repainting powder coated metal ?

It that time of year and the exterior bits need sprucing up, - railings and garden table and chairs (sheet metal). I know they need to be degreased, clean, dry etc but what about primer and prep ?

Edited By capnahab on 26/03/2017 12:44:12

I repainted a set of powder coated kitchen chair frames. I degreased, rubbed down with wet & dry paper to take the shine off, and used melamine cupboard paint as I thought that might adhere better to the coating. It did appear to work, but after a few months the paint started rubbing/peeling off.

There may be a paint/primer for the job but melamine paint is not it . . . but it is excellent on melamine and vinyl covered doors. Not a very helpful post but it might save some wasted time.

Mike.

Definitely need the proper primer. Data sheet for Dulux Trade Super Grip primer claims that its suitable for powder coated surfaces after light abrasion. Water based so it ought to be easy enough to get. That said I'd be looking into proper plastics primers with chemical adhesion capabilities. Trouble is not only do you need a good idea what the powder coat material is to select the right one but getting hold of anything other than water based paint is getting harder and harder.

Clive.

Would Hammerite Smoothrite do the job?

Ed.

Unfortunately powder coating is actually plastic coating. The powder coating industry will call it all manner of names but it is plastic coating. It is the quickest and cheapest way to produce a nice finish that will last as about long as a chocolate teapot.

The problem with it is as sooner as you damage the surface the moisture gets in and rusts like hell from the inside.

To paint it you need a plastic primer or an etch primer.

My local powder coaters bake old coated parts to make the remaining coating brittle before shot blasting the remains off.

If you can remove the loose bits mechanically & scuff-up the secure remaining coating, a two-pack etch primer should give a sound base to refinish. International Paints used to do a two pack etch primer for outboard motor bottom units that was particularly tenacious on aluminium castings (I used it brushed on to motorcycle alloy wheels to good effect), but it isn't cheap.

Nigel B

The powder coat paint on my outdoor custom made railings lasted 25 years with only minor problems. Rubbed down and recoated without problem using "self priming black enamel"

One problem is that most powder coating products contain wax.