Copper Leaf

[Kurt Johnson]

Looking through Dick Blick artist supplies on internet I came across a product called Copper Leaf, which is the same as Gold Leaf but Copper (duh). I never knew it existed. Actually never gave it a thought. Has anyone used this in ship modeling? It comes in 5 1/2 inch square sheets.

[druxey]

Leaf, whether gold, silver or copper, is incredibly thin. It will show every tiny flaw underneath the surface it is applied to. It is also very tricky to handle. Read any instructional on gilding (gold leafing) and you will see that it requires a lot of practice and skill to apply successfully.

[JerseyCity Frankie]

I’m curious about this too. But I have a caution for using it: it’s very delicate. If you have never seen gold leaf before, google it and you will be surprised: the sheets are so thin they are lifted by static electricity on a paintbrush. They eisily blow away on the lightest puff of air. The material has less structural integrity than ANYTHING and disintegrates into the tiniest bits with any handling with any tool. You can not lift a corner with your fingers, this just tears off the corner and what is pinched between your fingers has already disintegrated.

ive used the imitation gold version of this product on my Niagara brackets. I was able to glom sufficient quantities to cover, but I was unable to get the sheets on smooth and without bumps and wrinkles. 

what I am saying is: applying leaf is a skill that will take time to acquire. The issue for coppering  a hull will be the consistency with which you can lay the sheets on smoothly without bumps and ridges. 

On the other hand ALL OTHER actual copper coverings are grossly out of scale? I would say it’s worth pursuing leaf as a coppering solution, it’s REAL COPPER and as thin as is possible to achieve, but it’s not going to be a walk in the park getting it onto the hull. 

[Jaager]

This product offers an interesting possibility.

I coppered the MS brigantine Eagle using their copper plates - bonding with Weldwood Contact Cement.

The plates were flame treated to oxidize out the new penny look.  The result looked good, but after several

years, the bond started failing. 

With that adhesive "right out" , since epoxy seems both too thick and messy, CA I hate as well as it likely being subject to failure over time,

having a mistrust of whatever the bonding adhesive is on adhesive backed foil products, I wish to use PVA, so that lets out actual copper.

My thought experiment on this is to plate the hull with 100% cotton rag bond dissertation paper cut into plates.

Bond with PVA and prime and then coat with Modern Masters copper products and try their patina product to

add some verdigris  effect. 

Copper foil may be worth a try in place of the primer and genuine copper application steps. 

Experimental options:

1. copper layer at individual plate stage

2. copper layer after hull is plated

3. is a credible nail pattern possible by pre embossing the wet plates with a punch and die setup.  Is it worth the time

and tedium for a detail that is all but invisible at scales below Museum (1:48)?

[Kurt Johnson]

To be honest with you, I was wondering about also going a paper route. I was also considering just painting, with painting some plates subtlety different. The thought of things just falling off, doesn’t appeal to me. Although I might not be around to see it. Copper foil seems too darn bright! The aircraft guys come up with some really convincing finishes depicting individual metal plates. I don’t see why we can’t do it even better.

 

Kurt

[wefalck]

Jaager, if you didn't rub bright the back-side of your heat-treated copper it is no wonder that the plates are falling off ! The cement bonded to the copper oxide that slowly comes off the solid copper. I have stuck birght copper plates with contact cement to a model and they are still there after 30 years.

 

There have been various discussions about the colour of copper sheathing on this and other fora. The work-day look would be a dull reddish brown, perhaps with a bit of green in the zone between the wate and the air. It does not look metallic at all. Painted, very thin paper plates may be route to go for small-scale models.

[Jaager]

Wefalck,

You are correct, I did not remove the backside oxide layer.

I do have some old furniture with Lino on ply as a surface

that is attached with contact cement.  It would not that much

to separate the layers now.  But it was built in the late 1950's.

Contact cement is probably OK for a normal lifetime but not for a 100 year or more span.

An aspect of the interaction was that the copper oxide seemed to have infused

the cement and left the open area the same color as the plate

it once held.I have no idea what that hull looks like now.  It went with a partnership split that occurred long ago. 

 

An additional factor in the coppering = most of the time I have seen

that a layer of Fir was between the hull planking and the copper plates.

I think I have figured that out.  The Teredo larva enters a piece of wood

and does not leave it. No boring from one plank to the next.  I doubt that

without a welded seam, the larva could have been prevented from swimming

behind the copper plates.  Just a layer of copper would have not been enough

protection.  OK for easier removal of barnacles and seaweed, but not the worms

eating up the hull.  A sacrifice layer of wood with a under layer of sulfur or tar or

something else waterproof and toxic the the larvae would have solved the problem.

 

The point being that the hull thickness in the coppered region was more than just the

hull planking.  If a solid hull type building technique is used and the copper plates laid

directly on the shaped hull, the Fir layer as well as the actual planking thickness could

be investigated and the result added the hull outline when lofting.

Edited July 30, 2018 by Jaager

[wefalck]

The use of this additional layer of wood may have been at earlier times. The 19th century hull I have seen don't seem to have intermediate layer. However, there was a layer of tarred and sulftur-impregnated felt under the copper.

 

Before good antifouling paints were invented, iron ships were clad in a layer of wood before the customary tarred felt and copper sheathing was applied. This was needed in order to prevent the electrolytic corrosion of the iron hull by the more 'noble' copper.

