Re: [MV] Sandblast alternative Pressure washer?

From: Alan Bowes (inbox@todacosa.com)
Date: Wed Mar 01 2000 - 09:00:16 PST


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Renaud OLGIATI wrote:

> It works, BUT unless you dry the part straight away (and I mean within
> minutes) and apply a passivating agent, surface rust appears on your
> newly-cleaned steel with incredible rapidity.

Yes, a microscopically thin layer of flash rust will appear almost instantly, but
this should not be a problem at all. As Renaud mentioned, you can apply a
conditioning agent afterwards. Conditioning solutions will will actually remove
flash rust (via phosphoric acid) and also leave a passivated surface layer on the
metal, typically something like zinc phosphate, which will not only provide
temporary corrosion protection, but will also enhance paint bonding to the metal
surface.

DuPont Kwik Prep or Sherwin Williams Metal Prep come to mind. They're easy to use.
After applying a typical metal conditioner, it is usual to rinse the surface well
before the conditioning solution dries. This is to remove the unwanted reaction
byproducts before they can dry on the surface. If you let the solution dry before
rinsing, you'll have to reapply the conditioning solution to clean it up again and
rinse again.

Alan



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