Masking Between a Painted Exterior and a Natural Interior

Determining where to locate the transition between finished cabinet interiors and the exterior, and details of masking to isolate one from the other. December 6, 2011

How do you deal with frameless cabinet boxes with painted exteriors and natural interiors? How do you deal with the transition in a practical way for masking and spraying?

Forum Responses
(Finishing Forum)
From contributor J:
Applied end panels.

From contributor D:
The most cost effective as mentioned earlier is to use applied end panels. Then I like to use a PVC banding on the boxes to eliminate finishing completely, except the doors and panels. Prior to that the choices were to either mask off the interiors completely before spraying, to brush on the stain and clear coat, or to use plywood and spray the whole thing.

From contributor G:
I mask off the insides using corrugated cardboard and masking tape.

From the original questioner:
I should have been clearer. I want to know where you make the actual break between the two. The way I see it there will be a paint ridge left when the tape is removed. Where do you place this ridge on the box edge? Inside corner, outside corner, or elsewhere?

From contributor H:
Hope the cabinetmaker used pre-finished ply! If not then sand, seal, and clear finish the interiors. Do not worry about over-spraying the exteriors, the finish will make great sealer. Wait a day then mask the inter edge on the cabinets with blue long mask and burnish down. Next with white painter tape and 24" fan mask seal the openings off, taping to the blue tape.

Once the opening is sealed with the fan mask then take 12" paper mask and white tape and cover the perimeters with the paper. This is an extra step but it will keep your primer and paint from flaking off the "flake resistant fan mask". Nothing worse than blowing the dust off for a final and having your over-spray with a static charge imbed itself into you final finish. Providing that you do not leave the blue tape on longer than seven days and it was not in the sun, carefully pull it back on itself and you should not have any clear finish damage.