2K polyurethane (aromatic isocyanate PC25) over solvent-borne dye stain CTU + CFS1 binder
Finishing raised-panel doors (PU)
- Substrate
- Raised-panel doors in solid wood/veneer: flat areas plus routed profiles
- Result
- Stained clear PU finish with visible grain: matt to satin depending on the PTL20 grade (5–30 gloss), hard and chemical-resistant, for interior doors
- 01
Sanding flat areas
Abrasive: P150, P180, P220
Work up through the grits without skipping; de-dust before staining.
- 02
Sanding profiles/mouldings
Abrasive: K60, K80
Panel profiles and mouldings with flexible mats so the edges aren't cut through.
- 03
Staining
- 04
Drying
Drying: [object Object] °C, 5 min
Short flash-off — the stain is solvent-based. Check it isn't tacky before priming.
- 05
Sealer, coat 1
- 06
Drying
Drying: [object Object] °C, 1.5 h
Forced drying. At 20 °C allow 2 h to sanding (dealer, catalog).
- 07
Sanding flat areas
Abrasive: P240, P280, P320
Sand to an even matt surface, removing raised grain; don't cut through to the stain on edges.
- 08
Sanding profiles/mouldings
Abrasive: K120
Profiles with a K120 mat, light pressure.
- 09
Sealer, coat 2
- 10
Drying
Drying: [object Object] °C, 1.5 h
- 11
Sanding flat areas
Abrasive: P240, P280, P320
Final sealer sanding before the topcoat; de-dust.
- 12
Sanding profiles/mouldings
Abrasive: K120
- 13
Topcoat (lacquer)
- 14
Drying
Drying: [object Object] °C, 1.5 h
After forced drying let it rest: through-dry 4 h at 20 °C, pack/stack after 8 h (dealer); full chemical resistance takes several days.
Ask about this system
Answers are based on this finishing schedule and its products.
System characteristics
- System type
- Clear (stained) two-pack polyurethane finish: CTU dye + 2 coats PTS20 PU sealer + 1 coat PTL20 PU lacquer, PC25 aromatic hardener.official
- Total wet application (g/m²)
- 530–550official
- Mix solids % · Primer
- ≈35recommended
- Mix solids % · Lacquer
- ≈31recommended
- Dry film build
- ≈120 µm applied; ≈90–110 µm final after sandingrecommended
- Gloss
- по выбору лака: 5 (DM) / 10 (UM) / 20 (M) / 30 (SM) единиц блеска, ±3, геометрия 60° / per lacquer choice: 5 (DM) / 10 (UM) / 20 (M) / 30 (SM) gloss units ±3 at 60°dealer
- Transparency
- high clarity — grain and stain colour stay visibleofficial
- Hardness
- high: hard, easily sanded film; wear-, scratch- and chip-resistant (no figures published)dealer
- Elasticity
- medium: PC25 sits at the hard end of the chart; PTS20 itself is fairly flexible. For solid-wood panels that move seasonally, PC20 gives a more flexible film.catalog
- Wear resistance
- good for interior doors and furniture (qualitative)dealer
- Chemical resistance
- good physical and chemical resistance; resists moisture and household chemicalsdealer
- Light resistance
- limited: PC25 is an aromatic isocyanate, so the film yellows over time (on the catalog chart PC25 beats PC20/PC10/PC72 but trails PC60 and the aliphatics). CTU dyes are transparent and less lightfast than pigment stains (catalog). For pale tones use PC60 in the topcoat.catalog
- Adhesion
- good: every coat is the same PU system; CFS1 binds the dye under the sealer; P240–P320 sanding between coats keys the layersrecommended
- Pot life · Primer (h)
- 3–4
- Pot life · Lacquer (h)
- 4
- Pot life · Conditions
- 20 °C
- Drying time
- stain 5 min at 20–25 °C; each sealer/lacquer coat 1.5 h at 30–35 °C. At 20 °C: sealer to sanding 2 h, lacquer touch-dry 25 min, through-dry 4 h, packable 8 hofficial
- Hiding power
- n/a — clear systemrecommended
- Interior only
- yesrecommended
- Coats
- 4
- Coats detail
- 1 stain + 2 sealer + 1 lacquer
- Film coats
- 3
- Sanding stages
- 3
- Min cycle time (h)
- 4.6
- Min cycle time: why
- Сумма сушек схемы: 5 мин + 3 × 1,5 ч = 4,58 ч без учёта шлифовки и обеспыливания; к упаковке ещё ~8 ч после лака (дилер). / Sum of the schedule's drying steps: 5 min + 3 × 1.5 h = 4.58 h, excluding sanding/de-dusting; allow ~8 h more after the lacquer before packing (dealer).