Research Note

To keep shipworms from boring holes in the bottom of wooden ships, a number of systems were tried over many centuries (lead plates are known on Roman ships). Starting in the 1770s copper plates were tried and quickly became almost universal. They were most commonly about 14" x 48" in size and 1/8" to 1/4" thick. They were applied over a layer of tarred felt and attached with many flat headed copper nails, not rivets. These heads did not protrude significantly above the level of the plate, which would have caused added drag on the hull. However, even though they did not protrude, the heads could be seen as a diamond pattern on the face of the plate.

The plates were laid, most commonly, from the aft end of the keel forward and upward, in a brick-laid pattern, with an overlap of about 1" on the plate below and to the rear. At the waterline there was usually a finishing strake or two of full plates which covered the triangular ends of the lower strakes as they curved upwards with the shape of the hull. Occasionally this finishing strake was omitted and a wooden batten covered the top edges of the strakes to prevent damage from wind and water.

Modelers who want to replicate copper plating in a reasonably accurate way should burnish down any "rivet head" looking protrusions. Simulated nail heads can be achieved by making a die to impress (emboss) a lot of small dimples into the plate in a diamond pattern, which are then burnished down to form small imperfections which can barely be seen.

Most modelers use individual plates, which are more correct than using a roll of copper tape, and have the advantage of allowing a certain flexibility along the length of the strake. However, copper tape can be used with good results if the plate joints are scribed in. The copper can be colored with heat or one of several chemical solutions. Or it can be left to age naturally to the color of an old penny. In either case, be sure to clean off fingerprints, which will become very evident as the plates age.

To adhere the plates, the hull should first be sealed, sanded and sealed again with a gloss finish. As for glue - the most common for non-adhesive plates is contact cement (but make sure that the one you use is recommended for copper, some are not). Thin it and paint it onto the hull, but not yet onto the back of the plates. Once it is dry to the touch on the hull, paint a few plates, wait till it is tacky, and put the plates on. This will give you a little flexibility rather than trying to work with the glue dry on both surfaces. Copper tape from the stained glass store is self-adhesive and, in my experience, the glue is mighty strong. I have not had a plate come loose.

Experiment with a few plates on a piece of scrap wood to see how your glue and your technique work together before attempting to put plates on your model.

One of Dan's models with copper plates

Here is a photo of one of my models with copper plates. I used individual plates cut from a roll of stained glass copper tape. They were each embossed with 32 nail heads, then burnished down before applying to the hull. Nail heads along the overlaps were impressed with a pounce wheel after the plates were applied. The scale is 1/8" = 1', so each plate is about 3/16" x 1/2"

Hope this helps.
{Dan Pariser}

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