 

Heavy metal ions, including copper ions, can inhibt (partially) the polymerisation of cyanoacrylate cements. They can also interfere with the structure of other cements.

 

The fact that the area, where the copper was attached was brown, seems to indicate that the oxide layer became detached from the metal, leading to a failure of the bond. This is indeed one of the mechanisms by which copper antifouling sheathing works: the oxides slowly becoming detached and with them anything that intends to attach to it.

Edited July 30, 2018 by wefalck

[Jaager]

As far as the Fir layer, I first paid attention to that in

Marquardt's  HMS Beagle monograph from 1831.

He has a layer of Fir sheathing under the copper plating.

 

Perhaps the RN slow to change as well as their being subsidized

it was not as important to economize on weight or materials cost.

The Yankee traders and their competition were likely more sensitive to cost in every sense.

[Bob Cleek]

In my years of "simply messing around in boats," I've seen a number of coppered bottoms on small yachts and one major sheathing job done on a large pilot vessel. I've also applied my share of gold leaf in the wind, doing names and hailing ports on transoms. I have used the various "leafs" of copper, aluminum ("silver") and the rest. I'll just respond to a few points raised in the discussion.

 

Copper sheathing comes in stock sheets, sized about 14"X24" or thereabouts. It's not particularly heavy. I've only encountered what seems to be the same gauge sheet, and I presume it doesn't get thicker to match the size of the vessel because all it has to do is prevent borer damage and they are all pretty much the same size. It is laid over Irish felt, a type of felt similar to roofing felt and made of flax and asphalt. As mentioned, on larger ships, there may be an additional sacrificial layer of softwood between the copper and felt and the structural planking. Copper tacks are used to fasten the copper sheathing, not "rivets." Seemingly, a lot of modelers try to portray iron rivets by dimpling their copper foil, but the fact is, a copper sheathed bottom should be as smooth as possible to reduce friction and not studded with large rivet heads. Viewed from any distance, the copper tacks will be barely visible and hammered as flush to the copper as possible. (The softer Irish felt underlayment makes this possible.) It takes a practiced eye and a hard look to notice that a hull is coppered from any distance (e.g. 50 yards) except for the run of the seams, if they stand a bit proud. (See the photos of the newly coppered Cutty Sark's in the post immediately above this one.)

 

The metallic foils pictured in the OP are thicker than real gold leaf and much easier to apply. They are, however, not always what they appear to be. Many types which are called "copper" or "silver" and so on, are actually something else again and simply copper or silver colored. This product is basically a craft material, such as might be used in making Christmas tree and table centerpiece decorations and the like and it cannot be expected to stand the test of time. If you try it, make sure it is really and truly solid copper. They do come in a variety of finishes, some mottled and patinated. Some may be suitable for depicting a newly coppered hull, but once a coppered hull hits salt water, it will be a uniform verdegris green color if it is clean, and a mottled greenish brown if fouled. In all but unusually large scales pasting copper foil on a model will be out of scale and decidedly so if one attempts to dimple "rivets" on the copper sheets. If one is compelled to depict the texture of coppering, appropriate to the scale, they would be well-advised to very lightly score the otherwise perfectly smooth area and then paint "copper green" over it. (Assuming one is using a fine model paint that will not unduly fill the light scratches of the scoring. The watchword here is "subtle." If overdone, if will be out of scale and distracting.

 

There are two types of real gold leaf. (and they come in a variety of carat grades as all gold.) One is "gold leaf," which is just very thin gold leaf bound in "books" of twenty-five 3 1/8" x 3 1/8" "leaves" laying loosely between the "pages" of the "books." (The faux gold and other metals leaf pictured above are "leaves" 5" square.) This is the gold leaf that is tricky to use. It cannot be handled except with a specially designed "gold leaf tipping brush" that picks up the leaves with a static charge. It is not intended for outdoor use! Forget about it. Gold leaf is too expensive to practice on.  The other type of gold leaf is called "patent gold leaf." Patent leaf is lightly stuck to a tissue paper backing and the edges of the tissue may be handled with the fingers. As with all leaf, "sizing" if first applied and allowed to dry to a tacky state and then the leaf is simply laid on the tacky sizing and the gold is lightly burnished with a cotton ball. The patent gold leaf can be applied something like a blotter to the size so that irregular surfaces, such as carvings, can be completely covered with repeated applications. Bits of flaking or torn leaf can be brushed off or pushed to another uncovered tacky area with a soft bristle paint brush. The burnishing blends all the pieces of leaf together. Using patent leaf isn't difficult at all. The real trick is to be sure to use proper sizing. There is special sizing for gold leaf which dries quickly and stays tacky for a good while, but one can get the job done just as well with thinned varnish, which takes a bit longer to dry to tacky, or shellac, which dries tack-free rather quickly and is suitable only for small pieces that you will have time to gild before the tack dries up. One can come close with many of the fine gold paints available today, and even closer using a dusting of ground brass powder over size on small pieces, but there is nothing that truly mimics real gold. 

[shipman]

'Bare Metal Foil' is a self adhesive product used widely in the model car field successfully, even depicting the trim around windshields, door handles and other bits of trim. It comes in a variety of metal colours (steel, aluminium, chrome, gold and copper).

I've never seen it mentioned on this forum, yet I'm sure it has its use here.