Pre-finished and factory finishes

Overview

A factory finish is applied in a controlled shop before the product is installed or sold. The USDA Wood Handbook (chapter 16) says factory finishing gives consistent film thickness, avoids weather problems and can decrease cost, and that siding cross-cuts (cut ends) should be sealed. Which coating a factory uses is rarely stated to the buyer; industrial lines can use the catalyzed lacquers, conversion varnishes and UV-cured systems described elsewhere in this guide (Pre-catalyzed and post-catalyzed lacquer, Conversion varnish, Polyester and UV-cured finishes). This entry is short because we found no neutral source on factory finishes as a category, only the Wood Handbook passage and manufacturer statements.

Pros

• Consistent thickness and protection from weather during application (Wood Handbook).
• Can reduce cost compared with finishing on site (Wood Handbook).
• Industrial coating families are tested to standards: Mohawk says its DuraCoat pre-cat and CAB/acrylic lacquers pass KCMA (maker claim), and Finishworks says AristoMax meets or exceeds KCMA.
• Cure happens on the line; Finishworks says its UV coatings reach full cure in seconds.

Cons

• You often do not know the coating. Without the maker's data sheet you cannot choose a compatible repair or topcoat.
• Cuts, notches and drilled holes expose bare wood. The Wood Handbook says siding cross-cuts should be sealed; the same principle is the reason to treat any fresh cut end (Finishing end grain).
• Repair of a factory film is a matching problem, not a technique problem, and no source we read addresses it.
• Adhesion of a new coat is not guaranteed; General Finishes says to test adhesion on sealed or pre-finished surfaces.

Suitability

Factory finishes suit work where consistency matters and cuts are few: flooring, panels, doors and cabinets bought finished. For bare-wood projects you finish yourself, see Sanding schedule. For sheet goods that arrive pre-finished see Finishing sheet goods (plywood, MDF, MDO).

Coats and application

Not applicable for the factory coating itself. If you must refinish or touch up, General Finishes' instructions for sealed or pre-finished surfaces are: scuff clean with a non-woven pad and a 50:50 mix of denatured alcohol and water, let it dry 1 to 2 hours, sand lightly with 220 to 320, and test adhesion before committing to the whole surface. These are instructions for GF's water-based products; other makers may differ.

Compatibility

• Test a small hidden area first (GF: test adhesion).
• GF warns against water-based topcoats over linseed or Danish oils and against clear coats over white or light paints.
• Do not apply lacquer over polyurethane finishes (Minwax lacquer label), which matters when you do not know what the factory used.

Care and repair

Follow the manufacturer's care sheet for the product. For touch-up, test the surface preparation described above on an offcut.

Safety and environment

We read no safety data for factory finishes as a category; the coating is often unidentified, so ask the maker. Check the maker's declarations for formaldehyde or VOC if that matters for your project; Finishworks says its AristoThane is formaldehyde- and isocyanate-free and can be used in Greenguard Certified systems (maker claim). No food-contact claim is made here; see Food-safe finishes.

Related

• Polyester and UV-cured finishes: how many factory lines cure
• Conversion varnish, Pre-catalyzed and post-catalyzed lacquer: cabinet-shop coatings
• Finishing sheet goods (plywood, MDF, MDO), Finishing end grain
• Food-safe finishes