Pools · Across Victoria
Acid Washing & Surface Prep in Melbourne
The preparation that decides whether your pool coating lasts or peels.
Before: faded, stained shell during preparationAcid washing and surface prep is the descaling and abrading of a pool shell so a new coating can bond to it, for concrete and fibreglass pool owners in Melbourne who are about to repaint. Paint laid over scale, body oils or chalk bonds to that layer, not the shell, and peels once the pool is refilled.
Degreasing lifts sunscreen, body oils and algae film. Acid washing dissolves calcium scale and the chalky surface layer and opens the pores of concrete or render. Scarifying or abrasive etching then cuts a key into sound old paint or gelcoat for the new coating to grip.
It is a preparation service, almost always booked with Pool Resurfacing & Painting; cracks and hollows are sorted under Cosmetic Pool Shell Repairs first.
When you need it
- Your pool is due for a new chlorinated rubber, two-pack epoxy or polyurethane coating.
- A white crust of calcium scale has built up at the waterline or on the steps.
- The last coat peeled or blistered early, which usually means poor preparation rather than bad paint.
- A fibreglass pool with a dull, oxidised gelcoat that needs abrading before a new finish.
What is included
- Inspection of the empty shell for the existing coating, scale, chalking and oily residue.
- Degreasing of the whole surface, with extra attention to the waterline and steps.
- Acid washing to dissolve calcium scale and lift the weak surface layer.
- Scarifying or abrasive etching to profile sound old paint, bare concrete or gelcoat.
- Neutralising and flushing the shell, then vacuuming out grit before the first coat.
Our preparation and application process
Step 1: Drain and inspect
The pool is emptied, water kept out of the stormwater drain, and the shell checked for scale, chalk and old coating.
Step 2: Protect and degrease
Coping, tiles and fittings are masked, the area is kept clear, and alkaline degreaser is scrubbed over every surface and rinsed off.
Step 3: Acid wash and etch
Diluted acid goes on in sections to dissolve scale and open the pores, then scarifiers and abrasive pads key sound paint or gelcoat.
Step 4: Neutralise, rinse and dry
An alkaline wash neutralises the acid, the shell is flushed and checked with pH strips, then vacuumed and left to dry.
Materials and systems
Alkaline degreaser
A detergent wash that lifts sunscreen, body oils and algae film, since paint over these residues never bonds.
Diluted acid wash
Acid mixed down to working strength that dissolves calcium scale and opens the pores of concrete or render, then is neutralised.
Mechanical scarifying and abrasive etching
Scarifiers and abrasive pads that roughen the surface, giving the coating its key on sound paint and gelcoat, where acid does little.
What affects the cost
- Pool size and depth, which set the area to be washed and etched.
- How much calcium scale has built up and how long it has been there.
- Whether the shell is concrete, render or fibreglass, as each needs different prep.
- Whether you are changing systems, as going from chlorinated rubber to epoxy means stripping the old coating back.
- Access for equipment and where the drained water can go.
We do not publish prices because every surface is different (how pricing works). Get a free quote with the scope written down.
How long it takes
Acid washing and prep on a backyard pool typically takes one to two days once it is empty, depending on size, scale and how much old coating needs scarifying.
The shell then has to dry before coating. Concrete and render typically need several dry days, longer in cool, damp weather, while fibreglass is usually ready sooner.
How to prepare
- Tell us what the pool was last painted with, if you know, as it changes the prep.
- Switch off the pump and any chlorinator or dosing system before we arrive.
- Clear toys, furniture and the automatic cleaner from the pool and its surrounds.
- Keep children and pets away from the pool, and close windows that face it while acid is in use.
Real projects
Acid Washing & Prep from real jobs.
FAQ
Acid Washing & Prep: questions people ask.
Why did my pool paint peel so soon after it was done?
Early peeling is almost always a preparation problem, not a paint problem. A coating laid over scale, chalk or body oils bonds to that layer, not the shell, and water pressure lifts it off in sheets.
Does acid washing remove old pool paint?
No, it removes scale, chalk and the weak surface layer, not sound paint. An intact old coating has to be scarified or abraded to give the new coat a key, and on fibreglass the key comes entirely from abrasion.
Is acid washing safe?
Yes, with diluted acid, protective gear and full neutralising afterwards. We keep the area clear while acid is in use, then neutralise the shell and test it with pH strips before anything is coated.
How much does pool acid washing cost in Melbourne?
It depends on pool size, how much scale and old coating have to come off, whether the shell is concrete or fibreglass, and access for equipment and water. It is usually quoted with the recoat as one figure, and we give a free, no-obligation quote.
How long does acid washing and surface prep take?
Typically one to two days for an average backyard pool, depending on size and scale. Allow several more days for the shell to dry before coating, longer in cool or wet weather.
Free quotes
Get a free pool preparation quote
One enquiry can cover several jobs: a repaint and a roof clean, a pool recoat and the surrounds, a bathroom refresh before sale.
- Step 1: We read your request and look at any photos
- Step 2: We call, text or email you (your choice) to talk it through
- Step 3: Site visit if the surface needs a closer look
- Step 4: A free, no-obligation quote with the scope written down
Get a free pool preparation quote
Tell us about the surface and how you would like to hear back. Photos help us quote faster.
Acid Washing & Prep, done properly.
Get a free pool preparation quote. Free, no-obligation, across Melbourne and Victoria.