If painting a house's exterior is hard work, then removing the old paint during the preparation stage is exponentially harder and a lot less fun. Yet no prep stage project is more valuable to maintaining the long life of your paint than paint removal. Peeling, loose, and unstable paint will never provide a solid base for your next paint layers, so removing it is critical.
You can paint without scraping paint beforehand, provided the old paint is still in good shape and the surface has been cleaned; the new paint may adhere fairly well. But if the old paint is cracked, blistered, or peeling in any areas, you are begging trouble to paint directly over it. While you may have an initial sense of relief at seeing peeling paint covered by new paint, it won't be long before the underlying layer bubbles up and compromises all your work.
But the degree of paint removal necessary depends on the condition of the existing paint and on your appetite for work. When preparing for a new coat of paint, it is essential that any loose, blistering, or cracked areas of old paint be removed. This is usually done with a wire brush, a paint scraper—or more often, a combination of both tools. But surrounding areas of paint that are well bonded are likely to stay adequately bonded if they are painted over.
Taking the next step—removing all the paint down to the bare wood—is the very best way to achieve a paint finish that looks just like new, but doing so is very time-consuming, and it comes with the hazard of loosening old coats of paint that possibly contain lead. It can also cause damage to the wood. Make sure you understand the effort involved before deciding to remove all paint down to the bare wood. If you'd rather limit your efforts to the areas that are clearly blistered, cracked, or peeling, the rough edges where well-bonded old paint meets bare wood can usually be hidden by sanding so that the old paint blends in with the exposed bare wood.
Depending on the age of the old paint job, it is possible that it contains lead. Paint sold before 1978 very often contain lead as an additive used to accelerate drying, increase durability, and resist moisture. While recent coats of paint do not include lead, older underlying paint may. If paint containing lead is loosened during the removal process, it can pose a health risk if paint chips or sanding dust are inhaled or ingested. It is wise to test an area of the siding for the presence of lead. If lead is present, follow EPA recommendations for its removal, which includes collecting and safely disposing of paint chips and contaminated soil.
Here are three manual tools that are helpful for paint removal.
A brush with tines made of metal wire helps to remove raised peeling or blistering paint. A wire brush also aids in tidying up the work material after you have removed the paint. Wire brushes are inexpensive and quick to put into action, as opposed to a power sander, which requires set-up time. Wire brushes are valuable for cleaning paint scrapers and other tools you may be to remove paint, such as putty knives or wallboard knives.
How to Remove Paint With a Wire Brush
Sweep Brush Over Siding
On areas of prominently peeling paint, sweep the brush lightly up and down over the siding, parallel to the edge of the peeling paint.
Sweep in Direction of Paint
Where the paint more closely hugs the work material, sweep in the direction of the solid paint.
Clean Wire Brush
When finished, clean the wire brush under running water.
Be aware that brushing with a wire brush usually removed the loosest peeling or blistering paint, but it's rarely enough for complete preparation. It's usually necessary to follow up with some work with a manual paint scraper.
Manual Paint Scrapers
No single tool currently exists that will remove house paint all by itself, in every instance and every form. Instead, you need to be resourceful and have at your disposal several tools that can attack different angles of the job.
If you did have to choose just one tool, though, it would be this: a manual paint scraper. The manual paint scraper is the oldest and most reliable way of removing paint. You should have on hand not one but several low-cost paint scrapers to get under those stubborn layers of old paint.
- 3-inch flat heavy-duty scraper: With its handle, this scraper gives you a firm grip as you push into the paint. This tool is flat and is shaped like a large putty knife.
- 2 1/2-inch two-edge paint scraper: Shaped like a larger facial razor, this tool has a thin handle and a wide head. The head sometimes has replaceable scraper blades—shift to a new blade whenever the old one gets dull. This tool is designed to be pulled toward you rather than pushed forward.
- Multiple-use painter's tool: Going under names such as 5-in-1 tool, 8-in-1 tool, 14-in-1 tool, and several other permutations, this tool has great utility not just for painting but for many forms of home improvement work. You can use this tool for spreading wood filler, chiseling, opening paint cans, cleaning rollers, piercing, and push-scraping.
- Putty knife: While a putty knife is designed for using wood filler or joint compound, its blunt end makes it ideal for scraping paint while reducing the chance of gouging.
How to Remove Paint With a Manual Scraper
It takes a lot of muscle-work to scrape paint with a manual scraper but taking it slow and steady with plenty of rest breaks makes for a successful job.
Run Scraper Over Whetstone
It helps to have on hand a sharp scraper and a blunt scraper when removing paint. Run the sharp tool over a whetstone to hone the blade.
Scrape Loose Flakes
Begin with the blunt tool. Put the scraper end under any loose paint flakes and gently push.
Continue pushing until the paint no longer comes up easily.
Switch to Sharp Tool if Paint Has Raised Edge
If the paint still has a raised edge, switch to the sharp tool. If not, consider moving to the wire brush to smooth out the edge.
Press Scraper End Under Raised Paint
Press the scraper end of the sharp tool under the raised edge of the paint. Gently press forward until the scraper will not easily lift the paint. Take care not to gouge the wood when working with a sharp scraper.
An electric heat gun rated for 1,000 watts or more is a valuable tool for preparing the paint for easier scraping. While heat guns are slow, they are effective. Do not confuse a heat gun with a butane torch. A heat gun can get very hot but it does not produce a flame. A butane torch does produce a flame and should not be used as an aid for scraping paint, due to the safety risks.
This is the tool to use if you want to remove all paint down to bare wood.
How to Remove Paint With a Heat Gun
Fit Scraper Onto End of Heat Gun
With the heat gun unplugged, fit one of the included scrapers onto the end of the heat gun. Many heat guns come with a variety of matching scraper heads.
Plug in Heat Gun
Plug in the heat gun. Begin with the heat gun turned to its LOW setting. Increase the heat as needed.
Hold the tip of the tool close to the paint and let the paint heat up for about 20 seconds.
Press Heat Gun Forward
Gently press the heat gun forward several inches to peel away the heated paint. If the paint has been warmed enough, it will be slightly softened and easily peel away from the siding. Overheating the paint can make it gummy and harder to remove. Practice will help you determine the exact temperature for easy removal.
Alternatively, if the heat gun does not come with attachments:
- Hold the heat gun in one hand and the blunt scraper in the other hand.
- Hold the heat gun, turned to LOW, about 6 inches away from the surface.
- Lightly wave the heat gun over the surface for about 20 seconds.
- Quickly switch to the scraper. Push the scraper under the paint, press forward, and then lift off the loosened paint.