There are a few ways to seal wood gutters. One way is to use a primer and paint the gutter with an exterior paint. Another way is to use a sealant, such as a waterproofing sealant or roofing sealant. The best way to seal wood gutters is to use a primer and then paint them with an exterior paint that has been designed for metal roofs. Metal roof paints have special ingredients that make them better at resisting rust, chipping, and fading in the sun than normal exterior paints. You can also buy a sealant specifically designed for sealing wood gutters, but using a primer and metal roof paint is usually just as effective and much cheaper.

There are a few ways to seal wood gutters. One is to use a paintable silicone caulk. Another is to use roofing tar or roofing cement. Both of these will work well to keep water from seeping into the seams between the boards in your gutter system. Another option is to use metal mesh flashing tape. This is a self-adhesive, aluminum tape that can be used to patch up any holes or gaps in your gutter system. It's also great for repairing damaged or rotted sections of wooden gutters.