Aquablaster Guide

What each variable actually does

1) Pressure

• Higher pressure = faster stripping, deeper key/profile, higher risk of warping/etching.

• Lower pressure = safer on thin/soft substrates, more controllable.

2) Abrasive amount

• More abrasive = more cutting points hitting the surface (faster), but can:

  • increase surface roughness

  • increase media use

  • reduce visibility if you overdo it

• Too little abrasive = you’re basically pressure-washing with grit “sparkles”.

3) Water amount

• More water = less dust, cooler surface, gentler impact.

• Too much water = slows cutting, can reduce profile, can make contamination smear (paint/grease) rather than lift.

Quick start procedure (repeatable every time)

1. Start with mid pressure, low abrasive, mid water.

2. Do a 30–60 second test patch.

3. Adjust one variable at a time:

   • Need more bite → add abrasive a notch.

   • Still slow → raise pressure a notch.

   • Getting too harsh / hot / dusty → add water a notch (or drop pressure).

Recommended settings by material (starting points)

Mild steel (rust, paint, mill scale)

Goal: fast removal + solid profile for coating

• Pressure: Medium–High

• Abrasive: Medium–High

• Water: Low–Medium

Notes:

• For heavy rust/scale: increase abrasive before pushing pressure hard.

• If flash rust is a concern: don’t drown it — finish, rinse, dry, and protect quickly.

Stainless steel (weld tint, contamination, refurbishment)

Goal: clean without heavy profiling

• Pressure: Low–Medium

• Abrasive: Low–Medium

• Water: Medium

Notes:

• Keep it cooler with a touch more water.

• Don’t chase speed with aggressive media unless you actually want a rough key.

Aluminium (oxidation, paint removal, restoration parts)

Goal: strip without pitting

• Pressure: Low

• Abrasive: Low

• Water: Medium–High

Notes:

• Aluminium marks easily — use water as your “softener”.

• If it’s not moving: slightly more abrasive is safer than more pressure.

Galvanised steel (cleaning before paint, removing white rust)

Goal: clean without stripping zinc

• Pressure: Low

• Abrasive: Very Low

• Water: Medium–High

Notes:

• Treat it like “cleaning”, not “stripping”.

• If you see zinc coming off, you’re too aggressive (reduce pressure/abrasive).

Cast iron (engine blocks, heavy corrosion)

Goal: remove rust/paint, uniform finish

• Pressure: Medium

• Abrasive: Medium

• Water: Low–Medium

Notes:

• Cast is tougher, so you can lean on abrasive a bit more.

• Watch for trapped grit in cavities—flush thoroughly.

Stone / masonry (graffiti, smoke damage)

Goal: remove contamination without eroding detail

• Pressure: Low–Medium

• Abrasive: Low–Medium

• Water: Medium–High

Notes:

• Softer stone wants lower pressure and more water.

• Always test patch—stone varies massively.

Brick (paint/graffiti)

Goal: clean face without chewing mortar

• Pressure: Low

• Abrasive: Low

• Water: Medium–High

Notes:

• Keep the nozzle moving; don’t dwell on edges/mortar lines.

Wood (oak beams, furniture stripping)

Goal: remove coatings while keeping grain intact

• Pressure: Very Low

• Abrasive: Very Low

• Water: Medium

Notes:

• Water helps stop “furring” and burning, but too much can raise grain.

• Multiple light passes beat one heavy pass.

Fibreglass / GRP / gelcoat (boats)

Goal: remove antifoul/paint without damaging gelcoat

• Pressure: Very Low

• Abrasive: Very Low

• Water: Medium–Hig

Notes:

• If you see the surface go chalky/etched, back off immediately.

Powder coat removal (steel frames)

Goal: break coating cleanly without gouging metal

• Pressure: Medium

• Abrasive: Medium

• Water: Low–Medium

Notes:

• If it’s bouncing and not breaking, add abrasive slightly.

Fast troubleshooting cheat sheet

Problem: Not removing coating / rust

• Increase abrasive → then pressure → slightly reduce water if it’s “washing” rather than cutting.

Problem: Surface looks too rough / pitted

• Reduce pressure → reduce abrasive → increase water.

Problem: Warping on thin sheet metal

• Drop pressure a lot, keep abrasive low, use more water, increase stand-off distance, keep moving.

Problem: Media usage is crazy

• You’re probably over-feeding abrasive. Reduce abrasive, raise pressure slightly if needed.

Problem: Poor visibility / slurry everywhere

Too much water (or too much abrasive). Back one off, then adjust.