I recently needed a handful of long rivets to secure the sides of a centerboard trunk to its ledges and to fasten jaws to a boom. Even if I could even buy just 8 rivets, I didn’t want to wait several days for an online order so I decided to make my own. I started with some copper water pipe I had on hand and some 6-gauge copper grounding wire (about 5/32″ in diameter) sold by the foot or in coils from the electrical department of the local home-improvement store.
There are two things wrong with the wire as it comes off the spool: it’s round and it’s soft. Boat rivets are square to keep them from rotating as the wood around them moves; leaks would follow the slow wearing away of the wood. By hammering the wire I could make it square and at the same time work-harden the copper to make it rigid enough to drive into the slightly undersized holes I’d drill in the wood pieces I was assembling.
I hammered lengths of wire on the anvil at the back of my vise. A small pair of vice grips holding one end helped me orient the wire in 90° turns to hammer four flat faces. The wire curled as it stiffened but it was easy to straighten it by pinching it in the vise. Rather than try to form a head on one end I opted to put a rove on both ends of the squared copper rod.
I made roves from a short piece of copper 1″ pipe. (If you can’t buy a short piece, get a straight coupling.) I sawed through the pipe lengthwise, pried it open with pliers and hammered it flat on the anvil. To shape the rove I taped two 1/2″ washers (inside diameter 9/16″) on the anvil, with the face of the washer with the sharpest edge on top.
Two washers are required to provide clearance for the dishing of the rove. I taped the copper blank and the washers to keep everything in position during hammering. I set the peen of a ball peen hammer on the copper over the hole in the washers and hit it, face to face, with another hammer. Initially, fearing that one steel hammer might chip another and send shards flying, I used a wooden mallet but it didn’t completely shear the rove free. A second steel hammer was much more effective and neither hammer chipped. Naturally, I wore safety glasses. Taping a third washer on one hammer face will keep the two tempered hammer faces from making direct contact and still provide the sharp impact the copper requires.
The first blows dish the copper into a nice shape and work-harden it. A few more whacks shear it away into the hole in the washer. I used a fine-point nail set to tap a hole in the rivet’s concave side. A tap on the set with the rove on the anvil got it started; I finished driving the nail set through into a rove setting tool.
The first rove goes on the rivet while it’s held in the vice. To keep the rivet from slipping through my vise’s smooth jaws as I peened the end, I squeezed vice grips on the rivet. Putting a point on the other end of the rivet is easily done with the same nippers you’ll use to clip the excess length of the rivet. One diagonal snip is all it takes. It’s also easy to create a point with a file, disk sander or grinder.
Now the rivet is ready to use on the wood pieces. Proceed as you would with a store-bought rivet: drill, drive, apply the rove, nip the rivet, and peen the end.
Christopher Cunningham is the editor of Small Boats Monthly
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