The best soldering fluxes, compared.
Top pick: Quimtech liquid flux – Highest score on review depth (4.6 from 3,472) and a stated electronics RMA formula at about £11.11. Best value: Yiapinn paste flux – Lowest price in the set at about £3.69, with 4.5 from 742 reviews on a no-clean rosin paste tin. Updated October 2026.
If the joint will not wet, the missing piece is often flux you add yourself, not another length of flux-cored wire. Nothing here is an IPC cleanliness test or a wetting lab. What separates a useful tin from a frustrating one is chemistry you can read, a container that stays sealed, and residue you can accept. Rosin fumes are an asthma hazard in HSE guidance. A no-clean line on the listing is not permission to breathe the plume. A typical listing does not state a UKCA mark or a BS EN flux class in the fields we used. The decision order without the ranking sits in the [soldering flux buying guide](/hub/soldering-and-welding/soldering-flux/sub/soldering-flux-buying-guide). Soldering flux is a chemical you put on the joint so molten solder wets the metal instead of balling up. In this UK comparison it means a separate paste, gel, liquid, or a kit that includes flux. Flux-cored solder wire, and desoldering wick sold on its own, are different purchases. If the joint still will not wet, you may need a pot or a syringe as well as wire.
If the joint will not wet, the missing piece is often flux you add yourself, not another length of flux-cored wire. Nothing here is an IPC cleanliness test or a wetting lab.
28 products checked · 62 hrs invested · +21,400 readers
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Personal buying guide
Question 1 of 2
What are you joining?
Quimtech’s 30 ml bottle is the deepest review file in this comparison: 4.6 from 3,472 amazon.co.uk ratings at £11.11, sold as RMA rosin mildly activated liquid for electronics. The listing claims a neutral pH, RoHS-compliant wording, and a formula free of zinc chloride and ammonium chloride, aimed at tin-lead and lead-free alloys plus gold, silver and copper. United Kingdom reviewers describe daily use, metal that cleans well for soft soldering, and liquid that runs into the joint rather than sitting like paste. The same file includes a cap that was very hard to open, a tinned PCB that went black with poor flow, and a buyer who went back to paste. The included-components line names the bottle only, so do not assume a needle arrives. It is the top pick here when you want liquid flux with a large review sample and will ventilate, because RMA rosin still fumes.
Pros
Cons
Best for: Through-hole and soft-solder electronics where a brushable liquid suits the joint and you will ventilate.
Less suitable: Fine SMD pads where liquid floods the neighbourhood, or anyone who needs paste that stays put.
Specifications
Common questions
What form is the Quimtech flux?
It is a 30 ml liquid bottle. The included-components line names the bottle only, so do not assume a needle arrives.
Does the listing state no-clean?
No-clean is not stated on this listing. The chemistry line is RMA rosin, mildly activated. RMA rosin still fumes when heated, so ventilate.
Where do the price and stars come from?
The price is about £11.11 and the star line is 4.6 from 3,472 reviews on the amazon.co.uk listing. This is not a lab test.
The LA-CO 22105 Regular tin is 125 g of paste at £9.10, and a United Kingdom review in the file uses it on 15 mm solder-ring plumbing fittings rather than on a phone board. The amazon.co.uk line in this comparison is 4.6 from 270 reviews, with buyers calling it easy to use and saying the residue cleans off. Several texts still complain that the brush shown in older photos is missing, and that the previous lid had a handy brush. Amazon’s recommended-use field also names electronic components, which clashes with that plumbing use, so read the supplier sheet before you put Regular paste on a PCB. The material-type row lists alloy steel and tungsten without explaining the paste. For occasional copper or brass work where a trade-branded tin matters, it is the large pot in this set.
Pros
Cons
Best for: Occasional solder-ring or coarse metal work when you want a branded 125 g tin and will check the supplier sheet.
Less suitable: Fine PCB or SMD work, and anyone who expected a lid brush in the tin.
Specifications
Common questions
Is LA-CO Regular for electronics?
A UK review uses this 125 g tin on 15 mm solder-ring fittings. The recommended-use field also names electronic components. Those signals clash. Read the supplier sheet before the paste goes on a PCB.
Does a brush come in the tin?
UK reviews say the brush shown in older photos is missing, and that an earlier lid had a brush. Do not buy this tin expecting an applicator in the box.
