Rust Halt Rust Converter Gel Spray, 1 Litre
Spray it on, watch the rust turn black, paint over it in 3 hours. A trade-strength rust converter gel that clings to rails, brackets and panels instead of running off.
- Ready-to-use gel in a trigger spray
- Clings to vertical rails, brackets and seams
- Covers approx. 6–8 m²
- Converts in about 20 minutes, paint over in 3 hours
- Converts-or-it's-free guarantee
- Free next-day delivery: order by 3pm, ships today
Need the other size? Rust Halt 5L trade size, £49.99
1L gel spray
Clings to railingsIf you've typed any of these into Google
- "Rust converter that actually works"
- "Rust converter not turning black"
- "Does rust converter work?"
- "How much rust converter do I need?"
- "Rust converter cheap"
- "Can rust converter be painted over?"
Real UK search phrases. Every one is answered on this page.
What a litre usually costs
- Leading-brand rust converter, 1 litre£35.69–43.99
- Rust Halt Gel Spray, 1 litre£19.99
Jenolite Rust Converter 1L: £43.99 at jenolite.com, £39.50 at Homebase, £35.69 lowest of 7 stores on PriceRunner. Checked 9 November 2026.
How does rust converter work?
Rust is iron oxide, and it's porous. It holds water and oxygen against the steel underneath, so it keeps growing. Paint over it and you've sealed the problem in. That's why it bubbles back through by next winter.
Rust Halt changes what the rust is. Its phosphoric acid reacts with iron oxide and turns it into iron phosphate, a hard, stable layer that's no longer rust and that paint bonds to. Loose flaky rust dissolves; the tight rust left in pits and seams is converted where it sits. That's what "converts rust to primer" on the label means.
Not just phosphoric acid. Rust Halt is a phosphoric complex. We process it with ultrasonic technology so the active phosphoric acid is held inside surfactant-coated droplets, a micro-emulsion. Those droplets wet into pits and seams, cling to vertical steel, and release the acid where it meets the rust, so it converts evenly instead of running off.
You can watch it work. As Rust Halt converts the rust, it turns black and dries to a hard, paint-ready finish. If it turns black, it has worked.
Where it works, and where it won't
We'd rather tell you now than sell you a bottle for a job it can't do.
- Surface and pitted rust on iron and steel
- Gates, railings, fencing and steelwork
- Machinery, trailers, tools and plant
- Sills, arches, chassis rails and subframes
- Holes and rot: cut it out and weld it
- Aluminium, stainless, chrome or galvanised
- Rust you leave unpainted indefinitely
Before you buy any rust converter
Whichever brand you choose, it should tick all four.
- Converts the rust you can't sand outNot just paint that hides it. A chemical change in the pits and seams.
- Comes in the right form for the jobA gel spray that stays on vertical rails and panels, and a bulk size for long runs of steel.
- Leaves a surface paint sticks toA converter you can't paint over is a dead end.
- Backed by the people who made itA guarantee in writing, from the manufacturer, not a reseller.
How to use rust converter: four steps
No sandblaster. It converts in about 20 minutes, and you can paint over it after 3 hours.
Brush off the loose stuff
Wire-brush flakes and scale, and degrease. You don't need bright metal.
About 15 minutesApply
Spray the gel straight on. It clings to vertical rails and panels. Two thin coats beat one thick one.
About 10 minutesLet it work
Leave it to convert. You'll see the rust turn black. Then let it dry.
About 20 minutes to convertPaint
Paint over the converted surface once it's dry. Outdoors, a good topcoat is what keeps water off.
After 3 hours
Got a bigger job?
Most rust jobs need both: a gel spray for the fiddly bits and a bulk size for the long runs. The trade bundle gives you two of each for less than the price of three litres of the leading brand.
Best value2 × 5L + 2 × 1L Rust Halt for £9912 litres at £8.25 a litre. £139.96 bought separately, so you save £40.96.See the trade bundle deal →What you get, and what it costs
Rust Halt Gel Spray 1L
- Rust Halt Rust Converter Gel Spray, 1 litre£19.99
- Converts-or-it's-free guaranteeIncluded
- Next-day deliveryFree
£19.99 a litre, against £35.69–43.99 a litre for the leading brand.
Rust converter compared, per litre
The best rust converter in the UK is the one that suits your job and that you can afford to use properly. Here's how the main options line up.
| Jenolite | Fertan | Neutrarust 661 | Rust Halt 1L | |
|---|---|---|---|---|
| Per litre | £35.69–43.99 | £31.99–45.99 | £44.95 | £19.99 |
| Chemistry | Water-based converter | Tannin-based | Water-based, non-mineral-acid | Phosphoric complex (micro-emulsion) |
| Coverage | 6–8 m²/L | 12–15 m²/L | 10–12 m²/L | 6–8 m²/L |
| Cost per m² | £4.46–7.33 | £2.13–3.83 | £3.75–4.50 | £2.50–3.33 |
| Made by | Brand manufacturers, sold through retailers | Mifica, sold direct | ||
Prices for 1L seen 9 November 2026: Jenolite at jenolite.com, Homebase and PriceRunner; Fertan at frost.co.uk and marinestore.co.uk; Neutrarust 661 on eBay UK. Chemistry and coverage are as stated in each product's own listings. Cost per m² is price per litre divided by stated coverage.
