See full version: Paint Removal Guide: Caustic; Solvent Based Paint Strippers
Caustic paint removers are good to use to remove thick layers of paint and are great to use on surfaces with detailed moulding due to its consistency. However, you do run the risk of staining or scorching the wooden surfaces for example, whereas solvent based removers do not stain or damage the surface. more
Generally, solvent based paint removers are messier to use and are not that good at removing thick layers of built-up paint. They do provide a clear and clean finish with no damage or staining. They also tend to be slightly more expensive. more
Caustic paint removers work slightly differently, as the ingredients work towards breaking down the chemicals in the paint. They have a very high pH-level and the active ingredient is usually sodium hydroxide. It is the sodium hydroxide that reacts to the oily ingredients with the paint and starts breaking it down. Again, care should be taken when working with caustic paint remover as it can cause skin burns for example.
More importantly, when using any type of paint stripper, it is important to be aware of some basic health and safety considerations. Paint strippers contain chemicals and thus there are inherent dangers when dealing with them.
Michael Dresdner: Yes, the solvent-based ones do, though I would avoid waterbased ones if the temperature is much below freezing. There is a bit of a Catch-22, though. The solvents evaporate more slowly in cold weather, which is a plus, but they also work more slowly. more
The problem I seem to be running into is that everything we made over the winter was put out this spring and, within months, the edges of the painted and varnished boards are peeling and splitting. more
Caustic Alkalis: Caustic alkalis react with the paint coating and loosen it from the surface. One of the chemicals in this type of stripper is sodium hydroxide (lye). Some people do not use caustic alkalis because caustic products can darken wood and raise the grain. Caustics can cause severe burns to skin and eyes even on short contact. Therefore, be very careful to keep caustic chemicals away from skin and eyes and wear protective clothing. If contact occurs, wash off immediately with cold water. Caustics are also highly toxic if swallowed. [links]
General Safety Precautions:
1. Methylene Chloride (also called dichloromethane, or DCM): Methylene chloride is the most commonly used chemical in paint strippers. Methylene chloride products come in two varieties. One type is nonflammable, while the other type is flammable. The flammable paint strippers have less methylene chloride but have other flammable chemicals, including acetone, toluene, or methanol. Methylene chloride causes cancer in laboratory animals. The U.S. Environmental Protection Agency (EPA) and the U.S. Consumer Product Safety Commission (CPSC) consider the chemical to be a potential cause of cancer in humans. Methylene chloride evaporates quickly, and you can inhale it easily. Breathing high levels of methylene chloride over short periods can irritate the eyes, skin, nose, and lungs. It can also cause dizziness, headache, and lack of coordination. Your body changes some inhaled methylene chloride to carbon monoxide. Carbon monoxide lowers the blood's ability to carry oxygen. This can cause problems for people with heart, lung, or blood diseases who use methylene chloride paint strippers indoors without fresh air cross-ventilation. High exposures to methylene chloride for long periods can also cause liver and kidney damage. more
2. Acetone, Toluene, and Methanol: These chemicals are commonly used together. All three chemicals evaporate quickly and are very flammable. Breathing high levels of these chemicals can cause a variety of effects, including drowsiness, dizziness, and headache. Breathing high levels of toluene may harm unborn children. Breathing very high levels for a long period may cause brain damage. Toluene and methanol are poisonous if swallowed. here
Caustoc-Based Strippers (Not Flammable): [links]
Some paint strippers have a citrus smell or make "environmentally friendly" claims. However, these paint strippers may be hazardous despite the smell and environmental claims.
If you’ve been putting off indoor projects because you are concerned about the safety of removing paint or varnish, Speedheater™ can help! The Speedheater™ Infrared Paint Remover heats paint and varnish quickly and easily without the risk of toxic lead fumes, messy chemicals, or flying dust.
Speedheater™ infrared paint removal is the safest method for users and the gentlest method for wood. The Speedheater™ uses a very specific wave length of infrared rays to heat the paint only high enough to release it from the surface and make it bubble. Heating paint to this low level will not release toxic lead fumes. Immediately scraping soft paint creates clumps of paint waste and minimizes flying paint dust.
If you do start stripping paint on the outside of your house make sure that you are able to re-paint the surface immediately. Leaving bare wood exposed for weeks or months is not a good idea. The moisture in the air may soak into the bare wood. Moisture under paint is the most common reason for paint failure. [links]