GETMILK

Mist Catcher — Fog-Harvest Tent Roof

A drop-in replacement rainfly for any 2-person tent that pulls drinking water out of morning fog. Sized for hikers, refugee shelters, and high-altitude research camps where every litre of water matters.

complexity: mediumtolerance: general
Mist Catcher — Fog-Harvest Tent Roof

Snapshot

Feasibility at a glance

PT localization

9/10

Full

The whole build can be sourced in Portugal.

Per unit

€85–€140 per fly

at 1,500-unit volume

Starter batch

1,500units

minimum viable run

To first batch

12weeks

6 phases, design to ship

Budget

€128K–€294K

all-in estimate

Bottom line

Roll-to-roll laser texturing creates the alternating wet/dry zones.
Read full insight

Picked based on the localization score (9/10) plus the dominant process (laser cutting). For an early build at this batch size, this gives you the best balance of cost, risk, and speed of iteration.

What it does

4 capabilities

Catches microscopic fog droplets on a hybrid wet/dry mesh pattern.

Lets gravity walk those droplets along silicone channels into a bag at the foot of the tent.

Self-cleans during the first minute of contact rain — no maintenance needed.

Doubles as a normal rainfly when the weather is dry — no compromise on shelter.

How it's made

3 stations · build route

  1. 1

    Pattern the mesh

    Roll-to-roll laser texturing creates the alternating wet/dry zones.

  2. 2

    Stitch the canopy

    Industrial sewing with welded silicone channels — no leaks where there shouldn't be.

  3. 3

    Test on a fog wall

    Each batch sampled in a humidity chamber until the yield curve looks right.

Risks to watch

3 identified · 1 blocking

1 high
2 medium

High

Tooling amortisation locks the design

Cast / moulded parts demand tooling that is hard to revise once cut.

Mitigation — Run one full design review with a tooling shop before steel is touched.

Medium

Specialty material lead times slip

If the primary material (Hydrophilic-hydrophobic patterned polyester mesh) source delays, the whole line idles.

Mitigation — Qualify a second-source supplier in week 1 and keep a 4-week safety stock.

Medium

Building / safety regulation drift

Construction-adjacent products attract new EU-level fire and load standards every 18 months.

Mitigation — Subscribe to the relevant EN/ISO bulletins and budget annual recertification.

Production timeline

12 weeks to first batch

wk 1wk 7

Laser cutting

wk 1–2

Sewing

wk 3

Welding

wk 4

Final assembly

wk 5

Test & inspect

wk 6

Functional QA & batch sign-off

wk 7

wk 1–2 is the longest stretch — Laser cutting takes 2 weeks of the 7 weeks on this build.

What goes into it

5 materials · 6 processes

Materials

Hydrophilic-hydrophobic patterned polyester meshSilicone-coated nylon backingFood-grade silicone channelsReflective ridge cordBPA-free LDPE collection bladder

Processes

laser_cuttingsewingweldingfinal_assemblytesting_inspectionpackaging

Design philosophy and best practices

5 principles

A fog-harvest roof collects water from passing fog with mesh panels and channels. Mesh choice, wind loading and clean water storage decide how much usable water it gives.

1

Choose mesh for both capture and drainage

Patterned hydrophilic and hydrophobic mesh helps droplets form and run off. Fine meshes catch more but clog and load up in wind.

2

Design for wind load

Fog comes with wind. Tensioning, anchors and seams must hold gusts, and Eurocode wind loads give a reference.

3

Keep water food-safe

Channels and bladders that touch drinking water should use materials meeting EU food-contact or drinking water rules.

4

Make panels easy to clean and replace

Dust, salt and algae reduce capture. Removable panels make cleaning practical.

5

Orient to the local fog

Panels work best facing the main fog wind direction. Adjustable mounting helps.

Common pitfalls

Avoid

Ignoring UV damage to polyester and nylon in strong sun.

Avoid

Seams that leak or tear under tension.

Avoid

Stored water growing bacteria without regular cleaning.

Avoid

Expecting the same yield in all sites when fog varies widely.

10-year evolution forecast (2026-2036)

4 phases

Fog harvesting is used in dry coastal and mountain areas. The points below are trends.

2026–2028

Better mesh coatings

Trend: research into patterned and coated meshes raises capture per square metre.

2028–2031

Portable systems

Trend: lighter kits for camping, farms and emergencies.

2031–2034

Combined water sources

Trend: fog, dew and rain collection combined in one roof.

2034–2036

Climate adaptation

Trend: growing interest from areas facing drought.

Outlook

Expect use as a supplementary water source in foggy dry regions, not a main supply.

Materials intelligence

5 materials

Polyester mesh

Low supply risk

Fog capture panels

Sourced from: Polyester is produced mainly in China, India and other Asian countries; also in Europe.

Silicone-coated nylon

Low supply risk

Backing and roof fabric

Sourced from: Nylon fabric is made in Asia and Europe; silicone coating is common.

Silicone elastomer

Low supply risk

Water channels

Sourced from: Made from silicon metal and methyl chloride; large producers in China, the US and the EU.

Reflective cord

Low supply risk

Ridge lines and visibility

Sourced from: Widely made in Europe and Asia.

LDPE film

Low supply risk

Collection bladder

Sourced from: Polyethylene is produced worldwide, including Iberian plants.

Prototyping and rapid manufacturing in Portugal

2 companies from the atlas

ROQ Laser

Vila Nova de Famalicão

Laser cutting and welding

Metal fittings and anchor plates.

Compometal

Laser cutting and testing

Brackets and test rigs.

472 Portuguese manufacturers matched

None cover the whole build — it splits across steps.