TSP vs TSP Substitute (Krud Kutter, Simple Green)
When phosphate TSP actually matters versus when Krud Kutter or Simple Green clean just as well. A jobsite verdict on tsp vs simple green prep, per surface.
The 30-Second Answer
For most interior repaints, use a TSP substitute. Krud Kutter or diluted Simple Green cleans cabinet grease, trim hand-oil, and bathroom film well enough that the paint bonds, and you skip the phosphate etch, the caustic fumes, and the restricted rinse. Use real TSP only when the grime is heavy: kitchen-hood grease, woodstove soot, exterior chalk on siding you can rinse to soil. Either way, the cleaner is not a degloss step. Glossy surfaces still get scuff-sanded.
At a Glance
| Real TSP | TSP substitute (Krud Kutter / Simple Green) | |
|---|---|---|
| Cuts heavy grease & soot | 🟢 strongest | 🟡 good (Krud Kutter), 🟠 light only (Simple Green) |
| Light deglossing / etch | 🟡 slight caustic etch | 🔴 none |
| Residue after rinse | 🔴 alkaline film, rinse twice | 🟢 low residue |
| Safe on aluminum / paint film | 🔴 etches aluminum, can soften old paint | 🟢 safe |
| Rinse-water disposal | 🔴 phosphate, no storm drains | 🟢 down a household drain |
| Skin / lung hazard | 🔴 caustic, gloves + eye pro | 🟢 mild |
How to Tell Which Cleaner the Job Actually Needs
Wipe a damp white rag across the surface and look at it. Brown-yellow smear on a kitchen wall or cabinet is cooking grease. Black smear near a woodstove or fireplace is soot. A chalky white film that comes off bare exterior siding is oxidized binder. Those three are the real-TSP jobs. If the rag comes back with light gray dust and no oily smear, it’s ordinary settled grime, and any substitute handles it. Thirty seconds with a rag tells you more than the product label. Skip the test and you either over-clean a bedroom wall with caustic or under-clean a grease-loaded cabinet and watch the paint peel.
Cleaning Power on Grease
This is where real TSP earns its reputation. Trisodium phosphate is a strong alkaline salt. It saponifies grease, meaning it turns the oil into something water-soluble, then carries it off. On a 15-year-old kitchen cabinet with baked-on hood grease, full-strength TSP cuts it in one pass where a degreaser needs two or three.
Krud Kutter Original is the closest substitute. It’s a water-based surfactant degreaser, and on normal cabinet grease and trim hand-oil it does the job. On the worst grease (the sticky amber film above a stove), it’s slower but it gets there with a second application and a little dwell time.
Simple Green is the mildest of the three. Diluted, it’s a fine general cleaner for walls and dusty trim. On heavy grease it tops out. Use it concentrated and give it dwell time, or step up.
Winner: real TSP on heavy grease and soot. Krud Kutter is close enough for normal kitchens.
Deglossing and Etch
The myth is that TSP deglosses a surface so you can skip sanding. It doesn’t, not really. Because TSP is caustic, it slightly etches the top of the film and leaves a faint tooth. That’s all. It will not break a cured oil enamel or a factory cabinet finish enough to trust adhesion by itself.
The substitutes don’t etch at all. They’re pH-balanced cleaners. They remove contamination and leave the gloss exactly as glossy as they found it.
So here’s the rule that holds for every cleaner on this page: clean first, then create tooth. On glossy trim, cabinets, or old oil paint, scuff-sand with 220 grit or hit it with a liquid deglosser after cleaning. The cleaner gets the grime off. The sanding gives the new paint something to bite. For the full breakdown of when a chemical deglosser replaces sanding and when it doesn’t, see the deglosser vs sanding comparison.
Winner: real TSP by a hair, because the slight etch is better than nothing. Neither one replaces sanding.
Residue and Rinse
TSP leaves an alkaline film. If you paint over it without rinsing, that film sits between the substrate and the new coat and can drag down adhesion. So real TSP is a two-bucket job: wash bucket, then clean-water rinse, then a second rinse if the surface is large. Skip the rinse and you’ve cleaned the surface and then re-contaminated it with dried salt.
The substitutes are formulated low-residue. You still rinse (any cleaner leaves something), but one clean-water wipe usually does it instead of two. Less water on the wall also means a shorter dry-out before you can prime, which matters on a tight repaint schedule.
