Precleaning / Surface preparation before painting
It is most essential to completely clean all the oil, loose rust, dust, dirt grease and foreign matters form inside, outside of the steel tubes, angles, channels, metal and fabrications. Post painting anti corrosion depends grossly upon the total and complete pre-cleaning.

Important facts to use hydrochloric acid based de-rusting
Never use hydrochloric acid for MS or GI tubes pickling. Though very fast in cleaning, the acid will surely leave residual acid ions, in the micro-pores and crevices of the metal surface. This phenomenon is called as hydrogen embrittlement. This causes post cleaning corrosion (sub-surface corrosion) on the metal. Rusting will take place with double the speed. Re-rusting can happen from one day to 60 days. Rusting will take place below paint / coating film ( creeping corrosion ) the chloride fumes are continuously generated from HCI and these fumes pose a great health hazard to the operators, will corrode the steel structures, building trusses, metal buildings, chimney , steel stored in the nearly vicinity of this metal cleaning / pickling area. These fumes spread hydrogen chloride ions in the atmosphere and are very dangerous to mucous membrane and lungs and will prove as a very serious health hazard. These fumes will be extremely detrimental to the overall functioning of the equipment. Salvage costs will prove to be phenomenal in this case.

Process for carbon steel / mild steel and galvanized steel structural fabrications:-

Rustogel 1406: Rust cleaning and removal process by brushing application
The vertical and standing galvanized steel structures, support structures, get rusted due to oxidation in humid, damp and moisture in the atmosphere. This rust must be removed before applying any kind of paint. Rustogel is a phosphoric acid based de-rusting gel (viscous brushable liquid). It is applied by brushing all over the rested ms / gi fabrication. It is allowed to react with the rust for 10 to15 min. This loosens the rust. This treated surface is water washed neatly and immediately dried by using compressed air blow. The structure must be painted within 8 hours. Rustogel is water based acidic cleaner, is rohs compliant and safe for workmen. Rustogel is offered at Rs. 70 per kg in 35 kg HDPE Carbuos packing + Vat Ex Pune works.

De-rusting process by using oil based chemicals are very slow in rust removal (There is no chemical etching for rust removal and may need 4 hrs to 24 hrs for moderate rust removal). Oil based chemical cleaners are basically rust preventives, apart from slow action, these cleaners also leave a oil barrier coating on the treated surface. Due to oil film, this will totally mar adhesion for any paint/coating (zinc rich paint coating in this case). Hence oil based cleaners are not recommended for such applications which involve painting process, post de-rusting.

Zinc rich paints / Zinc metal sprays
These products offer a uniform zinc metal powder coating on all ms and galvanized metal. When used as recommended, zinc rich paints offer 15 to 20 years of total corrosion free surface. The company offer four products in this range. Zinkote 20 GP and premium and Tefkote 21 (PTFE Teflon blended zinc rich paints grades are offered in 20 litres packing can ex Pune .

Thinner for zinc rich paints: Toluene; XYLENE, Stoving ( Bhatti ) Thinner or NC thinner no 1 or 2 . Do not use GP Thinner / MTO. This will GEL with paint.

Salient features, quality standards and USP
These paints / sprays confirm to the requirements of most Indian, British and ASTM specifications. These Paints offer 20 to 25 microns film, 88 to 92 per cent zinc in the DFT, zinc purity of 99 per cent +. Pass 500 Hrs salt spray (15 yrs + in the normal weather conditions) Pass Cross Cut Hatch Test for Adhesion as per IS Specs. Complete details on all these Tech properties are available in company’s literatures / website.

Safety Pre-Cautions
During entire pickling, cleaning and painting process, every operator / worker must use all the safety gear, goggles, rubber aprons, gum boots, hand-gloves etc. In case of spillage / splashing of any of the treatment chemicals, flush the affected area with plenty of running water for 2-5 minutes.

Effluent treatment
All wash waters, floor swipping, splashing of chemicals must be neutralised by adding lime water, alkaline water, alkaline waste. Final pH of out-going water must be maintained between 7 to 8.5.

Contact:

Pradeep Vaidya, CEO,
Innovative Coating Industries
MIDC, Pune
Thane: B-7 / 701,
Vedant Comlex, Vartak Nagar Naka,
Thane (West) – 400606
Mobile: 09820181738
Email: puvpromtech@gmail.com
Sonia Vaidya, Tech
Mktg Executive, Thane
Tele: +91-22-25883265,
9819813015
Email: soniavaidya30@gmail.com