
New lubricated mussel-proof coating - tribonet
http://www.tribonet.org/new-lubricated-mussel-proof-coating/
======
CalChris
This sort of anti-fouling is the holy grail.

Copper based anti-fouling goes back centuries. The _USS Constitution_ was
copper bottomed in 1794.

[https://ussconstitutionmuseum.org/2015/08/12/copperbottomed/](https://ussconstitutionmuseum.org/2015/08/12/copperbottomed/)

I remember an NPR story about using _extremely_ hot peppers (adding capsaicin
to bottom paint) to defoul.

There was an anti-stick bottom paint but the trouble with it was that it
wouldn't stick to hull.

The trouble with copper is that it's a biocide, it kills. You're basically
putting poison on the bottom of your bottom which leaches into the soil. Like
tributyltin, copper's days are numbered.

It's a hard problem. When I get back into sailing, it'll be dry sailing (put
boat in water and haul out when done). BTW, bottom jobs are freaky expensive,
$10,000 for a race bottom every year.

~~~
jerf
"Copper = poison" is an oversimplification. Copper is also an important
mineral, with 2mg/day a rough guideline for human consumption:
[https://ods.od.nih.gov/News/Copper.aspx](https://ods.od.nih.gov/News/Copper.aspx)
(That number is at the very end, and that link also contains other interesting
details about it.)

It's not like lead, where basically every atom of it in you or the ecosystem
is doing no good.

~~~
SeanDav
Almost any compound is poisonous in high concentrations and/or doses. Even
water can be deadly if one drinks too much over too short a period.

[https://en.wikipedia.org/wiki/Water_intoxication](https://en.wikipedia.org/wiki/Water_intoxication)

~~~
jerf
In the context of discussing putting something into the _ocean_ , using the
example of "lots of water" being toxic is somewhat... amusing.

Given that copper is unambiguously a nutrient for life, I'd like to see a
mechanism for how it would be excessively concentrated in places other than
where it is directly being used before I get too concerned. In general, "in
the ocean" is what I'd reach for as my example of where it is very _difficult_
for something water-soluable to end up concentrating unexpectedly.

Copper is something we put in multivitamins, on purpose. You can buy copper
supplements for your cattle:
[https://www.jefferspet.com/products/copasure](https://www.jefferspet.com/products/copasure)
You can read about how to rectify copper deficiencies in your garden soil, as
well as the signs you've got too much:
[https://www.gardeningknowhow.com/garden-how-to/soil-
fertiliz...](https://www.gardeningknowhow.com/garden-how-to/soil-
fertilizers/copper-for-the-garden.htm) "Copper = poison" is an
oversimplification, in a way that "Lead = poison" isn't.

~~~
SeanDav
Since the subject of context has come up - in the context of water-living
invertebrates, copper is poisonous in anything other than very low
concentrations. This is why copper containing solutions are used to kill snail
and slug infestations in aquariums, gardens and elsewhere.

Not sure why there is any confusion about this. Any aquarium keeper for
example, knows to avoid copper religiously if keeping inverts.

------
SeanDav
> _" Large accumulations of mussels can weigh as much as 1,700 pounds per
> square foot."_

I really find it hard to believe that is a number based in reality.

Disclaimer: I am no expert!

EDIT: Even if the mussels were solid gold and it was a _cubic_ foot of them,
they would "only" weigh 1206 pounds.

source:
[http://www.coolmagnetman.com/magconda.htm](http://www.coolmagnetman.com/magconda.htm)

~~~
blacksmith_tb
A little digging around suggests 35kg per square meter is a more reasonable
estimate[1], which is about 8lbs per sqft. I suppose it's possible some
measures include the weight of the water in the mussels, and others don't?

1: [https://www.boatdesign.net/threads/boat-weight-increase-
due-...](https://www.boatdesign.net/threads/boat-weight-increase-due-to-the-
marine-growth.48041/)

~~~
Retric
That's ignoring the buoyancy from displacing water and only covers two years.
I could see the worst case say a stationary house boat being vastly more
problematic over 30+ years. But, they should generally fall off before the
weight gets crazy.

------
FabHK
Paper:

[http://science.sciencemag.org/content/357/6352/668](http://science.sciencemag.org/content/357/6352/668)

DOI: 10.1126/science.aai8977

It doesn't seem to contain the 1700 lbs per square foot number (it just
mentions pull-off energy in the order of 1J/m^2).

And linked article, originally hosted at harvard.edu (what's with these
websites just copying articles and hosting them themselves??):

[https://news.harvard.edu/gazette/story/2017/08/wyss-
develope...](https://news.harvard.edu/gazette/story/2017/08/wyss-developed-
antifouling-coating-a-boon-to-business-and-environment/)

------
carapace
(Unrelated, to hell with those popups that trigger when your mouse leaves the
window. To hell with them I say!)

------
exabrial
Barely anything sticks to HDPE, has that ever been tested?

~~~
hwillis
HDPE and PTFE (teflon) both have very interesting self-lubricating qualities;
their surfaces act almost like they are somewhat liquid, not unlike ice.
They're not nearly as good as SLIPS but they have similar properties. I don't
know if it's true but the way I've heard it explained is that PTFE and HDPE
are so long-chained that loose molecule ends act kind of like hairs on the
surface. The hairs can slip over each other very easily, so they act somewhat
like a liquid.

But in reality HDPE is specifically used to grow mussels on:
[http://www.plasticsnewseurope.com/article/20131011/PNE/31011...](http://www.plasticsnewseurope.com/article/20131011/PNE/310119980/hdpe-
platforms-used-for-mussels-farming)

~~~
mickronome
Isn't the HDPE only used as flotation devices to hang culture ropes from ?

If not, I've got another project I'll never do: Figure out how mussels adheres
to HDPE and make revolutionary paints and glues for it!

~~~
owenversteeg
Mussels use byssus threads, which are a keratin+polyphenolic protein core
coated in an adhesive protein mix. The keratin/polyphenolic core provides the
strong part, then the adhesive obviously adheres it. Both parts are very
important, and I imagine it'd be hard to have the adhesive work well by
itself.

The process of creating the threads also seems relatively difficult, but
Google seems to have some byssus-based adhesives. Who knows, maybe you'll end
up with something interesting.

Particularly this, seems like it might not be too difficult to make at home
with some equipment and knowledge: [https://www.livescience.com/6974-glue-
derived-clinging-musse...](https://www.livescience.com/6974-glue-derived-
clinging-mussels.html)

------
delafuentecaro
I never thought I would see the day ;)

