# What would happen if I painted a boat with Never-Wet? **URL:** \ **Category:** Factual Questions\ **Created:** [June 22, 2013, 3:30pm UTC](https://boards.straightdope.com/t/what-would-happen-if-i-painted-a-boat-with-never-wet/661635 "2013-06-22T15:30:41Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![NurseCarmen](https://avatars.discourse-cdn.com/v4/letter/n/5daacb/32.png) [@NurseCarmen](https://boards.straightdope.com/u/NurseCarmen)\ **Post date:** [June 22, 2013, 3:30pm UTC](https://boards.straightdope.com/t/what-would-happen-if-i-painted-a-boat-with-never-wet/661635/1 "2013-06-22T15:30:41Z")
Never-Wet is a superhydrophobic spray-on coating that repels water. Would the boat sink? ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [June 22, 2013, 3:35pm UTC](https://boards.straightdope.com/t/what-would-happen-if-i-painted-a-boat-with-never-wet/661635/2 "2013-06-22T15:35:39Z")
No, it wouldn’t sink (unless it would have sunk without the coating). For a boat of any practical size, the coating wouldn’t make a significant difference in how the floated in the water. For a very small (toy) boat, it might make a difference. Hydrophobic coatings are why ducks float - they sink if the coating is removed. ---
**Author:** ![hajario](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hajario/32/171_2.png) [@hajario](https://boards.straightdope.com/u/hajario)\ **Post date:** [June 22, 2013, 3:35pm UTC](https://boards.straightdope.com/t/what-would-happen-if-i-painted-a-boat-with-never-wet/661635/3 "2013-06-22T15:35:49Z")
> [@NurseCarmen](#): > > Never-Wet is a superhydrophobic spray-on coating that repels water. Would the boat sink? No. Never-Wet has no effect on buoyancy. From your perspective, nothing would happen. ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [June 22, 2013, 4:15pm UTC](https://boards.straightdope.com/t/what-would-happen-if-i-painted-a-boat-with-never-wet/661635/4 "2013-06-22T16:15:23Z")
> [@beowulff](#): > > No, it wouldn’t sink (unless it would have sunk without the coating). > For a boat of any practical size, the coating wouldn’t make a significant difference in how the floated in the water. For a very small (toy) boat, it might make a difference. Hydrophobic coatings are why ducks float - they sink if the coating is removed. That, surely, is because their feathers will become saturated with water so that they are no longer buoyant. It is not the not the hydrophobic effect as such that keeps them afloat. They float due to buoyancy, just like anything else (including a toy boat). For ducks, however, much of that buoyancy is provided by air trapped amongst the feathers. Really, it is not correct to say that hydrophobic stuff _repels_ water. There is no force pushing the water away. All it means when a surface is said to be hydrophobic is that water will not soak in, or wet the surface with a thin coat of water. Rather, if it gets wet, the water will run of easily, quickly and more completely than it will from non-hydrophobic surfaces. ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [June 22, 2013, 4:22pm UTC](https://boards.straightdope.com/t/what-would-happen-if-i-painted-a-boat-with-never-wet/661635/5 "2013-06-22T16:22:24Z")
Why, the same thing that would happen if you took Imodium and Ex-Lax at the same time. It would create a tiny black hole spinning off two alternate universes in which both of you are in agony. But seriously, a boat floats because its density is far, far less than its surface area. Unless the coating will increase the density of the boat to overcome the huge chamber of air the cabin holds, it won’t sink or even sneeze at the water. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [June 22, 2013, 4:23pm UTC](https://boards.straightdope.com/t/what-would-happen-if-i-painted-a-boat-with-never-wet/661635/6 "2013-06-22T16:23:07Z")
> [@njtt](#): > > Really, it is not correct to say that hydrophobic stuff _repels_ water. Except for very tiny things, like [water striders](https://en.wikipedia.org/wiki/Water_strider) which “float” by surface tension of the water, not buoyancy. They can only do that because their legs have hydrophobic hairs. ---
