[TheForge] krylon clear for exterior use

[RIES NIEMI]

on 6/3/03 11:12 AM, Catherine Jo Morgan at cjmorgan@hemc.net wrote:

> I haven't run tests on this myself, but a usenet blacksmithing and
> metalworking thread reported that someone else had run tests and found
> that Krylon clear didn't last well outdoors. Unfortunately it's the
> sunlight that seems to break down most clearcoats outdoors. Under a
> roof, it may fare better.
> 
> If I had to finish something now for this situation, without running any
> tests, I'd use General polyacrylic in the stronger version, their
> waterbased polyurethane - a brush-on varnish. It requires good
> protective gloves and fair ventilation, but brushes on well and is a lot
> less toxic than Kamar too. For use directly on iron I'd add a rust
> inhibitor, but over gun metal finish I'm not sure. Guess I'd have to run
> a test after all.
> 
> Catherine Jo Morgan
> Morgan Sculpture
> Iron and mixed media vessels
> cjmorgan@hemc.net
> 

I have tried a variety of finishes, and I dont think there is a really good
clear finish for outdoor use.
All paint requires repainting when used outside.
 Krylon definitely gets rusty after a few months to a year. I use it
indoors, and even there its not really long term.
I have had mixed success with clear powdercoating. I have used a low gloss
clear powdercoat over steel, and it will hold up alright in a mild
environment- for say 3-8 years.
I did have a few chairs that were clear powdercoat outdoors in san
francisco, and the salt air started peeling that powdercoat after about 2
years. 
I have found powdercoating in general is not a permanent outdoor finish. It
works best in places like phoenix, where there is basically no rain, but
even in LA, between sun, rain, and smog, I figure 5 years is about max
before powdercoating starts to crack, buckle and peel.