We pressure wash our covers on a rack using a 15 degree tip with a 2000 psi pressure washer. Once dry we apply 2 (two) coats of Sunbrella approved waterproofing. After the canvas is 2 or three years old this should be done annually or as needed. If the stitching looks weak or is coming apart in areas it's time to have it restitched by a professional.
We are willing to assist Duffy Boat owners with troubleshooting and repairs.