How is varnished trim painted in an older Saint John home?

Painting over varnished trim in an older Saint John home requires proper deglossing and priming — skip either step and the new paint will peel within months.

Older Saint John homes are full of beautiful wood trim — wide baseboards, door casings, window surrounds, and built-in millwork — often coated in oil-based varnish that's been applied in layers over decades. That varnish creates a hard, slick surface that fresh paint simply cannot bond to without preparation. The good news is that with the right approach, you can get a crisp, durable finish that does justice to the original woodwork.

Surface Prep Is Everything

Start by cleaning the trim thoroughly. Older Saint John homes, especially in the South End and older neighbourhoods, often have trim coated in a combination of varnish, old oil paint, nicotine film, and decades of grime. Wash with a TSP (trisodium phosphate) solution or a strong degreaser, rinse well, and let it dry completely before doing anything else.

Once clean, you need to break the gloss so the primer has something to grip. You have two options: mechanical scuff-sanding or liquid deglosser. Scuff-sanding with 120-150 grit sandpaper is the more reliable method — sand with the grain until the sheen is uniformly dulled across the entire surface. Liquid deglosser (sometimes called liquid sandpaper) is faster but less thorough on heavily built-up varnish. For thick, old varnish that's in good condition, sanding is the better choice. If the varnish is cracking, flaking, or bubbling, those areas need to be stripped back to bare wood before priming.

Lead Paint Warning

This is critical for older Saint John homes. If your home was built before 1978 — and many Saint John homes predate that by 50 to 100 years — there is a very real chance the trim has lead paint underneath the varnish layers. Never sand or scrape without testing first. Pick up a lead test swab kit at a hardware store (they're inexpensive and take minutes to use). If lead is present, use wet-sanding methods to suppress dust, wear a P100 respirator, and contain your work area carefully. For extensive stripping of lead-painted trim, hire a professional with lead-safe work practices — this is not a corner to cut, especially with children in the home.

Priming and Painting

After sanding, prime with a high-quality bonding primer or an oil-based or acrylic-alkyd primer — these adhere far better to slick varnished surfaces than standard latex primers. Zinsser BIN (shellac-based) is an excellent choice if there are any stains, knots, or discolouration in the wood. Apply one full coat, let it cure completely, then lightly sand with 220 grit before your finish coats.

For the finish, use a premium acrylic-alkyd hybrid trim paint — Benjamin Moore Advance or Sherwin-Williams ProClassic are the top choices available in NB. These paints level beautifully (minimising brush marks), cure to a hard, washable finish, and hold up to the daily wear that trim takes. Apply two coats in semi-gloss or satin, sanding lightly between coats with 220 grit for the smoothest result.

DIY vs. Professional

Painting trim in a single room is a reasonable DIY project if you're patient with prep and comfortable with a brush. However, if your Saint John home has extensive original millwork, multiple rooms of trim, or suspected lead paint, a professional painter will save you significant time and deliver a noticeably cleaner finish — especially on detailed profiles and corners. Need help finding someone local? New Brunswick Painting can match you with a painting professional in the Saint John area for a free estimate through the New Brunswick Construction Network.