Patio & exterior
Lithofin Stainstop PLUS dupe
Why pay around £43.80 for Lithofin? The bulk active is Lithofin Stainstop PLUS (same siloxane impregnator, 5 litre tin) — 8% less per working litre than a typical shelf pack.
From the retail pack to the active and the mix
1 · Retail
Lithofin Stainstop PLUS
1 litre · £43.80 typical snapshot
C9–C11 hydrocarbon solvent (white spirit)
2 · Active
Amino-functional dimethyl siloxane
17% on the label
69430-37-1
Bulk Lithofin Stainstop PLUS (same siloxane impregnator, 5 litre tin)
3 · Mix
Neat (ready to use; about 6–15 m² per litre)
£40.44 per working litre · 8% less than the shelf pack
- Active
- Amino-functional dimethyl siloxane
- CAS
- 69430-37-1
- Dupe
- Lithofin Stainstop PLUS (same siloxane impregnator, 5 litre tin)
- Saving
- 8% / L
Saving is per litre of working-strength mix versus a typical pack price, not versus the DIY kit total. Shop prices move — always check the listing.
Label teardown
What the pack promises versus what the label chemistry actually is.
The marketing claim
“Water- and oil-repellent impregnator that intensifies stone colour”
The chemical reality
Not Thompson’s water-based silane. The GB SDS for Lithofin Stainstop PLUS lists an amino-functional dimethyl siloxane (CAS 69430-37-1) at 15–20% in hydrocarbon solvent, plus a trace of methanol. It sinks in and darkens absorbent stone. Pro Tiler Tools lists the same tin at £43.80 for 1 litre and £202.20 for 5 litres (inc VAT) — about £40 a litre in the big tin, an 8% tin-size gap, not a stronger molecule.
Active vs filler
17% Amino-functional dimethyl siloxane · 83% carrier / filler — C9–C11 hydrocarbon solvent (white spirit)
- Typical retail
- £43.80
- 1 litre
- Estimated active cost
- £40.44
- Scaled from bulk £202.20 / 5 litres
- Indicative markup
- 1.1×
- Snapshot maths, not a live shop price
The Marketing Claim & The Catch
A 1 litre pack of Lithofin Stainstop PLUS typically retails around £43.80 in patio & exterior. That is a UK shelf-price snapshot for the maths on this page — not a live shop quote or a manufacturer RRP. Listings, sizes and deals move. The marketing line is that you are buying a finished lifestyle product, not a weighed chemical.
On the pack: Water- and oil-repellent impregnator that intensifies stone colour; Breathable finish for rough to honed natural stone, indoors and out; and Ready to use — brush, roller or cloth.
The catch: Not Thompson’s water-based silane. The GB SDS for Lithofin Stainstop PLUS lists an amino-functional dimethyl siloxane (CAS 69430-37-1) at 15–20% in hydrocarbon solvent, plus a trace of methanol. It sinks in and darkens absorbent stone. Pro Tiler Tools lists the same tin at £43.80 for 1 litre and £202.20 for 5 litres (inc VAT) — about £40 a litre in the big tin, an 8% tin-size gap, not a stronger molecule.
- “Water- and oil-repellent impregnator that intensifies stone colour”
- “Breathable finish for rough to honed natural stone, indoors and out”
- “Ready to use — brush, roller or cloth”
Proprietary Blend & Dosage Breakdown
The labelled active is Amino-functional dimethyl siloxane at 17%. Everything else in the pack is c9–c11 hydrocarbon solvent (white spirit).
At 17% active, most of what you pay for is carrier and packaging. The brand is selling convenience, fragrance and a label — not a uniquely potent molecule.
Branded working strength is whatever comes out of the bottle. The bulk alternative is 17% Lithofin Stainstop PLUS (same siloxane impregnator, 5 litre tin), mixed to Neat (ready to use; about 6–15 m² per litre).
- Labelled active
- Amino-functional dimethyl siloxane
- 17%
- Carrier
- C9–C11 hydrocarbon solvent (white spirit)
- Retail pack
- 1 litre · £43.80
The Active Chemical Alternative (Dupe Stack)
The dupe stack is Lithofin Stainstop PLUS (same siloxane impregnator, 5 litre tin) at 17% bulk. Indexed as CAS 69430-37-1. Buy it as 5 litres for around £202.20 from Amazon UK.
Working strength: Neat (ready to use; about 6–15 m² per litre). Indicative cost £40.44 per diluted litre — 8% below a typical branded pack on a per-litre basis, before you reuse leftover bulk.
Follow the mixing method and the supplier SDS. Wear the listed PPE. Do not mix incompatible oxidisers, acids or ammonia.
- Flammable solvent impregnator. Nitrile gloves, splash goggles, outdoors or very well ventilated. Aspiration hazard if swallowed. The siloxane fraction is an eye irritant; methanol is under 0.5% on the SDS. Keep off ignition sources, glass, plastics, asphalt and fresh paint.
