Mildly Acidic Ultrasonic Cleaner Solution vs Alkaline for Salalah Port Ships
Engine-room parts at Salalah Port come out of service with two kinds of dirt. One is burnt oil, carbon and soot. The other is rust, oxide and calcium scale from seawater cooling. A mildly acidic ultrasonic cleaner solution dissolves the rust and scale, and an alkaline ultrasonic cleaner lifts the oil and carbon. Use alkaline for fuel injectors, lube oil filter candles and valves, and a mild acid for rust and scale on steel. If parts carry both, run the alkaline bath first and the acid bath second. We supply alkaline ultrasonic cleaner concentrates from our Barka warehouse, with delivery to Salalah and Dhofar.
Mildly Acidic vs Alkaline Ultrasonic Cleaner: The Quick Answer
Choose by the soil and by the metal. Alkaline ultrasonic cleaning solutions are the usual general-purpose choice. They remove oil, grease, dust, soot and organic soils from iron, non-ferrous metals, glass, plastic, ceramic and rubber. Acidic solutions work best on scale, oxidation and tarnish. They are only mildly effective on oil, grease and cutting fluids.
A lube oil filter candle coated in sludge goes into an alkaline bath. A cast iron pump casing with rust bloom, or a cooler plate with white calcium scale, needs a mild acid. A heat exchanger plate with oil over scale needs both, in that order.
What a Mildly Acidic Ultrasonic Cleaner Solution Removes
A mildly acidic ultrasonic concentrate is diluted with water, typically to 1 to 5% depending on how dirty the parts are. It removes oxide film, rust, lime, mineral deposits and corrosion, plus some oil and grease. Acidic ultrasonic solutions are typically around pH 4.0, and some go as low as pH 2.5. A mild corrosion-removal grade typically cleans in about 2 minutes. Citric acid cleaners also belong to this mild group, and they help passivate stainless steel and titanium.
Use only mild grades. Very strong acid, such as 70% sulfuric, removes scale but also attacks the carbon steel underneath. Strong acids, especially hydrochloric, can cause pitting or hydrogen embrittlement on stainless and ferrous metals. Acidic formulations suit ferrous metals. They are not for light alloys that corrode easily, such as aluminium and magnesium.
Strong acids such as nitric, sulfuric, formic or hydrofluoric must never go into an unprotected stainless ultrasonic tank. In a ship's workshop, put the acid in an acid-resistant plastic insert and fill the main tank with water plus surfactant to carry the ultrasound. Acidic cleaners are corrosive and hazardous to handle. Wear gloves and eye protection, and keep an eyewash station within reach.
What an Alkaline Ultrasonic Cleaner Removes on Ships
An alkaline ultrasonic degreaser removes grease, oil, coolant, carbon, soot and wax from injectors, carburettors, gears, bearings, filters and screens. Oil and wax float to the surface, so you can skim them off and reuse the bath. On ships, alkaline ultrasonic cleaners are used on fuel and lube oil filters, cylinder heads and air coolers. Typical use is 5 to 25% in water at 50 to 70 °C for 5 to 30 minutes.
Our Ultrasonic Cleaner (RXSOL-16-3006-025) is a water-based alkaline, low-toxic product developed for ultrasonic cleaning. It contains corrosion inhibitors and no hydrocarbon solvents, and it is biodegradable and non-flammable. It is suitable for engine components like fuel and lube oil filters, injection nozzles, pump components, inlet and exhaust valves.
For heavier carbon on steel, use our Ultrasonic Cleaner Alkaline (RXSOL-16-3006-210). It is a highly alkaline, water-soluble solution used mainly on mild steel and stainless steel, and it removes carbon and oil by the dipping method. It is also listed as compatible with oily-water separators. If you prefer a powder, Ultrasonic Cleaner PD 450 (RXSOL-26-8660-030) is a highly alkaline powder made for steel, cast iron or stainless steel parts. Never use it on aluminium.