**Author:** ![NurseCarmen](https://avatars.discourse-cdn.com/v4/letter/n/5daacb/32.png) [@NurseCarmen](https://boards.straightdope.com/u/NurseCarmen)\ **Post date:** [June 22, 2013, 4:25pm UTC](https://boards.straightdope.com/t/what-would-happen-if-i-painted-a-boat-with-never-wet/661635/7 "2013-06-22T16:25:52Z")
So next question then, if I painted my boat with it, would it improve my gas mileage? ---
**Author:** ![hajario](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hajario/32/171_2.png) [@hajario](https://boards.straightdope.com/u/hajario)\ **Post date:** [June 22, 2013, 4:29pm UTC](https://boards.straightdope.com/t/what-would-happen-if-i-painted-a-boat-with-never-wet/661635/8 "2013-06-22T16:29:03Z")
> [@NurseCarmen](#): > > So next question then, if I painted my boat with it, would it improve my gas mileage? I think that it would slightly decrease drag but given all of the other forces in play, it wouldn’t have a noticeable effect. ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [June 22, 2013, 4:29pm UTC](https://boards.straightdope.com/t/what-would-happen-if-i-painted-a-boat-with-never-wet/661635/9 "2013-06-22T16:29:19Z")
> [@NurseCarmen](#): > > So next question then, if I painted my boat with it, would it improve my gas mileage? If it reduces drag, then yes. But probably very nominal at best. ---
**Author:** ![JWT\_Kottekoe](https://avatars.discourse-cdn.com/v4/letter/j/3ec8ea/32.png) [@JWT\_Kottekoe](https://boards.straightdope.com/u/JWT_Kottekoe)\ **Post date:** [June 22, 2013, 6:09pm UTC](https://boards.straightdope.com/t/what-would-happen-if-i-painted-a-boat-with-never-wet/661635/10 "2013-06-22T18:09:33Z")
> [@njtt](#): > > Really, it is not correct to say that hydrophobic stuff _repels_ water. There is no force pushing the water away. It is partially a question of semantics. At the atomic level, polar and nonpolar molecules may actually attract each other, but at the macroscopic level, we still see a repulsive hydrophobic force. This force is a so-called entropic force, resulting from the statistical trend toward higher entropy. It is very real at the macroscopic level, even if we can’t easily identify a repulsive force at the microscopic level. See for example: [Wikipedia: Entropic Force](https://en.wikipedia.org/wiki/Entropic_force#Hydrophobic_force). Note also that some have proposed that familiar forces like gravity are actually entropic forces. ---
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [June 22, 2013, 6:37pm UTC](https://boards.straightdope.com/t/what-would-happen-if-i-painted-a-boat-with-never-wet/661635/11 "2013-06-22T18:37:00Z")
> [@cmyk](#): > > …a boat floats because its density is far, far less than its surface area. I think you have the right idea here but you can’t compare density (m/v) to surface area (d[sup]2[/sup]). Also density can be a bit of a red herring unless you’re careful about how you measure it. A boat floats because its volume is greater than that of the water it displaces. ---
**Author:** ![Inigo\_Montoya](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/inigo_montoya/32/124_2.png) [@Inigo\_Montoya](https://boards.straightdope.com/u/Inigo_Montoya)\ **Post date:** [June 22, 2013, 7:39pm UTC](https://boards.straightdope.com/t/what-would-happen-if-i-painted-a-boat-with-never-wet/661635/12 "2013-06-22T19:39:10Z")
What if you coat a boat’s hull and propeller with the stuff and then put it in a river pointing upstream? The water would never come into contact with the propeller, so the prop couldn’t move the boat against the current, but the river would never touch the boat so it couldn’t push the boat downstream… ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [June 22, 2013, 8:10pm UTC](https://boards.straightdope.com/t/what-would-happen-if-i-painted-a-boat-with-never-wet/661635/13 "2013-06-22T20:10:59Z")
