Lapping compounds

Lap each part separately against a cast-iron lapping block. These blocks hold the lapping compound in their surface pores and must be recharged fre-quendy. Lap the block against the seat. Never rotate the block continuously, but use an oscillating motion. Extreme care should be taken throughout to make certain that the seats are kept perfecdy flat. 

If considerable lapping is required, spread a thin coat of medium-coarse lapping compound on the block. After lapping with the medium-coarse compound, lap again with a medium-grade compound. Unless much lapping is called for, the first step can be omitted. 

SRV seats must be lapped to a micro finish using special compounds. Prior to super finishing, the valve seats should be lapped flat and to a fine surface finish in accordance with the standard practice as described above A 3- i,m-size diamond lapping compound should be used as described in the following procedure... 

Fig. 9 AFM images of (a) a Pt electrode surface freshly polished with 0.1 pm diamond lapping compound and (b) the same Pt electrode after application of power ultrasound in a solution of acetonitrile. Note the difference in scale in (a) 2000 A and (b) 4000 A.

Those applications were for removal of acidic flux and flux residues from various printed circuit (wire) boards (PWBs), removal of camauba wax from optic materials, removal of buffing and lapping compounds from metal substrates, and some others. These applications share at least one characteristic — that high quality, thoroughly repeatable cleaning is essential. And these applications remain highly valued. 

Exposed drives sometimes have to work in abrasive environments. It is always good practice to lubricate these chains. Even though the abrasive mixed with lubricating oil forms a lapping compound, lubrication is recommended because the effects of no lubrication—galling, seizing, and scoring—can destroy the chain faster than abrasive wear. 

Auto, metal, plastic, and household polishes Anti-block agent for plastic film Fine lapping compounds... 

Each column of a measurement table can be expanded into an indicator table. The rows of an indicator table refer to the same objects and in the same order as in the measurement table. The columns of the indicator table represent non-over-lapping categories of the selected measurement. Table 32.1 has been expanded into the indicator Table 32.2 for compounds and into the indicator Table 32.3 for disorders. In the indicator table for compounds, a value of one in a particular row is recorded if a person has used the corresponding compound. In the indicator table for disorders, one in a particular row indicates that the person has been treated for the corresponding disorder. All other elements of the row are set to zero. Note that the order of the columns in the indicator tables is not relevant. 

Absorptions that aid in the identification of the CO, adduct of amines are listed. For most compounds other characteristic absorptions are described and assigned in the text and figures. For very weak or over lapping absorptions, a best guess for the location of a particular absorption has been made on the basis o peak picking by the FTIR instrument s computer and by analogy to similar comounds. 

Select the correct compound for the first lapping sequence. 

Squeeze a small amount of the compound on various spots of the lap. 

Proceed with a finer compound if necessary, same as with the disc lapping. 

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