Kilz vs Zinsser B-I-N vs Benjamin Moore Fresh Start: A Toronto Painter Compares Primers

Kilz vs Zinsser B-I-N vs Fresh Start: which primer actually blocks what?

Key Takeaways

• Water-based primers cannot reliably block water-soluble stains, because the water in the primer re-dissolves the stain it is meant to lock down
• Benjamin Moore Fresh Start 046 says in its own limitations that it is not recommended for sealing knots or over pine sap, and Zinsser routes knots to shellac even on its own oil-based primer's sheet
• Zinsser B-I-N publishes a maximum VOC of 550 g/L and a 12°C flash point. It is the strongest blocker here and the one to be careful with indoors
• "Kilz" is a family, not a product. Kilz 2's own sheet limits it to minor stains and directs heavy stains and fire damage to other Kilz products
• New drywall does not need a stain blocker. It needs a pigmented drywall primer, because the problem is uneven absorption between paper and joint compound, not staining

Most primer failures I get called to are not application failures. They are shopping failures.

Somebody had a water ring on a ceiling, went to the store, saw a shelf of white cans all promising to block stains, picked the one that said stain blocker on the front, rolled two coats, and watched a brown ring reappear inside a month. The primer worked exactly as designed. It was just the wrong chemistry for that stain, and nothing on the front of the can told them that.

So this is a comparison by what bleeds, not by brand. Three families: Kilz, Zinsser, and Benjamin Moore Fresh Start. And a mechanism at the centre of it that explains almost every primer failure in a house. If the stain you are fighting is nicotine or smoke rather than water, we deal with that case in painting over nicotine and smoke stains.

One thing first. If your question is whether you need primer at all, we answered that surface by surface in do I actually need primer. This article assumes you have decided you need one and are standing in front of the shelf trying to work out which.

The mechanism: why latex cannot block what shellac blocks

Most household stains that bleed through paint are water-soluble: tannin from wood, water stains from a leak, nicotine, soot, dye, marker. They sit in or on the substrate as dried residue. Put a water-carried primer over them and the water re-dissolves the residue, which then migrates up into the wet film and dries at the surface. You have not sealed the stain. You have given it a lift.

Cabot's technical bulletin on extractive bleeding puts it directly: since all water-based latex stains or paints use water as a carrier, they can actually create extractive discolouration problems (Cabot Technical Bulletin #2, Extractive Bleeding, updated 2/08).

Change the carrier and you change the outcome:

• Shellac primers are carried in denatured alcohol. Alcohol does not dissolve most water-soluble stains, and shellac dries to a hard, near-impermeable film very fast. This is why shellac is the reference standard for severe stains and the only chemistry here that claims to block odours.
• Oil and alkyd primers are carried in mineral spirits and block by forming a continuous non-aqueous film. Cabot's recommendation for tannin is explicitly a high-quality oil or alkyd stain-blocking primer, and it notes that acrylic latex stain blockers often need two coats to be effective.
• Acrylic and latex primers are carried in water. They are excellent at sealing porosity, evening out absorption, and bonding, and they are the low-VOC, low-odour, easy-cleanup option. They are the weakest at severe water-soluble stains, by chemistry rather than by quality.

The best confirmation of that hierarchy is not marketing, it is manufacturers routing customers away from their own products.

Benjamin Moore Fresh Start 046 is a 100% acrylic primer that claims to suppress tannin bleed, water stains, smoke damage, markers, crayons, nicotine, fingerprints, and coffee. Its limitations section then says: not recommended for sealing knots or over pine sap (BM Fresh Start 046 TDS, doc 046 US 030325).

Zinsser Cover Stain is an oil-based primer. Its own data sheet tells you to spot prime knots and sap streaks with B-I-N, the shellac product, before whole-surface priming with Cover Stain.

Two competitors, independently, both pointing past their own can toward shellac for the hardest stain. That is as close to an objective ranking as this category offers.

The three families, and what is actually in them

Kilz: one name, several very different products

The most useful thing I can tell you about Kilz is that "Kilz" is not a product. Buying the wrong one is the most common primer mistake in Toronto hardware baskets.

