Furniture Stripping
Stripping an old finish from furniture or trim is almost like
finding buried treasure. A good stripping job can transform a
yard-sale bargain or restore an antique to its original glory.
There are two ways to strip wood. A heat gun softens the finish
and works best on thick, many-layered paint. Chemical paint strippers,
on the other hand, partially dissolve paint, so they're favored
for removing fewer layers of paint and clear finishes. Either
way, you'll have to scrape the softened finish from the wood.
Professional strippers often use both methods on a single job.
Safety First
We'll give you step-by-step instructions on how to use heat
guns and chemical strippers, along with safety tips for each
method. Read through all the information before you begin your
project, and before you start to work, take
the necessary precautions to prevent fire and protect yourself
from harm. Let's start, though, with some important general safety
tips:
1. Before you start a stripping job, make sure that you have
the gear, workspace and knowledge to do it safely. Many strippers
can burn you chemically; a heat gun can burn you, period. Almost
everything you're working with is flammable, so be careful.
2. Always keep an AB-rated fire extinguisher handy when you're
working with a heat gun or solvent-based chemical stripper. Never
use solvents near an open flame (such as the pilot light in a
gas water heater or gas stove). Read the safety label on the
stripper container and take its commands to heart. That includes
knowing what you need to do right now if the unexpected
happens.
3. Toxic fumes can rise out of softening paint, and both chemical
and heat-gun methods can release them. That's why good ventilation
is important. A respirator is a good idea, too. Lastly, wear
gloves, goggles, long sleeves and old clothes.
4. Beware of lead-based paint. It was widely used on houses
built before 1978. Lead is wickedly toxic stuff. If you think
you have lead paint, do not remove it with
a heat gun, by sanding, or in any way that releases lead dust
or fumes into the air. There is no totally safe way to strip
lead paint, though chemical strippers come close.
Wear a respirator with a NIOSH-rated P-100 HEPA filter if there's
any possibility that you're dealing with lead. Contact your local
government's hazardous-waste program to find out how to dispose
of lead-based paint peelings. You'll find more on the lead question
in the U.S. Department of Housing and Urban Development's lead
paint safety guide.
If you suspect that there's a lot of lead paint in your house,
have it checked (and perhaps removed) by professionals. CornerHardware.com
can hook you up with reliable, prescreened experts; just visit
our Services department.
Heat Guns: An Overview
As we said earlier, heat guns work best on thick, built-up layers
of paint. While an inexpensive heat gun will eventually soften
any finish, you'll work faster with a gun that can blow air at
1,000 degrees. Hotter than that isn't better, since higher temperatures
release more vapors.
The thinner the paint, the less effective a heat gun will be.
To lift just one or two coats, use a chemical stripper. Same
goes for varnish, lacquer and shellac; heat will just make them
sticky, and they could catch fire. Use a chemical stripper on
window sashes, too: heat can (and will) break the glass.
Equip yourself with a putty knife and a molding scraper to remove
softened finish. Don't scrape paint with sharp chisels or knives:
they're liable to dig in. Your scrapers' blades may get hot,
so choose tools with substantial handles to protect your (gloved)
hand from the heat. You may want to keep a few scrapers handy;
the blades don't work as well when they're hot, so if you can
trade off, each one will be able to cool completely before you
need it again.
Heat Guns: Step by Step
1. Put down a canvas drop cloth to catch paint
peelings: newspaper catches fire too readily.
2. Hold the gun 5 inches away from the painted
surface, and apply heat until the paint bubbles. Keep the gun
moving. With your putty knife, scrape the softened paint away
from the wood as you direct hot air over the next patch of paint.
At times, you may need to bring the gun's nozzle closer to the
wood, but be careful not to scorch it unless you plan to paint
it again.
Take care not to scratch the wood with your scraper. Remove
only the finish that comes away easily. The last layer of finish
is often best removed with a chemical stripper.
3. Dump the paint peelings onto your drop
cloth or set up a box to scrape them into as you go. Left on
the workpiece, they'll reattach themselves as they cool. When
you're done, bag them and put them in the trash.
