Environment-Friendly Aircraft Paint Strippers
Paints protect aircraft from harsh weather conditions and need to be reapplied from time to time. But removing paint from old aircraft can be tricky because there are several coats involved and it is strong enough to endure severe weather changes for years. Conventional chemical compositions that have been used in the past are too toxic and dangerous for the workers and environment. Industrial aircraft paint strippers today need to comply with the U.S. EPA rules on emission.
Industrial grade paint strippers are used not only for aircraft but also for military vehicles, ships, trains, buses, buildings, graffiti and more. They need to be non-toxic, environment friendly and biodegradable. Toxic compositions in the past included methylene chloride, formic acid or carbonic acid among others.
Good paint strippers are the ones which can be applied to several kinds of surfaces without causing any damage to the underlying surface. They should work on metallic surfaces like aluminum, cadmium, magnesium, steel, titanium, and zinc and other surfaces like fiber glass, ceramic, cement, concrete, plaster, stone, wood, mason, brick and Proseal.
Some commercial grade heat guns are also very good at stripping paints. To know about the best heat guns you may check the articles of this site: bestheatguns.com
Water-borne aircraft paint stripper is a new technology that does away with dangerous chemical based ones. It is non-acidic, non-flammable and environment friendly. It does not cause hydrogen embrittlement and does not pollute the air. It is very effective in removing Proseal, the aircraft adhesive.
Starch is a very good aircraft paint stripper that is environmentally benign. Abrasive wheat starch particles are propelled by compressed air to remove the paint. The operation is safe enough to be conducted in open maintenance workspaces and aircraft hangars. Starch blasting works on both aluminum and composites. An advantage of this method is that it can remove both paint and primer at one go. Other methods rely on selective stripping – a difficult process.
Another alternative to toxic chemical strippers is plastic media blasting. Unlike sand or abrasive blasting that can potentially ruin sheet metal beyond repair, plastic medial blasting uses low air pressure and non-abrasive techniques. It is capable enough of removing paint, undercoating, old plastic fillers and literally blowing off heavy rust. It is a safe, quick and economical way of removing aircraft paint.
Some other methods of aircraft paint stripping are:
- High pressure water blasting
- Water blasting with chemical paint softeners
- Ice pellet blasting using carbon dioxide (with and without chemical paint softeners)
- Thermal paint stripping
- Wet media blasting (using sodium bicarbonate)
- Chemical paint stripping
Most chemical paint strippers are designed to be applied using sprays or brush. They need to be approved by EPA standards for safety of the workers and environment.
Types Of Air Craft Paint Strippers
Every two years the surface paint on commercial and military aircraft must be stripped off. This is to enable checking of the condition of the aluminum substrata beneath the underlying layer of paint. It is important to check the condition to ensure operational status of the aircraft. Basically three types of aircraft paint strippers are used to depaint aircraft. They include physical, chemical, and thermal paint strippers.
Physical strippers are in the form of sand which is used to blast the aircraft surface to remove the paint. For this a sand blasting machine is used. The sand is made to impinge upon the surface with high force. It removes the paint on the surface. The time taken to strip the paint off with the sand blasting approach is less than with chemical strippers. However, this method is not preferred because of the comparatively greater cost of stripping.
Chemical strippers involve the use of chemicals to strip the paint from aircraft. This approach has been used for the last so many years to effectively strip paint from aircraft at low cost. Earlier methylene chloride was the most widely used chemical used for aircraft paint stripping. However, its con is that it is bad for the health of the workers who are employed for the paint stripping operation. Methylene chloride has also proved to be hazardous for the environment. It results in environmentally hazardous waste products.
The US Environmental Protection Agency (EPA) has therefore banned the use of methylene chloride. It has also banned every other such chemical that proves to be a danger for the environment and/or the people. The exclusions list includes 189 chemicals.
Faced with this guideline from the EPA, a number of other chemicals have been developed by innovators that are biodegradable, environment-friendly, and also are safe for the paint stripping operators. Their use does not result in waste byproducts that are hazardous pollutants.
They include corn starch crystals and more or less benzyl alcohol based chemicals or other plastic media. All of these are also blasted on the painted surface. The operation is known as plastic media blasting (PMB). The only disadvantage of these environment and people friendly chemicals is that the process is comparatively more time taking than with the use of methylene chloride.
SWRI (South West Research Institute), based in San Antonio, Texas, has developed paint-stripping robots for the aircraft paint stripping operation. These computer-controlled robots are equipped with sensors and arms that have six degrees of freedom of movement.
The robots effectively blast environment-friendly PMB media to strip aircraft of its surface paint. It results in a quicker and more efficient stripping operation. This approach obviates the need to subject employees to health hazards involved in paint-stripping operations.
Thermal paint strippers are in the form of lasers that use searing heat to burn the paint off aircraft surfaces. Their effectiveness relies greatly on the experience of the operator. This paint stripping method is not very popular and efficient as are environment-friendly chemicals.
Some Eco-Friendly Aircraft Paint Stripper Formulas
Aircrafts are an essential part of the defense forces of a nation and are essential for the safety and security of the country. Thus, there is a dire need to look after them efficiently.
The basic maintenance of an aircraft includes paint stripping and recoating as they both are essential to enhance the life of the aircraft. Painting and recoating saves the aircraft from corrosion.
Earlier, enamels and acrylics were used to strip off the paint from an aircraft but they were very tough to remove. The toxic and hazardous aircraft paint removers were used to remove the paints. Later, it was found that these aircraft paint removers were the major source of waste generation. This forced the U.S government to bar the use of toxic aircraft paint removers.
The government directions made it inevitable to device new aircraft paint remover mediums. Owing to the stringent centralized ecological conventions, many toxic chemical paint removers were debarred. This compelled the aerospace industry to find out some other up-to-the-minute and environment friendly ways of aircraft paint removal.
Before choosing the aircraft paint remover, the prime concern is that the metal or the composite may not lose its properties. Out of the various ways available, Flashjet is a well known aircraft paint removal process that helps reduce the toxic waste significantly. It can be used for both, the primers and the composites. It is also reported that this method does not harm the mechanical properties of slender aluminum alloys or the epoxy materials used in the manufacturing of the navy aircrafts.
With the change in technology, there are now coming various new and eco-friendly ways to strip off aircraft paint. One of the eco-friendly and valuable mediums of aircraft paint removal is the compressed-air-blasting medium which is based on engineered wheat starch. It is a gentle mode of stripping the paint off the aircraft and the various other components of aerospace.
CAE Electronics Ltd, an aviation-simulation-systems company, is running a big business and selling millions of pounds of EnviroStrip blasting material every year. It also deals in supplying semi-automated and manually operated stripping systems which could be used in rooms and blast booths.
Another method that is used to remove paint off an aircraft is EnviroStrip. This method makes use of matrix of the starch polymer which is engineered to give a required hardness so as to reduce the impact of the induced stress which can be the outcome of the blasting. The work can be accomplished at maintenance workhouses and aircraft hangars without any danger as EnviroStrip is a dry medium which facilitates easy aircraft paint removal. The starch medium used for this purpose is non toxic and ecological in nature.
This starch- medium blasting is found to be equally useful for composites and aluminum. It is stated that this medium can safely remove the coatings of the aircraft paint without causing any damage to the surface. Also, it can simultaneously strip off the coatings of primer and paint proficiently. This strip can be recycled for about 10 times and in some exceptional cases it is reported to be used for 15 to 22 times. Thus, it is also a very cost effective method.