At £3.69 the Yiapinn rosin paste tin is the lowest price in the set, with 4.5 from 742 reviews and a rank line of 1 in Solder Pastes on the capture. United Kingdom buyers repeatedly say it is easy to put on solder spots, cleans off afterwards, and does everyday repair, including small electronics jobs. The listing says no-clean, no acid and lead-free rosin paste, while the title says 10 g and the weight fields say 20 g. One reviewer found the tin smaller than expected, one said it dried faster than other brands, one reported fumes that hid the joint, and one said solder would not stick despite three solders. Those are single reports rather than a pattern of defects, but they limit what a cheap pot can promise. It is the best value here for occasional bench paste if you reseal the lid.
Pros
Cons
Best for: Occasional electronics paste when you want the lowest price with a large review sample and will reseal the tin.
Less suitable: Metered syringe work on fine SMD, or a workshop that needs a known gram weight without a listing conflict.
Specifications
Common questions
Is the Yiapinn paste no-clean?
The listing states no-clean, no acid and lead-free rosin paste. No-clean still produces fumes. One review reported fumes that hid the joint. Ventilate if you solder more than the odd joint.
Is the tin 10 g or 20 g?
The title says 10 g and the weight fields say 20 g. Treat that as a listing conflict, not a settled pack size. One reviewer found the tin smaller than expected.
The second BEEYUIHF kit is the same £3.99 shape with a clearer rework brief: 10 ml of #9530 no-clean rosin paste with active agents, two tips, and 3 m of 2.5 mm wick, at 4.5 from 110 reviews. The listing aims it at phone PCBs, BGA and SMD ball work. United Kingdom buyers mention a precision nozzle, flux that helps solder wet the pads, a slightly sticky film that cleans with isopropyl alcohol, and braid that lifts solder after a mistake. One text calls it handy for occasional practice on small kits. You still get only 10 ml of flux, and the material line is simply Rosin. It is the stronger of the two wick kits on review count, though it is still a small syringe rather than a 30 ml bottle for brushing larger joints.
Pros
Cons
Best for: Occasional SMD and pad clean-up when you want wick in the same bag as the paste.
Less suitable: Coarse plumbing joints, or anyone who needs more than 10 ml of paste for a longer session.
Specifications
Common questions
What is in the #9530 kit?
About £3.99 buys 10 ml of #9530 no-clean rosin paste, two tips and 3 m of 2.5 mm desoldering wick. The flux portion is small. Judge the paste, not the wick, if flux is what you came for.
Does no-clean on this kit mean no fumes?
No. The listing states no-clean rosin. UK buyers mention a sticky film that one person cleaned with isopropyl alcohol. Rosin still fumes when heated.
BOJACK’s listing is a 30 ml no-clean syringe plus a 5 ml syringe you fill from the large one, with a needle and push rod, at £9.99. The amazon.co.uk line is 4.5 from 32 reviews, a thin sample next to Quimtech or Yiapinn. Two United Kingdom texts both call it fiddly: one says it was effective but fiddly, and another says it was fiddly while learning yet seemed to work. The bullets claim acid-free, lead-free, no-clean paste for phones, SMD, PCB and BGA work, with very little residue. Those are seller lines, not a cleanliness test. Pack weight is about 46 g in one bullet and 60 g on the package row. Choose it when you want a needle for spot work and will accept a small review count.
Pros
Cons
Best for: Spot rework if you already like working from a needle and can live with a small review sample.
Less suitable: Beginners who want a simple dip tin, or buyers who want hundreds of reviews behind the paste.
Specifications
Common questions
How many reviews does the BOJACK syringe have?
The amazon.co.uk line is 4.5 from 32 reviews, at about £9.99. That is a thin sample next to Quimtech or Yiapinn. Two UK texts call the syringe fiddly and say it worked.
What applicators are listed?
The listing describes a 30 ml no-clean syringe, a 5 ml syringe you fill from the large one, a needle and a push rod. No-clean on the bullets is not a fume-free claim.
This BEEYUIHF kit pairs a 10 ml no-clean rosin syringe, listed as 10 g and marked #7500, with 3 m of 2.5 mm copper desoldering wick for £3.99. The star line is 4.5 from 24 reviews, so treat it as a small sample. A United Kingdom review describes thick paste that stays put until heated, two blunt needles, a plunger, and wick that works with the flux. Another UK text says the flux cleans surfaces and the wick tidies mistakes. A reviewer who paid about six pounds still called the bundle decent value; the shelf price in this file is £3.99. Chemistry is rosin no-clean on the listing, not a published flux class. Buy it when you want a cheap flux-plus-wick pair and will not lean on 24 reviews as proof.
