How to Strip Metal Filing Cabinet
Stripping a metal filing cabinet can give it a fresh new look or help prepare it for painting or refinishing. With some time and effort, you can strip off the old finish to reveal the bare metal underneath. Here is a step-by-step guide on how to properly strip a metal filing cabinet.
Steps to Strip a Metal Filing Cabinet
Remove the Drawers
The first step is to empty out the filing cabinet and remove all of the drawers. This gives you full access to work on the interior and exterior surfaces. Place the drawers in a safe location where they won’t get damaged.
Clean the Surface
Use a degreaser or all-purpose cleaner to wipe down the entire filing cabinet. This removes built-up dirt, grime, fingerprints, and any oily residues. Make sure to get into crevices, corners, and carved details. Let it fully dry. This allows the stripping chemicals to penetrate better.
Protect Surrounding Areas
Cover any nearby surfaces like floors or walls with a drop cloth. Stripping chemicals can splash or drip, so you want to shield adjacent areas. Wear old clothes that can get stained. Rubber gloves and eye protection are highly recommended too. Ventilate the room by opening windows or turning on fans.
Choose a Stripper
There are a few options when it comes to choosing a paint and varnish remover:
- Liquid chemical strippers: These are very effective but contain harsh solvents like methylene chloride. Use them cautiously in a well-ventilated area.
- Citrus-based gels: Made from plant extracts, these are less toxic and better for indoor use. However, they may take longer to fully dissolve many layers of coatings.
- Soy gel strippers: Also made from plant-based extracts, soy gels are safe and eco-friendly. They tend to work slower than other options though.
For a metal filing cabinet, a methylene chloride-based liquid stripper will provide the most powerful paint dissolving action.
Prep the Filing Cabinet
Make sure the filing cabinet surface is free of grease, wax or dirt. Scuff it lightly with sandpaper to help the stripper penetrate the finish. Remove any loose flaking paint ahead of time as well.
Gather all necessary supplies before starting:
- Drop cloths
- Paint remover/stripper
- Plastic putty knife or scraper
- Metal brush
- Rags, paper towels, scrub pads
- Rubber gloves, safety goggles & mask
- Mineral spirits or paint thinner
- Fine sandpaper
Apply the Stripper
Follow the product directions closely. Liquid strippers typically need to be diluted first. Use a chemical-resistant brush or rag to apply a thick, even coat of stripper over the entire filing cabinet. Avoid letting it dry or sit open too long. The fumes can be very strong.
Many strippers will start bubbling up the old paint within 5-10 minutes. Thicker layers may take up to 30 minutes to fully dissolve. Don’t let it sit for more than 45 minutes before removing.
Scrape Away the Finish
Once bubbling action has stopped, take a plastic putty knife and gently start scraping off the melted paint or varnish. Apply pressure at around a 45° angle to get under the finish without gouging into the metal.
Use a fine grit sanding sponge over curved areas and crevices. Take your time to remove all of the softened finish. Avoid scraping so hard that you scratch the metal underneath.
Scrub with a Brush
Dip a stiff bristle brush in paint thinner or mineral spirits. Scrub all over the stripped metal to remove any remaining residue. Pay extra attention to carved details and corners. Change rags frequently to prevent just smearing around gunk.
Multiple rounds of stripping, scraping, and scrubbing may be needed for cabinets with many built-up layers of enamel, varnish or paint. Rinse thoroughly and let dry in between coats.
Sand Down the Metal
Once all remnants of the finish are removed, lightly sand the bare metal with fine grit sandpaper. This helps smooth out any uneven areas and allows fresh paint, stain or new finish to better adhere. Be gentle to avoid unnecessary scratches.
Clean and Rinse
Give the stripped filing cabinet one final wash with mineral spirits using clean rags. Rub gently to remove any last bits of grime and dust. Let it fully dry before moving on to prep for refinishing. Proper stripping and cleaning provides the ideal smooth surface for repainting.
Tips for Successfully Stripping a Metal Filing Cabinet
- Test the stripper on a small inconspicuous spot first to ensure it can effectively remove the finish without damaging the underlying surface.
