Reference · How-tos · Coppering

Planning the coppering belts with a template and paper strips

Mark out the belts for the copper plates along the sheer of a strake, using a template for the plate width and printed paper strips to see where the plates have to be cut at an angle.

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1. 1Choose a strake as the leading belt and tape it off

   Somewhere about halfway up the hull, choose a strake with a good sheer and tape it off on both sides with masking tape. Look at the hull from astern and from the side: the belts must run in line with the planking, not with the straight line of the keel. This belt becomes the base from which you work up and down.

   

   

   Tip from pietsan: The plates must follow your strakes, not the straight line of the keel. Choose a strake somewhere halfway up the hull, follow it neatly with the plates and then work upwards and downwards. At the bow the angled pieces (stealers) belong on the planking only; on the stem itself the plates run horizontally.

   Watch out: We had started at the keel and carried that straight line across the hull. That way you do not come out right at stem and sternpost, because the hull is not the same width everywhere. Everything had to come off again.

2. 2Make a template with the plate width

   Lay a copper plate on a strip of stiff paper or card and mark off its width a number of times in a row, like a ruler in plate widths. Number the marks. With this you can count anywhere on the hull how many plates fit between two lines.

   

3. 3Transfer the template and draw the belts

   Hold the template across the hull in a number of places, starting from the garboard strake or the taped belt, and mark the required plate width with a pencil tick. Join the ticks with masking tape to form belts. Check from the side that every belt runs with the sheer as nicely as the leading belt.

   

   Tip from Hans Groenenberg: Look at Paulbo's log; his coppering starts on page 14. There he explains how he tackled the belts.

4. 4Measure the sternpost and plan the stealers

   Use the template to count how many plates fit below a belt amidships and at the sternpost. For us belt 2 sat at 12 widths from the garboard strake at the bottom and at 14 at the sternpost. You take up the difference with stealers: here two, which come out at exactly one plate width.

   12 widths amidships against 14 at the sternpost

   

   

5. 5Fix the band along the waterline

   Reserve belt 1, directly below the waterline, as a band one plate wide. Look carefully at the curve at the sternpost: with whole plates gaps open up there, so the plates have to be cut to size on the short side as well. Cut the plates, do not use scissors: shearing pulls them out of shape.

   belt 1 is one plate wide

   

   Tip from pietsan: Copper the waterline first, so you know for certain you will come out right there and can cut the plates neatly to size. Keel and posts follow a separate line: there the plates run horizontally, so do not carry the line of the hull planking onto keel and posts.

6. 6Dry-fit the plating pattern

   Lay a few rows of plates loose on the cutting mat to see the pattern. Ours stagger by a third rather than the half you see more often. The plates slide about easily, so do not expect a tidy picture; it is the stagger that matters.

   

   Tip from *Hans*: I do not believe it strictly followed a fixed pattern. Coppering was protection against worm and weed growth, not a handsome copper hull. Function over form.

   Watch out: The manual (15.2) has you start at the keel, work from aft forward and stagger the rows by half, with one drop of thick CA in the middle of each plate; we started at the keel too and it went wrong because the rows then follow straight lines. Pietsan starts at the waterline and that worked. The kit also has an emergency measure for a crooked waterline (15.3): tape above the line and touch up the gap with copper paint; with a 1 x 1 mm strip that is not needed.

7. 7Print paper plates and lay them on the hull as strips

   Reproduce the plates at full size on the computer, print them and stick the sheets together. Cut the sheet into strips, stopping just short of the end, so the strips stay joined but can lie on the hull separately like real rows. Only then do you see where the plates really have to be cut at an angle: for us the first gore line comes at 11 plates from the waterline, with one more right under the ship that you never see.

   first gore line at 11 plates from the waterline

   

   

   Tip from Henkl: The knowledge base on henkvanluinen.com has an account by a former forum member of coppering his hull. It makes clear straight away that it is a big job you need to allow plenty of time for.

   Watch out: The paper exercise did not work out exactly in the end; on the hull the plates shift differently from the paper. Use the strips as a guide, not as an exact measure.

8. 8Finish the waterline with a strip

   Decide whether you want five straight rows below the waterline (as Paulbo did) or a single band (as Piet did); we went for five rows. Finish the top with a 1 x 1 mm strip along the waterline, as in the second example on Henk's website. Any unevenness in the top row then disappears behind the strip.

   1 x 1 mm strip, five rows below the waterline

   

Result

With the belts along the sheer, the stealers at the sternpost and the paper strips as a guide, the first nine rows below the waterline went on intact; a little fudging here and there, but you only see it if you know. Next time we would start with this planning straight away instead of at the keel, which would save pulling off a few hundred plates.