superhydrophic coating on wetsuit

[Vicko]

Open Cell suits already do something similar, if you manage to put them on without water or soap (nearly impossible)
I put on my suit on at 6 in the morning and at 6 in the evening the same soapy water is still inside (along some other liquids)

 

[MAKO Spearguns]

some yes, others no. If it says open cell, it doesn't have the inner lining. Dano @MAKO Spearguns can elaborate more on the nuances of those. I don't own/dive any of them, so I'm not fully in tune on them, just know they're warmer but a lot harder to put on

Yes most freedive/spearfishing wetsuits have a nylon/lycra layer on the outside, then neoprene and no additional liner on the inside. Eliminating the internal nylon layer of fabric that is used in "scuba" suits, helps to enhance flexibility, but it does reduce the tear resistance of the suit. The bare smooth rubber on the inside of a freedive suit requires care when putting it on and taking it off, finger nails on the inside are to be avoided.

However, if you take 2-3 minutes to carefully lube the entire inside of a freedive suit, it is EASY to put on. Especially compared to a thick scuba suit. You can slip into a freedive suit in less than 2 minutes and there is no struggling and hard pulling and stretching. It is really remarkable.

So a freedive suit is not harder to put on than a scuba suit and most people will say it is easier. Removal of the wetsuit jacket is best accomplished with the aid of a buddy, but their assistance consists of turning the jacket inside out and pulling off your shoulders. This takes literally less than 5-10 seconds. It can be done solo, but most people are not diving solo.

There are some freedive suits that use a reverse construction, they place the nylon layer on the inside and the smooth rubber outside. These types of suits are much less common and are a little harder to put on, they will not be quite as warm in the water (because the water can migrate and seep along the internal liner) but they are MUCH warmer on the boat.

The smooth rubber dries instantly in the sun and wind and evaporative cooling is greatly reduced - so this is a benefit for a diver who is in and out of the water frequently in cooler air temperatures and does not wish to put on a wind jacket or coat each time.

The drawback to this design is that the bare rubber is exposed to abrasion and abuse and the back and shoulder of the suit will be significantly damaged by UV from the sun. The back of the suit will show cracks etc. rather quickly. We don't offer a suit with the smooth rubber exterior due to these drawbacks and the resultant decrease in useful life span.

The idea of a hydrophobic (super water repellent) coating on the outside of a wetsuit is an interesting idea. IF it really worked and could hold up to abuse, I think the major benefit might be that the (nylon exterior) suit would dry super fast in the air and thus eliminate evaporative cooling in a manner similar to the smooth rubber exterior suits.

 

[D_Fresh]

I wonder what affect pressure at depth would have on the efficacy of a super hydrophobic coating.

I realize that the hydrophobic molecules "repell" water so well that a thin gap layer is formed between water and the coating, but that is under typical conditions at or above the water surface. But at what depth would the atmospheric pressure overcome that repellant characteristic?

Do we have any Materials Engineers around? LOL

 

[WetSEAL]

unless your suit has a hole in it, there is no transfer of water through the neoprene. Any water that comes in contact with your skin came through the zipper, or the ankle/neck/wrist seals.

Can confirm today that water was seeping through some of the wetsuit stitching seams. This does motivate me to do some testing to see if a superhydrophic coating prevents that. I will try it on the zipper too, it might make a difference. I'll let you know...

 

[Schwob]

Does anyone else wonder how reef-unsafe this might be or what it might do to any aquatic ecosystem?

From the MSDS (which is solely about the effects onto humans), downloadable under the link given in the original post:

HAZARDOUS SUBSTANCES:

Hydrotreated Light Distillate
Weight %: 50-75

Mineral Spirits
Weight %: 10-25

Aromatic Petroleum Distillates
Weight %: 2.5-10

 

[Damselfish]

By definition a superhydrophic coating will retain a thin bubble of air around it when it is submerged because the water cannot touch it. That's exactly why I called it a "drysuit"...because you would stay completely dry.

I have not tested it for prolonged periods or significant depths, but when I coated my boot, I could completely submerge it in shallow water and it would remain dry

It may maintain a thin layer of air against the treated material, but your skin isn't treated so I wonder that it would make any difference in water incursion.

Treating booties is a cool idea, would be nice if my booties were always dry! I'd have to think the abrasion on the inside would wear the stuff off somewhat quickly, that's actually how they say to remove it. Also wonder if it is something chemical wise you want against your skin, I imagine they intend it more for the outside of clothing items. The data sheet has all sorts of warnings that _I think_ only apply to the stuff before it is dry, though statements like "Causes damage to organs through prolonged or repeated exposure." give me pause. Also "Do not allow to enter waterways, wastewater, soil, storm drains or sewer systems."

This bit (of probably boilerplate) is kind of funny, given the product - "Remove contaminated clothing immediately and launder before reuse."

 

[KeithG]

Can confirm today that water was seeping through some of the wetsuit stitching seams. This does motivate me to do some testing to see if a superhydrophic coating prevents that. I will try it on the zipper too, it might make a difference. I'll let you know...

None. This is a water repellent, not a water sealing. It has nothing to do with making anything waterproof.

 

[tbone1004]

Can confirm today that water was seeping through some of the wetsuit stitching seams. This does motivate me to do some testing to see if a superhydrophic coating prevents that. I will try it on the zipper too, it might make a difference. I'll let you know...

it will not. It is still a hole in the suit. A membrane seal is the only thing that prevents water from migrating through a pore. The hydrophobic coating prevents water from migrating into whatever it is covering, but it won't seal a hole

@Schwob it should be inert once it is set.

 

[Tom Winters]

This is a bad idea. You’re going to jump off a dive boat in 100’ of water and fall straight to the bottom through the water column. If you have a camouflage suit on, they’ll never find you.

I forgot to add, but if you are wearing a thick rubber wetsuit and you fall through the water column in 100’ of water because you didn’t realize that there was no friction to slow you down, do not breathe as you near the bottom in case you bounce off the reef and get rebounded back to the surface.

Your lungs will surely explode, but at least none of your guts will stick to the suit.

 

[WetSEAL]

This is a bad idea. You’re going to jump off a dive boat in 100’ of water and fall straight to the bottom through the water column. If you have a camouflage suit on, they’ll never find you.

Please tell me you're joking. No, it may reduce suit friction with the water which reduces drag, but drag force is not what keeps you from sinking..that's buoyancy...and this wouldn't effect buoyancy.