What upkeep is needed to keep bronze looking nice? I'm replacing deck cleats. What will bronze cleats look like in 5 years if I do nothing to them? Geoff
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Eye of the beholder!
Unprotected bronze will turn dark brown, often with a touch of verdigris (which is the green color seen on copper, brass or bronze that is weathered and exposed to air or seawater over a period of time). Many find this natural look very desirable and it doesn't affect the hardware's utility. If you like the bright polished look, maintenance is pretty easy with Zud or Barkeeper's Friend. These mild scouring cleansers contain oxalic acid which is a reducing agent (as opposed to oxidizing agents such as chlorine bleach). Tarnish and rust are the result of oxidation, so a reducing agent is very effective in removing them.
Unprotected bronze will turn dark brown, often with a touch of verdigris (which is the green color seen on copper, brass or bronze that is weathered and exposed to air or seawater over a period of time). Many find this natural look very desirable and it doesn't affect the hardware's utility. If you like the bright polished look, maintenance is pretty easy with Zud or Barkeeper's Friend. These mild scouring cleansers contain oxalic acid which is a reducing agent (as opposed to oxidizing agents such as chlorine bleach). Tarnish and rust are the result of oxidation, so a reducing agent is very effective in removing them.
Geoff, they will look like five year old
bronze cleats and in twenty years they will still look the same. We have a bronze bell hanging in the tower on our church that is a nice pleasant blue-green and in the 36 years I have been seeing it its appearance hasn't changed. With you cleats when you use them you will polish some of the green off but most will stay and just get shiney.
bronze cleats and in twenty years they will still look the same. We have a bronze bell hanging in the tower on our church that is a nice pleasant blue-green and in the 36 years I have been seeing it its appearance hasn't changed. With you cleats when you use them you will polish some of the green off but most will stay and just get shiney.
Veridgris - the green crap that forms on bronze
Verdigris is the 'green' that forms on bronze, it is copper acetate - an oxidation of the copper with acetic acid (in seawater). Verdigris is slightly soluble in ethyl alcohol ... and not much else! you need to mechannically (sand/buff) remove most verdigris as there simply are NO magic solutions to cleaning BRONZE (without pulling either the tin or the copper out of the bronze). The 'ancients' used a mixture of fine pumice, salt, beeswax, olive oil, wine, and lemon juice to 'burnish' their bronze and to keep it clean and affect some protection. The pumice for abrasion; the beeswax and olive oil to offer protection and retard oxidation, the salt, wine and lemon juice to aid in removing the 'green'. For bronze that I want to turn a rich brown ... I burnish (fine sanding then machine polish with jewelers rouge) .... then apply rub in a paste of beeswax and olive oil several times (like 'seasoning' an iron fry pan ... and you can accelerate the 'seasoning' by putting the part (with the wax and oil mixture on it) in an oven for 300 degrees for several hours). For bronze that has been bright polished ---- (sanded @ 400-1000 grit), then machine buffed with *jewelers rouge*, etc.) I spray (spray can) on many successive coats of *exterior grade* clear polyurethane. If you are using one of the 'modern' two part acrylic-urethanes (Honey Teak, etc.) for your brightwork ... the clear overcoat is BEST for polished bronze and if applied 'thick' will last MANY years for exterior bronze; then polish the urethane lightly with 3M Finese-it / 3M Perfect-it to get the urethane FLAT and glossy. If you want your bronze to be shiney and good looking, the fastest and best way is to burnish/polish with high speed fabric wheels onto which you apply jewelers rouge (buy it in a hardware store). You can forget about most BRASS cleaners/polishes as they simply will not work on BRONZE.
