Leroy replied:

powder coating is the go. You will get uniform coverage as well of the powder. I'm not sure if it is more resilient to rusting through though as I have had bard start to rust over time that were powder coated.

Leroy

crfan replied:

The bloke at the local steel joint told me that powder coat is porous and lets in moisture don't know how true it is but he recomends two pack paint.

Kiwi Kia replied:

Powder coat is only as good as the preperation AND how it is applied. It can be thick or thin covering and have pore holes if it is not done right.

For outdoor use I would sand blast, use a good etch primer and then paint. Make sure you get into those hard to reach corners when cleaning and primeing.

Member - Trevor R (QLD) replied:

Chris,

I get machinery I use for work powdercoated regularly by CP Plating here in Brisbane and they do a fine job. All our stuff is blasted, zinc dipped and then powder coated and it seems to outlast all other methods we have tried in the past. If you are in Brissy give them a call 32683044.
I have no affilliation with them but I also would not use them if they weren't good.

Cheers Trevor.

Member - Blue (VIC) replied:

Something else to keep in mind is whether or not the existing coating is powder... I have blasted(mate used to own a blast business) powder and it's a dead set PITA. It takes bloody ages to get old powder off and will cost a fortune to blast.

F4Phantom replied:

i use penetrol a lot in my business, i paint it on light to heavily rusted metal. I dont think i have seen a better rust killer. Just paint it on underneath whatever you decide to do, it shouldnt allow rust to form. I am lazy, i just paint the aluminium version stright on to heavy un prepared rust and so far i have never seen rust come through it.

Old Nick replied:

Answer to your rust problem. When our steel boats are built we sand blast twice as new, prime,then two pack finish. regards Nick

Sarg replied:

Sandblast, prime, good quality 2 pack.The only way to do it for a long term effective solution.

Glenno replied:

If you dont have the means to blast and 2 pack, I use a wire brush on the angle grinder, then Penetrol (it rocks), then some Kill-Rust grey finish. Works a treat and looks good.

No rust poking through from about 8 yrs on my rack- its seen salt and plenty of rain. Not to mention gear being loaded and unloaded etc.

The localpaint shop advised that before you paint anything galvanised, use Penetrol as it will help the Paint bind to the zinc.