Pros
Cons
Best for: A first rework pair of paste and wick when the price matters more than review depth.
Less suitable: Buyers who want the larger review sample on the #9530 kit, or a standalone 125 g tin.
Specifications
Common questions
How does the #7500 kit differ from #9530?
Both are about £3.99 with a 10 ml syringe and 3 m of 2.5 mm wick. This #7500 listing has 4.5 from 24 reviews. The #9530 kit has 4.5 from 110 reviews and names phone PCB, BGA and SMD work.
Is the paste thick?
One UK review describes thick paste that stays put until heated, plus two blunt needles and a plunger. That is a single report, and the review count is only 24.
The Gruiqrd four-piece set at £15.99 is a starter box rather than a flux-only purchase: paste, lead-free solder wire, a dry tip cleaner and micro cutters, with 4.4 from 303 reviews. United Kingdom texts praise the cutters, a useful tip cleaner, and a decent pot of flux with a roll of solder for learning electronics. One reviewer notes that the box still omits the iron, and another is unsure whether the paste suits PC boards and micro-soldering. Package weight is 270 g, but the paste mass itself is not stated. At the highest cash price in this set you are paying for tools around the flux. It suits a first bench if you already own an iron and will treat the paste chemistry as unspecified.
Pros
Cons
Best for: A beginner who already owns an iron and wants wire, paste and cutters in one parcel.
Less suitable: Anyone buying flux by the gram for SMD rework, or a bench that already has cutters and a tip cleaner.
Specifications
Common questions
Is the Gruiqrd box only flux?
No. At about £15.99 the set is paste, lead-free solder wire, a dry tip cleaner and micro cutters. The iron is not in the box. The paste mass and chemistry are not stated.
Will the paste suit micro-soldering?
One UK reviewer is unsure whether the paste suits PC boards and micro-soldering. Treat the chemistry as unspecified and do not buy this set for a known flux class.
The GZGRYTRC six-piece listing at £7.59 claims three 20 g rolls and two 30 g rolls of 0.8 mm rosin-core wire plus 35 g of flux paste. The same capture has no customer star line and no review bodies, and the package dimensions say 10 × 10 × 0.5 cm and 10 g. That weight cannot hold 35 g of paste plus five wire rolls, so the box contents are unproven in this file. Best Sellers Rank is 94,423 in DIY & Tools and 67 in Solder, with a first-available date of 25 June 2026. Bullets promise low spatter and no residue issues, which are seller sentences rather than buyer reports. Consider it only if you will check the live page for reviews and the actual box weight before you rely on the title.
Pros
Cons
Best for: Only a buyer who will verify fresh reviews and the real box weight before trusting the title.
Less suitable: Anyone who wants a known flux mass and a review sample before the parcel arrives.
Specifications
Common questions
Why is there no star rating?
The capture has no amazon.co.uk star line and no review text. The price is about £7.59. Check the live page before you treat the title as the contents of the box.
Can the parcel weigh 10 g and hold the titled rolls?
The title claims several 0.8 mm wire rolls plus 35 g of paste. The package row says 10 × 10 × 0.5 cm and 10 g. That weight cannot hold the titled contents, so the flux mass is unproven here.
Scores rank the eight amazon.co.uk listings on this page only, using the shelf captured on 20 October 2026. They are not IPC cleanliness results, BS EN flux classes, or a wetting lab test. Star lines with no rating in the capture stay on a low base.
Amazon star line
35%Scaled from the amazon.co.uk rating. A 4.6 maps toward 92, a 4.5 toward 90 and a 4.4 toward 88. A listing with no star line starts from a low base.
Review depth
20%Thousands of ratings add confidence. Under about 50 ratings the bonus is capped. A missing star line scores zero on this block.
Job fit
20%Form (tin, syringe, liquid or kit), the chemistry the listing actually states, and whether that listing matches electronics or coarse metal work.
Review sentiment
15%UK review themes on the listings: wetting, a missing brush, fiddly syringes, dry-out and poor flow. Repeated complaints cost more than a single report.
