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hot zinc spray finish


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Hi, does anyone have any pics of their work finished with hot zinc spray, without a paint top coat? I'm ideally after a couple pics that show what the colour's like when it's first done then a pic to show how it mutes down over the years. Google's only giving me pics of structural steel work that's not going to be very inspiring to clients.

I've seen some intricate floral work at a gallery that's got a galv finish on it and it looked great, but I've been warned that my local galv firm are a bit heavy handed with items and work often comes back bent, so I'm more inclined to use another smaller local business that hot zinc spray & are a bit more considerate.

Cheers

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It's close to a flat battleship gray and may or may not darken or lighten with time but not a lot. This isn't in a high wear situation though.

 

That's just my experience, I haven't used it in years so it may be different nowadays.

 

Frosty The Lucky.

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  • 1 month later...

Hi, does anyone have any pics of their work finished with hot zinc spray, without a paint top coat? I'm ideally after a couple pics that show what the colour's like when it's first done then a pic to show how it mutes down over the years. Google's only giving me pics of structural steel work that's not going to be very inspiring to clients.

I've seen some intricate floral work at a gallery that's got a galv finish on it and it looked great, but I've been warned that my local galv firm are a bit heavy handed with items and work often comes back bent, so I'm more inclined to use another smaller local business that hot zinc spray & are a bit more considerate.

Cheers

 

 

I always preferred Hot Zinc Spray (Zinc Flame Metallisation) to Galvanising. It didn't have the problems of the drips and spikes of the galvanised process which required fettling. It has a better surface for the mechanical key for subsequent paint, and seemed to allow the burnished graphite paint to bring out the forged texture better than galvanising which seemed to obliterate any surface detail.

 

I don't think I have had anything back that was not damaged by the galvanisers. And I have only been having jobs done by them in the last four or five years. I think are are just used to doing girder work and forged metalwork is beyond their comprehension. In thirty years of Hot Zinc Spray I had only three projects that were dropped off the forks or not perfectly wrapped / palleted for transport.

 

That said the answer the your question is no. I do not have any photographs of un painted hot sprayed zinc. I never left it unpainted I always gave it a coat of a wash etch primer (Guard) and then finish coats. The top one often being eggshell with flake graphite which was burnished to highlight the forged texture.

 

You are lucky to have a hot zinc spray company near you, wish I did. All the firms that I used around here for zinc spray have turned over exclusively to powder coat systems with a zinc rich primer layer. Apart from the fact that they do not like doing solid heavy metal…takes too long to heat. I don't like the syrupy surface and the way it fails. I have had to go to Hot Dipped Galvanising if I want to do anything interesting with the surface or enable repair work to be done at a later stage.

 

I have tried the zinc rich rattle can stuff in the past but was not impressed. It may be better nowadays. I have recently bought some of the new cold zinc treatment stuff (Zinga) however, which looks to have possibilities…for handling damage repairs if nothing else.

 

Alan

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Joel,

 

I recently had a metal carport installed to cover my outside forge, the kind with galvanized square steel posts and galvanized base rails and sheet metal roof.  The uprights attach to the base rails by slipping them over a stub about 6" high welded to the rail. The stub/rail weldment looks like it has been sprayed with a sort of galvanized coating that is as shiny as the galvanized coating on the posts and rails.  Anyone have an insight as to what coating they might have used?  That might be something you could use.

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I lost my first draft and when I retyped it I missed out my first response which was:-

 

that I was told (by a hot zinc sprayer) that it should not be left un-coated or sealed if you want full corrosion protection. Unlike hot dipped zinc, it is porous. It is made up of droplets of molten zinc hitting the substrate and other already adhered zinc droplets and as such does not necessarily form a continuous layer.

 

Although it still works as a sacrificial element in the galvanic process, you could still get the initial rust showing in the interstices before the zinc salts could do their bit. In the same way that a hot dipped Galvanised piece will have bright red rust showing on a scratched area but it does not go any further/deeper until the adjacent zinc has all been used up.

 

Alan

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Here are some pictures I have finally managed to try and show the hot zinc spray finish.

 

This gate was treated in 2004 and so is now over 10 years in service. It has deliberately been left just as sprayed, in an attempt to see exactly how durable and effective it is, and how it copes with small potential water trap areas.

 

 

The gate is sited in a position which suffers a variety of weather and wind chill combinations and has very minor problems, only two  areas appearing to have a 'rust bleed problem, neither of which I would term serious. 

 

Gate in situ 

post-816-0-60457500-1421701499_thumb.jpg  post-816-0-07261900-1421701512_thumb.jpg 

 

The back stile journal clamp and lower pivot were not zinc sprayed, but red oxide primed, the stain is from the occasional oiling to maintain ease of use.

