Tips & Tricks
Veneer finishing is probably one of the most delicate subjects of our craft and has been the cause of many tears. Finishing problems find most of the time their origin in combination of events which none of the actors were controlling fully.
Over the years, Finaspan has made up a good deal of knowledge. We have listed on this page the most commons situations and what actions to undertake to avoid problems.
If you wish to finish boards yourself, don’t loose of sight a couple of tips. First of all, never loose sight of the fact that veneer is not solid wood; it is barely a few tenths of mm thick and has had to be jointed one way or another and bonded to its substrates. This means that on the other side of this thin layer of wood you will find either glue or zig-zag, or both and you will have to avoid the finishing products crossing this layer and coming into contact with the adhesives.
In addition, never try to save on sanding before the application of stains and varnishes. Our boards are sanded with grit 120, but for a good finish it is recommended to prepare them successively with grit 150 and 180. From a general point of view, our panels are properly sanded, but we can never rule out that, due to circumstances (difference in thickness in the carrier, tension in rigid and thick panels, porous veneer), glue traces may remain somewhere. Before you start staining, make sure that the surface is completely free of glue traces and if necessary touch up until everything is gone.
There are also countless finishing products, but also countless types, which have evolved in countless different environments. Any combination can have unexpected results, for which we cannot necessarily be held responsible.
So, one last piece of advice: if you want to avoid unpleasant surprises, always take a test!
Is flake a defect ? This question is a matter of endless discussion but before answering, we have to explain to you what flake is exactly. And first of all, what it is not : a veneer defect ; and secondly what it really is : a perfectly natural occurrence .
In each tree we find very thin cells whose function is to redistribute the nutritive materials from the cambium ( sapwood ) to the heart. In hardwood species, these are called « medullary rays ».
By most species these rays are so thin as to be invisible. In some cases however, they show up clearly and are called « flake ». For example Oak, but also Lacewood, Louro Faïa and, to a lesser degree, Beech and even Mapleshow us a well pronounced flake.
These rays cross the growth rings with a 90 ° angle and because of the cut angle it is in quarter cut veneer that flake is shown to us with all its brightness.
Composed of hard and dense cells, flake is as fragile as crystal and doesn’t react to stains and lacquers as does the rest of the veneer ; for this it is unfairly criticised by those who wish to stain or lime Oak or, more simply, to speed up a lacquer finish.
For centuries however, Oak flake was appreciated and even sought as it was the distinctive sign of a valuable wood ; those who couldn’t afford to pay for it would even copy it by painting on cheaper wood …
Even if times are changing and, with them, our perception of things, Oak does not change ! It should therefore never be forgotten that flake forms an integral part of quarter cut oak veneer ; only a very small proportion ( +- 2 % ) of veneers produced from a log can claim for appellation « straight grain without flake » and even then, the start of a half crown on an edge will not always be avoided, except on true Rift production on a Stay Log machine, but in such case, the grain will never be perfectly straight : it will always deviate slightly to the end.
As these veneers are very rare, they are automatically most of the time very expensive …
Those who are looking for straight grain, narrow and without flake will find an advantageous alternative in Quarter Cut Larch or Oregon Pine.
Strangely, the market doesn’t build up the same presumption against flake in Lacewood or Louro Faïa : the larger the flake, the more these two species will be appreciated but, once more, this is not the most common occurence.
We have seen above how veneer was sliced in crowns and quarters ; in practice however, things are not so obvious : when you slice half a log indeed, there is a moment where the knife is reaching the core of the log ; as this part is unusable, the flitches will have to be opened in a first step , then, in a second one, the log itself.
The result ? a substantial proportion of veneer in half-crown and false-quarter ( +-30% ). It is therefore unreasonable to expect large quantities of boards in full crowns only ( neither in full quarters too ) in species where the market is not very large ; on the other hand, when you fade from the crowns to the quarters, you will also come across half-crowns which will have to be classified somewhere ; except by particular agreement, half-crowns are classified among Crowns.
Steaming has the objective to make the wood softer in order to make the slicing operation easier. But it also modifies its colour ; the art consists in trying to achieve the most uniform colour, regardless of the production or the origin of the batch. Steaming however is not an exact science and many factors come into play. Therefore you must expect some variation from one log to another. On the other hand it is important to note that, if some species are mostly steamed for slicing, they are not necessarily steamed for sawing ; colour variations between solid wood and veneer should therefore not always be completely excluded.
