Every contaminant on every part belongs to one of two chemical families, and the difference decides what will remove it. Non-polar contamination is built mostly of carbon and hydrogen with charge spread evenly through the molecule — it repels water and shrugs off anything watery. Polar contamination carries uneven charge — partial positives and negatives — and it bonds happily with water and anything ionic.
The oldest rule in chemistry — like dissolves like — says a solvent removes what resembles it. Water, the most polar liquid there is, dissolves salts and minerals beautifully and slides straight off oil. That is the whole reason cleaning chemistry exists: to bridge the gap between a water-based bath and the soils water cannot touch.
A cylinder head off a high-hour diesel wears oil film and coked carbon (non-polar) over ash and corrosion (polar). A marine heat exchanger carries lubricant residues on one side and calcium scale with chloride attack on the other. A fire-damaged tool carries PAH-laden soot bonded onto flash rust. One bath cannot dissolve both families at once — the chemistry that attacks one barely notices the other.
The answer is sequence, and it is why our machines and processes are built in stages: an alkaline stage to strip the organic load, rinse, then an acid-side stage for scale and ash, rinse again, then protection. The two-stage carbon-and-ash chain on the chemicals page — alkaline decarboniser followed by RegeniK ash dissolution — is exactly this science applied to DPFs and engine components.
1 · Diagnose before you dose. Name the soil before choosing the drum: is it oil-family or mineral-family — or layered? A wipe test tells you a lot: oily smear says non-polar; white, crusty or rust-coloured says polar; both says staged process.
2 · Match the strength to the soil, not the frustration. When a correct-family chemistry stalls, the answer is usually temperature, time or the next strength up in the same family — not switching families, and not doubling the concentration. Needing to run far above recommended concentration is evidence of the wrong product, not the cure.
3 · Respect what the chemistry also wants to attack. The same acid that dissolves scale dissolves zinc plating; the same alkali that saponifies grease etches aluminium. Every product card in our range states its material cautions up front — read them as part of the diagnosis, not after the damage.
The fastest way to get the diagnosis right is to let the laboratory make it: send parts carrying the real contamination and the trial returns the family, the product, the concentration and the cycle — proven, not guessed.
That is a ten-minute answer in the laboratory — and the wrong guess costs a drum, a bath, and sometimes a part. Send us the real contamination.