I used thickened epoxy in a syringe on a long stick (1×2). Cut off the tip of the syringe and tape it to a long stick that has been notched to hold the syringe. Put eye screws in the stick to hold a dowel. Use a dowel to push the plunger on the syringe. This lays a nice thick bead of epoxy on the seam. I finish by rolling out the epoxy soaked tape over the bead, smoothing it into a fillet.