2K PU (polyurethane): PU primer for PU foam + PU enamel + solvent patina + 2K PU high-gloss clear
Finishing polyurethane-foam (PU) mouldings
- Substrate
- Cast polyurethane-foam parts: mouldings, cornices, beading, carved décor and onlays. Degrease the foam and remove mould-release (wax/silicone) before priming.
- Result
- Opaque coloured finish (white or any RAL/NCS) with patina left in the recesses of the relief, under a heavy coat of high-gloss (100 gloss) clear PU lacquer.
- 01
Priming
PPS20040 100 %C20040 20 % (Hardener)S50 30 % (Thinner)
- Consumption
- 150official
Spray one full coat onto clean, degreased foam; on porous castings or deep carving a second coat after an intermediate sand is fine. The primer is elastic and bonds well to PU foam, so it won't crack on flexible parts. Weigh the components.
- 02
Drying
Drying: [object Object] °C, 4 h
Dealer data for PPS400xx: touch-dry in about 30 min, ready to sand and enamel after 3–4 h.
- 03
Sanding
Abrasive: K120
Work the relief with flexible K120 mats (≈P120) so you don't cut through the primer on carved edges, then de-dust. On flat areas the dealer recommends P280–P320 before the enamel.
- 04
Intermediate coat (enamel)
PPL20 100 %PC20 50 % (Hardener)C61 50 % (Hardener)S50 30 % (Thinner)
- Consumption
- 150official
The enamel sets the base colour (white or tinted to RAL/NCS); the patina is worked over it. C20 is an aromatic hardener — fast, but prone to yellowing; for whites and pale colours C61 (≈ PC60, aliphatic) is the safer pick.
- 05
Drying
Drying: [object Object] °C, 4 h
Touch-dry ~30 min (dealer, PPL20). The schedule has no sanding of the enamel before the patina; if needed, only a light denib with a grey pad.
- 06
Applying the patina
CQS 100 %S10 100 % (Thinner)
- Consumption
- 80–100official
One coat. S10 is a fast thinner: the patina dries quicker and harder and is harder to rub back, giving a crisper contrast. S2000 or more thinner (up to 200 %) makes it easier to remove.
Mix for this step
Mix calculator
gRatio 100 : 100.0
Component Weigh out CQSpart A 250 g S10Thinner 250 g Total 500 g Covers roughly 6.25 m² at 80 g/m².
- 07
Drying
Drying: [object Object] °C, 5–10 min
Don't leave it longer than needed: the longer the patina dries, the harder it is to clear off the high spots.
- 08
Wiping back excess patina
Abrasive: steel wool No 2
Use steel wool (No 2 per the schedule) to clear the patina off the raised parts of the relief and leave it in the recesses. Go light so you don't cut into the enamel. De-dust before the lacquer. A non-woven pad also works (official CQS page).
- 09
Applying the lacquer
PTL500 100 %C200 70 % (Hardener)S80 40 % (Thinner)
- Consumption
- 150official
The thixotropic lacquer holds a heavy coat on verticals and relief without runs. The schedule mix (C200 70 %, S80 40 %) is the top of the dealer range; the official PTL500 page gives PC72/AC200 60 % and S70 20–30 %. Don't use PC72 (aromatic) over light enamels — it yellows.
Mix for this step
Mix calculator
gRatio 100 : 70.0 : 40.0
Component Weigh out PTL500part A 238 g C200Hardener 167 g S80Thinner 95.2 g Total 500 g Covers roughly 3.33 m² at 150 g/m².
Pot life of the mix: 4.
- 10
Drying
Drying: [object Object] °C, 12 h
Touch-dry ~1 h, full dry 12 h (dealer). If you want to polish to a mirror, wait at least 48–72 h.
Ask about this system
Answers are based on this finishing schedule and its products.
System characteristics
- Gloss
- 100 gloss (GU)dealer
- Hardness
- good hardness and scratch resistance (PTL500 topcoat)dealer
- Elasticity
- high in the primer (PPS400xx) — matters on PU foamcatalog
- Adhesion
- good primer adhesion to PU foam, provided it is degreasedofficial
- Hiding power
- high (PPL20 enamel)official
- Chemical resistance
- good against water, alcohol and coffee for interior furniture and décorrecommended
- Lightfastness
- topcoat is yellowing-resistant (AC200 — 8 of 10 on the catalog scale); the weak link is the enamel on aromatic C20 (PC20, 3 of 10). For white/pale RAL use C61.recommended
- Thixotropy
- yesofficial
- Pot life · Primer
- 3dealer
- Pot life · Enamel
- 3–4dealer
- Pot life · Lacquer
- 4–6dealer
- Polishable
- yesdealer
- Coats
- 4
- Film coats
- 3
- Min cycle time (h)
- 20.1