Dissolving cured resin

[philnolan3d]

I need to replace the FEP film in my printer vat. However some of the resin has gotten into the screw holes and cured there. I got about 5 of the 10 screws out but the others have really gotten locked tight. Even my handyman brother-in-law tried it and suggested getting something to dissolve the resin. Anyone have any suggestions? If I can't get them out I'd have to either drill them out (I don't have a drill) or spend $50 to replace the vat. I thought maybe acetone (nail polish remover) or a long soak in IPA.

[fred_dot_u]

I watched a video recently about using UV curing adhesive to attach copper foil to glass. The creator warned against using alcohol or acetone on the copper, as any liquid of that type that reached the UV adhesive would cause it to degrade and eventually fail.

You have many choices. Isopropyl alcohol of various concentrations, higher is better, denatured alcohol and acetone. Other solvents may work, but these are relatively safe. Use in a well ventilated area and/or enclosed container to avoid igniting and inhaling fumes.

You could save on quantity by building a set of dams around the screw openings with modeling clay, perhaps include two or three in a trough. Once filled, drape food sealing plastic over it to reduce evaporation. You could do each hole individually, but it would reduce the volume at the expense of a more concentrated solution as the resin dissolves. You'd want to compromise by having a bit more alcohol in which the resin can better disperse while it's working.

Alternatively, just dump a bunch in a tray to cover the bottom of the vat externally and cover the tray. Food (sandwich size) containers are handy for this.

[philnolan3d]

Yeah IPA alcohol is what you normally use to clean prints during the finishing process. I wasn't sure if it would have any effect on already cured resin though. Maybe I'll try that next. Right now I have it soaking in some acetone in one of those good storage containers but I put a metal baking sheet under it in case the acetone eats through the container.