When working with a softwood workbench top such as plywood many woodworkers find it important to add a finish to the workbench so it is easier to clean as well as help the plywood last longer.
Finish for a woodworking bench. Not much will stick to poly and you will certainly have spilled glue oil nondescript goo and other things on the bench over the years. Since plywood is a softwood it is much easier for liquid oils and other residue to get into the wood and cause damage. When finishing projects on the workbench wipe the bench down before whatever solvents you use have a chance to dry use the same solvent to wipe the finish off the bench as is used to thin it. If you are really going to do actual work on that workbench top then it won t look pretty very long.
For anyone out there wondering how to spiff up a workbench the right. Varnish will probably offer the longest most durable life. You can finish the other surfaces of your bench however you like with whatever finish you prefer. For some woodworkers the term workbench refers to a set of sawhorses and a salvaged door slab.
If you have installed some big dents or surface distortions over time you can renew the surface by planing it flat provided the surface is thick enough then put the oil finish on once more. You can t caulk a bench like you do the framing around windows. For a shop workbench i would put on a thinned coat of polyurethane varnish. Best finishes for outdoors.
Come back with a light wipe down using a dry rag this is especially important if you re using water based finishes or stains. For others no workbench is complete until it sports a beautiful high gloss finish.