What Is The Difference Between A Sealer, A Varnish And A Stain?
• A sealer penetrates deep into the wood and allows it to expand and breathe. If the wood has been previously treated with a sealer, you don’t have to remove it before applying a new coat. Finish can be matt or sheen.
• A varnish does not penetrate into the wood, but forms a thin layer on the surface. Old vanish layers need to be removed before applying a new coat. Finish can be matt, semi-gloss or gloss.
• A stain decorates and colours the wood, but does not give adequate protection. Wood needs to be coated with a sealer or a varnish to protect. The more stain applied, the darker the end result will be.
Approval From The Hans Merensky Foundation
The main objective of the Hans Merensky Foundation is to promote and assist in the development of the resources of South Africa and neighbouring territories, particularly such natural resources as soil, water, minerals, flora and fauna, and to promote the health and welfare of the inhabitants; more specifically by research, experiment and demonstration and through the correlation and application of scientific knowledge.
The foundation annually makes a large investment in agricultural research and development. However, the foundation does not limit its investments to financial contributions, but actively involves itself in the transfer of knowledge to and the development of skills of all people at all levels employed by the Foundation. Success over the years has also been shared with other growers, thus carrying out Dr Merensky’s will.
Nova 14 Novaseal and Nova 16 Novaglow both carry Merensky Foundation recommendation.
General Tips For Better Coating
• Read the instructions on the pack before starting any project
• Good surface preparation is the key to a good finish. Surfaces should always be prepared according to the instructions on the pack.
• To avoid colour variations, products of the same batch should always be purchased. Always test that the colour purchased corresponds to the colour required. This test should also be done for matt and gloss finishes.
• In the case of any doubt, contact us for professional advice. Remember, if in doubt … ask, that’s what we’re there for!
Various types of wood accept stains differently, making experimentation a necessity. Firstly, select the desired colour and apply it according to the directions. Areas that have been filled may not take stain as readily as the surrounding wood, therefore, it is necessary to experiment with those areas to obtain the desired results. For example, the knots in knotty pine will absorb very little stain, whereas the other areas will soak it up. Experiment with scraps of wood or hidden areas of your project to determine your final colour finish.
Stains are difficult to remove and often require repeated applications. You may be trying to remove what appears to be a stain, but is actually a paint primer or wood filler. Experimentation is necessary to obtain the best method for your particular situation. Remember to always observe proper and adequate ventilation procedures and follow all cautionary statements precisely. After you have completely finished the stain and/or removal process, allow the area to dry for 24 hours prior to sanding and starting the next phase of refinishing.
Any of these methods or combinations of methods may work in removing stains:
• Apply a coat of Nova 8 Novastrip and allow it work for 5 to 10 minutes. While still wet, scrub with steel wool. Do not allow it to dry out on the surface.
• Mix one part household bleach to eight parts Nova 8 Novastrip. Apply to the surface and allow to work 10 to 15 minutes, then scrub with steel wool.
• Bleaching out the stain might be accomplished by using straight household bleach or oxalic acid. Repeated applications may be necessary in order to obtain the desired shade or tone. Oxalic is not as strong as household bleach, therefore it will not lighten with wood as much. Apply the bleach or acid and allow it to set for 10 minutes. Scrub the bleached area with a No. 2 grade steel wool or a scrubbing brush.
• Wet the surface with warm water. After it raises the grain of the wood, allow the surface to dry thoroughly, then sand. This process, like others, may require repeated application until the amount of stain you desire to remove has been accomplished.
Years ago, furniture manufactures used a variety of wood in making furniture. They used wood fillers to fill in the pores and rough grains in the odd assortments of wood. The wood filler used was generally off white or cream coloured. They then applied a coat of stain and/or varnish stain to the surface, followed by the finish coats which were usually lacquer-based products. Note; when stripping these objects, should you run into variegated surfaces which look like wood filler, at this point there is nothing you can do but sand the surface to bare wood and restain the piece with Nova 18 Novadye, followed by the application of Nova 17 Novathane. Do not attempt to remove the wood filler foam from the surface.