Renovate and furniturerefresh shutters or simply change of sceneryfaces the dilemma of either covering the old layer of protection, either pickle. On reflection, imagining a door smeared with multiple coats of paint that hide the grain of the wood, erase the detail of the moldings and ripple the flat surfaces with blocks, is really not satisfactory. It is therefore necessary to strip!
This article lists the various options to achieve this.
Regardless of the method used, stripping wood is a messy and potentially dangerous, which requires protecting the performer and his living space. Ideally, it is best to transport the construction site to the open air. If this is not possible, cover furniture and floors, open exterior windows and close interior distribution doors. Wear a headgear, waterproof gloves, long-sleeved shirt, dust mask and eye protection.
The tools needed
Some techniques may require specific equipment, which will be detailed in the corresponding section. In all cases, provide putty knives of different widths, screwdrivers, a wire brush, a stiff nylon or brass brush, a soft brush, a sponge, a bucket of water, abrasive paper, or steel wool and a vacuum cleaner.
To do a clean and efficient job, the pieces of wood must be cleared of all their accessories. For a perfect finish, take this opportunity to clean, deoxidize and protect them. Dismantle the hinges, the textile coverings, the latches, the locks, the corner protections, the hinges, the hinges, the cremones, the espagnolette, the handles, the security bars… Finally, anything removable !
To save precious time during reassembly, take care to mark the location of each screw by planting them on a piece of cardboard on which you will have marked their destination.
Mechanical stripping of wood
The mechanical stripping of paint is a long and painful operation. The dust raised may contain lead. Extremely dangerous for health, this metal was commonly used in the formulation of paints, until the beginning of the 1960s. To remove any doubt, do not hesitate to perform a test, available online or in DIY stores. If it turns out to be positive, wear a specialized filter mask and deposit the dust in a specialized recycling centre.
A sanderpreferably orbital eccentric and dust collection by aspiration, allows you to work faster, cleaner and without health risks. For manual sanding, the sandpaper block is an inexpensive tool, which greatly facilitates the work, respects the flatness of the surfaces and minimizes scratches in the wood.
In any case, print to your tool figure 8 movements, without excessive pressure and always in the direction of the grain of the wood. This gesture avoids tearing of the fibers and leaves the surface smoother. Start with a coarse grit abrasive, 60 or 70 grit for paint and 80 grit for varnish. Gradually reduce the grain size of the abrasive so as not to scratch the wood, when the paint is completely worn. Finish with a fine sanding with 180 or 220 grit to remove the last scratches from the wood.
As you have understood, the enemy of mechanical stripping is the scratching of the wood. To minimize this risk, eliminate the sanding particles after each passage or change of grains, by sweeping the surface, or better, by passing a vacuum cleaner nozzle with his brush. Finish with a damp sponge stroke, still in the grain of the wood.
Chemical stripping of wood.
Chemical strippers are generally aggressive liquids for support and dangerous for the operator and the environment. It is therefore imperative to take precautions and carefully follow the conditions of use published by the manufacturer. On the other hand, these products are of formidable efficiency. For the surfaces verticales or in ceilingprefer strippers in gelwhich do not flow.
Whatever the product, the implementation procedure varies little:
- Scrape the parts chipped or peeled off.
- Brush the paint with a stiff wire brush to scratch the surface.
- Apply a layer grasse stripper, using a paintbrush synthetic bristlescar les natural bristles melt.
- After a few minutes, the paint gondola, inflatedthen takes a aspect fripé. At this point, the pickling phase can begin.
- The painting must come sans effortwhen lifted by sliding underneath a putty knife. In case of multiple and old resistant layers, repeat the process, then finish with the nylon brush with hard bristles.
- Rinse with a sponge soaked in clear water or with a water jet, until all traces of the product have disappeared. Avoid rinsing with pressure washerwhich lifts the wood fibers, forcing the surface to be sanded.
- wait for deep drying (24/48 h)before sanding the surface, with fine sandpaper (220) or triple zero steel wool (for varnishes), always in the direction of the grain of the wood
In general, strippers, chemicals do not attack the wood, but exceptionally, certain species can blacken. For varnished surfaces, it is recommended to test the harmlessness of the treatment on a hidden part. Never wash them marquetry where the veneers at great water, under penalty of detachment.
Make your “homemade” stripper
There is a paint stripping solution, very simple to make yourself, natural, ecologicalsuitable for the most fragile surfaces and without risk for health.
To do this, combine 250 g of flour, 2.5 l of water and 250 g of soda crystals (or Saint-Marc washing powder). Method of preparation :
- Heat the flour in 1.25 l of water and allow to thicken, stirring, until thick.
- Dilute the soda crystals in 1.25 l of lukewarm water.
- Mix everything to obtain a ready-to-use gel.
This product is used as a chemical stripper.
Thermal stripping of wood
This technique involves the use of a heat gun. The use of a gas torch is possible, but difficult to implement. The risks of burn from the surface, even fromfire are real.
To get good results:
- Choose one suitable nozzle on the surface to be treated.
- Move the heat gun according to alternating, slow and regular movementsmaintaining a constant distance of +/- 10 cm paint.
- When the surface blisters, scrape the painting still warmusing a putty knife.
- Repeat the process until you reach bare wood.
This method requires a fine sanding before applying a new varnish. Avoid overheat them glass surfacesunder penalty of cracking orburst glass.
For objects of value or simply if this work puts you off, do not hesitate to call on the professionals of the sector. They have high-tech equipment (sanders or air gummers) beyond the reach of the best handyman and know-how offering the best guarantee, for an irreproachable result, in complete safety for your property and for your environment.