Infrared Paint Removal— A Safer, Gentler, Eco-Friendly Method
Removal of thick layers of paint off old wood is a challenge for historic restorationists, contractors and homeowners. Professional and experienced preservationists know that most paint applied before 1978 is lead-based. Often remodeling and painting contractors do not. Most homeowners of older homes also do not. Common renovation activities that disturb lead-based paint, like sanding, power planning, dry scraping and heat gun usage can create hazardous lead dust, chips and vapors that are harmful to adults and children.
In fact, national public health discovery of the prevalence of lead poisoning in children has precipitated a new EPA regulation called “Renovate Right”. This national law requires contractors’ to use lead-safe work practices during Renovation, Remodeling and Painting (RRP) in pre-1978 housing and child-occupied facilities. Of particular relevance for contractors are the requirements to contain, store and transport paint waste material safely to prevent release of lead dust and debris and the prohibition of use torches and heat guns above 1100° or power sanders or planers unless attached to a HEPA vacuum. What methods for efficient and safe paint removal are left?
In the late 1980s a safer and more eco-friendly method was developed in Sweden by a restoration specialist. This method uses mid-range infrared heat waves to heat both the wood and the paint at a lower temperature. Therefore, it greatly reduces the hazards of removing lead-based paint in three ways:
1) Metallic lead vaporizes at 1,100°F (the temperature at which heat guns operate.) Lead oxide used in paint most likely vaporizes at 800° F. The mid-range infrared heat waves heat the paint and wood only to 400-600º F. Therefore, dangerous lead fumes are not released from the heated paint.
2) Containing lead dust is difficult and costly but very important to keep the lead out of user and building occupants’ lungs, as well as out of the environment. The scraping of the softened paint created by the infrared paint remover generates minimum dust unlike dry scraping, sanding or planing.
3) The soft paint scrapings clump together and drop onto a tarp, which makes them easier to contain and faster to clean-up. Pressure washing often used by painting contractors leaves the water with paint chips remaining in the work area’s soil, making it difficult to clean up without removing the top soil itself. Use of toxic or non-toxic chemical paint removers leaves messy goo also difficult to contain.
Another key consideration in paint removal is the impact of the method on the wood. This is particularly relevant for historic properties where preservation of the original, old wood is desired. Chemicals can leach out natural resins and leave a residue in the wood even after it has been rinsed or neutralized. High heat (1,100ºF) from heat guns can force the paint pigment back into the wood and risk scorching and even igniting the wood. Sanding and shaving can leave gouge and scorch marks if not done by a skilled technician. Pressure washing drives moisture back into the wood which threatens adherence of new paint and can also leave irregular surface marks in the wood. All of these methods can damage historic wood. Infrared heat paint removal can be the gentlest process on the wood. The infrared heat penetrates into the wood and pulls up some of the natural resins deep in the wood to rejuvenate it. It also pulls up some of the paint or varnish that has sunk into the wood, allowing them to be scraped off more thoroughly. The heat removes extra moisture deep in the wood and kills mildew and fungus. Yet, the lower temperature of 400-600° F. minimizes the risk of scorching the wood or catching it on fire.
With the infrared heat method the wood is immediately ready for application of primer paint. Little if any sanding is necessary on the wood surfaces that have been heated and scraped using the infrared heat method. There is no waiting time for drying or neutralization. The heated wood is immediately dry enough to receive primer. In fact, it is preferable to prime within days of scraping to assure ambient moisture does not seep back into the wood.
There are, however, some less frequently used old paints that do not react to the infrared heat process. Milk, protein, or blood paint and stains usually have penetrated into the grain of the wood and are not easily separated from the wood. Shellac reacts similarly.
Beyond the removal of the old paint, old windows present other challenges. Removing hard, dry glazing often requires harsh chiseling which can damage the wood and risks breaking the glass. Another use of infrared heat particulary popular with historic restorationists is to soften window glazing for removal. The evenly distributed, radiant heat from the long infrared bulbs almost eliminates the breakage of the glass common with heat guns. The more pliable glazing material separates more easily from the wood.
Find out more about infrared paint removers that gently and safely remove paint, especially for lead-based paint. As with most products, their features vary.
Look for infrared paint removers which provide the following features:
• UL listing to verify safety testing.
• Shock absorbers around the infrared bulbs to reduce breakage.
• An automatic, overheat shut-off mechanism to prevent damage to the machine and overheating of the wood and paint.
• Built-in safety shields extending beyond the infrared bulbs that easily set the correct distance between the bulbs and the painted wood. These shields eliminate the operator’s guesswork about what distance is safe yet effective and reduces the risk of overheating.
• Infrared heat using mid-range, infrared wavelengths to heat the wood and the paint at a lower temperature to prevent scorching, fire, and lead fume emission.
• Comprehensive instruction materials and training videos to assure quick operator proficiency, safe operation, and proper maintenance of the machine.
Infrared heat for paint removal is a new technology whose time has come. Historic preservation rather than demolition is growing in preference for ecological reasons. Awareness of the damage of lead-based paint is now a national health issue with national laws. Infrared paint removal offers a safer, gentler, and more ecological method to remove lead-based paint.