Kilz 2 All-Purpose is the water-based one most people reach for. Its data sheet lists what it blocks: minor water stains, rust, grease, ink, pencil, and felt marker. Note the word minor. The same sheet then directs you elsewhere for anything worse, naming Kilz Restoration, Kilz 3 Premium, or Kilz Original for heavy stains, and for fire restoration it rules itself out entirely and names Restoration or Original instead. VOC is under 100 g/L, coverage 300 to 400 sq ft per gallon, dry to touch 30 minutes and recoat at one hour. Drywall is explicitly listed. It is not recommended on flooring, and new masonry needs 30 days to cure first.

Kilz 2 is a perfectly good general-purpose primer. It is just not a stain killer, and the branding invites people to believe otherwise.

Kilz Original is the solvent-based one, and it does block much more. It also deserves a straight description of what you are bringing into your house. Its safety data sheet classifies it as Flammable Liquid Category 3 with a flash point of 23.9°C, Carcinogenicity Category 2, suspected of causing cancer, a Category 1 skin sensitizer, and Category 3 for narcotic effects. It calls for explosion-proof general and local exhaust ventilation. VOC is 442 g/L.

None of that makes it unusable. Painters have used oil primers for a century. It does mean Kilz Original is not the thing to roll across a whole condo interior with the windows shut in February.

Kilz Restoration (formerly Kilz MAX) is water-based, at 76 g/L for the coating, and is the product Kilz itself points to for heavy stains and fire work.

Kilz Adhesion is the bonding primer in the family. I could not verify its current VOC or coverage against a manufacturer document, so I am not printing numbers for it.

Zinsser: the stain-blocking specialists

B-I-N Shellac-Base is the reference standard, and its Canadian data sheet is worth reading in full if you ever deal with damage:

• Resin: shellac. Solvents: denatured alcohol and water
• VOC: maximum 550 g/L
• Coverage: roughly 500 sq ft per gallon practical
• Dry to touch 15 minutes, recoat 30 minutes, full cure 1-3 days
• Flash point: 12°C (54°F)
• Temperature: -18°C to 32°C, so it can be applied in freezing temperatures
• Humidity: relative humidity below 70%, and not within 9.5°C of the dew point
• Cleanup: denatured alcohol, or ammoniated detergent; tools in one part ammonia to three parts water
• MPI: #36, #46, #136

What it blocks, per the sheet: water, grease, rust, smoke, asphalt, graffiti, creosote, crayon, lipstick, markers, knots, sap streaks, tannin bleed, and dark colours. It is recommended for permanently sealing heavy fire and water stains and the odours caused by fires, and it seals urine and animal odours as well as nicotine stains and tobacco odour.

Odour sealing is the capability nothing else here claims. If you have bought a house that smells of cats or cigarettes, this is the product that solves it, and no amount of good latex paint will.

The limitations matter too: not for whole-surface exterior application, not for floors or decks or anything subject to immersion. Outdoors, B-I-N is a spot primer for knots and sap streaks, then you prime over it with something rated for exterior.

That 12°C flash point deserves a sentence of its own. It means the vapour is ignitable at ordinary room temperature. Zinsser's own guidance is to wear a NIOSH-approved respirator, provide adequate ventilation, and keep it away from flames such as a pilot light. In a Toronto basement with a gas furnace or water heater, that is not a theoretical warning.

B-I-N Advanced is where the naming gets genuinely confusing. Despite being sold as "synthetic shellac," its data sheet lists the resin type as acrylic, carried in glycol ethers and water. It is under 100 g/L VOC, cleans up with soap and water, dries to touch in 25 minutes, recoats in 45 to 60 minutes, seals for stains at two hours, and reaches full hardness in seven days. It seals tannin, knots, sap streaks, nicotine and cigar odour, fire and smoke, and pet urine. It is not for full exterior use, not for excessively humid interiors, and not under wallcoverings.

It is a genuinely useful low-odour alternative. It is not chemically the same thing as B-I-N and should not be treated as a drop-in substitute for severe fire work.

Cover Stain is Zinsser's oil-based primer: under 350 g/L VOC, 56.3% volume solids, coverage 400 sq ft on smooth and 300 on rough, dry to touch 35 minutes, recoat two hours, full cure four to seven days. It is called out as excellent for sealing water-soluble tannin bleed on cedar and redwood. And, as noted, it defers to B-I-N on knots.

