TASK 70-22-06-110-043
1 . General.
A.Two bolthole cleaning methods are given in this procedure, Method A: Scotch-Brite Cleaning, and Method B: Flex-Hone Cleaning. Use Method A first for removal of light oxides from the boltholes, where past experience has shown it to be effective. Use Method B for removal of thicker oxides from the boltholes and on specific hardware where Method A is not effective.
2 . Equipment.
Subtask 70-22-06-110-431
B.The equipment necessary to do this process is as follows.
(1)0.375 in. (9.5 mm) variable speed drill, 0.33 hp electric drill, or equivalent.
(2)2.0 in. (50.8 mm) nylon screws with a diameter of 0.15 in. (3.8 mm), or a nonmetallic equivalent.
(3)1.2 in. (31 mm) OD washers with a 0.35 in. (8.9 mm) ID and 0.050 in. (1.27 mm) thick, or nonmetallic equivalent.
3 . Materials.
Subtask 70-22-06-110-432
 
Consumable Product
No.
 
A. Solvent
C04-001  
C04-003  
C04-004  
C04-014  
 
B. Scotch Brite pads
C10-010  
 
C. Bristle brush
C10-108  
 
D. Cotton swabs or equivalent
---
 
E. Stainless Steel Brush
C10-173  
 
F. 120 Grit Silicon Carbide Flex-Hone
C10-164  , C10-165  , C10-168  , and C10-172  
4 . Method A: Scotch Brite Cleaning.
Subtask 70-22-06-110-433
C.Prepare the cleaning tool as follows. Refer to Figure 1, steps1-5.
(1)Cut the head off the nylon screw.
(2)Cut a strip of Scotch Brite C10-010   about 0.5 in. (13 mm) wide by 4.0 in. (102 mm) long.
(3)Fold the Scotch Brite over the nylon screw.
(4)Insert the flap ends into the drill chuck until 1.5 in. (38 mm) is exposed. Tighten the drill chuck.
(5)Place the washer over the screw and seat it against the chuck.
D.Clean the boltholes as follows. Refer to Figure 1, step 6.
(1)Align the drill so that the nylon screw/pad is in line with the bolthole. Start the drill and insert into the hole.
NOTE:
For the Scotch Brite to be effective, the rotation speed of the drill should not exceed 2500 rpm.
(2)Move the pad in and out of the hole until all scale and deposits are removed. Be sure that the nylon screw/pad stays aligned at 90 degrees to the entry surface.
NOTE:
If the bolthole length is greater than the nylon screw/pad, clean the hole from each end.
(3)Clean each bolthole and replace the Scotch Brite pad as necessary.
NOTE:
In severe cases, it is not uncommon to replace the pad every other bolthole.
(4)After cleaning each hole with the Scotch Brite, clean each bolthole with a cotton swab or bristle brush C10-108   and solvent.
Figure 1   Bolthole Cleaning Setup
5 . Method B: Flex-Hone Cleaning.
Subtask 70-22-06-110-434
E.Select the correct Flex-Hone size for the hole to be cleaned. Refer to table 1.
F.Cut the Flex-Hone so that there is approximately a 3.0 in. (76 mm) shaft beyond the brush.
G.Insert the Flex-Hone shaft into the drill chuck and tighten.
H.Clean the bolt hole to remove all oil, dirt, etc. Use a cotton swab and an approved solvent to clean the bolt hole.
CAUTION:
ONLY ONE FLEX-HONE IS TO BE USED PER HOLE. THIS IS VERY IMPORTANT.
I.Align the drill so that the Flex-Hone is in line with the bolt hole and perpendicular to the entry surface. Start the drill and insert into the hole. Clean the entire hole by moving the Flex-Hone up and down in the hole for 30 seconds. Avoid concentrating on a specific area.
NOTE:
The recommended drill speed for Flex-Hone is 500-1200 rpm and is not to be used with air or high speed.
NOTE:
Make sure the Flex-Hone is rotating upon entry and removal from the bolt hole.
J.Remove any abrasive residue in the bolt hole using a cotton swab and an approved solvent.
K.Honing process may be repeated, at 30 second intervals, for a maximum of 4 minutes per bolt hole.
NOTE:
Clean the Flex-Hone between each 30 second interval by passing the stainless steel brush C10-173   over the Flex-Hone for approximately 10 seconds while it is rotating in the drill.
 
Flex Hones - Table 1
 
Bolt Hole Size
Flex-Hone Part Number
Consumable No.
 
.245"-.255"
BC 6.4MM (.250")
C10-164  
 
.295"-.302"
BC 8MM (.315")
C10-165  
 
.309"-.318"
BC 8MM (.315")
C10-165  
 
.312"-.319"
BC 8MM (.315")
C10-165  
 
.329"-.338"
BC 9MM (.354")
C10-168  
 
.331"-.338"
BC 9MM (.354")
C10-168  
 
.336"-.345"
BC 9MM (.354")
C10-168  
 
.338"-.345"
BC 9MM (.354")
C10-168  
 
.396"-.403"
BC 10MM (.394")
C10-172  
 
.515"-.530"
BC 12.7 mm (.500")
C10-235  
 
.598"-.608"
BC 16 mm (.625")
C10-236