their superior chemical resistance, making them stable and effective in environments exposed to diesel fuel and other harsh chemicals. This stability helps prevent damage and degradation over time..."

"...
Performance Characteristics

  • UV Stability: Polyaspartic coatings are UV resistant, preventing discoloration and degradation when exposed to sunlight.
  • Durability: These coatings exhibit high tensile strength and abrasion resistance, ensuring they maintain their integrity even in challenging conditions.
[My comment, not as good in tensile strength as epoxy]

  • Quick Cure Time: Polyaspartic coatings cure rapidly, often within a few hours, allowing for quick application and minimal downtime.
Comparison with Other Coatings

Polyaspartic coatings outperform many traditional options, such as epoxy, in terms of chemical resistance and durability. They are specifically designed to handle the stresses and exposures typical in industrial settings, including those involving diesel fuel.


In summary, polyaspartic coatings are highly stable and effective when used in environments with diesel fuel, providing excellent protection and longevity..."

Cost. They are high but compared to gelcoat or epoxy not so much. They also can be applied in thick coats.

Here's a price I got from Kretus Polyaspartic 85 EZ Kit,(no financial interest on my part)
Kretus Polyaspartic 85 - Clear - EZ - 2 Gallon Kit - Concrete Decor Store$201.50


Compared to West epoxy and looking at the benefits it seems a bargain.

Think about all the people that tear their water and fuel tanks out because they don't look so good. What if instead you sand blasted the interiors then coated with Polyaspartic? These tanks aren't cheap and the fiberglass many are made of, maybe with a few extra wraps of new fiberglass, could be perfectly sound and sterile after coating the interior. Just a thought.

Some speculation. I have NOT used this but have seen several garage jobs and they look good. I would guess that it would be difficult to not have lines from rolling it. On garages they pour out five gallons at a time then use a squeegee to spread it over the floor. So it does spread out some. They also use these in basements for waterproofing. So maybe it could be rolled on.

More guesses/speculation, I saw on Beau and Brandy's sailing channel where they refurbed a boat they used a two roller technique to paint. They rolled the paint on with one roller then used a cleaner roller over the same spot not loaded with paint. The results were impressive.

003 Painting with Awlgrip 3 Beau and Brandy Sailing - Beau and Brandy Sailing (720p, h264)
@3:51

They have some great videos

"Maybe" this could be done with the Polyaspartic. This stuff hardens super, super fast so you can only mix small batches at a time. Possibly, I'm guessing, using the two roller technique, maybe even three rollers, you could paint it on with one brush, smooth a little with another and after a slight drying hit it with another clean roller. If not you may be consigned to slathering it on best you can then hitting it with a fine sandpaper to even things out and remove brush streaks.

This stuff also appears to have good adhesion properties. Epoxy floor coating are notorious for peeling up from hot tires. Apparently Polyaspartic does not do this. Though, a warning, some people are using epoxy to "soak" into the concrete, then coming back with a Polyaspartic coating. With fiberglass you don't need "soaking" I would presume, so no need for epoxy. I see no reason this can't be substituted for gelcoat. Mix in fine powdered titanium dioxide and paint it on.

You also have to careful who you get this stuff from. The one I quoted a price on I have no financial interest in and have not used. They did seem to come from a decent chemical company and it seemed to me decent prices and you could buy in smaller qualities to test. I have heard some people cut their resins and you don't get enough of the solids to have a good product. So buyer beware.

And BTW you can paint this stuff when it's really cold, still hardens up in minutes. A BIG advantage.
 
Mar 24, 2012
71
O'Day 40 BC Coast
I'm looking for something to recoat my molded non-skid with. This stuff looks promising.
My molded non-skid is in good shape but, sometime in its past it was painted. I didn't realize that until a clumsy fibreglass worker spilled acetone on it, exposing the original gelcoat.
Now the Admiral is unhappy with the splotchy look.
 
Sep 24, 2018
3,973
Catalina 30 MKIII Chicago
I've commented here about my odd ideas and using new materials to lower cost and hopefully much more rapid, better and cheaper, revitalization of older fiberglass boats. I think it likely the newer Polyaspartic resins could be a huge advance. Here's a link to a guy who used these to coat the cockpit in a commercial fishing boat. Seems to have held up well.