If it doesn't convert the rust, you don't pay.
Prep the steel as directed (loose rust off, grease off) and apply. If the treated rust hasn't converted within 24 hours, send us a photo and your order number. We refund you, and you don't need to send the bottle back.
What it covers: rusted iron and steel prepared and treated as directed. What it doesn't:
- Aluminium, stainless, chrome or galvanised surfaces
- Metal rotted through. That needs welding, not treatment.
- Rust returning because the treated surface was left unpainted
We can offer this because we make it. Rust Halt is formulated and filled at our own plant in East Kilbride, and every batch is tested before it ships.
Order tonight. Treated by Saturday.
- Tonight
Order by 3pm. Packed and shipped from our Glasgow unit.
- Tomorrow
Your order arrives by courier, free.
- Saturday a.m.
Wire-brush, degrease, apply. Kettle on while it works.
- Saturday p.m.
Three hours later, paint it.
- Sunday
Second coat of paint, if you want one.
- Next winter
No orange bleeding through.
Gates, railings, steelwork, machinery
For rust treatment on gates and railings, steelwork and machinery, car bodywork and chassis, and household metal.
How much do you need?
Tick your jobs.
Based on approximately 6–8 m² per litre, one coat; the checker uses 6 m² to be safe. Heavy pitting uses more.
Phosphoric acid rust converter: the specs
Formulated by our own chemists, made and filled in East Kilbride, and batch-tested before it leaves.
- FormulaPhosphoric complex: ultrasonically processed micro-emulsion
- FinishBlack, paint ready
- Sizes1L gel trigger spray · 5L jerrycan
- CoverageApprox. 6–8 m² per litre
- Clean-upWater, straight after use
- ConvertsAbout 20 minutes
- Paint overAfter 3 hours
- ForIron and steel only
What our trial customers say
★★★★★ 4.5 out of 5 from 24 reviews
From customers who bought Rust Halt in our pre-launch trial, before it went on general sale. All 24 reviews are shown as written, including the 3- and 4-star ones.
Brought my Land Rover chassis back to life
Applied Rust Halt to the rear crossmember and underside of my Defender 110 after wire-brushing the flaking stuff off. Turned black within about 20 minutes. Painted over it with chassis black two days later and it looks solid as a rock.
Game changer for garden furniture
Had an old wrought iron bench that was looking ready for the tip. Sanded the worst off, brushed this on, and watched the rust turn to a dark cured layer. Repainted it dark green and it looks brand new. Super easy to use.
Does exactly what it says on the tin
I've used chemical rust converters before that left a sticky mess, but Rust Halt dries to a tough, hard primer finish. Easy cleanup with water off the brushes too.
Essential for garage restorations
Used this on an classic Mini subframe. Penetrated deep into the pitted areas that wire wheels just can't reach. Excellent coverage rate—a little goes a very long way.
Saved my greenhouse frame
Rust spots were taking over the base legs of our metal greenhouse. Brushed Rust Halt straight on after a quick scrub down. Stopped the rust in its tracks before winter hit.
Great barrier coat
Was skeptical at first, but the black reaction is really satisfying to watch. You can physically see it working. Provides a top key for overcoating.
Used on outdoor steel gates
Our driveway gates were badly pitted. Applied two thin coats of Rust Halt, waited for it to cure, then put a trade satin coat over top. Zero bleed-through after three months of rain.
Brilliant for van conversion prep
Treated all the surface rust on the interior floor of my Sprinter before insulating and ply-lining. Gives total peace of mind knowing the rust won't spread underneath the floor.
Saves hours of grinding
If you deal with rusted steel frames, this saves so much labor time. You still need to remove loose scale, but you don't have to grind down to bare silver metal everywhere.
Read all 24 reviews
Feathered edge works great
Worked brilliant on the arches of my daily driver. Sealed the area nicely ready for filler and touch-up paint.
Viscous enough not to drip everywhere
Perfect consistency. Not like water, so it doesn't run down your arm when working underneath a vehicle.
Ideal surface prep
Dries fast, cures hard, takes acrylic and enamel topcoats without any lifting or reaction. Will keep a bottle on the shelf permanently.
Trade strength performance
As a steel fabricator doing refurb jobs, Rust Halt performs as well as, if not better than, the big legacy chemical brands. Very impressed with the barrier layer.
Restored an old cast iron radiator
Scraped the heavy flaky bits, wiped it down, and brushed on Rust Halt. Worked into all the tight decorative crevices seamlessly.
So simple to use
No complicated mixing required. Just pour a small amount into a pot, brush it on, and let the chemical reaction take place.
Unbeatable value
Bought the larger size for treating trailer chassis rust. Coverage was fantastic and performance was top tier.
