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Gilding a cast aluminum plaque

Hand Lettering topics: Sign Making, Design, Fabrication, Letterheads, Sign Books.

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Keith Margis
Posts: 3
Joined: Thu Oct 06, 2011 1:49 pm

Gilding a cast aluminum plaque

Post by Keith Margis »

Hi, I'm going to be gilding the raised lettering on a cast aluminum plaque. I'm pretty inexperienced with gold leaf and would appreciate any suggestions,
as far as say what carat or type of leaf to use, or should I use sealer,

The plaque is new, and has a clear coat.
The finished sign will be outdoors, in San Jose CA

Any tips will be appreciated

thanks
Kent Smith
Posts: 569
Joined: Fri Dec 31, 2004 6:41 pm
Location: Estes Park, CO
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Re: Gilding a cast aluminum plaque

Post by Kent Smith »

If the clear coat is two component then you will have issues with adhesion of the gold size if you don't abraid the surface. If it is lacquer, then be certain that it is fully sealed with no voids or cracks because electrolysis between the gold and aluminum will eat away the aluminum even with the gold size between. Use a high Karat of gold, 23 to 23 3/4 for best outdoor durability.
BruceJackson
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Joined: Mon Sep 06, 2004 7:28 am
Location: Melbourne, Australia
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Re: Gilding a cast aluminum plaque

Post by BruceJackson »

I would like to know what type of clear coat it is before giving a definitive answer. Only because I would want some confidence that the clear is a good long-term proposition, otherwise, it will end up being the weak layer.

Assuming the clear is good for outside use, you could simply do the gilding straight onto it using gold size (oil-based...for example one-shot gold size).
I suggest you dab the area with talc or some other fine powder, to stop the gold sticking where you don't want it. Blow off the excess, and paint the goldsize, wait for it to dry to a gilding tack, then gild with 23, 23.5 or 24 carat gold. For outside, the higher the purity, the better, but 23carat will still hold up well for many years.

No need for a clear sealer unless it will get a lot of handling, which i assume is highly unlikely.
Keith Margis
Posts: 3
Joined: Thu Oct 06, 2011 1:49 pm

Re: Gilding a cast aluminum plaque

Post by Keith Margis »

Thanks for the response,
The clear is a two part automotive grade acrylic polyurethane,

Their Gemini aluminum plaques
Kent Smith
Posts: 569
Joined: Fri Dec 31, 2004 6:41 pm
Location: Estes Park, CO
Contact:

Re: Gilding a cast aluminum plaque

Post by Kent Smith »

I have had excellent success with Gemini plaques as long as the clear has cured at least 14 days.
Keith Margis
Posts: 3
Joined: Thu Oct 06, 2011 1:49 pm

Re: Gilding a cast aluminum plaque

Post by Keith Margis »

Well, the plaques are arriving today, but 14 days after clear coat won't be until next Thursday?
Is it really necessary to wait that long, my installation deadline is next Saturday, and I'm not sure how long the gilding will take.

Also, should I lightly sand before applying the size?

thanks
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