|
Inhibiting Compounds |
|
After a part is cleaned, deburred, smoothed, or burnished, it must be protected from oxidation, corrosion, and tarnishing. These reactions occur when there are three things present: the part, moisture (water), and oxygen. If either moisture or oxygen is removed from the part, oxidation cannot occur. An inhibiting compound deposits a layer of chemical, which repels or absorbs either oxygen or moisture preventing oxidation. Inhibition is sometimes performed in the vibratory machine, but is more often carried out after the vibratory operation utilizing a post-inhibit dip or spray. Corrosion protection is not only required for the parts but for the steel media used in burnishing applications also. Steel media is a sizable investment and must be treated properly to keep that investment in good shape. Most steel burnishing applications use acidic compounds. Acidic compounds by nature are reactive. If the steel media is not protected, rusting will occur. Once the case hardened surface of the media has been broken, adequate protection cannot be given even with the use of inhibitors. Most inhibiting compounds are designed to be used at 5-20% concentration. Since process compounds are usually used at 1-2% they offer little corrosion protection even if they are formulated with corrosion resisting raw materials. Some process compounds at 1-2% will offer some corrosion protection, but a post-inhibit treatment is usually required. The reason for many different inhibiting compounds is that some metals are more susceptible to darkening than other metals. Ferrous metals usually need different inhibitors than non-ferrous metals. The most popular inhibiting compounds are: L-78 is a non-ferrous inhibiting compound used primarily on brass and copper and will not darken the parts except at concentrations of over 10%. Its operating pH is 10.1. L-78 has good cleaning and wetting properties and is a low foaming compound. -------------------------------------------------------------------------------- L-78SLF is a non-ferrous inhibiting compound designed based upon L-78 but to be used with soft water. It is a lower foaming compound than L-78. -------------------------------------------------------------------------------- L-79 is formulated similarly to L-78 but contains no dye. ------------------------------------------------------------------------------- L-326 is a ferrous inhibiting compound. Its operating pH is 8.8. L-326 has poor cleaning capabilities but has good wetting and dispensing properties. It can be used as a process compound if no soils are present on the parts. L-326 is often used to store steel media overnight. -------------------------------------------------------------------------------- L-620LF2 was designed as a deburring compund but offers excellent corrosion protection as well. It was designed as an extra low foaming version of L-620 (an excellent deburring compound) to be used at a higher concentration (4-5 oz. per gallon water) with ceramic media on all metals (especially steel). L-620LF2 not only cuts down the deburring cycle time but offers sufficient corrosion protection without post treatment. -------------------------------------------------------------------------------- L-656 is a ferrous inhibiting compound. Its operating pH is 9.1. L-656 is formulated similarly to L-326 with lower foaming properties.
-------------------------------------------------------------------------------- L-656S is a ferrous inhibiting compound based upon L-656 but for use with soft water. It is a lower foaming compound than L-656. It can be used as a dip or spray. -------------------------------------------------------------------------------- RTC-192 was developed as a spray inhibiting compound to follow spray wash applications. RTC-192 works for all metals and will not darken metals. RTC-192 was designed to function as a spray wash compound but can be used very successfully as a dip solution and will offer corrosion protection as good or better than L-656. It can be used to protect steel media overnight and on long shutdowns. -------------------------------------------------------------------------------- XL-78 was developed as a non-chelating version of L-78. It is a low-foaming, non-ferrous inhibiting compound. -------------------------------------------------------------------------------- XL-528 is a multi-metal inhibiting compound. Its operating pH is 8.3. XL-528 is a moderately foaming compound and offers excellent corrosion protection. It can also be used as a process compound to do light deburring on most metals (especially aluminum). -------------------------------------------------------------------------------- XL-1224 is a non-chelating inhibiting compound that was designed specifically for abcut media. It helps protect pitted media. XL-1224 will not interfere with non-chelating waste treatment chemistry. It has poor cold weather stability. -------------------------------------------------------------------------------- XL-1231 is a heavy duty inhibiting compound designed for sintered and cast iron. Its operating pH is 7.5-7.8. XL-1231 also works very well as a process compound for deburring and will give some burnish. -------------------------------------------------------------------------------- XL-1257 is a non-amine based inhibiting compound. Amines may react with animal and vegetable oils (usually found in cutting and lubricating oils) to produce potential carcinogens. Many inhibiting compounds contain amines as their active ingredients. XL-1257 will offer short-term corrosion protection only. -------------------------------------------------------------------------------- XL-1287RA was designed to be used as a spot-free rinse and does not offer much corrosion protection. XL-1287RA can be used in spray wash applications or in a power washer where spot-free parts are desired. -------------------------------------------------------------------------------- XL-1290N is a nitrite-based inhibitor to be used with ferrous metals as a dip or spray at 5-20%. Nitrites by themselves are not hazardous but can react with secondary amines to form nitrosamines which are potential carcinogens. Secondary amines are very common in human and animal fats as well as amine-based inhibitors. Some synthetic cutting and cooling oils also contain animal fats. -------------------------------------------------------------------------------- XL-1290NX is a version of XL-1290N buffered to a lower pH and does not have to be placarded as a corrosive material. -------------------------------------------------------------------------------- XL-1335 is an acrylic-based inhibitor designed to be used with metals when long term corrosion protection of more than one year is required. XL-1335 will cause a film on the part and the part should be run through heated crushed corn cob to give a homogeneous film. -------------------------------------------------------------------------------- XL-1345 is an emulsion that contain water-insoluble oils as inhibiting agents. XL-1345 will cause a film on the part. XL-1345 is normally used on ferrous metals where long term rust protection over one year is required. |
Contact Us1-800-536-1916 |