Benjamin Moore Fresh Start: the current line is smaller than you think

If you have read older articles about Fresh Start you have probably seen product codes that no longer apply. Benjamin Moore's current Fresh Start line is 046 (High-Hiding All-Purpose, acrylic), 032 (Undercoater and Primer/Sealer, alkyd), and 094 (Deck and Siding). Codes 023, 027, and 028 are legacy. Do not spec them.

The other correction worth making: 046 is 100% acrylic, and 032 is the alkyd. Plenty of comparison articles have those the wrong way round.

Fresh Start 046 (acrylic):

• VOC under 50 g/L, the lowest here, and flash point none
• Volume solids 41 ± 2%, coverage 400-450 sq ft per gallon
• Dry to touch 30 minutes, recoat one hour, water cleanup
• LEED v4 eligible, CDPH emissions certified, CHPS, MPI 6/17/39/50/137, ASTM E-84 Class A
• Spec'd for drywall, plaster, wood, Formica, Masonite, ceramic tile, and exterior wood, aluminum, hardboard, vinyl siding and masonry
• Not recommended for sealing knots or over pine sap
• On hard non-porous surfaces, maximum adhesion and hardness may take 3-4 days
• $87.99 CAD per 3.78L on Benjamin Moore Canada's own site

That CDPH emissions certification is worth more than the VOC number alone. VOC is a content figure; CDPH is a chamber-tested emissions standard. In a nursery, a condo you are moving into next week, or an allergy household, it is the credential I would actually look for.

Fresh Start 032 (alkyd):

• VOC under 350 g/L, volume solids 58 ± 2%, the highest-build primer here
• Coverage 400-500 sq ft per 3.79L, dry to touch one hour, recoat or sand at two hours
• Mineral spirits cleanup, flash point 33.3°C, MPI 45 and 136
• Spec'd for water stains, tannin bleed and tannin-rich woods, smoke damage, markers, crayons, nicotine, and coffee
• Named by Benjamin Moore as the undercoater for interior wood trim and doors, for enamel holdout
• Carries a spontaneous combustion warning: rags, steel wool, or waste soaked in it can catch fire if improperly discarded. Seal them in a water-filled metal container

Enamel holdout is the reason 032 exists and it is under-appreciated. On trim, a high-solids alkyd undercoater stops the topcoat sinking into the substrate unevenly, which is what produces that patchy, dull-in-places look on a sprayed door.

That chart is the trade-off in one picture. The primers that block the most are the primers you least want to breathe. Which is exactly why the right approach is usually to spot prime the problem with the strong stuff and use something low-VOC everywhere else, rather than coating an entire condo in shellac.

The decision table: match the primer to the defect

New drywall is a different problem entirely

This is where people over-buy the most, so it is worth separating out.

The defect on new drywall is not a stain. It is joint photographing, also called joint banding: the finished joints show through the paint as shadows. The Gypsum Association defines it as the shadowing of the finished joint areas through the surface decoration (GA-214-2021, Levels of Finish for Gypsum Panel Products).

USG explains the cause: decorating problems commonly called joint banding or photographing are usually caused by differences between the porosities and surface textures of the gypsum panel face paper and the finished joint compound, and are magnified by the use of gloss paints. And the fix, in USG's words: unlike a sealer, a drywall primer does not provide a film that seals the surface, it minimises porosity differences by equalising the absorption rate between the face paper and the finished joint compound, and supplies the pigments and fillers to equalise surface texture differences.

Three practical consequences:

1. A stain blocker is the wrong tool here. Shellac at 550 g/L will not fix differential absorption any better than a $50 drywall primer, and it costs far more in money and air quality.
2. Dark and non-flat colours make it worse. GA-214 says non-flat and dark or deep-tone paints are not recommended over a Level 4 finish and directs you to Level 5, a full skim coat, which it calls the most effective method to minimise joint photographing. If you are painting new drywall a deep navy in gloss, the primer will not save you. The finish level has to be higher.
3. Temperature matters before you ever open a can. GA-214 requires a minimum of 10°C maintained continuously for 48 hours prior to and throughout finishing. Toronto basements in March routinely fail that.

There is a related trap on damaged drywall. Zinsser's procedure for torn facing paper or exposed gypsum core is to spot prime with Zinsser GardZ first, skim coat with drywall mud, and then prime with B-I-N. Skipping straight to B-I-N over torn paper does not fix a torn-paper problem.

