Acid in Gel form for Stainless Steel Cleaning

Many years ago there was a product available from most very good hardware stores in the U.S.A.. It was called "Naval Jelly" and it was thick and did not easily run, and it did not dry. It works by etching away a very thing layer of metal and corrosion.

This stuff is still available from http://www.mcmaster.com/ Just type Naval Jelly in the dialogue box and you will be taken to the page. Funny that you mention your need, as I need to buy some myself to clean some tarnished chrome.

Regards,

Ing. Robert Forbus

We use a company called Anopol http://www.anopol.co.uk/ in the UK for 304 stainless cleaning products, they make pastes & gels. Our equipment is high vacuum & has to be cleaned to meet the standards of the semiconductor industry.

Numerous companies use a xantham gum powder that retails for about $ 7.00 per pound to make a gel slurry that basically changes water to a jel solution that is capable of a tremendous cling on most metals, woods and plastics. A production group will add the desired cleaner ( acid or alkaline ) to this jel solution for the desired results. In metal finishing it is used to remove milkstone and weld burns in large food processing tanks, they use it to passivate some stainless steels and also for removal of laser HAZ scale and tenacious mil scales and rusts. Xanthum gum is commonly used to thicken mayonaisse among other foods and is a key part of the kids "gummy bears" type candies. The xantham gum powder basically looks like "Tang" orange juice powder and needs approximately 4 - 8 ounces of the powder into a gallon of ambient temp water and mix aggressively for about five minutes to make your desired jel consistency. When the solution is observed to cling to the stirring stick / mixer rod and cling for about five minutes you can add the desired acid / alkaline cleaner to your hearts content. High alkaline products like a smokehouse / oven cleaner might require say 6-8 ounces of powder to get the ideal cling effects time. One gallon of the final jel mix solution will cover about 100 square feet of surface area and you will need a high spray pressure impingement to remove the jel solution after the desired cleaning time is done. Jel will stay moist on your parts surface four up to four hours if a ambient 65 F - 90 F water is used to mix it up. Hotter temperature waters will dry the jel out prematurely. Jel solution can be painted on, dipped on, rolled on with a brush and sprayed through a hand held pressurized sprayer or with a large sprayer / foamer. Unused solution should be stored in a properly marked and sealed container as per plant SOP's and should stay stable for two months plus some. Its nice because it reduces vapors, extends cling and dwell time, can be used on large parts where building a spray or soak tank is not cost effective or not practical and its very forgiving. If you buy a pre-mixed solution expect to pay $ 15 - $ 30 plus per gallon as compared to a mix solution that you could easily make as ( strong or weak ) as needed for your particular needs for @ $ 5 - $ 7 per gallon. It is ideal for passivating a stainless steel 304 and developing a chrome rich oxide surface on the welded areas of the surface. Nitric acid and citric acid packages that are used in passivating stainless steels will go into the jel solution very easy. It will also hold phosphoric acids in place where any weld burns, weld smuts, free tramp iron and heat tint areas are needing attention.

Hello Lampola,

You have given me a lot of advice for which I am very much grateful. English is not my 1st language so I may not be able to express my thanks properly, but I would like to know that I value you advice very much.

I am based in Sri Lanka (close to India) and so does not have the access to sales Reps like in the US! typically we try to do develop most of the things we need for two reasons, non availability ex-stock and also price factor.

Thanks once again

Sisira

I meant to include in the previous note most of today's chemical companies have both the ready to use gel packages or xantham gum and the various cleaners in their sales line items. If your close to your vendor and this is a fairly small one time job most sales reps will get you a no-charge sample for a couple of hundred square feet.

First consider the type of cleaning to be done--Is it general cleaning of minor blemishes, or is it hard to remove oxides from heat, such as produced by welding?

Acid is only a very generic term, and the exact type of acid is critical to success.

Further different types of acids will destroy different types of thickeners.

For the latter type of cleaning I use Classic Pickling paste-101 by AverstaPolaritt Welding AB, Chemical Products.

This product contains Nitric and Hydrofluoric acids, thickeners and polishing agents, and is made for removing stubborn stains.

The above acids are highly toxic and hazardous to work with, but are necessary for heat blemish oxide removal.

Hydrofluoric acid with a small electric current passed through it (20v 500mA) works best.

To do this, ground the metal to a terminal of the power supply(I forgot the polarity) then use a hemostat to hold a cotton swab which is saturated with the acid, and connected to the other supply terminal to wipe away the oxidation.

The above method will remove virtually all types of blemishes--Try both polarities.

Using the method I have removed oxidation which previously needed to be ground away using stones, where stainless wire brushing would not work.

The Classic Pickling Paste works with or without electrolysis, but electrolysis becomes more necessary as the metal is more burned.

Use correct Personal Protective Equipment for hydroFluoric acid, as it may be dangerously toxic.

This type of cleaning is good for manufacturing. If you need to do routine cleaning such as on a barbecue grill, then the metal was overheated, or unsuitable for the application--Try ceramic coated metal, coated by something like Coatings for Industry ceramic coatings, Jet Hot Coat etc.