A modern method of removing paint from wooden surfaces is the use of infrared rays. This method has gained popularity over the past decade as an alternative to mechanical and chemical methods of removing paint. Mechanical methods such as sanding, grinding, or shaving usually increase hazards such as lead dust. Chemical solutions minimize the lead dust but result in a gooey mess that requires cleanup and more chemicals for neutralization. Infrared paint removers ofter an alternative which minimizes dust and eliminates chemicals. When exposing a painted surface to infrared rays, the rays penetrate the paint, warm the substrate below the paint, thus releasing the paint’s grip. In practice, the infrared paint remover (IPR) held over a painted spot will cause the paint to slowly bubble and lift, making it easy to scrape it off with a scraper. IPRs are seen most often used by people restoring old houses or windows. They are, however, increasingly seen used in a variety of applications. The disadvantage of an IPR is that it is not guaranteed to be effective in every situation. See the conclusion of this article for more detail. IPRs are most effective on thick layers of old paint, especially aligatored paint. They do not work well on calcimine, milk paints, and will not remove shellac or varnish.
Note that IPRs are not the same as "hot plates," which heat paint via convection. Hot plates scorch and boil the paint through proximity to a heated element. That method risks scorching the wood substrate and releasing toxic gases. IPRs rely not on convection, but mostly on radiation. The goal is to penetrate paint and warm the substrate (wood), releasing the bond between paint and wood, slowly, without raising the temperature high enough to vaporize lead. When you stand at a sunny window on a cold winter day, and you feel the sun’s heat on your face even though the air outside may be zero degrees, you are being heated by radiation. In such case, energy is transferred directly to you and not via physical contact with an warmer object (conduction), nor using air as a carrier of heat (convection).
In August of 2004, frustrated at the high cost of commercial Infrared Paint Removers ("IPRs"), I cobbled together a home-made unit using a quartz heater and some miscellaneous hardware. I wrote up a small page outlining my experiments for the benefit of other old house restorers out there. The response was unexpected. It seems there are many out there like to tinker, save $, and DIY.
Here now is Version 2 of the IPR. Having traded my original scratch-built quartz unit for a Herbeau fireclay sink, and in need of an IPR, I elected to investigate this new and promising modality of paint removal: ceramic infrared.
Commercially sold IPRs use quartz rods to generate infrared rays. My unit would be based on a ceramic emitter instead. Why ceramic? One reason is that a ceramic unit would be easier to build with fewer parts. Commercial ceramic emitters are readily available. Efficiencies for ceramic emitters run from 85 to 96% whereas quartz ran around 60%. Therefore, a higher percentage of the energy supplied to the unit would be transmitted as infrared rather than light. Quartz rods tend to have infrared hotspots. Cermaic on the other hand, produces a more evenly distributed heat.
Anyway, yet again, this is the time to point out some safety issues and make a disclaimer. Making your own IPR involves electricity. The project involves wiring as well as drilling, sanding, and cutting. (jeez doesn’t sound too bad) I am not advocating that you run out and build one, I am presenting my method here for your review. If you do make one, you do so of your own accord. If you electrocute yourself, or burn your house down, well, hey, that’s life, and your own responsibility. I am comfortable with the potential hazards. You may not be, and I urge that if you should make one anyway, you proceed with safety in mind and a good dose of common sense.
Thus my intention to build a new, ceramic based, IPR for the same or less money.