> [@JWT\_Kottekoe](#): > > It is partially a question of semantics. At the atomic level, polar and nonpolar molecules may actually attract each other, but at the macroscopic level, we still see a repulsive hydrophobic force. This force is a so-called entropic force, resulting from the statistical trend toward higher entropy. It is very real at the macroscopic level, even if we can’t easily identify a repulsive force at the microscopic level. See for example: [Wikipedia: Entropic Force](https://en.wikipedia.org/wiki/Entropic_force#Hydrophobic_force). Well, you seem to be using “macroscopic level” in a bit of an odd sense here. AFAIK the notion of a “hydrophobic force” (as a sort of useful fiction) may have a certain value when you are talking about things at or around the molecular level, such as the the conformation of protein molecules or the formation of cell membranes. It is a way of talking about, and even getting quantitative about, how, in an aqueous environment, hydrophobic molecules, or molecule parts, tend to clump together. At the more realistically macroscopic level that this discussion was actually concerned with, the level of ducks and boats, it is not at all helpful to talk as though some repulsive force or pseudo-force is operating. A boat will not ride higher in the water if you paint it with never-wet, and the water is not repelling it. All “hyrophobic” means at the level of macroscopic surfaces like a boat’s hull, is that water does not “wet” it, i.e., stick to it, coat it in a thin film that does not easily run off, as water does tend to do with non-hydrophobic surfaces. And, **scr4** , I am reasonably sure that there is no use or value in invoking a “hydrophobic force” to explain those insects that walk on water, either. I have always understood that phenomenon to be a result of water’s surface tension. The insect’s feet probably do have to be hydrophobic to prevent the water wetting them, i.e., sticking to them, but the water is not thereby _repelling_ the feet (or vice-versa), just failing to be attracted to them. ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [June 22, 2013, 8:23pm UTC](https://boards.straightdope.com/t/what-would-happen-if-i-painted-a-boat-with-never-wet/661635/14 "2013-06-22T20:23:34Z")
> [@The Great Sun Jester](#): > > What if you coat a boat’s hull and propeller with the stuff and then put it in a river pointing upstream? The water would never come into contact with the propeller, so the prop couldn’t move the boat against the current, but the river would never touch the boat so it couldn’t push the boat downstream… Presumably you are joking, but just in case there is a real misunderstanding here, water is perfectly capable of being in contact with a hydrophobic surface, and if you put a boat, or anything else, with a hydrophobic coating into water, the water touches it, just like it touches anything else. The only difference is that water does not _stick to_ hydrophobic surfaces, but does tend to stick to other ones. Coating your boat in never-wet might make it capable of moving a tiny bit faster, as it will not experience so much drag from the water clinging to it. (I do not know if this really happens, or if the effect is more than negligible, but I think it is plausible that it might.) There could, that is, be an effect akin to lubrication, reducing the friction between boat and water. It will not, however, float any better (or worse). > [@NurseCarmen](#): > > So next question then, if I painted my boat with it, would it improve my gas mileage? So, yes, maybe, but probably not by very much. By the way, I am baffled by why you would even imagine that the boat might sink. ---
**Author:** ![Ethilrist](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ethilrist/32/4604_2.png) [@Ethilrist](https://boards.straightdope.com/u/Ethilrist)\ **Post date:** [June 22, 2013, 8:55pm UTC](https://boards.straightdope.com/t/what-would-happen-if-i-painted-a-boat-with-never-wet/661635/15 "2013-06-22T20:55:27Z")
> [@NurseCarmen](#): > > So next question then, if I painted my boat with it, would it improve my gas mileage? Consider it the equivalent of a really good wax job on your car. ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [June 22, 2013, 9:01pm UTC](https://boards.straightdope.com/t/what-would-happen-if-i-painted-a-boat-with-never-wet/661635/16 "2013-06-22T21:01:17Z")