These coating seem to have all the ideal properties needed for coating and are far superior, it seems, for boats. They are more waterproof than epoxy, they are more elastic and they had very, very good UV protection qualities. I guess the only deficit is they have less tensile strength but they are not weak. Right now the big use base is garage floors, auto show room floors, aircraft hangers, etc. My understanding is that large showrooms and hangers have very positive results over time. They can be food safe so might be a great alternative for water tank coatings. From an AI,

"...polyaspartic coatings are known for their superior chemical resistance, making them stable and effective in environments exposed to diesel fuel and other harsh chemicals. This stability helps prevent damage and degradation over time..."

"...
Performance Characteristics

  • UV Stability: Polyaspartic coatings are UV resistant, preventing discoloration and degradation when exposed to sunlight.
  • Durability: These coatings exhibit high tensile strength and abrasion resistance, ensuring they maintain their integrity even in challenging conditions.
[My comment, not as good in tensile strength as epoxy]

  • Quick Cure Time: Polyaspartic coatings cure rapidly, often within a few hours, allowing for quick application and minimal downtime.
Comparison with Other Coatings

Polyaspartic coatings outperform many traditional options, such as epoxy, in terms of chemical resistance and durability. They are specifically designed to handle the stresses and exposures typical in industrial settings, including those involving diesel fuel.


In summary, polyaspartic coatings are highly stable and effective when used in environments with diesel fuel, providing excellent protection and longevity..."

Cost. They are high but compared to gelcoat or epoxy not so much. They also can be applied in thick coats.

Here's a price I got from Kretus Polyaspartic 85 EZ Kit,(no financial interest on my part)
Kretus Polyaspartic 85 - Clear - EZ - 2 Gallon Kit - Concrete Decor Store$201.50


Compared to West epoxy and looking at the benefits it seems a bargain.

Think about all the people that tear their water and fuel tanks out because they don't look so good. What if instead you sand blasted the interiors then coated with Polyaspartic? These tanks aren't cheap and the fiberglass many are made of, maybe with a few extra wraps of new fiberglass, could be perfectly sound and sterile after coating the interior. Just a thought.

Some speculation. I have NOT used this but have seen several garage jobs and they look good. I would guess that it would be difficult to not have lines from rolling it. On garages they pour out five gallons at a time then use a squeegee to spread it over the floor. So it does spread out some. They also use these in basements for waterproofing. So maybe it could be rolled on.

More guesses/speculation, I saw on Beau and Brandy's sailing channel where they refurbed a boat they used a two roller technique to paint. They rolled the paint on with one roller then used a cleaner roller over the same spot not loaded with paint. The results were impressive.

003 Painting with Awlgrip 3 Beau and Brandy Sailing - Beau and Brandy Sailing (720p, h264)
@3:51

They have some great videos

"Maybe" this could be done with the Polyaspartic. This stuff hardens super, super fast so you can only mix small batches at a time. Possibly, I'm guessing, using the two roller technique, maybe even three rollers, you could paint it on with one brush, smooth a little with another and after a slight drying hit it with another clean roller. If not you may be consigned to slathering it on best you can then hitting it with a fine sandpaper to even things out and remove brush streaks.

This stuff also appears to have good adhesion properties. Epoxy floor coating are notorious for peeling up from hot tires. Apparently Polyaspartic does not do this. Though, a warning, some people are using epoxy to "soak" into the concrete, then coming back with a Polyaspartic coating. With fiberglass you don't need "soaking" I would presume, so no need for epoxy. I see no reason this can't be substituted for gelcoat. Mix in fine powdered titanium dioxide and paint it on.

You also have to careful who you get this stuff from. The one I quoted a price on I have no financial interest in and have not used. They did seem to come from a decent chemical company and it seemed to me decent prices and you could buy in smaller qualities to test. I have heard some people cut their resins and you don't get enough of the solids to have a good product. So buyer beware.

And BTW you can paint this stuff when it's really cold, still hardens up in minutes. A BIG advantage.
This sounds very intriguing. I'm very interested to hear what our resident chemists have to say
I'm looking for something to recoat my molded non-skid with. This stuff looks promising.
My molded non-skid is in good shape but, sometime in its past it was painted. I didn't realize that until a clumsy fibreglass worker spilled acetone on it, exposing the original gelcoat.
Now the Admiral is unhappy with the splotchy look.
The yard should be adding pigment to some paint to match the color and touching it up.

The interlux non-skid is about as abrasive as your feet can withstand without being uncomfortable. We did get the occasional road rash from it during mishaps
 
Dec 8, 2025
16
Oday 27 Tuscaloosa
I saved some data on these and got some AI responses.