- Stone must be clean, dry and free of wax. Apply neat with a brush, roller or cloth until the surface looks evenly wet. Do not puddle. On polished stone, wipe residues before they dry. Rough stone: keep it looking wet, then remove excess.
- Most solvent leaves in about two hours. Walk-on after 12 hours; full water-bead after 24–48 hours. Lithofin quotes about 6–15 m² per litre depending on absorbency (tighter on sawn granite, more on slate).
- The 5 litre tin is the same 15–20% siloxane. Five 1 litre tins at £43.80 are about £219; the 5 litre tin is £202.20. Do not dilute it with water, and do not swap it for a water-based octyltriethoxysilane.
- This is not a cleaner. Wash algae or oil off first (quat, hypochlorite, acid or degreaser — one chemistry at a time), rinse, dry, then impregnate.
Dilution recipe
1 L working batch
Working strength Neat (ready to use; about 6–15 m² per litre). Educational estimate from the listed ratio — check the SDS before you mix.
Chemical
1,000 millilitres
Lithofin Stainstop PLUS (same siloxane impregnator, 5 litre tin)
Water
0 litres
Carrier / diluent
100% concentrate · 0% water by working volume (solids are dissolved into the water share).
Required PPE
Loading calculator…
Side-by-Side Price & Potency Comparison
Head-to-head comparison
| Measure | Retail brandedLithofin | Raw active dupeDupeStack |
|---|---|---|
| Product | Stainstop PLUSAmazon UK search — listing, not a confirmed seller | Lithofin Stainstop PLUS (same siloxane impregnator, 5 litre tin) |
| Pack / unit | 1 litre · £43.80 | 5 litres · £202.20 |
| Active | Amino-functional dimethyl siloxane at 17%Carrier: C9–C11 hydrocarbon solvent (white spirit) | 17% bulk— |
| CAS number | Not disclosed on pack | 69430-37-1 |
| Working strength | Ready-to-use pack | Dilute Neat (ready to use; about 6–15 m² per litre) |
| Cost per litre | £43.80 / L typical pack | £40.44 / L mixed from bulk |
| Headline saving | Baseline | 8% cheaper |
| COSHH / PPE | Follow the branded SDS | Gloves. Chemical-resistant gloves (nitrile or neoprene)Eye protection. Indirect-vent splash goggles — not ordinary spectaclesVentilation. Use outdoors or with mechanical extraction |
Active ingredient and cheaper alternative — FAQ
Is Stainstop PLUS the same as Thompson’s Water Seal?
No. Thompson’s Water Seal is a water-based n-octyltriethoxysilane emulsion (CAS 2943-75-1), diluted from a 50% concentrate. Stainstop PLUS is a solvent-borne dimethyl siloxane reaction product (CAS 69430-37-1) at about 15–20%, used neat. Different molecule, different solvent, different look — PLUS darkens absorbent stone; Thompson’s is sold as a clear water-bead.
Will this stop algae the way Patio Magic does?
No. This is a water-repellent impregnator, not a biocide. Green film still wants BAC, DDAC, hypochlorite or an oxygen powder. Seal after the stone is clean and dry, not instead of the wash.
How do you mix the Stainstop PLUS dupe stack?
Flammable solvent impregnator. Nitrile gloves, splash goggles, outdoors or very well ventilated. Aspiration hazard if swallowed. The siloxane fraction is an eye irritant; methanol is under 0.5% on the SDS. Keep off ignition sources, glass, plastics, asphalt and fresh paint. Stone must be clean, dry and free of wax. Apply neat with a brush, roller or cloth until the surface looks evenly wet. Do not puddle. On polished stone, wipe residues before they dry. Rough stone: keep it looking wet, then remove excess. Most solvent leaves in about two hours. Walk-on after 12 hours; full water-bead after 24–48 hours. Lithofin quotes about 6–15 m² per litre depending on absorbency (tighter on sawn granite, more on slate). The 5 litre tin is the same 15–20% siloxane. Five 1 litre tins at £43.80 are about £219; the 5 litre tin is £202.20. Do not dilute it with water, and do not swap it for a water-based octyltriethoxysilane. This is not a cleaner. Wash algae or oil off first (quat, hypochlorite, acid or degreaser — one chemistry at a time), rinse, dry, then impregnate.
DupeStack provides chemical concentration data and educational mixing guides only. Wellness pages compare food supplements, not medicines or prescribed treatments. Always review the supplier Safety Data Sheet (SDS) and comply with UK Health and Safety Executive (HSE) and COSHH regulations when handling concentrated substances. Mixing and storage are at your own risk. Some links are affiliate advertisements (Amazon Associates, eBay Partner Network, and Awin when those programmes are live). Commissions do not change listed concentrations or calculator output.
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