For repair work specifically, we cover the sequence in the Toronto tenant's guide to drywall repair, and the wider prep order in our wall prep guide.

Speed, and the thing that fools people

Primer dry times vary more than paint dry times, and B-I-N's are startling:

Thirty minutes to recoat is genuinely useful when you are spot-priming a ceiling and want to get the finish coat on the same afternoon.

But note the caption. Recoat is not cure. STIX recoats in three to four hours and needs three to four days to reach maximum resistance to scrape-off. Fresh Start 046 recoats in an hour and warns that on hard non-porous surfaces, maximum adhesion and hardness may take three to four days to develop. Two separate Benjamin Moore documents landing on the same three-to-four-day window is not a coincidence, and it is the reason primed cabinet doors and trim chip when they go back into service too quickly.

Bonding primers: the "no sanding" claim, honestly

Two products here claim adhesion to glossy surfaces, and both add a caveat.

Zinsser B-I-N states excellent adhesion to glossy surfaces without scuff sanding. It is literally named a primer-sealer, stain killer, and bond coat.

INSL-X STIX is a urethane-modified acrylic bonding primer: VOC 87.6 g/L, volume solids 40 ± 1%, coverage 300-400 sq ft per 3.79L, tack free in 30 minutes, recoat in three to four hours, and a minimum application temperature of 1.7°C. It bonds to PVC, vinyl, most plastics, glass, tile, glazed block, glossy paints, pre-coated siding, fibreglass, galvanized metals, and Formica.

STIX also carries the honest caveat: although it is formulated for hard-to-coat surfaces without sanding, proper surface preparation should still be completed, and Formica, ceramic tile, and glossy painted surfaces should be properly deglossed. Its limitations rule out immersion, below-grade use, polyethylene and polypropylene, and whole-house exterior priming over wood.

My rule after twenty years: a bonding primer buys forgiveness, not a free pass. On a surface nobody touches, bonding primer alone is fine. On trim, doors, handrails, or cabinets that get handled every day, scuff sand and use the bonding primer. For the specific case of old oil-based trim, we go through the test and the sequence in how to paint over glossy oil trim.

Pricing in Toronto

Only the Benjamin Moore figure was confirmed directly on a retailer page; Home Depot Canada blocks automated price checking, so treat the rest as indicative and check the shelf.

The more useful point is one of proportion. On a cabinet job the same logic applies to the topcoat, which we compare in Advance vs Command vs Emerald vs Cabinet Coat. On a Toronto interior repaint, the difference between the right primer and the wrong one is a few tens of dollars. The cost of getting it wrong is doing the room again.

How I actually buy primer for a house: one gallon of Fresh Start 046 or a comparable low-VOC drywall primer for the general work, and a quart of B-I-N in the van for the three or four specific things that need it: the ceiling ring, the knot in the new trim, the marker on the kid's wall. Spot prime the defects, general prime the surfaces. That approach costs less and puts far less solvent in the house than picking one strong primer for everything.

If you have a stain that keeps coming back, that is usually a diagnosis problem rather than a product problem, and it is worth having someone look at it before you buy another can. A water ring that reappears may mean the leak was never fixed.

Call me directly at (416) 875-8706 or request your free quote. Send a photo of the stain if it is easier and I will tell you what it will take.

We handle drywall repair and painting and water damage repair as one job rather than sending you to two trades, which matters when the repair and the stain-blocking have to happen in the right order.

Bottom line for Toronto homeowners

The pattern across every row: primer is chosen by the defect, not by the brand, and the strongest product is almost always the one you should use least of.

About the author

Chad Caglak is the co-owner and lead painter at HomePaintersPro, a Toronto-based residential painting company. He has spent more than 20 years diagnosing why paint fails in Toronto homes, from water rings in Cabbagetown Victorians to nicotine-saturated condo units that needed sealing before anything else could happen. His work covers primer and stain-blocking specification, shellac and alkyd and acrylic chemistry, tannin and extractive bleed, and drywall finishing levels.

He writes about Toronto painting from the job site, not from a marketing desk. Every specification here comes from the manufacturer's own technical or safety data sheet, and where a figure could not be confirmed against a primary document, including several retail prices, this article says so instead of supplying one.

Knows about: primer and stain-blocking specification, shellac and alkyd and acrylic primer chemistry, tannin and extractive bleed, drywall finishing levels and joint photographing, Toronto residential painting.