Are Sikkens coatings lead free?
Sikkens coatings do not contain any added lead.
Do shade cards and colour labels accurately represent the colour I will get on my timber?
Shade cards and colour labels should only be used as a guide. The following factors will all affect the final colour:
- The natural colour of the wood and any existing coating
- The texture and absorption of the surface
- The way the products are applied
- The build of the coating e.g. Sikkens Cetol HLS plus will look different to Sikkens Cetol Filter 7 plus
How much woodstain will I need to treat my windows and doors?
On average, every litre of woodstain will give two coats, indoors and out, on two partly glazed doors or four windows.
I have used another woodstain brand in the past, can I now use Sikkens to redecorate?
Providing the surface is sound, there will be no problems in applying Sikkens woodstains. Any peeling or flaking areas must be removed and any bare timber thoroughly sanded back to clean, bright wood.
Bare areas should be patch primed with a basestain such as Cetol HLS plus to even up the colour and then one or two coats of Cetol Filter 7 plus can be applied.
In warm, dry conditions, Cetol Filter 7 plus is touch dry within a couple of hours. Can I apply another coat the same day?
The simple answer is NO.
Water-borne stains, paints and emulsions can be overcoated as soon as they are fully dry and two coats can be applied in the same day.
Solvent-borne coatings undergo a two-stage process - firstly the solvent evaporates away (within 2-4 hours), leaving the surface dry to the touch; the coating then undergoes "oxidative curing", i.e. the resin/binder within the coating reacts with oxygen in the atmosphere to give a chemically hardened (or cured) surface.
This process can take as long as 12 hours and it is therefore essential that the coating is left to dry overnight before overcoating. Applying the second coat too soon can lead to wrinkling and a soft finish which can be easily damaged.
My fencing was dry and ready for staining, then it rained heavily for a whole day. Can I stain it straight away, or do I have to wait?
Although timber is a porous, absorbent substrate, it will not 'soak' water up like a sponge and therefore although the surface may be wet, the main body of the timber is likely to be dry.
While it is difficult to be precise, two good drying days should be adequate. If rainfall has been for a longer period, as much as one week or more of dry weather may be necessary for the moisture content of the timber to reach an acceptable level.
What is the lowest temperature at which solvent-borne (alkyd resin) coatings can be applied?
We do not recommended the application of solvent-borne coatings when the temperature is likely to drop below 5°C during application and drying.
What is the lowest temperature at which water-borne woodstains can be applied?
We do not recommended the application of water-borne coatings when the temperature is likely to drop below 8°C during application and drying.
Are there any special requirements for the application of water-borne coatings on timber substrates?
Water-borne coatings are quicker drying and have different flow/levelling characteristics to traditional alkyd based (solvent-borne) coatings.
We recommended the use of brushes designed for the application of water-borne coatings (i.e. synthetic bristle) and not to apply in extremes of hot or cold conditions.
Can water-borne coatings on wood be recoated with solvent-borne ones, or vice versa?
A water-borne coating is generally more flexible than a solvent-borne one, and preferably we would recommend recoating water-borne with water-borne.
However, providing that the existing finish is sound and fully dry, there is no problem with overcoating solvent-borne with water-borne or water-borne with solvent-borne.
How much woodstain will I need to treat my windows and doors?
On average, every litre of woodstain will give two coats, indoors and out, on two partly glazed doo
rs or four windows.
I have used another woodstain brand in the past, can I now use Sikkens to redecorate?
Providing the surface is sound, there will be no problems in applying these woodstains. Any peeling or flaking areas must be removed and any bare timber thoroughly sanded back to clean, bright wood.
Bare areas should be patch primed with a basestain such as Cetol HLS plus to even up the colour and then one or two coats of Cetol Filter 7 plus can be applied.
In warm, dry conditions, Cetol Filter 7 plus is touch dry within a couple of hours. Can I apply another coat the same day?
The simple answer is NO.
Water-borne stains, paints and emulsions can be overcoated as soon as they are fully dry and two coats can be applied in the same day.