Chemical Paint Strippers: An Overview
Except for furniture refinishing compounds, stripper usually comes as a thick
gel that you apply in a heavy layer. That keeps the active ingredient from
evaporating too quickly.
Strippers can be highly specialized, so select the right type
for the job you're planning. Follow the recommendations below,
and always read the label so you're sure of what it is and how
it works.
Furniture refinishers are solvents that dissolve
aging shellac and lacquer. You can then remove the finish altogether
using steel wool or, working more gently, just take off the cracked
or dirt-impregnated top layer. Hazardous (and flammable) ingredients
acetone, toluene and methanol make good ventilation essential.
Again, never use solvents near an open flame.
Methylene chloride stripper loosens finish
from the bottom up, lifting multiple layers in one go. This stripper
works fast and well on all finishes, but its fumes are seriously
toxic use it outdoors only, wearing old clothes, rubber gloves,
goggles and a respirator with black (organic vapor-rated) filter
cartridges.
Solvent-based stripper works
more slowly than methylene chloride, but faster than the "safe" types
described below. While not as dangerous as methylene chloride
strippers, solvent strippers require protective gear and good
ventilation. And, of course, they're flammable.
"Safe" strippers are
safe (to varying degrees) for use indoors. 3M Safest Stripper™ is
a very slow but very safe product whose active ingredient is
dibasic esters (DBE). You don't have to wear a respirator when
you use it and it won't hurt your skin. It can take up to 24
hours to do its work.
Citristrip® and other relatively
safe strippers use n-methyl pirrolidone (NMP) and other solvents
that aren't as volatile as the traditional strippers. Nonetheless,
you'll still want to work in a well-ventilated area and wear
gloves and eye protection. These chemicals work slowly, so
apply several coats, then cover the stripper with plastic to
slow evaporation.
Chemical Paint Strippers: Step by Step
1. Prep your work area . If you're stripping
inside, make sure your ventilation is adequate. Put down newspapers
to catch the mess. Again, wear old clothes, long sleeves, goggles
and rubber gloves.
2. Apply the stripper. Pour some stripper
into a wide-mouthed container. With a cheap or worn-out natural-bristle
brush, paint it thickly on the workpiece. Brush only in one direction,
and go slow to minimize splashes. If you're working on a large
piece with fast stripper, do one part at a time one side of a
wooden chest, for example. To improve a slow stripper's performance,
cover the piece with a plastic (poly) sheet or seal it in a plastic
garbage bag.
3. Wait for the bubbles, then scrape off the finish. When
the finish has softened, it will form bubbles and wrinkles and
pull away from the wood surface. That's when you start scraping.
Apply more stripper in areas where this loosening hasn't occurred. Note: Latex
paints don't always bubble; let the stripper work awhile, then
test for softened paint with your scraper.
Scrape flat surfaces with a putty knife and contours with a
molding scraper. Use an awl or probe and a toothbrush to get
into tight spaces. Use a fistful of dry wood shavings to scour
complex surfaces; shavings also absorb leftover stripper. To
remove finish from the crevices of lathe-turned legs, pull twine
back and forth as if shining your shoes. Keep those goggles on:
the gunk will fly.
Don't scrape too hard where finish is reluctant to come off.
You can always apply a second coat.
4. Rinse and smooth the wood. Citristrip makes
a wash with a mineral spirit base that removes chemical residue.
Soak a fresh scrub pad with it and wash the piece thoroughly.
This stuff puts out a lot of vapor, so ensure good ventilation
and use your goggles and gloves.
Let the wood dry and smooth it with very fine sandpaper or steel
wool before you put on the new finish. Look closely for areas
that need attention: loose veneer and holes that need patching,
for example.
5. Clean up the mess. While the mixture of
stripper and old finish is wet, it's hazardous. Let your slime-covered
newspapers dry in the open air before you bag them.
The safe DBE- and NMP-based strippers take a long time to dry.
Find a place where your safe-stripper-based mess can dry out
without the risk of a child or pet getting into it: perhaps an
open-topped cardboard box in your attic or up in the rafters
of your garage.
Check with your local hazardous-waste office to see if you can
add the stuff to your ordinary trash. Many municipalities require
that you take old paint, cans, residue, solvent and the like
to a special disposal facility.