chemical to clean bronze oxide?

Do any of you have a suggestion for something you can brush onto big bronze seacocks that have a lot of verdigris oxide on them to restore them to at least close to their normal reddish-brown color?

Mine have been like that since I got the boat (about 4 years). I could care less aesthetically, but I'd just like to be able to tell whether the hose or one of the fittings is weeping at all, however gradually. I figured if I could clean it up well initially, i'd be able to spot a little trail of green if there is any kind of leak. My guess is there's no weeping, and they just look the way they do because of where they are.

-- Paul

Use a mild acid. The easiest way to make some on-the-spot is to mix vinegar and salt. Brush a little on, wait a few, and rinse with water. Copper based alloys -bronze, for instance- come out shiny clean.

Wow, thanks for the quick reply. I'll try that. Can you give me a rough idea of the proportions of vinegar (I assume white vinegar) to salt?

-- Paul

I've used muriatic acid before and it works well. Need to take all the heavy acid precautions though , safety glasses, gloves,good ventilation. I brush it on and let it bubble and then rinse with the hose. Nice to have the hose handy if any splashes around. Also a great way to clean those old zinc anodes out of the brass plugs when they break off; just submerge them in a cup of muriatic overnight and you can re-use the brass again. This of course done outside in a safe place, Good Luck!...........................Pat

There's no exact ratio re the salt and vinegar. I make a runny paste...............my wife taught me that trick. Artists do it all the time to clean copper.

Once they are clean, if you spray them with Corrosion-X they will stay that way. The stuff is amazing.

Does anybody have a solution to clean aluminum? The channels that hold my enclosure on the bridge are awful looking. Need something to get them looking decent again. :mad:

The acid used to etch (clean) aluminum is hydroflouric. You can buy a dilute solution on it combined with some detergents at a welding supply house, ask for "weld-o" or equivelent. It's used to clean aluminum before X-ray quality welding. You can't use it on aluminum that is "in place", but must instead remove the parts and etch them alone, because the acid will eat anything else (glass, paint, gelcoat, etc.) that it contacts. Also, hydroflouric is readily absorbed through the skin and settles in the liver. So gloves etc. are mandatory.
Sure does work great on aluminum, though.

Luckydave,
You are technically correct regarding HF Acid and Aluminium, however we need to underscore the dangers associated with that material. HF acid is much more agressive than hydrochloric (muriatic). I would not recommend its use by a casual DIY boat owner.

Remove the piece to be treated and send it to a plating shop specializing in anodizing or conversion coating.

I tried removing the track but it has 5200 under it, won't budge. The acid is not an option because it is overhead, under my arch. I may try the vinegar and salt treatment. Thanks for your help, Ron

Most aluminum has an anodized finish which is not very cleanable. It is like a plating, but not as durable as, say, chrome. If you use the salt and vinegar it will cut right through the anodizing, exposing the raw aluminum. This will oxidize rapidly . Probably you should just replace the parts, or clean and paint them.

For bronze use toilet bowl cleaner and brush it on with a paintbrush, keep it wet until corrosion is gone and then flush with water. I use Sno-Bol toilet bowl cleaner that also will remove brown stains from your hull and rust stains. Keep it away from your stainless because it will make the surface porous and create the small crevices that allow corrosion. The only way to clean stainless is with polishing.

For anodized aluminum don't use chemicals, scrub it with bronze wool that you can get at most boat supply stores, hardware stores or even supermarkets. The bronze wool is softer than the anodizing on your aluminum but harder than the white crusty aluminum corrosion. It will remove the corrosion and polish the anodizing that is still intact. Bronze wool will not rust and leave orange stains either.

This might sound stupid but I think I remember my Dad using coca-cola and a toothbrush to get the bronze cleaned up. Must be a fresh can. I could be wrong. Its been awhile since I cleaned em up.

For Al use a green scotch brite and a water rinse to clean up the surfaces. Once clean, follow with a white scotch brite using alcohol, and rinse and dry using the alcohol. The net effect is the alcohol aids the clean Al in forming a thin Al oxide of about 20 ang. The good news is you can repeat the process many times over when ever the corrosion reappears. However, do not use water in any portion of the final cleaning step, water and Al creates a hydroxide and prevents a protective oxide from forming. This is a simple process that works....it is used in a number of hi-tech industries for processing chambers that are exposed to highly corrosive liquids and gases.

What kind of alcohol do you use? Denatured, Iso, Methanol? Thanks, Ron

We used to use coca-cola in Boot Camp to clean the heads and showers. Just pour it on and it does all of the work for you.

Warm the 5200 up carefully with a heat gun...it will weaken enough to come off.

HF acid will etch glass and the fumes are deadly. Do not use this acid, period unless you are working with gloves in a lab hood.

Bronze is a tin/copper alloy. The oxidation is one or a combination of those salts and oxides. Products that clean copper and/or tin are bound to help.

Ted

Didn't really get anywhere with the vinegar/salt mixture.

Toilet bowl cleaner...bingo, BUT it eats everything, including carpet. Just the slightest drop on the carpet and it melted it like crazy until I got some water on it to dilute it. Good thing I am planning to rip the carpet out anyway (it was aleady a mess). I'm not sure I want that stuff coming into contact with any of my hoses, though.

Well, I've got one clean strainer. I'd like to find a safer method that is still effective. Is there such a thing?

Ang

I am in danger of learning something here. Green and white Scotchbright? I assume the different colors reflect different courseness? I have a bunch of brown (donated) and notice that it can scratch stuff easily. Please provide some insight.
Gary

You are correct different colors reflect different courseness, green is more course than white.