Some years ago, under market pressure ( mainly prices ) European Oak had been more and more replaced by North American Oak, finishing with a sometimes damaged reputation. Of course, American Oak was generally lighter in colour when it was freshly sliced, but, if European Oak was sometimes darker indeed, it was above all a question of drying ; with appropriate drying, it is perfectly possible to produce European Oak veneer of a fairly light colour. Meanwhile, all European producers have adapted their production process to the expectations of the market and the Oak veneer is now dried at low temperature what enables the veneer to keep its nice light colour. Actually it is more a matter of shades : American Oak is moving in the grey shades when European Oak is moving in the brown shades. With time, European Oak will actually take a much warmer sheen which explains why it has the favour of parquet flooring producers. In conclusion, don’t throw the anathema on one Oak or the other according its origin ; simply learn to appreciate good things and make your choice in function of objective considerations.
Just before cutting the boards you discover some defect or a character that you don’t like. Please hold on ! Under all trade agreements, a cut board is an accepted board. If it doesn’t suit you for whatever reason, pass the message to us and let’s agree together over the next step. A board that you send back will have a certain value for the producer. Once cut and refused afterwards, it has no value for anybody else which will just increase the bill.
Whether you are a distributor or a user, sooner or later you will be required to store decorative veneered panels : protect them well ! These panels do not always stand up well to a long period of storage, as the veneers are sensitive to light, moisture and dust. A simple cardboard covering will therefore only protect your boards during transport or during 2/3 weeks in storage. If some of your panels are likely to remain in storage for a period of months, it is important that you protect them with a covering panel, preferably rigid, or at the very least applied over the entire surface and held in place with a certain amount of pressure to prevent damp air or dust from spoiling the veneer.
During the slicing process, the pores of the wood are cut on an oblique angle and reflect light differently according to the incidence angle. A lighter coloured strip will appear darker if looked from the other side of the panel and vice versa. A clear lacquer will only make this phenomenon more obvious; this is particularly visible on quarter cut veneers. If this light and dark effect disturbs you, ask for a slip matched or a random matched veneer. The differences of colour will be minimal but above all the repetitive effect will be gone.
The bubbles indicate the presence of moisture during the application of the final coat, possibly with a spray gun. The water repels the lacquer and then evaporates, leaving small bubbles or craters. Resand and start again, taking care to work in a dry environment.The bubbles indicate the presence of moisture during the application of the final coat, possibly with a spray gun. The water repels the lacquer and then evaporates, leaving small bubbles or craters. Resand and start again, taking care to work in a dry environment.
The stain has come into contact with the layer of glue bonding the veneer on the substrates. It is possible that this is due to bleed through of glue, but it is also possible that the veneer has been over sanded or that the stain has penetrated too deeply. If you are faced with a problem like this and are caught by time, there is however to get rid of the problem quite easily.
Most stain producers manufacture what could be called an "isolator". This is a product that is applied as an under coat and which fills the bottom of the pores of the veneer in such a way as to create a uniform barrier at a depth of 0.2 / 0.3 mm over the entire surface. Next, the stain can be applied as a second coat: obviously, it will penetrate less deeply and the contrasts will no doubt be less marked, but the stain will be more uniform and free of blotches.
The colours of most species of wood are each more beautiful than the next. They are not permanent, however, and will change under the effect of light and moisture. Paradoxically, light species will become darker and dark species will become lighter. In fact, over time, all species turn grey ! Hence the importance to avoid direct exposure to sun light and to apply a good finish protecting the wood as well as possible from both UV and humidity.
Certain species, however, take a few days for the fullness of their splendour to show. This is true of African Mahogany ( Khaya ) and European Larch, which both take on their brighter sheen after a matter of months or years.
The colours of most species of wood are each more beautiful than the next. They are not permanent, however, and will change under the effect of light and moisture. Paradoxically, light species will become darker and dark species will become lighter. In fact, over time, all species turn grey ! Hence the importance to avoid direct exposure to sun light and to apply a good finish protecting the wood as well as possible from both UV and humidity.
Certain species, however, take a few days for the fullness of their splendour to show. This is true of African Mahogany ( Khaya ) and European Larch, which both take on their brighter sheen after a matter of months or years.
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