- Apply an even layer of stripper over the entire surface so that it works consistently.
- Start scraping gently and increase pressure as the finish softens. Take it slow to avoid gouging metal.
- Use a plastic putty knife instead of a metal one which could scratch the cabinet surface.
- Wipe vertical surfaces from top to bottom to prevent drips from re-wetting stripped areas.
- Ventilate the workspace very well and take breaks outside for fresh air to avoid inhaling toxic fumes.
- Work in sections for easier control on intricate carved cabinets versus tackling the whole thing at once.
- Be patient and willing to do multiple applications if the finish is very thick and built-up.
- Properly dispose of used strippers, rags and residue according to manufacturer’s recommendations.
Supplies Needed to Strip a Metal Filing Cabinet
Here are the basic supplies you’ll need to have on hand for stripping a metal filing cabinet:
- Paint stripper (liquid, citrus or soy gel)
- Plastic putty knives and scrapers
- Metal wire brush
- Paint thinner or mineral spirits
- Fine grit sandpaper
- Rags, paper towels, scrub pads
- Drop cloths
- Rubber gloves
- Safety goggles & mask
- Plastic paint trays or buckets
- Paintbrushes for applying stripper
Make sure to also have materials ready for properly disposing of used stripper, rags, and the liquefied finish residue. Check local regulations on solvent disposal methods.
Step-by-Step Stripping Instructions
Follow these steps closely when stripping a metal filing cabinet:
- Remove drawers and clean cabinet surface thoroughly first.
- Cover floors, walls, and other surfaces with drop cloths.
- Put on gloves, goggles, old clothes and mask if working indoors.
- Select a strong paint stripper suitable for metal.
- Dilute or prepare stripper according to label instructions.
- Apply a thick even coat of stripper over the entire cabinet.
- Let it sit for adequate time to fully dissolve the finish.
- Use a plastic scraper to gently peel off softened finish.
- Scrub with a wire brush dipped in paint thinner to remove residue.
- Sand lightly to smooth and prep surface for new finish.
- Rinse thoroughly with mineral spirits and let fully dry.
- Properly dispose of used stripper and residue.
Repeat process as needed until all old paint or varnish is removed from the metal filing cabinet.
Which Type of Stripper is Best for Metal?
The most powerful stripping chemicals for removing paint and varnish from metal surfaces are methylene chloride based liquid strippers.
Methylene chloride can dissolve multiple layers of thick, stubborn finishes. It provides fast-acting results superior to citrus or soy gel strippers.
The trade-off is that methylene chloride is extremely harsh, toxic and flammable. It requires very cautious use with maximum ventilation, gloves, and goggles. The fumes are potent and can be dangerous if inhaled too much.
Citrus and soy gel strippers are gentler, safer alternatives. However, they work slower and may struggle to eat through very thick, baked-on enamel or finishes.
For stripping metal specifically, a methylene chloride formula is the most efficient choice if proper precautions are taken. It will provide the strongest stripping power. Soy or citrus strippers can work too but require more applications.
Hazards When Stripping Metal Furniture
Stripping metal furniture like filing cabinets comes with certain hazards to be aware of:
- Toxic fumes – Wear a respirator mask and ventilate the area to avoid breathing in solvent vapors. Take frequent breaks outside for fresh air.
- Skin irritation – Direct contact with stripping chemicals can cause burns or rashes. Wear long sleeves, gloves, and eye protection.
- Fire risk – Strippers are highly flammable, especially indoors. Avoid all ignition sources and have an extinguisher nearby.
- Hazardous waste – Dispose of used stripper, rags, and residue properly according to local environmental regulations.
- Fumes headaches – Work for limited time periods before getting fresh air to avoid headaches from inhaling chemical fumes.
- Metal damage – Don’t gouge or scratch the cabinet when scraping off finish. Use gentle pressure with plastic scrapers.
Take all necessary precautions when stripping metal filing cabinets. Work slowly and safely to avoid health hazards or ruining the furniture you’re trying to refinish.
