Gypsum Matt Sealer (Dipping Penetrating Sealant)

Designed for porous castings, this water based gypsum sealer penetrates below the surface to reduce moisture absorption, dusting & chalk-like powder transfer. It works well as a dipping sealer for gypsum crafts, Plaster of Paris (POP), casting powder, Jesmonite-type materials & cement-based decorative pieces.

Unlike a thick varnish, the low-viscosity acrylic formula soaks into surface pores with very little change to the natural appearance. Once dry, it leaves a matt finish with very little shine & helps protect the casting from light moisture, stains & handling marks. The sealed surface remains suitable for applying compatible acrylic varnish, wax polish, PU varnish or solvent based paint/spray paint.

Important Notes:

• Due to the sealer’s water-repelling properties, some water-based products, such as acrylic paints & emulsion paints, may not bond well to the sealed surface. If you plan to paint your item, apply the colours directly to the dry, unsealed casting, then finish with a compatible acrylic varnish.
• Pigments from coloured gypsum or plaster may bleed into the sealer during dipping. Colour-contaminated sealer may stain other pieces dipped in the same liquid. Always test a small piece first, use a separate portion of sealer for coloured items & do not return used sealer to the original container.
• Test on a small area first, as the colour may deepen slightly & the surface appearance may change. This product improves moisture resistance but does not make the casting fully waterproof.

Why Use Matt Penetrating Sealer?

• Reduces chalky powder transfer onto hands & other surfaces
• Helps control water & stain absorption
• Strengthens & stabilises porous surfaces
• Maintains a natural-looking, low-shine finish
• Helps compatible varnishes stay on the surface instead of soaking deeply into the casting
• Can reduce the number of finishing coats required
• Suitable as an economical base coat for compatible finishes or as a simple matt finish
• Water-based, low odour & quick to apply

How to Use? Make sure the casting is completely dry, clean & free from dust. Gypsum castings may take 2-4 days or longer to dry fully, depending on their size, thickness & environmental conditions.

1. Pour enough sealer into a clean container.
2. Dip the casting for approximately 10-30 seconds.
3. Remove it slowly & allow the excess sealer to drain back into the dipping container.
4. Apply a second dip coat if the material is highly porous.
5. Leave it to dry completely before handling or applying a compatible varnish, if required.

Suitable for: Gypsum, POP, casting plaster, eco casting powder, Jesmonite-type castings & porous cement crafts.