DK169613B1 - Process for cleaning woodwork - Google Patents

Abstract

A process for cleaning and preserving both old and new woodwork. The process involves workpieces made of wood being immersed in hot (150-250 degrees centrigrade) vegetable oil. This thereby softens or dissolves the adhering layers of paint, and any remnants which do not become loose are removed by relatively gentle mechanical cleaning. When this method is used, all the profiles and markings in the woodwork will, after the cleaning, appear as sharp and precise as immediately after manufacture. Adding fungicidal chemicals to the oil will ensure that the wood will subsequently be resistant to such attack. Attack by insects or by fungi will likewise be disrupted due to the high temperature, which can also be achieved in the middle of the workpieces by immersing them in the hot oil for a relatively long period of time. The drying process after the treatment can be accelerated by drying the workpieces in a hot chamber. In the case of window frames with glass in them, for example, these frames can be heated (for example in a hot chamber) before being immersed in hot oil, so as to avoid shock stresses in the glass which are associated with the immersion. The glass remains intact and the linseed oil putty is softened for the glass to be disassembled, where appropriate. Vegetable oil (for example linseed oil) expands during hardening and will therefore help to strengthen the structure of the wood and stabilize joints in the workpieces. Even relatively rotten wood becomes solid again. It is not necessary to dismantle fittings (for example hinges in the case of windows) because the hot linseed oil also penetrates in under these fittings, and, in this way, it is possible to cut down on what is a substantial procedure when renovating windows. The method is also suitable for workpieces (panels, doors) in historical buildings which may have been attacked by fungi and/or which are only to be cleaned. This method is also well-suited for impregnating new woodwork. Colour pigments can be added to the oil, such that the priming process in normal painting treatment can be omitted. A siccative is added to the oil in order to promote drying of the oil which has been applied by the immersing and which has penetrated in.

Description

The invention relates to a method for cleaning woodwork whose surface has previously been treated with paint.

It is known to clean woodwork for old paint by manually scraping the paint, which, however, requires significant mechanical force on the wood by the operator. However, this is not appropriate because the impact of force can cause scratch marks in the wood, possibly deformation or destruction thereof, especially if the wood is already weakened.

The object of the invention is to provide a method of the above-mentioned type, which enables cleaning and priming of the woodwork in a more gentle and inexpensive manner than hitherto known, since the paint must be removable with little mechanical force, the articles must be able to be cleaned successively and divided into individual 15 sections, any residue of the cleaning fluid in or on the woodwork must be able to be a natural part of a subsequent paint treatment, and no disassembly of 20 fittings mounted on the workpieces must be required to impregnate the hidden woodwork as the cleaning fluid via the tree penetrates behind the brackets.

The process according to the invention is characterized in that the woodworking objects are dipped preferably in hot vegetable oil, preferably linseed oil, heated to 150-250 ° C until the paint is dissolved or loosened and can be cleaned by lighter mechanical action. Thereby, it is achieved that a subsequent mechanical cleaning with a trowel, brush or the like can easily be done without damaging the items. Profiling and finer details of the workpieces will, 30 after the cleaning, appear clean and sharp, when the workpieces 2 were new. Linseed oil kits by e.g. Window glass will also be softened by the hot oil and will therefore be easy to remove. The oil penetrated into the blanks will, after a natural drying-off, thereby give the wood and any joints some stiffness. The subjects will be very little inclined to settle. It is unnecessary to remove brackets and the like on the items, because the oil easily penetrates behind them. Once the paint is removed, oil residues on the blanks will form a primer layer upon which new paint can be applied if desired.

An embodiment of the method according to the invention is characterized in that the immersion in the warn oil is carried out so long that at least oil penetrates into the wood, thereby obtaining a particularly effective softening of not only old paint but also linoleum kits on the blanks so that particularly effective cleaning is possible.

According to the invention, the wood in connection with the immersion in the oil for dissolving the paint can be heated so much that the temperature in the interior of the woodwork exceeds the living conditions of timber sponges. This provides yet another means of combating fungus-20 pest attacks on and in subjects from construction and housing.

According to the invention, the wood in connection with the dipping in oil for dissolving the paint can be heated so much that the temperature in the interior of the wood exceeds the living conditions of the insects, thereby effectively fighting back any insect attacks.

According to the invention, the vegetable oil used may contain fungicides to obtain a fungus-resistant wood surface. This design of the method has also proved very effective.