Solvent-borne coatings undergo a two-stage process - firstly the solvent evaporates away (within 2-4 hours), leaving the surface dry to the touch; the coating then undergoes "oxidative curing", i.e. the resin/binder within the coating reacts with oxygen in the atmosphere to give a chemically hardened (or cured) surface.
This process can take as long as 12 hours and it is therefore essential that the coating is left to dry overnight before overcoating. Applying the second coat too soon can lead to wrinkling and a soft finish which can be easily damaged.
My fencing was dry and ready for staining, then it rained heavily for a whole day. Can I stain it straight away, or do I have to wait?
Although timber is a porous, absorbent substrate, it will not 'soak' water up like a sponge and therefore although the surface may be wet, the main body of the timber is likely to be dry.
While it is difficult to be precise, two good drying days should be adequate. If rainfall has been for a longer period, as much as one week or more of dry weather may be necessary for the moisture content of the timber to reach an acceptable level.
What is the lowest temperature at which solvent-borne (alkyd resin) coatings can be applied?
We do not recommended the application of solvent-borne coatings when the temperature is likely to drop below 5°C during application and drying.
What is the lowest temperature at which water-borne woodstains can be applied?
We do not recommended the application of water-borne coatings when the temperature is likely to drop below 8°C during application and drying.
Can water-borne stains and paints be removed using a hot-air stripper?
Yes, however, this is not an easy task. The preferred method would be to use a chemical stripper to soften the finish, remove with a metal scraper, followed by thorough sanding.
N.B. Naked flames (blow torch/lamp) are not recommended if a woodstain is to be used, as the timber surface can become charred. Furthermore, they can be a serious fire risk, and their use should be avoided.
Do I need to use a timber preservative before I stain my wood?
Many hardwoods such as Oak, Teak and Iroko, are naturally durable and have their own natural resistance to decay and rot.
Most softwoods and "cheaper" hardwoods are not durable and must be treated with a preservative if they are to be used outside.
Some of these timbers are treated in the factory to stop them rotting, but if this has not been done, Cuprinol Clear Wood Preserver or Cuprinol 5 Star Treatment are ideal for use as superficial preservative pre-treatments.
How do I remove lead paint?
Some old paint coatings may contain lead which is poisonous to humans and before removing or preparing existing paint coatings it is important to determine whether the paint concerned contains lead.
Remove all such coating materials in accordance with the appropriate legislation. A guide on "How to remove old lead paint safely" is available via the British Coatings Federation Ltd. (Tel. 01372-360660).
There are a lot of knots in the timber i'm using, should I use a knotting agent?
The phenomenon of resin exudation is both natural and highly unpredictable, being dependent both on timber species and timber grade/quality.
The traditional answer was to apply Shellac Knotting and 'seal' in the resin. However, many years of research and on site experience have shown that this method is not completely effective, even with paints, with which it is traditionally used. Moisture vapour permeable (sometimes referred to as microporous) woodstains such as the Sikkens Cetol range, attempt to deal with the problem in a different manner by allowing resin to filter through the finish without blistering or peeling , hence full protection is maintained.
In the short term, resin exudation tends to look unsightly, but within a year or so the excess resin becomes exhausted and exudation ceases. The initial resin should be cleaned from the timber using a lint free cloth dampened with cellulose thinners or methylated spirits.
I decorated my windows with a woodstain a year ago, but it is peeling off the putty, which is dry and cracked. Why is this?
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).
I have used Cetol Novatech on exterior cladding , but there is a brown stain under every nail?
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.
My plywood soffits looked great when I stained them with Cetol HLS plus a few months ago, now they look as though they've gone mouldy. What has happened?
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.
My windows are now very dark, but I would like to use a lighter shade. What can I do?
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 Cetol BL Opaque, Rubbol XD Gloss, Rubbol AZ plus or Rubbol Satura plus.)
Sikkens Cetol woodstains offer excellent protection without over-darkening any existing woodstain finish.
How do I remove any spillages?
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.
I don't want to colour the wood. I just want to protect it from the weather. What should I use?
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.
What causes blister formation in coatings?
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.