Cleaning Copper Cladding

[Blue Stocking]

Ask a Tile-layer. Barnacles are made of the same thing as grout. Ask him what he cleans outdoor tile with.

[Neeltje]

Originally Posted by Blue Stocking

Ask a Tile-layer. Barnacles are made of the same thing as grout. Ask him what he cleans outdoor tile with.

Let me guess: hydrochloric acid? Unfortunately most of the tile layers I employed left that chore to their helpers, and neither one had to worry about subjacent wood structures. Nice try though!

[senormechanico]

Cleaning Copper Clappers

Copper Clappers - YouTube

[Tantalus]

Originally Posted by Neeltje

senormechanico: Yes, I found that out the hard way when restoring an old Morgan many moons ago.

SVTatia: Bad advice. Crocheting is harder on your elbows than most anything else you can do with your hands aside from knitting.

perchance: I've got enough Stainless Steel Wool on hand to scrub the Queen Mary from top to bottom. What's lacking is the elbow grease to go with it.

Jacques

That's why god made power tools

[Neeltje]

Originally Posted by senormechanico

Cleaning Copper Clappers

Thanks Steve,

What a beautiful blast from the past! One of Neeltje's previous owners (and Johnny's contemporary) was Dan Rowan of "Rowan & Martin's Laugh-in" fame. Unfortunately, all of the above left us without any viable replacements...

Jacques

[Blue Stocking]

Originally Posted by Neeltje

Let me guess: hydrochloric acid? Unfortunately most of the tile layers I employed left that chore to their helpers, and neither one had to worry about subjacent wood structures. Nice try though!

I wasn't being facetious. Working with TransChem tile cleaner, 20% Hydrochloric, 31% Muriatic, is what I use to clean bronze props and coral growth off of lead and iron keels. On vertical surfaces such as your rudder, if the wood is completely copper clad, you shouldn't have much penetration to the wood. Use gloves, on a windless day, and a spray bottle carefully applied. The iron will get surface rust within about 12hrs of being cleaned by the acid.
BTW, I have worked, some years ago, at completely copper cladding the bottoms of 52 ft Royal Navy Pinnaces.

[Neeltje]

Originally Posted by Tantalus

That's why god made power tools

True, and I've probably got more of them than Harbor Freight, but since the copper was already paper thin even before the barnacles dug into it, I think it best to pamper what's left of it with a hand job (so to speak).

Jacques

[Andrew Troup]

I concur with those who advocate acid, and advise against alkali (eg drain cleaner).

It's hard to quantify because there are many variables, but alkaline attack on copper can be quiet severe.

I would personally start with white vinegar: It does the trick remarkably quickly on calcified deposits on engine thermostats (ok these are bronze or brass, but I imagine the effect would be similar for copper)

You can then escalate if need be.

[Jim Cate]

Originally Posted by Blue Stocking

I wasn't being facetious. Working with TransChem tile cleaner, 20% Hydrochloric, 31% Muriatic, is what I use to clean bronze props and coral growth off of lead and iron keels.

Uhhh, Mr Stocking, I think you will find that Muriatic acid and Hydrocloric acid are one and the same thing. You might want to recheck that label!

Cheers,

Jim

[Blue Stocking]

Jim, Just quoting the label for the OP's sake, did my ULCI exams years ago in Chemistry

[DefinitelyMe]

Originally Posted by Blue Stocking

I wasn't being facetious. Working with TransChem tile cleaner, 20% Hydrochloric, 31% Muriatic, is what I use to clean bronze props and coral growth off of lead and iron keels. On vertical surfaces such as your rudder, if the wood is completely copper clad, you shouldn't have much penetration to the wood. Use gloves, on a windless day, and a spray bottle carefully applied. The iron will get surface rust within about 12hrs of being cleaned by the acid.
BTW, I have worked, some years ago, at completely copper cladding the bottoms of 52 ft Royal Navy Pinnaces.

I would have thought the wood would be OK...... but it's your wood! The recipe above is a little off. Hydrochloric acid and muriatic acid are the same thing. Perhaps you mean 20% phosphoric acid? Also, 31% is quite a concentrated solution. HCl in it's purest form is a gas. Concentrated, lab-grade HCl is 37%. The stuff you can buy at a hardware store is about 34%, at which concentration it fumes and is quite corrosive. You'd definitely want to dilute it before using it to clean thin-sheet metal otherwise you run the risk of going right through it. Incidentally, using an acid to clean props, or any alloy, is a very bad idea. Most propellers are made of bronze, which is an alloy of copper and tin. Since tin is more reactive than copper, the acid will dissolve the tin while leaving the copper intact. Your prop will look nice and clean but the removal of the tin will have considerably reduced the strength of the metal and removed it's corrosion resistance. Props should be cleaned manually.

[Blue Stocking]

As I said above, and not to be-labor the point, I was quoting what is written on the manufactures label, to give the OP some idea of what is available off the shelf in any h/ware store. He/She should exercise extreme cautuion when using any of these chemicals.

[Cheechako]

Uhh... why take the copper oxide off?

[Neeltje]

Originally Posted by Cheechako

Uhh... why take the copper oxide off?

I thought it might help the primer adhere a little better. Are you saying I shouldn't?

Jacques

[Cheechako]

Good question; smooth copper or rough oxide? hmmm... not really sure. My guess is the oxide will hold it just as well if it's tight like most... but not sure if anybody knows. We all tend to sand our props and then the paint doesnt stick well... what if we just cleaned them only?