Works great, but don't skip the prep work
Excellent product, but word of advice: you MUST scrub off thick loose scale first. It won't magic away thick crusty rust flakes, but on surface rust and pitted metal, it turns it solid black fast.
Good product, wear gloves!
Does a fantastic job sealing surface oxidation, but make sure you wear nitrile gloves when applying—it will stain your skin black if you splash it!
Solid converter, needs 2 thin coats
Found one thick coat can pool a bit in corners. Two light coats with a brush gave an even black key coat ready for topcoat.
Great results, took a bit longer to dry in cold weather
Worked really well on my boat trailer rust. Took a couple of hours to fully turn black and dry because I was working outdoors in November, but cured rock hard by next morning.
Saves time on steel fence posts
Treated 12 rusted fence posts. Worked very well. Only downside is brush clean-up needs to happen immediately before it cures on the bristles.
Does the job, but pour into a separate pot first
Product works fine, turned rust to a hard black surface. But DO NOT dip your brush directly into the main container—it will contaminate the rest of the liquid in the bottle.
Average drying time, decent seal
It converts rust okay, but takes slightly longer to cure than solvent-based rust converters I've used in the past. Fine if you aren't in a rush to topcoat immediately.
Good for light to medium rust
Great for minor surface rust on car panels, but on heavy structural corrosion you really still need to cut out bad metal. Handy to have in the shed though.
Rust converter questions, answered
What is rust converter?
A chemical treatment that changes rust into a stable compound instead of just covering it. Rust Halt is a phosphoric complex that turns iron oxide into iron phosphate, which you then paint over.
Does rust converter work?
Yes, on sound iron or steel with surface or pitted rust, when you brush the loose stuff off first and paint over it afterwards. It won't fix metal that's rotted through. That needs welding.
How does rust converter work?
Phosphoric acid reacts with iron oxide and forms iron phosphate, a hard, inert layer that's no longer rust and that paint bonds to. Loose rust dissolves and the tight rust in pits is converted in place.
Rust remover vs rust converter: which do I need?
A remover takes rust off to bare metal, which is best for parts you can soak or strip. A converter treats rust in place on gates, frames and seams you can't get back to bright metal.
Rust converter or primer: do I need both?
Rust Halt converts the rust into a primed, paint-ready surface; that's the "converts rust to primer" on the label. Paint over it after 3 hours. Outdoors, a good topcoat is what keeps water off for the long term.
Is it a rust converter paint?
No. It's the treatment that goes on before your paint, which is why it works out cheaper: you're not paying for paint you'd put on top anyway.
What's the difference between the 1L and the 5L?
The 1L is a ready-to-use gel in a trigger spray that clings to vertical surfaces. The 5L is the trade size for brushing on or decanting into your own sprayer. The £99 trade bundle gives you two of each.
How much do I need?
About 6–8 m² per litre, one coat. So the 1L covers roughly 6–8 m². Use the job checker above.
Why hasn't it turned black?
It needs rust to react with, so clean bright metal won't change colour. If rusty areas don't turn black, there may be oil or grease on the surface, thick loose scale still in place, or it's cold: in winter it can take a couple of hours. If it still doesn't convert, the guarantee covers it.
Tannic acid vs phosphoric acid rust converter?
Both convert rust in place. Tannin converters form a tannate layer; phosphoric acid converts rust to iron phosphate and etches the surface, giving paint a strong key. Rust Halt is a phosphoric complex: ultrasonically processed so the active acid sits in surfactant-coated droplets that wet into pits and cling to vertical steel.
Will it damage paint, chrome or alloy?
Keep it off anything you don't want marked: chrome, aluminium, stone and good paintwork. Mask around the repair and wipe off splashes straight away.
When will it arrive?
Order by 3pm Monday to Friday and it's dispatched the same day from our Glasgow unit by courier, delivered next working day, free, UK mainland.
What if it doesn't work?
Converts or it's free: send us a photo and your order number and we'll refund you.
Made in East Kilbride by the people who formulate it
Rust Halt is made by Mifica, a UK chemical manufacturer. We formulate and produce coatings, cleaning and surface-care chemicals and garden products at our own plant, and have done since 2017. We sell direct through mifica.com, Amazon, eBay and TikTok Shop.
Rust Halt is made the same way: formulated in-house, batch-tested, filled and dispatched from our own site. There's no importer or distributor and no retailer margin, which is the whole reason it costs £19.99 a litre here and £35–44 a litre on the shelf.
Mifica Products is a trading name of Natures Merchant Ltd, company no. SC571495 · Manufacturing & dispatch: Units 1–5 South Cathkin Farm, Glasgow G73 5RG · 0141 459 0168
Fabricators, gate makers, garages, farms
Pallet quantities and trade accounts direct from the manufacturer. Call 0141 459 0168 or see trade accounts.
Rust guides from the people who make it
Treat it once. Paint it. Done.
Rust Halt Gel Spray 1L · ready to use · clings to vertical steel · converts in 20 minutes · paint over in 3 hours · £19.99 a litre · converts or it's free · free next-day delivery.
