How to seal wood

2023 Author: Martin Macey | [email protected]. Last modified: 2023-05-21 06:41

If you have natural wood furniture and want to accentuate its natural beauty instead of painting it, sealing the wood can be a great way to accentuate the structure of the wood and protect the wood from external influences. Before sealing the wood, you must prepare it in such a way that the sealant adheres properly to the wood. The most common sealants are of three types: polyurethane, shellac and varnish, each of which requires its own method of application.

Steps

Method 1 of 4: Preparing the tree

Step 1. Sand the wood to make it smooth

Before applying polyurethane, the wood is prepared by sanding it.

• Using sandpaper, ranging from coarse to fine-grained, will remove large irregularities to begin finishing.
• Use the lowest grit sandpaper to finish smoothing the wood.
• Sand the fibers (just back and forth along the wood grain line) so that not even the slightest blemishes remain.
• Wear a face shield while sanding to avoid inhaling wood particles.

Step 2. Wipe off the sawdust to prevent wood particles from getting into the sealant and getting stuck in it

Use a dry cloth or special sticky cloth to remove dust from the wood.

• Avoid getting water on untreated wood, as it can change the structure of the wood.
• Use a dry cloth before using the sticky cloth, as the sticky cloth is designed to remove small particles that cannot be removed in the usual way.

Step 3. If desired, stain the wood before applying the sealant

You may want to stain the wood before sealing as this will not be possible after sealing.

• Rags are usually used for staining.
• Dab the stain with a damp cloth and let it soak.
• Then wipe it down with a dry cloth.

Method 2 of 4: Polyurethane Sealing

Step 1. Apply polyurethane to the wood

Pour polyurethane over the end of the wood grain of the ends of the wooden object and let it flow smoothly in all directions.

• Dampen a clean cloth with polyurethane and polish the wood surface.
• Polyurethane is a self-leveling compound, so it spreads itself in a fairly thin layer so you don't have to worry too much about how that layer will turn out.

Step 2. Spread the polyurethane over the entire piece of wood

Spread the polyurethane in long strokes with a clean brush or cloth (a cloth soaked in polyurethane is the easiest way).

• Apply extra polyurethane to the ends of the wood fibers (open cuts of wood at the end of the object) because this is the most absorbent part of the wood.
• Work from one side to the other, making sure that the polyurethane distributed on the surface of the wood creates an even and smooth layer.
• Wear gloves during this process to avoid contamination of your hands.

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Step 3. Apply several coats of polyurethane to achieve the desired result

Apply several coats of polyurethane to the surface of the wood, apply each subsequent coat after the previous one has dried.

• Watch out for drops of polyurethane and smooth them out to avoid an uneven surface.
• Sand between coats to smooth out unevenness.
• Apply layers of polyurethane until you achieve the desired result.
• After applying the last coat, use a thin metal washcloth to remove dust and polish particles from the last coat, however, if you are using glossy polyurethane, this should not be done.
• Drying times vary, so read the instructions for the polyurethane and keep an eye on the ambient temperature and humidity.

Method 3 of 4: Sealing with shellac

Step 1. Take a damp sponge to apply shellac

Shellac is usually applied with a wetted sponge.

Moisten the sponge with shellac as best as possible before use

Step 2. Apply shellac in stripes

When processing each strip, keep the edge of the sponge wet, work quickly on each wood surface, making one strip at a time.

• Start at one end of the wooden surface and work quickly on it, making sure that the sponge is always moistened with shellac when applying the stripes.
• Shellac is a tricky sealant to use because while you are working with one strip, the previous strip must remain wet.

Step 3. Do not interfere with the shellac drying process

Unlike polyurethane, you should not interfere with the drying process of shellac or do anything with it.

• Do not use steel wool.

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• Do not sand the shellac between coats.

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• Shellac absorbs each subsequent layer, creating a smooth surface as a result.

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• You can apply anything over the top of the shellac if you want a different desired result.

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Method 4 of 4: Sealing with varnish

Step 1. Before starting to apply varnish, figure out what it is

Varnish is a very durable coating that can be applied with a spray gun.

• A varnish spray gun can be purchased for not very big money.
• Varnish is a very high performance finishing material that dries quickly to a durable hard coating.
• It is not easy to apply to a layman and does not forgive mistakes made when applying.

Step 2. Apply the varnish in thin layers to avoid the "orange peel" effect

The varnish should only be applied with a spray gun in a very thin layer, avoiding the accumulation of varnish in one specific place on the tree.

• Press the trigger on the spray gun when you bring it closer to the object, move the spray gun over the surface, overlapping the previous painted area by about 50%, and release the lever as you go over the edges.

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• When spraying varnish, quickly move the gun back and forth across the surface.

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• Apply 3-4 coats of varnish in total, each time waiting for the previous coat to dry.

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• Do not aim the spray gun at one point for a long time to avoid drips and the "orange peel" effect.

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Step 3. Work in a ventilated area and beware of sparks

Make sure you take all the necessary precautions when spraying the varnish.

• The varnish is very toxic if inhaled, so make sure the area is well ventilated and wear a respirator.
• Also, the varnish is highly flammable, so beware of sparks.
• If you are using a fan for ventilation, make sure it does not spark.

Advice

• When sealing wood, make sure the fibers are well impregnated and protected from water ingress and damage.
• Use special wipes called sticky wipes to remove dust after sanding.
• Avoid rubbing wood with water to maintain the integrity of the wood fibers.
• If you want to end up painting the wood, don't use a sealant, use a primer instead. The primer is intended for wood surfaces if you intend to paint the wood later, and can be applied in one layer with a spray gun or brush.
• Always remember to sand.
• Use even strokes, no matter what type of sealant you are applying.