Applying sanding sealer is a vital step in finishing high-quality furniture and trim. Sanding sealer gives an added layer of protection to the wood and creates a nice smooth finish. It can be used on stained or unstained wood. Staining or leaving the wood natural is your first step in finishing.
“As for a sanding sealer, I usually just use shellac. Typically a 1 lb cut. There are two ways to do this. I either buy pre-mixed shellac (Bullseye SealCoat), and dilute it from 2lb cut to 1lb cut.
A sanding sealer must be applied after the stain but before the finish coat because otherwise it would prevent the stain from penetrating.
I would always suggest you avoid sanding sealers unless you have a specific reason to use one. Sanding sealers place a clear base coat between the wood and finish. But because the sealer is formulated to build fast and be easy to sand it can often be softer than the top coat which is problematic.
But polyurethane doesn't bond so well over finishes marketed as sealers, especially over sanding sealer. This sealer is good for use under non-polyurethane varnishes because regular alkyd varnishes gum up sandpaper. So to speed production, a sanding sealer can be used for the first coat.
If you don't sand between layers of polyurethane, the surface may become streaky or discolored. This formula prevents chemical solvents from bonding to it. Once the first layer of paint is dry, you can apply a second coat to make sure everything remains. Each coat of oil-based polyurethane finishes is applied on top.
Sanding sealer is a clear liquid base finish that is applied to bare natural wood or to any uncoated wood product. Sanding sealer always must be sanded down smooth after it has dried. Sanding sealer helps improve the condition of subsequent coats of paint or clear finish by sealing the wood pores.
Upon exposure to excess moisture, wood flooring can stain, warp, and split. This kind of damage is expensive to repair, which is why many buyers look for any protection they can get. Sealing your engineered hardwood floors creates a moisture barrier that prevents leaks and spills from seeping into the wood.
A sanding sealer is not the same as a wood conditioner. Whereas a wood conditioner is a pre-stain treatment that reduces blotchiness when staining, a sanding sealer is applied only to bare wood that is not going to be stained.
We recommend no more than 1-2 coats, then finish with 1-2 coats of topcoat.
The thin viscosity makes it easy to spread and allows it to penetrate into porous woods. To start apply 1 thin coat and allow it to dry. Lightly scuff sand to remove any raised grain fibers, then apply an additional 1 to 2 coats to seal wood and provide an excellent surface that will be ready to topcoat.
These back marks are called metallic discoloration, or iron stains, caused by elemental iron reacting with phenolic chemicals in the wood, forming black iron tannates. Iron stains require the presence of iron, water, and wood and will not occur if one of these elements is absent.
Sand Thoroughly
When preparing wood for stain, you'll need to sand its surface. Use a sanding sponge or orbital sander. Sandpaper with a lower grit number will make wood rougher, allowing more stain to absorb and creating a darker color. Start with 120-grit sandpaper for pieces that already have a finish.
Ingestion May cause nausea, headache, dizziness and intoxication. Skin contact This product is rapidly absorbed through the skin and may cause symptoms similar to those of ingestion. Repeated exposure may cause skin dryness or cracking. Eye contact Causes serious eye damage.
Lightly sand the surface with 220-280 grit sandpaper. A powder should develop when sanded. Do not over-sand to avoid removal of the sanding sealer or previous stain.
Regular readers will know that we do not recommend over-thinning the Cellulose Sanding Sealer; it's a common myth that it needs to be thinned 50/50 to work better, but as a general rule this is incorrect.
The main difference between an undercoat, sealer, and primer is that primers are applied to a new surface, while sealers are used as either the substitute to a primer or they are applied before the primer. An undercoat is typically used on a surface that has already been painted.
If you're just using a regular stain, it can provide some degree of protection compared to totally unfinished wood. But it isn't good enough. If you set a drink on a piece of wood that you've stained by not sealed, for example, it's going to leave water rings that you can't wipe out.
With regular wear and tear, the finish on your hardwood floor should last about 7-10 years. Floors in high-traffic areas or that are exposed to a lot of sunlight may need to be refinished more often. So if we do some quick math, your hardwood floors will last up to 60 years with being refinished every ten years!
Sanding Sealer is not recommended as a final finish because it is not as durable as a topcoat. Seal Sanding Sealer with any General Finishes water-based topcoat, EXCEPT General Finishes Enduro- Var, for improved water and chemical resistance.
After you've sanded the wood go over it with a rag to wipe it down and remove any excess material. While you can use any cloth to do this, a tack cloth will pick up the most dust. If you don't wipe down the wood before you apply your stain, you can cause uneven parts and blemishes.