Teak toe rail repair

[drlove]

A friend of mine has an Endeavor cutter which has a teak toe rail. They had to replace some of the teak as it was damaged. They used varnish which looks great but the seams between the boards (where they meet end-to-end) are where the varnish is cracking. Some of the seams are a little wide but most are very tightly matched together. Is there some way to fill these seams to keep the varnish from cracking? We have thought about thickened epoxy or to just use a flexible sealant after varnishing. This toe rail is fairly wide (4-6 in) and 1/2 - 5/8 in thick.

Any suggestions?

[PorFin]

DrLove,

It's pretty common to have polysulfide caulk laid in the seams -- most caprails are intentionally built with small gaps to act as expansion joints like you see in concrete driveways and sidewalks. However, to be effective the gap's gonna need to be a 1/4" or more for the caulk to do its job of stretching before becoming detached.