Price band
10%Value inside this shelf, including how much flux you get rather than wick, wire or cutters alone.
Choose flux for the joint you actually make, then for the container, then for the residue and the fume. The eight listings on this page are the ones that stayed after category-fit checks on amazon.co.uk. A plumbing paste and a phone-board flux solve different problems, and the listings do not always keep those jobs apart. Kits can look cheap per parcel and dear per gram of flux, because wick, wire and cutters are in the price. Prices, stars and review counts are the stored amazon.co.uk figures.
Soldering flux is a chemical you put on the joint so molten solder wets the metal instead of balling up. In this UK comparison it means a separate paste, gel, liquid, or a kit that includes flux. Flux-cored solder wire, and desoldering wick sold on its own, are different purchases. If the joint still will not wet, you may need a pot or a syringe as well as wire.
Active paste for solder-ring fittings can be the wrong chemistry for a PCB or SMD pad. LA-CO Regular’s plumbing review and its electronics recommended-use field do not agree. Read the supplier sheet before the paste touches a board.
No-clean is a residue claim on the listing, not a statement that rosin fume is safe to breathe. HSE links rosin-based solder flux fume to occupational asthma. Use extraction for repeated work and keep your head out of the plume.
Flux-cored solder and a wick without flux do not replace a separate paste or liquid when the joint will not wet. Kits in this set add those extras around a small flux portion. Score the flux, then decide if you wanted the wick at all.
Job and chemistry decide whether a tin belongs on your bench. Fine PCB and SMD work needs a mild rosin or a no-clean flux matched to the solder, plus a decision about washing whatever film remains. In this set that is the direction of the Quimtech RMA liquid, the Yiapinn rosin paste, the BOJACK syringe and the two BEEYUIHF rosin syringes, which are sold with electronics wording. Plumbing and coarse copper or brass may suit a more active paste.
Form decides how much flux lands on the joint. A metal tin, such as Yiapinn or LA-CO, suits a bench pot and tip tinning, and it dries if you leave the lid off. A syringe, such as BOJACK’s 30 ml or the 10 ml BEEYUIHF kits, suits BGA, SMD and spots. UK buyers call the BOJACK syringe fiddly, and the review count is only 32. A liquid bottle, Quimtech’s 30 ml, brushes larger pads and runs into the joint, and it can flood neighbouring SMD pads. The included-components line names the bottle only.
Three typical situations, each with a recommendation from this comparison.
You repair phones, consoles or LED boards now and then and want a small paste you can reseal. The Yiapinn tin is about £3.69 with 4.5 from 742 reviews. The title says 10 g and the weight fields say 20 g, so treat the mass as unresolved.
You want liquid that runs into the joint and a large review sample. Quimtech’s 30 ml RMA bottle is about £11.11 with 4.6 from 3,472 reviews. Ventilate, because RMA rosin still fumes, and do not assume a needle is in the box.
You want a branded 125 g tin for solder-ring or coarse metal work. LA-CO Regular is about £9.10 with 4.6 from 270 reviews. A UK review uses it on 15 mm fittings, while the recommended-use field also names electronics, so read the supplier sheet first.
In this set of eight amazon.co.uk listings, Quimtech’s 30 ml RMA liquid is the top pick for electronics where a brushable liquid and a large review sample matter. Yiapinn’s rosin paste is the best value at about £3.69 if you reseal the tin and accept the 10 g versus 20 g listing conflict. LA-CO Regular is the coarse-metal tin, not a default for fine boards. No listing here states a BS EN flux class, and no-clean wording is not a fume-free claim.
Quimtech liquid flux
Highest score on review depth (4.6 from 3,472) and a stated electronics RMA formula at about £11.11.
Yiapinn paste flux
Lowest price in the set at about £3.69, with 4.5 from 742 reviews on a no-clean rosin paste tin.
Editorial
Peter F. is the editor for DIY & tools at productscompared.co.uk. Comparisons in this category are checked against amazon.co.uk listings, review evidence and public UK sources.
Guides on what to look for, how to use a product, and common mistakes.
Public UK sources from the research digest, last checked on 20 October 2026.
This article contains affiliate links. If you buy through these links we may earn a small commission, at no extra cost to you. Prices, stars and review counts come from stored amazon.co.uk listings. We did not run a lab test.
