So you want to change the colour of something that’s already painted with acrylic enamel.
Seems simple enough, right?
Just grab a brush and go for it. Yeah, well, that’s what I thought too until the new paint started coming off in sheets about three weeks later.
Acrylic enamel’s one of those paints that looks fantastic when it’s done – all shiny and professional – but trying to paint over it later is like trying to stick something to glass.
Your new paint just doesn’t want to grab onto it.
What makes acrylic enamel so bloody difficult
It’s water-based, which is good because it doesn’t stink up the place like oil-based stuff. Dries fast too, usually within a few hours rather than overnight.
The finish is tough and glossy, which is great when you first apply it but becomes your enemy when you want to change colours.
Low VOCs means it’s safer to use indoors. Won’t give you a headache like some of the older paints used to.
But that smooth finish – that’s the problem. New paint just slides right off if you don’t know what your doing.
Used heaps on metal, wood, trim work. Anywhere you want that professional shiny look. Holds up well to scratches and weather, which is why people like it in the first place.
Can you paint over it without stuffing up?
Look, you can, but there’s prep work involved and most people try to skip it.
I’ve seen blokes at Bunnings buying paint to go straight over acrylic enamel without any prep – waste of money, that is.
The glossier the existing paint, the more work you’ve got ahead of you. Matte finishes are bit easier but still need attention.
And if there’s already damage – chips, cracks, whatever – fix that first or you’ll just make it worse.
Oil-based or acrylic topcoats both work, sort of depends what your trying to achieve and how much smell you can tolerate.
Cleaning – boring but can’t skip it
First thing is getting all the crud off. Grease, dirt, dust, hand prints, whatever’s on there.
Soap and water for most stuff, degreaser for the really oily bits. Metal surfaces might need rubbing alcohol to cut through stubborn grease.
Rinse everything off properly and let it dry. Completely dry, not just feels dry. Moisture under paint causes all sorts of problems later.
Sanding – the bit everyone tries to avoid
We get calls at Perth City Painters all the time from people who skipped the sanding step and now their paint’s coming off in sheets.
Most people hate this step and try to convince themselves they can skip it. You can’t. Well, you can, but don’t come crying when your paint peels off.
220 to 320 grit sandpaper works.
Don’t need to sand back to bare surface, just rough up that glossy finish so the new paint has something to grab. Feels slightly rough when you run your hand over it, that’s about right.
Dusty work, wear a mask. The dust gets everywhere and you don’t want to breathe it.
Primer – don’t cheap out here
Bonding primer’s what you want. High-adhesion stuff specifically designed for slick surfaces.
Creates a bridge between the old paint and whatever you’re putting on top.
Brush it on, spray it on, whatever works for the job. Let it dry properly – I mean properly, not just surface dry. Check the tin but usually few hours minimum.
Some primers are better than others, cheap ones from the discount stores might not grip acrylic enamel well. Worth spending a bit more here.
Topcoat choices
Acrylic latex is easy to work with and clean up. Oil-based is tougher but takes longer to dry and smells.
Can even use another acrylic enamel if that’s what you prefer.
Test a small area first, make sure everything’s compatible. Matte, satin, gloss – pick whatever suits the job. Each has its place.
Slapping it on
Thin coats, not thick ones. Thick coats drip and look rubbish. Use proper brushes for detail work, rollers for flat areas.
Got a spray gun and know how to use it? Even better for large jobs.
Two coats usually does it. Wait between coats properly even though you want to get finished.
What goes wrong and why
No sanding – paint peels. Wrong primer – paint doesn’t stick. Thick coats – drips and runs. Painting over damp surfaces – bubbles. All avoidable with a bit of patience.
People also try to rush the drying times. Paint feels dry on top but isn’t underneath, then you get adhesion problems.
Stuff you’ll need
Sandpaper, cleaning gear, primer, topcoat paint. Brushes or rollers depending on the job. Tape for clean lines if you need it.
Drop sheets to protect the floor.
Nothing fancy, just decent quality gear. Cheap brushes leave marks, cheap primers don’t stick.
How long it takes
Day or two usually, depending on drying times and temperature. Cleaning and sanding an hour or so. Primer few hours to dry. Each topcoat another few hours.
Warm dry conditions speed things up. Cold or humid weather slows everything down.
Random questions
Oil-based over acrylic enamel? Yeah, with proper prep. What if it peels anyway? Scrape it off, sand, start again.
Clear coat needed? Not really, acrylic enamel’s pretty tough on its own.
Metal needs degreasing and rust treatment if there’s corrosion. Just painting over rust is pointless.
Brands that don’t suck
Rust-Oleum, Krylon, Benjamin Moore make decent stuff for this type of work. Nothing exotic, just quality products that do what they say.
When to get help
Not rocket science but takes time and patience. Valuable items or big jobs where mistakes get expensive, might be worth getting someone else to do it.
Especially if you’re not confident about the prep work.
Bottom line
Works fine if you do it right. Clean, sand, prime, thin coats. Skip steps and you’ll be doing it again sooner than you want.
Not complicated but does need attention to detail.