Choosing by Part in a Salalah Port Engine Room
- Fuel injectors and injection nozzles: use alkaline. Carbon and burnt fuel are organic soils.
- Lube oil filter candles: use alkaline. Dismantle them first, for example by removing the rings from the candles. Immerse them fully, keep the parts separated, then spray them with a strong water jet.
- Purifier discs and stainless parts: use alkaline for the sludge. Follow with a mild acid only if mineral scale is still there after degreasing.
- Air cooler fins: use alkaline for the oil film. Check the fin metal before any acid step, because acid is not for aluminium.
- Heat exchanger plates with seawater calcium scale: degrease with alkaline, then descale with a mild acid.
- Aluminium pistons and turbocharger parts: test light-alloy parts for 5 to 10 minutes first. Strong alkaline solutions can quickly etch aluminium, magnesium and zinc. For these metals, neutral or mild alkaline solutions (pH 8 to 10.5) are recommended.
- Zinc and galvanised parts: mild alkaline marine cleaners do not suit zinc or galvanised parts. Our RXSOL-16-3006-210 may attack zinc, aluminium and magnesium at concentrated solutions.
The same method applies ashore to heat exchanger parts, nozzles and pump parts. In every case, degrease first and descale second.
Ultrasonic Cleaner Dilution, Temperature and Cycle Time
Ultrasonic cleaning solutions are often run at 49 to 82 °C. If the bath is too hot, volatile components boil off. If it is too cool, the surfactants may not work. Low-foaming, free-rinsing formulas suit ultrasonic baths best.
| Item | Mildly acidic class (typical values) | Ultrasonic Cleaner | Ultrasonic Cleaner Alkaline | Ultrasonic Cleaner PD 450 |
|---|---|---|---|---|
| Part number | Generic class, no part number | RXSOL-16-3006-025 | RXSOL-16-3006-210 | RXSOL-26-8660-030 |
| Form and pH | Liquid concentrate, typically around pH 4.0, some as low as pH 2.5 | Water-based alkaline liquid | Colourless, pH neat 12, density 1.0 g/cm3 at 20°C | Highly alkaline powder |
| Application | Rust, oxide film, lime, mineral deposits and corrosion | Fuel and lube oil filters, injection nozzles, pump components, inlet and exhaust valves | Carbon and oil removal on mild steel and stainless steel by dipping | Heavy duty degreasing, carbon dust, rust and burned oil removal on steel, cast iron and stainless steel |
| Dosage | Typically 1 to 5%, about 2 minutes | Fresh 1% solution (10 grams in each liter of water) | On request | 5-10%, 50 to 80°C, typically 5 to 20 mins |
| Metals | Ferrous metals; not for aluminium or magnesium | Can be used on soft metals such as copper, aluminum, zinc and magnesium if rinsed promptly. Corrosion testing may be advisable. | May attack zinc, aluminium and magnesium at concentrated solutions | NEVER use with Aluminum |
| Packing | Not applicable | 1 Ltr, 5, 10 and 25 Ltr | 25 Ltr, 50 Ltr and 210 Ltr | 5 Kg Jar and 25 Kg Bucket |
| MSDS | On request | |||
For RXSOL-16-3006-025, make a fresh 1% solution, which is 10 grams in each liter of water, in cold, warm, or hot water. Use warm water if you have it. For difficult soils, raise the water temperature and use more detergent. Do not use it in spray machines, because it will foam.
For PD 450, fill the tank with water, preferably DI or soft, and add the powder at 5-10%. Heat the bath to 50 to 80°C, immerse the parts and run the ultrasound, typically for 5 to 20 mins. Rinse the parts thoroughly with water afterwards, then dry them by air blow or in an oven if needed.
Two-Step Cleaning and Flash Rust in Salalah Humidity
- Degrease the parts in the alkaline bath and skim off the oil that floats up.
- Rinse them with a strong water jet so no alkaline cleaner carries over into the acid.