Verdigris is the 'green' that forms on bronze, it is copper acetate - an oxidation of the copper with acetic acid (in seawater). Verdigris is slightly soluble in ethyl alcohol ... and not much else! you need to mechannically (sand/buff) remove most verdigris as there simply are NO magic solutions to cleaning BRONZE (without pulling either the tin or the copper out of the bronze). The 'ancients' used a mixture of fine pumice, salt, beeswax, olive oil, wine, and lemon juice to 'burnish' their bronze and to keep it clean and affect some protection. The pumice for abrasion; the beeswax and olive oil to offer protection and retard oxidation, the salt, wine and lemon juice to aid in removing the 'green'. For bronze that I want to turn a rich brown ... I burnish (fine sanding then machine polish with jewelers rouge) .... then apply rub in a paste of beeswax and olive oil several times (like 'seasoning' an iron fry pan ... and you can accelerate the 'seasoning' by putting the part (with the wax and oil mixture on it) in an oven for 300 degrees for several hours). For bronze that has been bright polished ---- (sanded @ 400-1000 grit), then machine buffed with *jewelers rouge*, etc.) I spray (spray can) on many successive coats of *exterior grade* clear polyurethane. If you are using one of the 'modern' two part acrylic-urethanes (Honey Teak, etc.) for your brightwork ... the clear overcoat is BEST for polished bronze and if applied 'thick' will last MANY years for exterior bronze; then polish the urethane lightly with 3M Finese-it / 3M Perfect-it to get the urethane FLAT and glossy. If you want your bronze to be shiney and good looking, the fastest and best way is to burnish/polish with high speed fabric wheels onto which you apply jewelers rouge (buy it in a hardware store). You can forget about most BRASS cleaners/polishes as they simply will not work on BRONZE.
oooops ... forgot the salt. Please pass the salt
previous post corrected. Thanks Ross. Next time try using straight grain alcohol and salt (or if you have it and dont mind wasting some, some overproof rum instead of the vinegar). The vinegar (5% acetic acid) will promote the acetate formation.
previous post corrected. Thanks Ross. Next time try using straight grain alcohol and salt (or if you have it and dont mind wasting some, some overproof rum instead of the vinegar). The vinegar (5% acetic acid) will promote the acetate formation.
Never let it be said that I don't check.
1. Table salt is not soluble in denatured ethyl alcohol 2. A mixture (paste) of alcohol and salt has no effect on a dark brown copper fitting. 3. Copper fitting is now soaking in a glass container with vinegar and table salt and getting brighter by the minute.
1. Table salt is not soluble in denatured ethyl alcohol 2. A mixture (paste) of alcohol and salt has no effect on a dark brown copper fitting. 3. Copper fitting is now soaking in a glass container with vinegar and table salt and getting brighter by the minute.
The 'green' is soluable in alcohol, not the 'brown
The dark brown is copper oxide and is unaffected by alcohol. the 'green' is verdigris (copper acetate) and that IS soluable in alcohol. So once you finish etching (reducing with the vinegar), rinse with alcohol so you have less verdigris formation later on.
The dark brown is copper oxide and is unaffected by alcohol. the 'green' is verdigris (copper acetate) and that IS soluable in alcohol. So once you finish etching (reducing with the vinegar), rinse with alcohol so you have less verdigris formation later on.
Try Zud or Barkeepers Friend
If you really want some empirical knowledge. Otherwise, please don't knock it if you haven't tried it. I don't recommend things I haven't thoroughly tested or used myself. I've been using oxalic acid in various forms on boats and in my workshop for over thirty years. It is very effective in removing rust stains as well as tarnish on bronze. brass and copper. The cans of household cleanser named will also work as the cheapest and most effective teak cleaner you can buy. Since its active ingredient is oxalic acid which is a reducing agent and a strong organic acid that is 10,000 stronger than acetic acid. It works a heck of a lot faster on a boat than removing hardware, burnishing it and then reinstalling it. If you use the abrasive houshold clensers, a green 3M pad speeds things up. Check on the chemistry, it is not a "magic solution" as has been implied.
If you really want some empirical knowledge. Otherwise, please don't knock it if you haven't tried it. I don't recommend things I haven't thoroughly tested or used myself. I've been using oxalic acid in various forms on boats and in my workshop for over thirty years. It is very effective in removing rust stains as well as tarnish on bronze. brass and copper. The cans of household cleanser named will also work as the cheapest and most effective teak cleaner you can buy. Since its active ingredient is oxalic acid which is a reducing agent and a strong organic acid that is 10,000 stronger than acetic acid. It works a heck of a lot faster on a boat than removing hardware, burnishing it and then reinstalling it. If you use the abrasive houshold clensers, a green 3M pad speeds things up. Check on the chemistry, it is not a "magic solution" as has been implied.
every day
We polished the bridge bronze and brass every day in the Navy, with NeverDull. Bronze and brass will begin oxidizing right away and require constant attention. It will last a long time unattended, but will of course turn green.
We polished the bridge bronze and brass every day in the Navy, with NeverDull. Bronze and brass will begin oxidizing right away and require constant attention. It will last a long time unattended, but will of course turn green.
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