The use of linseed oil putty for glazing in conjunction with Sikkens woodstains is not recommended.

Putty contains drying oils which are necessary in order for the compound to remain pliable. These oils migrate into the timber and oxidise with the atmosphere unless the compound is sealed by a film-forming system, such as a traditional gloss paint.

Sikkens systems are moisture vapour permeable, and therefore do not seal the glazing compound. The resulting loss of the oils allows the glazing compound to dry and crack, causing a failure of the glazing seal. For this reason we recommend the use of approved elastomeric sealants (polysulphide, silicone or acrylic).

Because of the vapour permeable nature of Sikkens woodstains, iron or steel nails are not ‘sealed off' from air and moisture, thus rusting of the nails can still occur.

Rainfall then washes the rust away and is seen as a brown ‘tear-like' discolouration of the timber. Any loose or rusty nails, screws, etc. should be replaced with galvanised or non-ferrous fixings, which will not corrode, even if exposed to the weather.

Wherever possible it is preferable to use lost head nails, but if this is impractical, nails should be punched home and any remaining holes filled with a suitable woodfiller.

The white deposits found on the plywood surfaces are sodium salts which originate from within the glueline of the plywood.

During the board manufacture, caustic soda is added to the glue mix to render the adhesive more soluble in water. Once the glue is cured, the caustic soda becomes superfluous. Under the influence of atmospheric moisture, it can migrate to the plywood surface and appears as a white crystalline powder. In the normal course of events, the action of rainwater washes these salts away and they are rarely visible. However, in sheltered areas, such as soffits, the salts are not removed by rain action and remain as a ‘bloom' on the surface.

The remedy for this is to wash down the affected areas with clean water and a bristle brush (not metallic bristles), thereby removing the salts. Provided that the finish is not damaged by over-vigorous scrubbing it need not be re-treated. It may, at some time in the future, reoccur to a lesser extent before the salts are fully depleted. Again, removal is by washing. This phenomenon seems to vary with the type of plywood and country of origin. It should be pointed out that the loss of these salts in no way affects the strength or integrity of the plywood and does not blister or crack the finish.

In order to highlight the natural features of timber, woodstains are translucent (i.e. semi-transparent).

The final shade achieved is a combination of the colour of the surface to which they are applied and their own pigmentation. A light coloured wood stain onto a dark surface will therefore always allow the dark colour to be seen, and thus the finish remains dark.

To achieve a lighter shade requires either stripping of the existing finish and re-coating or the application of an opaque, paint-like coating (such as Rubbol AZ or Rubbol Satura.)

Sikkens Cetol woodstains offer excellent protection without over-darkening any existing woodstain finish.

Care should be taken to avoid spillages on to glass, cement, brickwork, carpets, clothing etc.

If spilled, solvent-borne coatings should be removed immediately while wet using white spirit.

Water-borne coatings should be removed using a warm detergent solution. Once dry, the coatings will be very difficult to remove without damage to the surface.

Using a coating with no colour and expecting it to work well is like using sunglasses with no shading.

In order to protect timber from the effects of sunlight (and ultra violet light in particular), it is necessary to reduce the amount of light reaching the surface. In order to do this, the coating must contain a pigment/colour, which by their very nature will alter the appearance of the timber.

In addition, clear finishes have less protection for themselves from sunlight, and may become brittle, peel and crack, leading to extra work at redecoration.

Sikkens Cetol woodstains offer the ideal compromise between protection and colour, giving long-term protection with an easily maintained coating, along with a translucency which enhances the natural features of the timber.

Blisters in any coating form as the result of isolated areas of poor/insufficient adhesion of the coating to the surface beneath.

This phenomenon occurs especially in warm and sunny weather, and is often related to the expansion of air in the wood pores, the gassing of gums or resin, or the evaporation of trapped moisture, which pushes the coating film away, shortly after application.