Thread: Best metal finish for outdoor workbench

hey jill
this may not be the answer you want but i have done this before..

it was at a clients house in st ives sydney..
she is orchid show enterant. and has many many many plants.
she had the same thing as an outdoor planting table but hated how it scratched the paint when she used it.
so the answer....
i went to our local scrap steel joint. found a sheet of stainless steel bench top which was about a foot too long and a bit too deep. and it cost me a per kilo rate to buy it off them (which came to $8..alot cheeper than paint.) all i did is cut it down to size then sika-flex adhisive to the old table. and this thing looked like it should have been in a commercial kitchen. and a result that would last many many years.
she was so happy that i got extra jam on my scones that day..
wound up ....every body was happy....

it is just an alternative. thats all.
Glen boultoN

You should have used an etch primer on the galv, or try wiping it down with white vinigar, even though you wire brushed the surface it most likley would not have removed all the galv, so you need to etch the surface to provide a key for the primer

Thanks for these quick replies, Glen and China. Yep, I agree, stainless steel would have been ideal.

China, are you saying to do an etch primer on top of the cold gal first coat, or do the etch primer on the zinc alume ?

you would want to do etch primer first

Also i would be a good idea to not use turps to clean it ever as that is the solvent for the paint = remove paint

...not quite sure why you'd want to paint zincalume with a gal topcote in the first place - it doesn't need protection from rusting (wire brushing would only thin out/scratch through the coating, making it less rust resistant).

But anyway...degrease (strong laundry detergent and nylon brush), etch prime with an epoxy etch primer, overcoat with an epoxy based topcoat or a hammer finish paint.

You can also paint it directly with Solaguard or similar paints, but this might not give you a hard film finish.

Next step up in durability from that would be car or marine paints.

Turps is not a good pre paint cleaner for anything except oil based paints as it can leave oily residues on the surface.

Spray thinners do a much better job (wipe some turps on your fingers and you don't get much change to your skin...wipe spray thinners or wax/grease remover on your fingers, and your skin will get a white powdery look as the skin gets defatted by the solvent).

Thanks for this valuable information, Master Splinter. You have highlighted a number of traps for beginners.

Well, we have just finished a wet season here in Nth Qld. I had left some 4x2 timber on the zinc alume benchtop, and the benchtop surface rusted very badly undeneath the timber. So I ended up wirebrushing the lot.

I also noticed that previously that some bird poo also badly corroded the surface - bloody big Ibis birds, I think, even though the bench was covered with blue polytarp.

Pretty harsh environment, eh? Ah well, but cyclone Thomas didn't blow this heavy bench away

many thanks,

Jill

Not surprising - timber can do nasty things to metal, especially ones with an active surface like zincalume.

If its had rust issues, I'd also be wiping it over with phosphoric acid to get rid of any minute particles of rust in the surface (degrease/dry/phosphoric acid wipe/wipe off acid with cloth saturated in paint thinners/prime/paint).

Hammerite paint tends to be my favourite for buggered surfaces - it has an uneven finish which is good at disguising a less than perfect substrate.

Thanks Master Splinter, much appreciated. I hadn't thought of the phosphoric acid. I was toying with the idea of rust removal by electrolysis, which I have had some success with on smaller parts ( eg an old outdoor metal vice), but the bench cover is too big to handle.

regards,
Jill

Another valuable lesson learnt too. Blue polytarp is not water proof, merely "water resistant"
Hence the acidic bird poo going through and damaging the surface without my knowledge

Jill,

The problem you are having with paint not sticking to your galvanised bench is most likely being caused by a reaction between the zinc in the galvanised bench top and the oil (turps) based paints you are attempting to use.

Most turps based paints, including the kill rust epoxy enamel top coats, are not suitable for use over zinc rich surfaces such as hot dip galvanised steel or any surfaces coated with a cold gal product.

As mentioned above the cold gal coating is of no use on a surface that has already been hot dip galvanised.

A kill rust hammered finish would work well as a top coat however it should not be painted directly over the galvanised surface. A water based or spirits based primer must be used first if you want to top coat the bench with an oil based finish. You might like to try the Wattyl killrust heavy duty metal primer which is spirit based and is suitable for use over galvanised surfaces and obviously will work well with a wattyl killrust hammer finish topcoat. Alternatively just about any water based metal primer will also work.

The other cheaper and easier alternative is to simply apply a few coats of a water based paint, however this may not provide a durable enough top coat in terms of wear and tear resistance and also resistance to oils, turps and other other solvents likely to be spilled on a work bench.