Yet another embodiment of the process of the invention is characterized in that the oil used contains drying (siccative) to promote the drying of the oil which has penetrated into the blank at dipping, thereby ensuring an effective drying of the oil on and off. the topic.

Still, according to the invention, the items prior to dipping in the hot oil can be subjected to preheating, thereby preventing iced glass (e.g. on window frames) from leaking at the dipping in the oil. In the case of window frames with antique glass, preheating can be done by lowering the items in lukewarm oil so that the glass is not exposed to shock stress and thus remains intact. Optionally, window frames plus glass can be preheated in a heating chamber.

Finally, according to the invention, the blanks can be exposed to heat after dipping in the hot oil, e.g. in drying chamber. During drying / curing, e.g. linseed oil through the uptake of oxygen molecules expand by 5-10%. This results in a stiffening of the inner structure of the wood, so that the wood becomes firm again and again 15 can be machined mechanically. Collections, e.g. loss joints at windows will become tight and firm.

The invention is explained in the following with reference to three embodiments.

Example 1 20 15 window frames bearing old paint were sequentially cleaned by the method of the invention. The cleaning was done by immersing the window frames, after their glass was broken, for approx. 15 minutes in a 180 ° C hot bath containing linseed oil. After taking the bath from the bath, the frames were cleaned of paint and putty residue using a putty, as the old paint had become soft and could be easily scraped off. Some of the paint and the kitten fell off themselves in the bath. The last remains of paint and putty were removed by mechanical brushing. 1

Then the window frames were placed in the drying chamber for approx. 24 hours to promote oil drying. In addition to dissolving the 4 old paint, the oil also penetrated under brackets and into the joints of the wood, e.g. at splinters and in corner joints, whereupon after drying, a strengthened (harder and denser) wood surface at these sites. The old paint on the woodwork consisted of several layers of oil paint (based on natural oils) and synthetic oil paint.

During treatment, the window frames were neatly clean and this was achieved without the frames breaking. The treatment could be carried out so gently that there were no unfortunate scratch marks to look for the mechanical part of the cleaning process.

Example 2 10 window frames with old paint on and fitted with antique glass were preheated in heating chamber by gradually increasing the temperature here from room temperature to approx. 120 ° C.

15 Then the window frames were immersed one by one in approx. 190 ° C hot bath of the same nature as in Example 1. After approx. For 20 minutes, the window frames were taken up and then subjected to mechanical surface cleaning as in Example 1.

The cleaned window frames could easily be freed from the antique glass, 20 without breaking it. The frames now appeared neat and clean and could easily be mounted in their old space in the building they had previously been in and which was undergoing renovation.

Example 3 25 window frames similar to those mentioned in Example 2 were treated in the same manner as in Example 2, with the bath temperature being approx. 200 ° C. Re-heating of the frames in the drying chamber was carried out at approx. 50 ° C. The pre-cleaned window frames got a nice appearance and their surface became suitably hard so that a paint-ready surface was obtained, similar to a traditional one.

Claims (8)

A process for cleaning woodwork whose surface 5 has been previously treated with paint, characterized in that the woodwork is dipped in hot vegetable oil, preferably linseed oil heated to 150-250 ° C until the paint dissolves or is dissolved and can be cleaned through lighter mechanical impact. A method according to claim 1, characterized in that the immersion in the hot oil is carried out so long that oil penetrates at least a bit into the tree. Process according to claim 1 or 2, characterized in that the wood is heated so much as to allow the temperature of the wood to exceed the living conditions of the sponge in connection with the immersion in the oil for dissolving the paint. Method according to claim 1 or 2, characterized in that the tree is heated so much as to immerse the insect's living conditions in connection with immersion in the oil for dissolving the paint. Process according to one or more of claims 1-4, characterized in that the vegetable oil used contains fungicides to obtain a fungus-resistant wood surface. 5 grounding. Claims. Process according to one or more of claims 1 to 5, characterized in that the oil used contains drying (siccative) to promote the drying of the oil which has penetrated into the workpiece during dipping. 6 Process according to one or more of claims 1 to 6, characterized in that the blanks are subjected to preheating prior to dipping in the hot oil. Method according to one or more of claims 1-7, characterized in that the articles are exposed to warnings after dipping in the hot oil, e.g. in drying chamber.