If you have questions about how to protect and preserve your wood, please check out the FAQ's below.

Can you apply an alkyd (solvent) based product on top of an acrylic (water based) and vice versa?

Yes. However, it is extremely important that the old layers are completely dry. If they are not, the layers can work against each other and result in a cracking surface.

What does the Slow Release technology do?

The Slow Release technology is active only during high humidity and counteracts the growth of mould. This means that the active ingredients are only taking effect, when it is needed. When wood is attacked by mould growth, the humidity in the wood increases considerably.

Is there any difference in the layer thickness when using oil base or water based?

When using water based products, you have a tendency to increase the coverage too much and thereby reduce the durability. You simply spread the product on a larger area than inteded (more m2/liter). Therefore it is important that you try to apply rich layers according to the on-can instructions and instructions stated in the Technical Data Sheet. Normally, you will not experience these problems with solvent based products, as the friction is higher than for water based products.

What is the function of the pigments in the products?

When you use a transparent product, the rays from the sun will be reflected from the base of the wood and the pigments, because the wood protection is transparent. When you use an opaque product, the sun’s light will only be reflected from the pigments. The more pigments, the better protection.

Can I use a clear/transparent wood protection outdoor on its own?

Clear/colourless wood protection products are available, but the durability is significantly lower compared to products, which contain (colour) pigments. In order to compensate for the ’missing’ pigments, anti-UV agents are used (as in sunscreen), but these are far less effective and also very expensive. If you use colourless wood protection, you need to apply min. 3 coats.

Can I use products with fungicides/insecticides indoor?

PPG does not recommend the use of products containing fungicides for indoor use unless there are special circumstances.

What is special about preservatives?

Wood preservative products are made of active ingredients, additives and solvents. Active ingredients have fungicide and/or insecticide properties. They are fixed to the wood through fixatives. Both penetrate the interior of the wood through the solvent, which acts as a vehicle. Their main properties include: effective action against
degrading agents, product stays in the wood and protective action continues for a certain time. The preservative is often neglected in wood protection systems. However, if you use a preservative you will ensure: improved adhesion of the top coat, reduction of moisture absorption and biological protection of the wood. Normally, you will only need to apply a preservative on softwood (spruce, pine, fir) and not on hardwood (mahogany, teak etc.).

Preservatives on new wood
New, untreated wood should not be left for too long without treatment. The natural degradation of wood starts on the first day the wood is outside. New wood may be infected by mould, which is not visible to the naked eye. If you are in doubt, clean the wood with a suitable detergent before applying treatment.

Preservatives on previously treated wood
If the wood protection looks worn down and has started peeling off, it is time to give the wood a new treatment. Check the wood before treating it:

• Rotten wood must be renewed
• Water traps must be mended by leading water away from the wood
• Mould and incrustations must be removed with a cleaner

Preservatives on wood attacked by insects and/or wood worm
Remove all the previous finishes such as paint, coatings and varnish. Strip the surface or brush off any decayed parts. Treat all wood surfaces two times or submerge the wood in the preservative for a couple of minutes.  Treat all wood, which is in contact with other wood, their respective joints and parts embedded in walls. Replace
any parts, which are excessively affected and thereby weakened.

Which products are best for outdoor use?

Depending on taste and climate: water based, hybrids and solvent based products. Each have their advantages and downsides.

What is the difference between a translucent wood stain and an opaque wood finish?

In general you can say that the more pigments there are in the product, the better the protection is. A transparent product/material will reflect the sun’s rays both from the wood underneath and from the pigments, because the coating is transparent. When you have applied an opaque product, the light is only reflected in the pigments in the product. The purpose of a transparent product is to leave the wood grain visible.

How do I find out, whether my new house was treated with a water based or a solvent based product?

When you try to assess, if the treatment applied is water based or solvent based, you can rub a little white spirit on the surface. If the coating dissolves, the surface has been treated with a water based product. If the coating does not dissolve, it is likely that the surface has been treated with a solvent based product.

The filler is visible through the surface treatment...why?

If the colour of the filler is lighter than the colour of the top coat, remember to sand after you have applied the filler.

Can I apply on top of linseed oil?

No. If you apply wood protection on a surface, which has previously been treated with linseed oil, the new top coat will bubble. Linseed oil does not work with modern wood protection - this applies to both water based and solvent based wood protection products. If you want to apply wood protection on a surface, which has  previously been treated with linseed oil, you need to remove the layer of linseed oil first plus an extra milimeter. This is extremely important in order to get a good result. Linseed oil can be removed with a special lava- or (dry ice rinse), or it can be sanded down. However, if the linseed oil has burned off (it does that rather quickly), the best solution is a thin solvent based product - no cleaning needed.

What are wood preservatives?

Wood preservatives contain a fungicide and an insecticide for maximum protection. The main characteristic of the wood preservative is that it penetrates deep into the wood to prevent both fungal and insect attacks. Wood preservatives not only have preventive properties, but can also cure already infested areas.

What is wood protection?

Wood protection products can be divided into two categories: translucent and opaque. The translucent, pigmented stains are translucent coatings, to which insoluble pigments are added. They form a translucent film with a coloured tint, through which the underlying wood grain is visible. Opaque wood protection is covering coatings - the entire colour film is pigmented and the underlying wood is no longer visible. The majority of the PPG wood protection products contain fungicides, which offer surface protection against fungi and mould.

What is a varnish?

A varnish is a clear, transparent, hard coating or film. It is not a stain... Varnish is primarily used as a wood finish, where - stained or not - the distinctive tones and grains in the wood are intended to be visible. Varnish finishes are naturally glossy, but satin/semi-gloss and flat sheens are available.

What is an oil?

Oils are normally used for wooden decks and garden furniture. The difference between oils and wood protection
is that the oil will not form a film on the treated surface, but will penetrate into the wood. This is especially preferable for wooden decks, where you would notice cracking of the film, if a regular wood protection product had been used.

Why is it important to use products especially designed for outdoors?

The PPG outdoor products contain fungicide for optimum protection of the outdoor wood against mould and fungi. As these ingredients are of a chemical origin, we do not recommend indoor use