Sansin Foundation

Sansin Foundation is a penetrating wood conditioner designed to prepare and protect wood for optimal stain absorption. Acting as the first coat in Sansin’s two- and three-part exterior systems, Foundation helps equalize absorption, stabilize wood fibers, and reduce blotchiness and over-absorption on uneven or porous surfaces.

Whether you’re finishing logs, timbers or siding Sansin Foundation ensures that subsequent coats of stain or topcoat bond more evenly and perform longer. Its water-borne formula penetrates deeply, improves dimensional stability, and enhances finish uniformity—especially on softwoods and newly milled substrates.

What Makes Sansin Foundation Unique?

Unlike traditional sealers that sit on the surface, Foundation penetrates the wood, conditioning it from within and reducing the risk of uneven stain absorption. It is designed to work in harmony with Sansin SDF and Classic creating the ideal foundation layer without blocking future coats. Especially useful for soft or porous woods, Foundation levels absorption and allows colors to appear richer and more consistent.

Key Benefits of Sansin Foundation

• Pre-treatment that enhances stain performance and appearance.
• Equalizes porosity and absorption across soft or rough wood.
• Improves wood fiber stability and reduces blotchiness.
• Penetrates deeply without blocking stain penetration.
• Ideal for new logs, rough-sawn siding and timbers.
• Compatible with Sansin Classic and SDF systems.

Application Notes

• System Use: Apply Foundation as a first coat before using Sansin Classic or SDF. It is not a standalone finish.
• Surface Preparation: Wood must be clean and dry, with moisture content under 25%. Remove dust, dirt, loose fibers, or mill glaze by sanding or media blasting.
• Tools: Brush, spray, or flood coat. Always back-brush to ensure even penetration.
• Mixing: Stir well before and during use. Do not thin or shake.
• Dry Time: 6 hours to touch at 20°C. Allow 24 hours before applying stain or topcoat.
• Temperature Range: Apply between 10°C and 30°C (50°F–86°F). Avoid rain, frost, or direct sun during drying.

Coverage

Coverage Rate
250–350 sq. ft./gal

These figures are based on average conditions and can vary depending on factors such as wood porosity, surface preparation, and application method. For precise planning, it’s advisable to conduct a test application or consult with a specialist.

Maintenance Required

• Sansin Foundation is not a topcoat and does not require maintenance itself.
• It must be followed by a primary finish such as Sansin SDF or Classic for full protection.
• After applying Foundation, complete the stain system within 2 weeks for best results.
• Maintain the full system as directed by the topcoat product used.

Frequently Asked Questions

What is Sansin Foundation used for?

It is a pre-treatment conditioner that improves the absorption and performance of Sansin stains and finishes.

Can I use Foundation on its own?

No. It is not a protective finish. Always follow with a full Sansin system such as Classic or SDF

Which products can I apply over Foundation?

Sansin Classic or SDF are both compatible topcoats designed to bond well over Foundation.

What types of wood benefit most from Foundation?

Softwoods like pine, fir, and spruce, and rough-sawn or porous surfaces benefit greatly from more uniform absorption.

How soon after applying Foundation can I apply stain?

Wait at least 24 hours in good drying conditions. Do not exceed 14 days between coats.

Does Foundation change the appearance of the wood?

It may darken the wood slightly but does not add significant color. It is designed to disappear once stained.

Can Foundation be used indoors?

It is intended for exterior wood, though may be used on interior log components if finishing with an exterior system.

Is Foundation VOC compliant?

Yes. Like all Sansin products, it is low-VOC and water-borne, making it safer for applicators and the environment.

Can I spray Foundation on logs?

Yes, spraying followed by back-brushing is recommended for even saturation on round or textured surfaces.

Will Foundation reduce maintenance down the line?

Yes. It improves stain adhesion and uniformity, helping reduce premature wear and ensuring longer life of the overall system.

Downloads

• 📎 Technical Data Sheet (PDF)
• 📎 Safety Data Sheet (PDF)