Comment

Comment by Merrick on March 7, 2013 at 7:26am

Could be very helpful in reducing boundary layer effect in the hull though:

http://www.unm.edu/~solgel/publications/Pubs2006/2006%20Phys%20Rev%...

Interesting stuff always taking me away from doing what I should: -building my ROV!-

Comment by Frank on March 1, 2013 at 9:45pm

there are some interesting "lotus effect" textiles where they are able to bond the nanostructure compounds which minimize the contact with water directly to the clothing, so that it can be washed repeatedly.  (as long as you dont use fabric softener). examples are "ion mask" used in teva shoes and "nanosphere".  

The "proprietary additive" is most probably flourocarbon compounds.  Maybe they found a really good one or have some sort of nice way they are putting it into their "proprietary polymer".   It would be interesting to know if it is a flouropolymer with side chains which are 6 carbons long or 8.  It turns out the former shorter chained ones do NOT bioaccumulate as much as the longer ones, and I think there may even be some regulation in this area as these compounds are not good for you.  I believe some carcinogenic effects and also reproductive/ endocrine system effects (please dont quote me on that as I am hazy on details).

These things are all around us, non stick coatings on all of our pans and whatnot, but it turns out that microwave popcorn is one of the biggest sources of this stuff!

I think this is a nice step forward in the area but definitely share some of eric's reservations in terms of how much good it will do OpenROV folks.  They should send Eric a free quart of the stuff :-)

Comment by Merrick on March 1, 2013 at 8:08pm

MSDS

top coat: acetone(96%), silica(2%), +"Proprietary Additive" (<%1)

base coat:

Ingredient % by Wt C.A.S. No.

Xylene 66 106-42-3

Naptha 12 64742-89-8

Hexane 6 110-54-3

Methylethylketone 2 78-93-3

Toluene 5 108-88-3

Proprietary Polymer 9 -

Proprietary Additive <1

Comment by David Lang on March 1, 2013 at 1:46pm

Eric's voice of reason...

I hate to rain on this parade (okay, a little bit of a pun was intended there!) but I want to be a voice of caution here. Sprays that supposedly 'make electronics waterproof' have been the content of late-night infomercials for years. 'Nano-technology' is just a fancy way of saying that they're using a chemical (generally some sort of oil) that has water-repelant properties at the molecular level (just like the silicone spray we already use) and perhaps some stuff that causes the chemical to bond with the material it's applied to

Here are some examples:
CorrosionX, Liquipel, NeverWet, HzO, P2i, ... the list goes on.

All of these companies have managed to get sensationalistic press that reads something like "new revolutionary invention changes everything"

Here are some examples:
http://www.zagg.com/community/blog/your-next-iphone-may-be-waterpro...
http://www.huffingtonpost.com/2012/01/17/liquipel-waterproof-phone_...
http://techland.time.com/2012/05/16/waterproof-smartphones-coming-s...
http://www.foxnews.com/tech/2012/01/09/finally-can-throw-your-phone...

They work by adding a hydrophobic substance to the surface of a material, but it is just a coating and will not hold up over time if submerged

How do they dunk electronics in water without ruining them? It's fresh water. Although their spray will help prevent water from accumulating (just like rain-x on a windshield that helps water "roll off" the surface) it's not actually insulating anything. I could do a similar demo with an electronics board that has no coating on it in fresh water, and as long as the water that's accumulated on the board were removed afterward, you'd see just about the same results.

There are also ways of *actually* putting an insulating layer over electronics which is called conformal coating, but even this is not something people would trust while being submerged in salt water.

What's more, is that even if something like this worked reliably, electrical insulation isn't our issue with the motors, it's corrosion on the bearings. Because the bearings used in our motor are made with high carbon (non-stainless) steel, they oxidize over time. Because they are moving parts, any spray or coating wears off.

We've already been using a "hydrophobic nanotechnology" to help reduce this process, and it doesn't cost $150 a bottle. Here's a link.

Okay- so all of this is a bit harsh, I'll admit. Sprays and coatings like this one *can* actually help protect electronics if they get wet accidentally. But I want to disband and claims that they make things anything more then splashproof- especially with moving components. Would you spray your laptop with this stuff and take it scuba diving with you?

I think it's worth doing some research and experimentation with various chemicals to see how they improve the longevity of things underwater, and getting the discussion going about the topic is a good idea, but our methods and recommendations should ultimately be based on testing

Comment by Peter Christensen on March 1, 2013 at 12:14pm

How durable is it over time?  All of the materials in the demo were briefly exposed but a submersible will (obviously) be submerged for long periods of time and frequently.  It might wear off even sooner on the motors because of the movement.

It seems like a no-brainer insurance policy for the internal electronics.

Comment by Jim Trezzo on March 1, 2013 at 10:56am

pretty cool.  Looking at existing distributor 

http://www.globalindustrial.com/g/janitorial-maintenance/paint/liqu...

1QT - top coat + bottom coat = $158.90.

If we can get smaller quantities (maybe a few ounces in a spray container) that could be cost effective.  Else we can have a nano-spray day where we share a quart!

Jim

Comment by David Lang on March 1, 2013 at 10:31am

Also, the quarts can go a really long way. We could buy it at the OpenROV HQ and coat all the motors before they go in the kits. And sell coated motors in the store. We could also coat the beaglebone and cape.

Comment by David Lang on March 1, 2013 at 10:27am

Good question. I'm going to talk to him about that.

Comment by Philip and Nathanael Mathieu on March 1, 2013 at 10:09am

Looks prohibitively expensive, at least at the current volumes sold on Amazon Supply.  Will smaller volumes be available for people like us (who don't need a quart of each layer)?