now I’m wondering if it would be of use on the planing surfaces of my scale hydroplanes… hmm… ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [June 22, 2013, 9:05pm UTC](https://boards.straightdope.com/t/what-would-happen-if-i-painted-a-boat-with-never-wet/661635/17 "2013-06-22T21:05:33Z")
> [@NurseCarmen](#): > > So next question then, if I painted my boat with it, would it improve my gas mileage? Unlikely. It’s not “like a wax job”. It would mostly like increase drag vs a fiberglass hull. The never-wet surface is not that smooth after application, and would be much less smooth than finished fiberglass. See > **[The Internet-demanded, partially scientific testing of Ultra-Ever Dry (in HD!)](https://arstechnica.com/gadgets/2018/07/the-internet-demanded-partially-scientific-testing-of-ultraeverdry-in-hd/)** > > From the archives: It’s coating versus a toilet, a Slip-n-Slide, and one editor’s dignity. > [@](#): > > Slipping and sliding—or not > > A Slip-n-Slide lets you slip and slide because water acts as a lubricating layer between your body and the smooth plastic. The texture Ultra-Ever Dry brings with it—at least when applied with the hand sprayers—totally undermines that smoothness. > > A Slip-n-Slide’s plastic surface already repels water pretty well; adding Ultra-Ever Dry makes the surface even more hydrophobic, but also rougher. The result is… well, the result is more of a Slip-n-grind-to-a-halt. Also, I hurt my back because I’m old. I hope you’re all happy Plus it’s very expensive and wears off quickly. ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [June 22, 2013, 9:45pm UTC](https://boards.straightdope.com/t/what-would-happen-if-i-painted-a-boat-with-never-wet/661635/18 "2013-06-22T21:45:42Z")
> [@astro](#): > > Unlikely. It’s not “like a wax job”. It would mostly like increase drag vs a fiberglass hull. The never-wet surface is not that smooth after application, and would be much less smooth than finished fiberglass. not necessarily. Hydroplanes “skim” across the surface of the water, and the fastest ones have “speed coatings” on the planing surfaces to reduce drag. Scroll down to “question 7” on [this page.](http://www.rottentomatoes.com/quiz/hydroplanes-and-there-history/) The black paint on the planing surfaces is very rough. I can’t find a cite other than I’ve seen this boat in person. ---
**Author:** ![Inigo\_Montoya](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/inigo_montoya/32/124_2.png) [@Inigo\_Montoya](https://boards.straightdope.com/u/Inigo_Montoya)\ **Post date:** [June 23, 2013, 2:53am UTC](https://boards.straightdope.com/t/what-would-happen-if-i-painted-a-boat-with-never-wet/661635/19 "2013-06-23T02:53:00Z")
> [@njtt](#): > > Presumably you are joking Yeah it was sort of an “airplane on a treadmill” scenario. I thought it was funny… ☹ ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [June 23, 2013, 3:07am UTC](https://boards.straightdope.com/t/what-would-happen-if-i-painted-a-boat-with-never-wet/661635/20 "2013-06-23T03:07:58Z")
> [@jz78817](#): > > not necessarily. Hydroplanes “skim” across the surface of the water, and the fastest ones have “speed coatings” on the planing surfaces to reduce drag. Scroll down to “question 7” on [this page.](http://www.rottentomatoes.com/quiz/hydroplanes-and-there-history/) The black paint on the planing surfaces is very rough. I can’t find a cite other than I’ve seen this boat in person. A hydroplane plane coating is a precisely engineered surface designed to have specific surface tension properties at speed. See [http://www.wearloncorp.com/index.php/product/Wearlon\_Super\_F-1M](http://www.wearloncorp.com/index.php/product/Wearlon_Super_F-1M) A never-wet coating is made up of a matrix of silica particles and is most closely analogous to hyper-fine sandpaper. I doubt it’s going to help drag or offer any benefit over a smooth fiberglass surface. It’s likely IMO to perform worse, plus you have the weight of the coating to contend with, plus the coating wears off relatively quickly which will further add to the rough uneven texture of the surface. [Next page](https://boards.straightdope.com/t/what-would-happen-if-i-painted-a-boat-with-never-wet/661635.md?page=2)