Factory Finish vs Field Painting - Wood-Clad Window Coatings

Why this matters

Wood-clad windows (interior wood, exterior aluminum or fiberglass cladding) come in two finish paths: factory-applied coating with a published warranty referencing AAMA performance specs, or a "primed for paint" exterior the customer or contractor finishes in the field. The cost delta between the two is real; the durability delta is larger and runs the opposite direction. A field-painted exterior on a south or west exposure starts chalking in 3 to 5 years and requires repainting in 5 to 10. A factory finish to AAMA 2605 carries a 10-year color and 20-year film-integrity warranty. The decision is not just a finish budget question; it is a 30-year-ownership math question. Reps who do not run that math leave money on the table on premium quotes and create warranty calls on the budget ones.

This Reference defines the three AAMA coating performance levels and frames the factory-vs-field decision.

The three AAMA coating performance specifications

AAMA 2603 - Pigmented Organic Coatings on Aluminum Extrusions and Panels

The entry-level coating specification. Tests cover:

• Color retention: 1 year South Florida exposure with limited color change tolerance
• Chalk resistance: 1 year South Florida exposure
• Film adhesion, hardness, abrasion
• Salt spray: 1,500 hours

Typical use: economy aluminum windows, light commercial. Warranty terms in the field commonly 5 years color, 5 years film.

AAMA 2604 - High Performance Organic Coatings on Aluminum Extrusions and Panels

Middle tier. Tests cover:

• Color retention: 5 years South Florida exposure
• Chalk resistance: 5 years South Florida exposure
• Salt spray: 3,000 hours
• Humidity resistance and other accelerated tests at higher thresholds than 2603

Typical use: mid-grade residential and commercial. Warranty 10 years color, 10 to 15 years film.

AAMA 2605 - Superior Performance Organic Coatings on Aluminum Extrusions and Panels

The premium tier. Tests cover:

• Color retention: 10 years South Florida exposure with very tight color-change tolerance
• Chalk resistance: 10 years South Florida exposure
• Salt spray: 4,000 hours
• Highest accelerated weathering and erosion resistance levels in the family

Typical use: high-end residential, commercial architectural, coastal. Warranty 20 years film, 10 years color (and many manufacturers extend further with care).

The chemistry behind the spec

AAMA 2603 is typically polyester or acrylic.

AAMA 2604 is typically a 50 percent PVDF (polyvinylidene fluoride) resin blend such as Kynar 500 or Hylar 5000.

AAMA 2605 is typically a 70 percent PVDF resin blend such as Kynar 500 / Hylar 5000 at the premium specification.

PVDF resins are the durability differentiator. They are chemically very stable under UV exposure, which is why the color and chalk performance scales so steeply across the three tiers.

Field paint - what the customer is actually buying

A "primed for paint" exterior is typically a baked-on primer (often a polyester primer designed for over-coating) that the customer or contractor paints in the field with a high-quality exterior acrylic.

The field finish is:

• Acrylic latex (the practical choice; oil enamels chalk faster on aluminum or fiberglass)
• Applied by brush, roller, or spray
• Cured at ambient temperature, not baked
• Susceptible to chalking, fading, and adhesion failure within 3 to 10 years on south and west exposures

The field finish gives the customer color flexibility (any color, any time) and serviceability (repaint when desired). It does not match the durability of a factory finish at any tier.

The 30-year ownership math

Factory AAMA 2605:

• Premium up-front (manufacturer adds a coating-line surcharge per window)
• 20-year film-integrity warranty
• Customer expectation: no field maintenance for the warranty period

Field-painted primed-for-paint:

• No factory surcharge
• Customer-paid field paint job at installation
• Customer-paid repaint at 7 to 10 years (south and west elevations may need it sooner)
• Customer-paid repaint at 17 to 20 years
• Three paint events over 30 years

Across a whole-house replacement on a south or west exposure, the lifetime cost comparison usually favors factory finish; the customer pays less in total and gets a much more uniform appearance over the period. The exception is the historic-color or specialty-color case where no factory option meets the customer's color requirement; field paint is the only path.

When factory finish is the clear right call

• Coastal exposure (salt-spray performance of AAMA 2605 vs field acrylic is dramatic)
• Long-term ownership intent (customer plans to stay 15+ years)
• South or west elevations with intense UV
• HOAs that mandate specific color codes and uniformity over time
• Premium product lines where the customer already accepted the cost tier

When field paint is the right call

• Historic restoration requiring a specific color match not in the factory palette
• Customer who wants flexibility to repaint colors over time
• Shaded or north-facing elevations where UV exposure is low
• Budget-driven replacement where the customer accepts the maintenance trade-off knowingly

Color selection logic

Dark exterior colors (deep bronze, deep green, black) absorb more heat and accelerate coating failure across all tiers. The temperature rise on a south-facing dark-bronze frame in summer can exceed published spec limits on some lower-tier coatings; manufacturers exclude dark-color warranties on some product lines for this reason. AAMA 2605 in dark colors is the typical safe choice; AAMA 2603 in dark colors on a south wall is a 5-year repaint plan whether the customer expects it or not.

What to put on the quote

For factory-finished windows:

• Coating specification: AAMA 2603, 2604, or 2605
• Resin chemistry: polyester, 50 percent PVDF, or 70 percent PVDF
• Color name and manufacturer color code
• Warranty terms (color years, film years) per the manufacturer's published warranty

For field-paint windows:

• "Primed for paint exterior" called out explicitly
• Recommended paint specification (high-quality exterior acrylic latex from a major manufacturer)
• Statement that field paint is excluded from any manufacturer coating warranty
• Recommended repaint interval and customer maintenance responsibility

The quote-stage clarity prevents the year-5 call where the customer expected a "premium" finish but received primed-for-paint.

Field-painting workflow (when chosen)

1. Wash the primed surface with a manufacturer-approved cleaner; remove all installation residue (fingerprints, sealant smudges).
2. Light scuff sand with 220 grit.
3. Tack rag.
4. Apply two thin coats of high-quality exterior acrylic latex; do not skip the second coat. Single-coat applications chalk faster.
5. Touch-up the operating sash and hardware areas after the window has been operated through one cycle to find any rub points.

References

• AAMA 2603 (Voluntary Specification, Performance Requirements and Test Procedures for Pigmented Organic Coatings on Aluminum Extrusions and Panels)
• AAMA 2604 (Voluntary Specification for High Performance Organic Coatings)
• AAMA 2605 (Voluntary Specification for Superior Performing Organic Coatings)
• AAMA/WDMA/CSA 101/I.S.2/A440 (NAFS, references coating performance in product certification)