How to Neutralize Stripping Chemicals on Metal
Once you’ve finished stripping paint or varnish from a metal filing cabinet, it’s important to properly neutralize any chemical residue left behind. Here are a few ways to neutralize strippers on metal:
- Scrub with baking soda and water solution, then rinse. The sodium bicarbonate reacts with acids in strippers to neutralize them.
- Wash with an ammonia solution followed by clean water rinses. Household ammonia counteracts alkaline-based strippers.
- Spray leftover stripper with white vinegar and let it foam for 2-3 minutes before a thorough wipe down. The acetic acid cancels out the active ingredients.
- Use mineral spirits to give a final scrub across stripped metal. This solvent cuts through remaining grime and stripper haze.
- For store-bought citrus or soy gel strippers, follow the manufacturer’s recommendations for neutralizing and removal on metal surfaces.
Any residual stripper left on the bare metal cabinet could impede performance of new paints, stains or finishes. Proper neutralization prevents this and ensures you start with a clean slate when refinishing stripped metal furniture.
Will Stripping Remove Rust From Metal Furniture?
Stripping chemicals work very effectively to dissolve layers of paint, varnish, enamel and lacquer from metal surfaces like filing cabinets. However, paint strippers alone will not remove rust on metal furniture.
Rust formation requires a different approach:
- For surface rust, use a wire brush or sandpaper to scrub the spots away. Wipe clean with mineral spirits afterwards.
- For deeper rust layers, apply a rust removal solution or acid specifically formulated to dissolve rust buildup and convert it into a water soluble layer for scrubbing off.
- Severe rust may need to be sanded down to the bare metal before rebuilding the surface with primer, putty and fresh paint.
So while stripping will remove finishes from rusted metal, it doesn’t address the rust itself. Combine stripping with other rust removal methods as needed to fully restore metal furniture. Taking off the existing finish is an important first step for allowing you to combat rust formation directly.
How to Avoid Pitting When Stripping Metal Furniture
Pitting occurs when stripping chemicals react with the surface metals in furniture, causing etching or cavities across the bare metal. To avoid pitting when stripping metal filing cabinets:
- Test stripper on inconspicuous areas first to check for compatibility with the metal substrate.
- Avoid letting stripper sit for longer than maximum times recommended on the product label.
- Use a plastic putty knife instead of a metal blade to prevent scratching metal that exposes it further to chemical interaction.
- Rinse thoroughly with mineral spirits after stripping to remove all residue.
- Opt for citrus or soy-based strippers which have less harsh chemical actions than solvent formulas.
- Add silicon carbide or aluminum oxide inhibitors to methylene chloride strippers to reduce etching capabilities.
- Mix strippers weaker than the concentrations on their labels to dilute their strength on delicate metals.
- Skip stripping on furniture where bare metal has become pitted already, and instead fill pits and reapply paint or other finishes directly.
With proper application techniques, most metal filing cabinets can be stripped without significant pitting. But the condition of the original surface and type of stripper formula does impact the risk.
What to Do if You Accidentally Strip Off Too Much
If you are overzealous with the scraping or leave stripper on too long, it’s possible to end up stripping away too much of the finish on a metal filing cabinet. Don’t panic! Here are some tips for repairing over-stripped metal:
- Immediately neutralize any residual chemicals so they stop reacting with the bare metal.
- Sand down any uneven edges between stripped and non-stripped sections to help blending.
- On flat surfaces with large areas stripped to bare metal, apply a thin skim coat of wood filler or metal-specific epoxy filler to rebuild a uniform surface.
- Use 100-150 grit sandpaper to smooth and level the filler layer across the metal cabinet panels.
- Spot prime stripped areas with a suitable metal primer before painting the entire cabinet.
- Replace stripping with simply sanding later coats of finish to avoid stripping down to the bare metal again.
- If necessary due to extensive damage, completely strip and refinish the entire filing cabinet for an even look.
