Skip to content
Dugan Design
← All products
+ Add with a base product
HardenersHardener

LNB837

LNB837 hardener for polyurethane (2K PU) coatings

MILESI polyurethane hardener (component B, isocyanate) for two products in the range: the thixotropic gloss PU lacquer LDA846 (50 %, i.e. 2:1) and the PU isolating sealer LQA836 (100 %, i.e. 1:1). No official t-color.ru page; no stand-alone data sheet for the hardener was found. The dealer describes it through the LQA836 system: strong isolating action, good penetration into the wood, excellent clarity.

  • Hardener for LDA846 thixotropic gloss PU lacquer — 50 % by weight and volume
  • Hardener for LQA836 PU isolating sealer — 100 % by weight and volume
  • Within the LQA836 system: isolating oily/exotic species (rosewood, teak, etimoe, padauk, zebrano, etc.) and MDF before LRA polyester

Ask about LNB837

Answers are based on the LNB837 data and the products it mixes with.

Questions and answers are stored to improve the assistant and prevent abuse; the question text is processed by Anthropic (USA). Privacy policy

Mixing matrix

  • LDA846base
    % by weight: 50 %official% by volume: 50 %official

    Always for LDA846 — it's the only hardener listed for it.

    Fixed ratio — weigh it. The mix is ≈ 16 ± 2 s CF4, basically ready to spray. Official thinning is 0–30 % (LZC1026/LZC1051); the MILESI TDS says 0–10 % — start at 0–10 %. Pot life ≥ 6 h.

  • LQA836base
    % by weight: 100 %official% by volume: 100 %official

    Always for LQA836; isolating oily/exotic species and MDF before LRA polyester primer.

    1 : 1 + 10 % LZC1051. Pot life 4 h at 20 °C. Don't substitute another PU hardener.

  • other PU basesbase
    % by weight: do not use %recommended

    Don't use with other PU bases unless the supplier confirms it.

Percentages are per 100 parts of component A.

Characteristics

Chemistry
polyisocyanate (2K PU component B); aliphatic vs aromatic not published — probably an aromatic (TDI-adduct) typerecommended
Solids
not published; ≈ 30–40 % by back-calculationrecommended
Viscosity
not published for the hardenerdealer
Density
≈ 0.9–1.0 g/cm³recommended
Pot life · With LQA836
4 hdealer
Pot life · With LDA846
≥ 6 hdealer
Drying · Dust-free
30dealer
Drying · Touch-dry
120dealer
Drying · Full cure
8dealer
Drying · Conditions
ambient (≈ 20 °C)
Moisture sensitivity
high — the isocyanate reacts with air moisturerecommended
Lightfastness
yellows like a standard PU — avoid under white/pastel pigmented or pale-maple clear finishes when non-yellowing is requiredrecommended

Application

HVLP

Nozzle
1.3–1.5 mmrecommended
Pressure · air · Inlet pressure
2.0–2.5 barrecommended
Pressure · air · Cap
≤ 0.7 barrecommended
Spray viscosity
16 ± 2 s CF4 (mixed, unthinned)dealer
Consumption
100–150 g/m²official

Airmix (air-assisted airless)

Nozzle
tip 09–11 thou (0.23–0.28 mm), fine-finish 20–40° fan mmrecommended
Pressure · fluid
60–100 barrecommended
Pressure · air
1–2 barrecommended

Conventional spray

Nozzle
1.3–1.5 mmrecommended
Pressure · air
2.5–3.0 barrecommended
Consumption
70–100 g/m²official
Coats
one light veil coat, no sandingdealer

Brush

Consumption
70–100 g/m²official

Brush only for LQA836 (per the official page); LDA846 is spray-only.

Process and compatibility

Overcoat, LQA836 system
LRA polyester over the isolator without sanding: 30 min at 25–28 °C, 1 h at 21–25 °C, 1.5 h at 17–20 °C. Miss the window and you have to sand the isolator. Keep to the polyester recoat intervals.dealer
Goes with
LDA846, LQA836
Temperature and humidity
15–25 °C, RH ≤ 70 %recommended
Don'ts
  • Never apply the hardener on its own or dose it by eye — weigh it.
  • Don't put LNB837 into other PU bases, and don't swap another hardener into LDA846/LQA836.
  • Don't leave the can open — air moisture ruins isocyanate (it goes cloudy, thickens and skins).
  • Don't seal leftover mixed material airtight — it gives off CO₂.

Storage

Shelf life
4 months (part B)dealer
Storage temperature
5–25 °Cdealer
Packaging
5 л, 25 л, фасовка из 5/25 л; розница 1 429 ₽ при 7 145 ₽/л (≈ 0,2 л)

Safety: Solvent-borne isocyanate hardener: a respiratory and skin sensitiser, and flammable. Spray in an extracted booth with an A2P2 respirator (air-fed is better), nitrile gloves and eye protection. Keep tightly closed and away from ignition sources. Check the MILESI SDS for the exact H-statements.

Used in finishing systems

    Mixed into

    LDA846 / LQA836

    Sources

    Value tags: “official”, “dealer”, “catalog”, “schedule” are Technocolor data; “workshop” is from our own datasheets; “recommended” is our engineering estimate (hover to see the reasoning).

    Not covered by the sources
    • No official t-color.ru page and no stand-alone MILESI technical data sheet or SDS for LNB837 found (the web-search budget ran out, so no new TDS search was possible this run)
    • Aliphatic vs aromatic isocyanate type — not published (aromatic only inferred)
    • LQA836 + LNB837 drying times (dealers disagree whether the '4 h' is pot life or full dry)
    • Official temperature/RH limits for application
    • Shelf life/storage only from the LDA846 TDS (UA dealer); not confirmed for the RU supply
    • No official finishing schedule (information/technology) uses LNB837
    • Hardener's own NCO content, viscosity and measured density — not published (solids ~30–40 % and density 0.9–1.0 only back-calculated)