Hydrophobic Nano-Coating

Coatings for plastics · Spray applied

Hydrophobic nano-coating is an ultrathin water-repellent treatment that lowers surface energy so droplets bead and shed.

3D printingStandard cost $$Unchanged

Quote a part with Hydrophobic coat Compare coatings for plastics

Hydrophobic Nano-Coating on a machined part

What is Hydrophobic coat?

It can reduce wetting and moisture ingress on complex parts, but it does not make an unsealed assembly waterproof.

How it works

A low-surface-energy silane, fluorinated, silicone, or hybrid chemistry is sprayed, dipped, or vapor deposited onto a clean dry surface. Molecules bond to or form a very thin film over the substrate, increasing water contact angle and reducing capillary wetting. Coverage must be continuous around pores and edges, yet the layer is too thin to bridge gaps, close seams, or correct porous bulk structure. Abrasion, detergent, ultraviolet exposure, and handling oils gradually reduce repellency.

Why specify it

Adds water repellency with minimal dimensional change
Can reach complex external geometry
Usually preserves appearance
Reduces wetting and contamination adhesion

Where it falls short

Does not seal joints, open pores, cracks, or connector paths
Thin treatment wears off under abrasion and cleaning
Adhesive bonding and painting may fail on treated areas
Performance needs a named contact-angle and durability test

Hydrophobic coat at a glance

Hydrophobic coat is a middle-of-the-range finish; its best score is lubricity (45 of 100), at a standard cost. Surface hardness is not rated: the finish leaves the part's own surface.

Corrosion protectionLow25 / 100

Surface hardnessNot rated—

Cosmetic qualityLow20 / 100

LubricityFair45 / 100

Relative costStandard35 / 100

Each score is 0–100 against every finish in this catalog. Corrosion comes from salt-spray life (ASTM B117, log scale) and hardness from the finish layer's Vickers or pencil hardness; cosmetic, lubricity and cost are FabDigit's engineering assessment. Economy on the radar is the inverse of cost.

Hydrophobic coat key numbers

Typical values from the governing specifications and shop practice; bars are this finish against the highest value among coatings for plastics finishes.

Electrical

Unchanged

Colours

clear

Appearance

Usually visually clear with little gloss change; porous surfaces can darken or become uneven.

Specifications for Hydrophobic coat

The documents a drawing cites to define this finish, with the Type / Class rows that apply. Each links to a page explaining the standard.

Drawing call-out

APPLY CLEAR HYDROPHOBIC NANO-COATING TO ALL EXTERIOR SURFACES EXCEPT MASKED AREAS; WATER CONTACT ANGLE AND ABRASION RETENTION PER APPROVED PRODUCT SPECIFICATION; MASK BOND, CONTACT, AND OPTICAL SURFACES

Which materials take Hydrophobic coat?

Verdict per material family, with the grades that behave differently. Each family links to its datasheets in the material library.

Material family	Verdict	Notes
Aluminum	Yes	Common on anodized or cleaned aluminum after a named product qualification.
Polymer	Yes	Surface activation and chemistry depend on polymer.
SLA	Yes	Clean and fully post-cure before treatment.
Brass	With care	Clean tarnish and qualify adhesion.
Composite	With care	Open porosity may remain a leak path.
Copper Alloy	With care	Clean tarnish and qualify adhesion; some solvents stain copper.
DMLS / SLM	With care	Can reduce wetting; it does not close AM porosity.
FDM	With care	Open porosity still leaks; the film is not a sealant.
Magnesium Alloy	With care	Needs conversion coating or primer before an organic film.
Stainless Steel	With care	Needs mechanical or chemical activation for adhesion.
Steel	With care	Does not replace a corrosion coating on carbon steel.
Titanium	With care	Needs activation or primer for organic films.
Zinc Alloy	With care	Needs conversion coating or primer; some solvents attack zinc.
MJF	Limited	Bulk porosity and seams remain.
SLS	Limited	Water repellency does not make porous SLS nylon pressure-tight.

How Hydrophobic coat is applied, and what it does to the part

1Clean
2Dry completely
3Mask
4Activate if required
5Apply named treatment
6Drain or flash
7Cure
8Test water repellency and assembly ingress

Dimensions	Treat as negligible buildup only after the named chemistry is selected; never use it to compensate for a leaking gap or porous wall.
Build-up per side	— — Usually dimensionally negligible, but the named product must define film behavior.
Masking	Usually needed. Mask adhesive, paint, solder, optical, gasket-friction, electrical-contact, and fluid-wetting surfaces.
Electrical	Unchanged
Appearance	Usually visually clear with little gloss change; porous surfaces can darken or become uneven.
Added lead time	2–6 working days on top of the bare part

Design rules for Hydrophobic coat

What to decide on the drawing before the part goes to the finisher.

Design seals and enclosure ingress protection independently.Hydrophobic chemistry cannot close a mechanical leak path.
Mask every later bond or paint area.Low surface energy defeats adhesion.
Require repellency after abrasion and cleaning.Initial droplet beading does not prove service durability.
Define a named product and contact-angle method.The term nano-coating covers incompatible chemistries and thicknesses.

Hydrophobic coat versus the alternatives

Finishes engineers weigh against Hydrophobic coat, and when each wins.

Finish	Corrosion	Hardness	Cosmetic	Cost	Thickness	Choose it when
Hydrophobic coat this page	25	—	20	$$	—	—
Clear Coating Hydrophobic coat vs Clear Coating →	20	12	85	$$	15–50 µm	when a measurable protective film and gloss control are required
Surface Sealing Hydrophobic coat vs Surface Sealing →	30	—	55	$$$	≥ 0 µm	when porous printed material must become pressure-tight

Hydrophobic coatClear Coating

The radar overlays Hydrophobic coat with Clear Coating, its most common alternative — chosen when a measurable protective film and gloss control are required. Scores in the table are 0–100 across every finish in the catalog.

Cost, lead time and compliance

Relative cost

Hydrophobic Nano-Coating is a standard-cost finish ($$): cheaper than about 60 % of the finishes FabDigit quotes.

Finishing is priced per part with a lot minimum, from FabDigit's own China-side rates. The exact figure appears on the instant quote once the part is uploaded.

Lead time and compliance

Added lead time	2–6 working days
RoHS	Compliant
Notes	Confirm exact chemistry; some fluorinated formulations may face substance restrictions beyond baseline RoHS.

What Hydrophobic coat is used for

Electronic covers
Sensor housings
Wearable prototypes
Moisture-shedding fixtures
Contamination-resistant surfaces

Hydrophobic coat — frequently asked

does hydrophobic coating make a part waterproof

No. It reduces wetting, but it cannot close seams, cracks, connector gaps, or porous walls. Waterproofing requires enclosure and seal design plus an ingress test.

how thick is nano coating

There is no defensible class-wide thickness because silane monolayers, sprayed hybrids, and thicker conformal products are all marketed this way. Use the named product specification.

how long does hydrophobic coating last

Life depends on abrasion, detergent, ultraviolet exposure, and chemistry. Require contact angle or water-shedding performance after a defined aging and wear cycle.

can you glue over hydrophobic coating

Usually not reliably. The low-surface-energy treatment that repels water also reduces adhesive wetting, so bond areas should be masked.

hydrophobic coating vs conformal coating

Hydrophobic treatment mainly reduces wetting and may have negligible buildup. Conformal coating forms a measurable protective film over electronics and can provide a more substantial environmental barrier.