kpdavis2000

How to Safely Remove Galvanized Coating?

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Hello, I have wanted to get into casting so that i can make bars for easier forging. I have a couple of galvanized steel fence posts that i want to melt but I am aware of the health hazards of zinc fumes, so I would like to know if anybody can tell me how to remove the coating safely with no health hazards.

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Welcome aboard KP, glad to have you. If you'll put your general location in the header you might be surprised how many of the IFI gang live within visiting distance.

Please don't take this the wrong way but if you have to ask you don't know enough to attempt it on any level.

First casting steel for home use is terribly wasteful of time fuel and is tremendously dangerous. There are guys on this forum who make their own iron and steel but certainly NOT by melting scrap. 10 lbs. say a coffee mug size crucible worth of molten steel has the potential explosive power of around a CASE of 40% dynamite. One mistake and you're wearing a couple lbs. of molten steel in the burning remains of your shop.

Stripping galvy is easy to do, a little research will answer that question. I'm not going to here, you need the practice doing real research.

I'm not being mean, we like to see folk being successful but it takes effort on all levels on your part.

For something to forge, especially just beginning keep it simple and buy some mild or A36 steel. It's a known quantity so the techniques you learn are applicable. Scrounging is a necessary blacksmith skill but learning to evaluate what you're salvaged is a different set of skills you don't need to try to learn while developing basic hammer control and forging skills.

Frosty The Lucky.

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Wow casting your own bars to forge would probably be only 10 to 100 times MORE expensive than buying new steel; just the cost of fuel, crucibles, hundreds of dollars in safety equipment, and the fact that what you melt is not necessarily what you get in the pour...

Can you explain the *why* you want to do this?

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also the legally required  HAZ MAT  disposal for the zink  you removed will cost even more, as we explained in the other thread about this

Your comment about wanting to get into casting  to make forging easier make no sense at all.

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I always hear people telling me dip in acid bath of muriatic acid but can I use muriatic acid to brush it on???

I want to use a brush and just wipe down my anvil.

smaller galvanised fittings I can get away with a bucket of acid. But the anvil is too big.

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Steel exposed to acid in the presence of oxygen will rust FAST.  The muriatic or vinegar baths work well to strip zinc coatings or derust items, BUT only if they are submerged so that oxygen can't get to the steel's surface.   You may have seen on here people talking about using muriatic acid in their shop and just from the fumes nearly everything that can rust within 20 or 30 feet of where they were using it gets rusty.  I think there are better options for your anvil, but since all I've ever done on mine is wire brushes and wheels I'll leave the wipe down suggestions to someone else.

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I gotta wonder about people that make such a strange post like this one, then never return to IFI again

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3 hours ago, Steve Sells said:

I gotta wonder about people that make such a strange post like this one, then never return to IFI again

His dad probably told him he can't use the fence posts around the house. When I was a kid I used to go off in a huff when one of my ideas got met with practical experience. Sometimes I'd sit and think they were going to be really sorry when I didn't speak to them when I was rich and famous from inventing whatever the idea was about.

I'll get over it someday.

Frosty The Lucky.

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On 04/10/2016 at 1:59 AM, Buzzkill said:

Steel exposed to acid in the presence of oxygen will rust FAST.  The muriatic or vinegar baths work well to strip zinc coatings or derust items, BUT only if they are submerged so that oxygen can't get to the steel's surface.  

I've recently used an angle grinder with a flap disc to clean the surface rust on my anvil and then left it there for about a week and a half and there are rust spots on it again.

Im thinking maybe I should have applied some grease of oil to prevent the anvil from rusting?

How quick would acid strip galvanisation if I left it in an acid bath?

IMG_1456.JPG

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Don't bother with the flap disk again.  It is more harmful to your anvil, by far, than a little rust.  Every particle of metal you remove from the thin, high carbon surface is irreplaceable.  Instead, just coat it with a little automatic transmission fluid if you want to protect it.  Then use it.  Grease would probably make a mess on your tools, clothes and your work pieces.

There is also no need to use acid on your anvil.  It is not galvanized and doesn't need to be etched.  It would likely just damage the anvil.  All you need to do is oil it and then use it.  If appearance matters to you hit it with a wire wheel before you oil it.

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1 hour ago, Gorō said:

How quick would acid strip galvanisation if I left it in an acid bath?

There's pretty much no chance at all that your anvil has a zinc coating on it, and Lou already gave you good anvil care tips.  If you have to remove the galvanized coating from other objects an acid bath can work, but how fast it will strip depends on several things.  The thickness of the coating, the concentration of the acid, the ambient temperature - all these things affect how quickly the coating will be removed.  I find that typically one day in 5% vinegar (normal strength from the store) is enough.  It also works for loosening/dissolving the scale from forging.  If you do that just make sure you use something to neutralize the acid after removing it from the bath  or it will rust quickly.  Baking soda, an old toothbrush, and some water are all that's really needed.  Rinse well and dry after that.

Some of the guys on here do use electrolysis to clean up large rusty items such as anvils and get great results.  I have not done this yet, so I'll leave those recommendations to someone who has.

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I didn't say my anvil was galvanised. I was talking about something else.

Yeah I've heard of those methods myself aswell. 

 

 

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Like others said, the more you clean it the more you expose the steel to the air. Leave the surface rust and oil it. if you really want you could rub it with wet and dry sandpaper and oil, but the important thing is the oil.

You could also rub it with plumbago. Fanciful but will make it look very nice. 

Your anvil surely has a history. I like it. Is it a Peter Wright?

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