Boat Buzz

Our boat was restored using the Danenberg enhanced traditional method per the book. My deck seams between planks are opening up causing cracks in the paint. Sikaflex was used for the seams and a interlux boot stripe paint for the white. When the boat sits in the sun for the day the cracks get worse. I'm surprised these planks move even after being bedded in 5200 but apparently they do. How should I go about to fix this?

Hi Jim,
This usually happens on the live seams, which looks like here. It helps on the deeper seams if you pay in a little cotton before you caulk those.

Hello Captain Nemo! Thank you for the tip. Yesterday at the Algonac show I did get the same answer from a local restorer. I now need to consider if it's worth the time and effort.

It happens all the time. Just tape off the seam and push in some more sikaflex, smooth it out and then paint the seam white. You can't stop it, but you can reduce it by adding a little more caulk. I would not use the cotton method because your planks are not thick enough and they are not beveled to receive the rope. and could really stress or crack the plank when the boat swells.

On my current project, prior to deck planking would skinning with plywood underlayment help this issue?

It absolutely would help if you don't mind getting dinged by a judge at a show. Treat it like a 5200 bottom. Seal 1/8" marine plywood with CPES on both sides and seal the back of your new deck planks. Spread a thin coat of 5200 on the plywood as you install the new thinner deck planks with screws and bungs. Fair the deck and stain and seal. I would seal with CPES and then varnish. The only place the edge of the plywood would be visible is on the ends of the hatches.
This system really helps with a blonde deck boat like a Capri where there are no seams between the blonde planks.That is why you often see these boats with painted seams in the blonde parts. Someone is just trying to hide the cracking and it looks awful.