A wet substrate is a peeling substrate. Whichever cleaner you use, let the surface dry fully before primer. On cabinets and trim, that’s at least a few hours; on a humid bathroom wall, longer. Painting over a damp rinse is a top cause of early peel. See why paint peels for the rest of the adhesion-failure list.
Winner: TSP substitute. Lower residue, faster rinse, quicker dry.
Surface and Paint Compatibility
TSP has two compatibility traps. First, it etches aluminum and can dull or pit it. Keep it off aluminum window frames, gutters, and trim. Second, on old, soft, or already-failing paint, caustic TSP can soften the film and lift it, which is great if you’re stripping and bad if you’re trying to keep the existing coat.
The substitutes are inert toward aluminum and gentle on existing paint. You can clean an aluminum-trimmed door or a chalk-painted dresser without worrying that the cleaner is attacking the surface you want to keep. That makes them the default for furniture and laminate work, where you’re cleaning a piece you intend to leave mostly intact. The laminate furniture guide leans on a substitute degreaser for exactly that reason: laminate and its existing finish don’t want a caustic wash.
Winner: TSP substitute. Wider compatibility, fewer surfaces it can damage.
Safety and Cleanup
Real TSP is caustic. It dries and cracks skin fast, it stings eyes, and the dust irritates lungs if you mix the powder without a mask. Gloves and eye protection aren’t optional. Then there’s the phosphate. Phosphate runoff feeds algae blooms, which is why many regions restrict it and why you should never send TSP rinse water into a storm drain. On an exterior job, rinse onto soil or vegetation where the ground filters it, not down the driveway to the gutter.
The substitutes are mild. Bare-handed use won’t burn you (gloves are still smart on a long job), the fumes are low, and the rinse water goes down a household drain in most areas without a second thought. That’s the whole reason the phosphate-free formulas exist: the cleanup is ordinary, not a hazmat exercise.
Winner: TSP substitute, clearly.
A Word on “Phosphate-Free TSP”
There’s a third product worth naming: phosphate-free TSP, sold as TSP-PF or “TSP Substitute” in a box that looks like the real thing. It uses sodium carbonate (washing soda) and other salts instead of trisodium phosphate. It’s more alkaline and more aggressive than Krud Kutter or Simple Green, so it cleans heavy grime better than those two, but it skips the phosphate disposal problem. It’s the middle option. If you want stronger cleaning than a spray degreaser without the phosphate runoff, TSP-PF in a bucket is the pick. It still leaves an alkaline residue, so rinse it like the real thing.
Verdict by Use Case
- Pick real TSP if: the grime is heavy and the surface can take it. Kitchen-hood grease, woodstove soot, exterior chalk on siding you’re rinsing to soil. Best when you’re stripping or fully recoating anyway, so the slight etch and the rinse hassle are worth it.
- Pick Krud Kutter if: it’s a normal interior repaint with real grease. Cabinets, trim, a greasy backsplash wall. You want strong cleaning without phosphate, fumes, or aluminum damage. This covers most cabinet jobs.
- Pick Simple Green if: the surface is ordinary walls or dusty trim with no heavy grease. Living rooms, bedrooms, light-duty prep where you mainly want dust and hand-oil gone.
- Pick phosphate-free TSP (TSP-PF) if: you want bucket-strength cleaning on heavy grime but can’t or won’t deal with phosphate runoff.
- It’s basically a tie when: the surface is lightly soiled drywall in a low-traffic room. Any of them cleans it; pick whichever is already under your sink.
Top Picks by Side
Cleaning before a cabinet repaint? A substitute degreaser plus a scuff-sand is the standard prep. See the best cabinet paint round-up for what goes on after the surface is clean.
Prepping furniture or laminate? Stick with a substitute and follow the laminate furniture guide for the full clean-scuff-prime sequence.
Stripping a grease-loaded or smoke-stained wall? Real TSP or TSP-PF, two-bucket method, full rinse, full dry before primer.
What’ll Bite You in Two Years
The failure I see most isn’t the cleaner choice. It’s skipping the rinse, or painting before the surface dried. You clean a cabinet with TSP, leave the alkaline film, and the new enamel never fully bonds. Eight months later it chips at the door edges where a fingernail catches it, and it keeps spreading from there.
The second one is treating any of these cleaners as a degloss shortcut. Cleaned but unsanded gloss looks ready. It isn’t. The paint sits on a slick surface, holds for a season, then peels in sheets the first time the door gets bumped. Clean it, sand it, rinse it, dry it. In that order, every time.