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CORROSION AREA A-A
Typical Usage of Straight Edge in Determining Depth of Corrosion
Figure 1
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A-A
CORROSION DEPTH MEASUREMENT
1. MEASURE THE DEPTH PERPENDICULAR TO THE RADIUS OF CONCAVE OR CONVEX SURFACES. SEE THEMAIN VIEW.
2. MEASURE THE DEPTH ON EDGES ADJACENT TO CORROSIONDAMAGE OR BLENDED DEPRESSION (POINTS "A" AND "B"). DO THIS NEAR THE CENTER OF CORROSION DAMAGE OR BLEND DEPRESSION (SEE DETAIL I) AND USE THE DEEPESTVALUE AS POINT "C". CALCULATE THE DEPTH AS FOLLOWS:
DEPTH = C -(A + B) 2 DETAIL I
Corrosion Damage and Repair Depth Measurement with a Depth Dial Gage
Figure 2
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Abrasives for Corrosion Removal
Figure 3
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NOTE: ALL LOOSE CORROSION PRODUCTS ARE REMOVED FROM THE PIT.
CORROSION DAMAGE BEFORE REPAIR
NOTE: ROUGH EDGES ARE SMOOTH AND ALL CORROSION IS REMOVED. BUT DEPRESSION IS NOT CORRECTLY SHAPED.
DEPRESSION AFTER CORROSION REMOVAL
NOTE: THE BLEND NOW HAS THE RATIO AND
DIRECTION SHOWN IN FIG. 5.
Single Depression Blends
Figure 4
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DAMAGE REMOVED AND SURFACE IS SMOOTH
WITH SHALLOW ELLIPTICAL BLENDOUT
EXAMPLE OF 1:5 BLEND RATIO
NOTE A-A
D = DEPTHOF DEPRESSION
1.
SEE SPECIFIC REPAIR FOR MAXIMUM DEPTH
2.
BECAUSE THE MAXIMUM DEPTH IS DIFFERENT AT DIFFERENT LOCATIONS, MAXIMUM SIZE OF BLENDOUT WILL ALSO BE DIFFERENT
3.
USE THE SAME BLEND RATIO AT ALL TIMES UNLESSTHE REPAIR INSTRUCTIONS ARE
DIFFERENT
Multiple Depression Blends
Figure 5
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Corrosion in Limited Clearance Areas
Figure 6
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PORTABLE ABRASIVE BLASTER COMPONENTS
(CLEMCO MODEL E-10A UNIT SHOWN)
NOTE: FOR BEST RESULTS, THE BLAST NOZZLE SHOULD BE HELD ON THE SURFACE SO THAT IT REMOVES CORROSION IN AN APPROXIMATE 1-INCH
DIAMETER PATH.
NOTE: THE BLAST HEAD OF THE CLEMCO PORTABLE
BLASTCLEANERHAS A CONCENTRICARRANGE-
BLAST NOZZLE ON WORK SURFACE
MENT. THE INNER TUBE BLASTSTHE GLASS
HEADSAGAINSTTHE CORRODEDSURFACEAND
THE OUTER PASSAGERETRIEVES BEADS AND
DUST.
BLAST HEAD
Portable Abrasive Blaster
Figure 7
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FASTENERSNEAROR IN THE AREA OF CORROSIONMUST BE REMOVED. CORROSION REMOVALON THE EXTERNALSURFACEWITHOUT FASTENERREMOVALWILL NOT STOP CORROSION UNDER THE FASTENER HEAD OR IN THE HOLE.
Corrosion at Fasteners
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