Accidental over-stripping can happen, especially on intricate carved metal furniture. With some filler and sanding, the damage is usually repairable. Just take care to avoid stripping too far into the base metal underneath the old finish.
How to Dispose of Used Paint Stripper and Residue
Leftover stripper, soaked rags, and the liquefied finish residue may contain dangerous chemicals, so they must be handled and discarded very carefully:
- Allow rags to fully dry in an open metal container before disposal to avoid spontaneous combustion.
- Pour excess liquid stripper into the container it came in for reuse later or proper hazardous material disposal.
- Scrape paint residue off surfaces into thick plastic bags. Allow any wet residue to fully harden before bagging.
- Bring materials to a household hazardous waste collection center in your area. Do not pour down drains or place in normal trash.
- Follow all regulations from your local waste management authorities regarding proper chemical waste disposal methods.
- Consider using less toxic citrus or plant-based strippers which can be more safely discarded compared to harsh methylene chloride formulas.
Proper stripper disposal prevents environmental harm and avoids exposing others to dangerous chemical fumes or direct contact. Handling leftover stripper carefully protects both people and places.
Can You Strip Powder Coated Metal?
Powder coating creates an extremely durable, baked-on finish that can be difficult to remove from metal. Stripping powder coating is challenging but possible using these methods:
- Methylene chloride-based chemical strippers can penetrate and swell the powder coat for removal. Multiple applications may be needed.
- Hold a heat gun several inches from the surface while scraping with a putty knife. The warmth softens the powder coat to make scraping easier.
- Sandblasting media at low pressure can abrade away powder coating without damaging the underlying metal. This requires hiring a professional with the right equipment.
- Use an angle grinder with a coarse wire wheel attachment to grind through the finish. Keep the grinder moving constantly to avoid grinding too far.
- For small furniture pieces like filing cabinets, an aircraft paint remover system with contained plastic bead media may be able to strip off powder coating when used properly.
Test to find the most effective stripping method for the particular powder coated finish without damaging the metal underneath. Expect the process to take more time and effort compared to stripping regular paint.
What Grit Sandpaper to Use When Stripping Metal Furniture?
After stripping paint or varnish from metal furniture, sanding ensures a smooth, even surface for reapplying finishes. Use these sandpaper grits:
- Coarse 80-100 grit to remove stubborn finish remnants, then smooth with 120-150 grit.
- Fine 120-220 grit for light smoothing of already stripped metal before repainting.
- Extra-fine 220-400 grit if applying an ultra smooth clear coat finish directly onto bare stripped metal.
The condition of the metal after stripping determines the sandpaper needed. For general smoothing, 120-150 grit works for most applications. Start gentle and work up to coarser paper only where absolutely needed.
Always sand in the direction of the metal grain and avoid excess pressure to prevent deep scratches. Wipe frequently with mineral spirits to clear residues. Lubricate sandpaper with liquid soap or oil for easing gliding over metal.
Proper finishing sanding seals bare metal, blends transitions, and prepares the ideal stripped substrate for flawless refinishing results.
What Products Can Be Used to Refinish Metal Furniture After Stripping?
After thoroughly stripping and preparing a metal filing cabinet or furniture piece, consider these products for refinishing:
Primers
- Metal primer – Forms a corrosion resistant base layer that finishes adhere well to.
- Epoxy primer – Extra durability and water resistance on metal for indoor and outdoor use.
- Rust inhibiting primer – Chemically converts rust into an inert layer if any remains after stripping.
Paints
- Alkyd enamel – Traditional durable gloss oil-based paint suitable for metal.
- Acrylic latex – Water-based option good for indoor metal furniture and low odor.
- Hammered finish – Creates a textured look resembling hand-hammered metal.
- High heat paint – Withstands temperatures up to 1,200°F for refinishing metal oven parts.
Clear Coats
- Polyurethane – Tough, protective clear coat that resists scratches and water damage.
- Spar varnish – Helps protect metal when used outdoors.Flexible to prevent cracking or chipping.
- Clear powder coating – Provides an attractive glossy transparent finish over stripped metal.
