Thursday, November 28, 2013

Sunfish Coaming Rivets or Rivnuts

The Sunfish coaming or splashguard is held on to earlier models by machine screws and riveted nuts (rivnuts) or by rivets on later models. you can tell by whether there is a slotted screw head or a rivet head. Sometimes coamings come loose, leak, are broken or need to be removed for repair and restoration. Here is a Sunfish damaged by Hurricane Sandy, it has rivets that you can see in the coaming remnants and fractures around the deck holes where the rivets pulled out.

From Small Boat Restoration 2013

Here is a Sunfish that has clean rivet holes on the deck. The owner is cleaning up old silicone and a makeshift screw and wall anchor repair.

From Small Boat Restoration 2013

Rivets can be purchased from a Sunfish parts house like Yankee Boating Center and installed with a rivet gun, available from your local hardware store. The demonstration holes in this piece of particle board are 1/4 inch.

From Small Boat Restoration 2013

The rivet is inserted into the gun and then the barrel is placed though the coaming into the deck hole.

From Small Boat Restoration 2013

Squeeze the rivet fun handle, keeping rivet flush against surface. As the rivet shank is pulled the barrel will expand inside the hole. Continue to pull the shank until it snaps under pressure or will pull no further, gently rock rivet gun back and forth to shear top of shank if needed.

From Small Boat Restoration 2013

Here is comparison of a pulled rivet on the left vs new rivet. You can see how the barrel is shortened and expanded, filling the hole. It will expand below the deck on a Sunfish and anchor the coaming, the collar of the rivet holds on the top and the expanded barrel holds on the bottom.

From Small Boat Restoration 2013

This is what the rivet looks like on top of the hull and inside the hull.

From SBR 2013

From SBR 2013

Rivet nut (rivnut) ans stainless steel 10-32 x 3/4 inch machine screws.

From SBR 2013

From SBR 2013

From SBR 2013






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