 

post-816-0-05886100-1421701567_thumb.jpg

 

The only appreciable rust bleed is here   post-816-0-81908200-1421701552_thumb.jpg

 

From the remaining pictures you can see the potential areas where you may expect a weatherproof seal to be questionable. The areas which have been abraded when the gate is being used show up, but the coating has not been penetrated. They also appear as a bright silvery finish which if done intentionally with a burnishing method appears to have a pewter like smooth finish.

 

post-816-0-09940800-1421701536_thumb.jpg  post-816-0-66447700-1421701582_thumb.jpg  post-816-0-08063600-1421701600_thumb.jpg  post-816-0-63594100-1421701616_thumb.jpg  post-816-0-86907500-1421701634_thumb.jpg  post-816-0-06020100-1421701649_thumb.jpg  post-816-0-38515000-1421701669_thumb.jpg  post-816-0-26151800-1421701685_thumb.jpg  post-816-0-95097300-1421701700_thumb.jpg  post-816-0-73924000-1421701714_thumb.jpg  post-816-0-85479600-1421701727_thumb.jpg

 

The colouring and texture has not changed much since first applied.

 

Hope this is of assistance and goes someway to answering the original question.

 

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  • 1 month later...

Cheers for those pics John. I referred back to this thread the other day and only just saw them for the first time, doh.

I'm going to take my first gate (2 gates in fact) for blasting and zinc spraying next week. Having heard about alkyd based paints blistering on top of zinc coatings I was a bit nervous about which types of paint to use for the top coat so I got the guys to do me a little test patch sample of zinc spray as I wanted to try out the acrylic paints I plan on using to check their compatibility. I also wanted to see what the zinc looked like on it's own.

I cut up the sample they gave me into 3 pieces, one bit to leave outside to see how it fairs over time, one bit to leave indoors as to show what it's like when it's new, (having seen some of the work at the Fire and Iron gallery which looks great with just a zinc finish on it I may well suggest to clients that a zinc finish alone can look the nuts), and the other piece I sprayed with etch primer and then also satin black.

The pic that shows all 3 stages together is probably the truest to real life in terms of colour, but even then it's not great. I purposely haven't taken out any of the lumps and bumps and have tried to show the natural surface texture as best as possible...uploading these in case they're of use to anyone else. The gate's I've made a full of scrolls so there's no way on earth I'm painting them by brush, but I don't yet have a compressor so I'm limited to rattle cans. Of the variety of rattle cans I've experimented with I prefer the acrylics as IMO they sit nicest on the surface - they're not like a glossy oil slick that's be dolloped on.

Zinc-Primer-Top-Coat.jpg

Zinc.jpg

Primer-Top-Coat.jpg

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Cheers for those pics John. I referred back to this thread the other day and only just saw them for the first time, doh.

I'm going to take my first gate (2 gates in fact) for blasting and zinc spraying next week. Having heard about alkyd based paints blistering on top of zinc coatings I was a bit nervous about which types of paint to use for the top coat so I got the guys to do me a little test patch sample of zinc spray as I wanted to try out the acrylic paints I plan on using to check their compatibility. I also wanted to see what the zinc looked like on it's own.

I cut up the sample they gave me into 3 pieces, one bit to leave outside to see how it fairs over time, one bit to leave indoors as to show what it's like when it's new, (having seen some of the work at the Fire and Iron gallery which looks great with just a zinc finish on it I may well suggest to clients that a zinc finish alone can look the nuts), and the other piece I sprayed with etch primer and then also satin black.

The pic that shows all 3 stages together is probably the truest to real life in terms of colour, but even then it's not great. I purposely haven't taken out any of the lumps and bumps and have tried to show the natural surface texture as best as possible...uploading these in case they're of use to anyone else. The gate's I've made a full of scrolls so there's no way on earth I'm painting them by brush, but I don't yet have a compressor so I'm limited to rattle cans. Of the variety of rattle cans I've experimented with I prefer the acrylics as IMO they sit nicest on the surface - they're not like a glossy oil slick that's be dolloped on.

Zinc-Primer-Top-Coat.jpg

Zinc.jpg

Primer-Top-Coat.jpg

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Some better pics of what the stuff actually looks like when it's first on. I'm kind of amazed how little info there is out there on the net about hot zinc spray considering it's advantages over galv, even the companies that offer flame spraying have rubbish pics and info on their websites. Uploading these for the sake of folks in the same boat as me who want to know more about the stuff.

DSC_0453.JPG

DSC_0456.JPG

DSC_0459.JPG

DSC_0462.JPG

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  • 5 years later...

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