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Osmo WR Base Coat 4001 Clear

Name: Osmo WR Base Coat 4001
Brand: Osmo
SKU: 4001

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Details

A clear, penetrating wood-preservative base coat for exterior softwood and hardwood. Designed to help protect against blue stain, rot and fungal decay, and to improve adhesion of subsequent Osmo exterior finishes. Not a standalone finish; overcoat is required.

Key Features

Clear, penetrating primer for exterior timber
Helps protect against blue stain, rot and fungal decay
Microporous; supports natural wood movement
Improves adhesion and durability of Osmo topcoats
Brush or dip application
Low odour once dry

Suitable For

Exterior joinery: windows, doors, fascias, cladding, fences, pergolas
Non-structural timber components above ground

Not suitable for: Interior use, in-ground contact, or as a final weatherproof finish.

Sizes, Coverage & Drying

Size	Approx. Coverage*	Coats	Drying Time**	Recoat
0.75 L / 2.5 L / 10 L	Up to 5–8 m² per litre (depending on wood absorbency)	1	~12 hours	When fully dry

*Coverage varies by species, surface preparation, and application method. **At 23 °C and 50% RH; lower temperatures or higher humidity will extend drying.

How to Apply

Ensure wood is clean, dry (max 20% moisture), and free from previous film-forming finishes.
Stir well. Do not thin.
Apply thinly and evenly with a natural-bristle or synthetic brush along the grain, or use a dipping process.
Allow to dry fully, then overcoat with a suitable Osmo exterior finish (e.g., Osmo Natural Oil Woodstain or Osmo UV-Protection Oil).
Pay special attention to end-grain: saturate edges and cut ends.

Safety & Notes

For exterior use only. Contains biocides—use safely and read label before use.
Not weather-resistant on its own; always finish with an appropriate topcoat.
Dispose of oily cloths responsibly; risk of self-heating—lay flat to dry before disposal.

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Delivery & Returns

Most UK deliveries are shipped within 1 working day providing the order is placed before 12pm but can take up to 4 working days to be delivered.

All Machined To Order Products Have A Lead Time Of 10 - 14 Working Days From Order, These Items Will Be Dispatched On A Next Day Courier.

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