- Descale them in a mildly acidic bath. If the acid is stronger than a mild grade, use a plastic insert.
- Rinse thoroughly. Stronger acidic grades need a good rinse or neutralising.
- Dry the parts straight away with compressed air or in an oven, then preserve them.
Steel parts flash rust quickly in the damp air of the khareef season on the Dhofar coast. Bare steel coming out of an acid bath is the most exposed. To give ferrous parts temporary protection, add a rust inhibitor to the cleaning or rinse tank. Then dry the parts at once and oil or wrap them before they go back to the store. Some alkaline engine-part degreasers contain silicates to prevent flash rusting, which also helps at the first step.
Looking After the Ultrasonic Tank and the Bath
Metal fines and hard particles in a used bath wear holes in the tank bottom. Clean them out each time you replace the solution. Chemicals not designed for ultrasonic use can corrode the tank. A contaminated bath stops cleaning well, so renew it regularly.
A bath is spent when cleaning takes longer than before, an oil layer keeps coming back after skimming, or sludge builds up on the bottom. Skim off floating oil at the end of each shift. Dispose of spent solution according to local regulations. On a vessel at Salalah Port, ask your ship agent about the port's waste reception for oily and chemical waste.
Where to Buy Ultrasonic Cleaner in Salalah
Salalah Chemical (RXSOL group, Oman) ships from our Barka warehouse, with deliveries to Salalah and Dhofar. That includes vessels at Salalah Port and plants in the Salalah Free Zone. Call +968 77333599 and give us the part list, the metals and the type of deposit, and we will match the cleaner and the pack size. Our liquid grades come in packs from 1 Ltr up to 210 Ltr, and PD 450 comes in 5 Kg jars and 25 Kg buckets. You can find related products in our deck, cabin and galley maintenance range.
The same alkaline ultrasonic cleaner is listed on our Muscat site for buyers in Muscat. It is also on our Sohar site for vessels at Sohar port. A fleet that calls at several Oman ports can therefore quote one part number everywhere.
To request a quote, message us on WhatsApp at +968 77333599 or use our contact page. Give us the part number, the pack size and your delivery point in Salalah.
Frequently asked questions
When should I use an acidic ultrasonic cleaner instead of an alkaline one?
Use a mildly acidic solution for rust, oxide, lime and mineral scale on ferrous parts. Use an alkaline cleaner for oil, grease, carbon and soot. Acidic solutions are only mildly effective on oil and grease, so parts with both deposits go through the alkaline bath first and the acid bath second.
Is an alkaline ultrasonic cleaner safe on aluminium, zinc or galvanised parts?
Strong alkaline solutions can quickly etch aluminium, magnesium and zinc. For these metals, neutral or mild alkaline solutions at pH 8 to 10.5 are recommended. Test light-alloy parts such as pistons and turbocharger parts for 5 to 10 minutes first. Our RXSOL-16-3006-210 may attack zinc, aluminium and magnesium at concentrated solutions, and PD 450 must never be used with aluminium.
Can I put acid directly into a stainless steel ultrasonic tank?
Strong acids such as nitric, sulfuric, formic or hydrofluoric must never go into an unprotected stainless ultrasonic tank. Put the acid in an acid-resistant plastic insert, and fill the main tank with water plus surfactant to carry the ultrasound.
How do I stop flash rust on steel parts after ultrasonic cleaning in Salalah?
Add a rust inhibitor to the cleaning or rinse tank to give ferrous parts temporary protection. Then dry the parts straight away with compressed air or in an oven, and preserve them with oil or wrapping before storage. This matters most during the humid khareef season and after an acid step.
How often should the ultrasonic cleaning solution be changed?
Renew it when it stops cleaning well: cleaning takes longer, an oil layer keeps returning after skimming, or sludge builds on the bottom. When you change the bath, remove metal fines and hard particles, because they wear holes in the tank bottom. Dispose of spent solution according to local regulations.