AI categorization,

"...

Both polyaspartic and epoxy coatings are designed to provide protection against various chemicals, including diesel fuel, gasoline, and sewage. However, their performance can differ based on their chemical composition and application.
application.

Comparison of Chemical Resistance

Coating TypeDiesel Fuel ResistanceGasoline ResistanceSewage Resistance
PolyasparticExcellentExcellentExcellent
EpoxyGoodGoodModerate
Key Points

..."

So water tanks renewal, sewage, paint "IF" true and there are some long lived floors but I;m not sure about the rest this stuff seems ideal.

If it had better tensile strength then it would make a MOST EXCELLENT vacuum infused resin. It might anyway as it has better flexibility. Super fast dry, UV stability with low viscosity.


ME,"if used as a resin in composites is Polyaspartic stronger than epoxy"

AI answer,

"...Polyaspartic coatings are generally more flexible and resistant to impacts compared to epoxy, but epoxy can be stronger in terms of hardness. The choice between them depends on the specific application and performance requirements.

Strength Comparison: Polyaspartic vs. Epoxy in Composites
General Properties
PropertyPolyasparticEpoxy
StrengthHigh strength, flexibleHigh strength, rigid
ToughnessMore impact-resistantBrittle under heavy impacts
Chemical ResistanceExcellentVery good
UV StabilityUV stable, does not yellowProne to yellowing
Key Differences
  • Flexibility: Polyaspartic coatings are more flexible, which helps them absorb impacts better than epoxy. This flexibility reduces the risk of cracking under stress.
  • Curing Time: Polyaspartic cures much faster than epoxy, allowing for quicker application and use in various conditions.
  • Durability: While both materials are durable, polyaspartic coatings tend to perform better in environments with temperature fluctuations and heavy impacts.
Conclusion
In composite applications, polyaspartic can be considered stronger in terms of toughness and flexibility, making it more suitable for dynamic environments. However, epoxy is also strong and offers excellent rigidity, which can be beneficial in specific applications. The choice between the two depends on the specific requirements of the project..."

ME,"what are the tensile strengths of epoxy, vinyl ester and polyerter cured resins"

AI answer condensed,

"...
Resin Type Tensile Strength (Psi) MPa
Epoxy Resin 9,000 - 9,756 70 to 90
Vinyl Ester Resin 7,000 - 9,000 50 to 70 MPa
Polyester Resin 7,000 to 10,000 psi ? 50 and 70 Megapascals
I get varied answers to polyaspartic looking at data sheets

polyaspartic 6,000 psi other 10 mpa = 1450.377 psi
Simiron Polyaspartic HS: 4,000 psi
MF Performance MF344: 3,900 psi

But none of this really tells you what it does in fiberglass. I would theorize that a little more glass with it's flexibility it would be safer. Maybe not stronger but safer.

Viscosity

AI
The viscosity of 85% polyaspartic resin is generally lower than that of vinylester resin, which tends to be thicker and more viscous. Viscosity can be measured using a viscometer, which provides a numerical value indicating the resistance of a fluid to flow, allowing for direct comparison between different resins...
Viscosity of 85% Polyaspartic Resin

Viscosity Range: Polyaspartic resins typically have a viscosity range of 200 to 1,000 centipoise (cP) at 25°C, depending on the specific formulation and concentration.

Viscosity of Vinylester Resin

Viscosity Range: Vinylester resins generally have a viscosity range of 300 to 1,500 cP at 25°C. This can vary based on the specific type and any additives used.
 
Dec 8, 2025
16
Oday 27 Tuscaloosa
And a bit more, this stuff sounds miraculous.

Dragon Shield Polyurea Coating for Hull Strenghtening

Now this thread is for polyurea which was used before it was modified into polyaspartic. Polyurea dries almost instantly. They use a gun to mix the two part solution in a sprayer nozzle and blast it onto surfaces. Nasty industrial places so that they stay clean and do not absorb water. According to AI's,

"...Polyaspartic coatings generally bond better to fiberglass than polyurea due to their modified formulation, which enhances adhesion and UV stability. However, both types can be used on fiberglass, but polyaspartic is often preferred for its superior performance..."

This link is for Polyurea exterior hull liners so whatever it says about the Polyurea the polyaspartic is most likely better.


This will blow your mind. This is a water melon they dropped of a tower coated with Polyurea.


Keep in mind supposedly the polyaspartic is better than the Polyurea, or so I'm told.