This article will address chemical stripping of oil-based finishes. Blasting media and the removal of water-based finishes will be covered at a later date.
This article may seem elementary to some of you; however, there are some parts that will be of benefit to all.
Ask the homeowners if they have ever had any problems with water intrusion. This way you can avoid possible problems and may be able to make small repairs (caulking, etc.) prior to starting. The first thing to do is to cover objects such as plants, statues, sidewalks, etc. We usually use 3 or 4 mil plastic, which is less vulnerable to wind damage and tearing. We use stakes to prevent the plastic from harming plants by “tenting” the plastic over the plants. This allows air circulation around the plants and to help avoid damage from heat build up.
Connect hoses with spray nozzles to the exterior faucets to enable you to keep exposed areas that might be exposed to the stripper wet during the stripping process.
Exterior doors: Cut the plastic approximately 2 feet larger the door. With the door open, wrap the plastic around the four sides of the door from the outside. Tape the overhanging plastic to the inside of the door and carefully close the door to form a seal around the door.
Garage doors: Cut the plastic approximately 2 feet larger than the door. With the door open about half way, wrap the door from the outside. Tape the overhang to the inside of the door and carefully close the door to form a seal around the door.
Lights: Remove the lighting fixtures where possible (make sure the switch is turned off or turn the power off at the circuit breaker box). If some cannot be removed, cover carefully with plastic and tape. Cover openings where fixtures have been removed.
Stripping the house:
Access: There are different methods of accessing the higher areas of the house.
For the purpose of this article, it is assumed you have already tested the stripper on the finish of the house and have arrived at the proper strength and dwell time required.
Work in the shade as much as possible when applying the stripper to allow for maximum dwell time. Apply the stripper from the foundation up to the roofline.
There are many types of chemical sprayers available. Below are photographs of some we have put together inexpensively. As you can see, they hold a large volume of chemicals. They also have an 8” opening on the top of the tank and a drain plug at the bottom. We use standard power washer guns so we can change applicator tip sizes and also to allow for extensions. There is a three way valve mounted on the inlet side of the pump to allow for cleaning of the pump, hose and gun without having to empty the tank. We use 100’ of 3/8” braided hose.
Power wash the home (normally from the top down). Keep the windows rinsed while you are pressure washing, however, be careful to not apply pressure directly to the glass to avoid harming the glass seals. Continue until the entire house has been stripped.
Repeat the same process as above with your neutralizing agent.
Fold the plastic back from the plants to avoid heat damage.
Allow a couple of days for the siding to thoroughly dry (use a moisture meter to check the moisture content of the siding)
Replace the plastic you may have previously removed.
There are a couple of choices when it comes to protecting the windows and other exposed surfaces such as electrical and utility boxes boxes, etc.
Upon completion of the job, we recommend cleaning these surfaces with Formula 409 cleaner to remove the stain residue. Formula 409 contains an ingredient (ethylene glycol monobutyl ether) that emulsifies the stain residue. Below are photographs that show how it works. The pane was sprayed with Quick n Brite and allowed to dry. We then painted a heavy coat of oil-based stain on top and allowed it to dry in the sun for a day; we then sprayed some Formula 409 in the center of the glass and wiped it with a rag.
You will need a pump-up sprayer filled with mineral spirits handy in the event of spill, drips, etc. In many instances, the concrete foundation below the siding is painted or just left the natural concrete color. The easiest method to keep the stain off the concrete is to stop spraying about a foot above the concrete and finish that area with a brush.
However, in more cases than not, we convince the homeowner that the exposed concrete foundation will look better if they allow us to spray it along with the siding. The fact of the matter is that the painted or bare concrete does look much better because the stain evens out and dries to match closely the color of the siding.
Keep the hoses nearby and wet down concrete or other objects not covered (oil floats on water).
Overspray may become a problem if the house is in close proximately to other houses or immovable objects that may be in the way of the overspray. There are several ways to minimize and/or eliminate this problem.
This method is complicated and can get expensive as you can go through several spray tips before you reach the desired results. You will also have to locate a machinist that has the proper equipment and who will be willing to work with you on this project at a “reasonable cost”. Fortunately, as long as you continue to spray thinner oil based stain (A/C, Ready Seal, TWP, etc.) and use the same type of airless sprayer, the tips will wear negligibly and last a long time.
The preferred method is to spray the house from the roofline down with a saturation coat and when you complete one section of the house, return to the starting point on that section and spray again with a lighter coat. This will enable more of the transoxide pigment in the second coat to remain closer to the surface and offer additional protection.
Leave the plastic in place until you are sure all dripping has stopped. Remove plastic, replace lighting fixtures, clean up any spills/drips, etc. We usually hire professional window cleaners to complete the cleaning of the windows. We find a reliable company and give them all of our window cleaning business. More often than not, the window cleaners are also hired by the homeowner to clean the insides of the windows. This will help in negotiating price with the window cleaner. Having a professional window cleaner clean the windows on completion makes you look much more professional and is appreciated by the homeowner.
I realize I may have not addressed all your questions and/or concerns pertaining to cedar home restoration. Please feel free to ask any questions you may have.