(b)
Make sure the channel is clean.
(c)
Apply a precoat of BMS 5-26 Type II Class A-2 sealant to the channel surfaces with pipe cleaners or a long, bristled pencil brush.
NOTE: If the channel cross-section is 0.07-inch (1.77 mm)
____ or less, it is not necessary to apply precoat.
1) Make sure you do not seal the channel with the precoat of BMS 5-26 Type II Class A-2 sealant.
NOTE: If you seal the channel, it will prevent the
____ flow of the sealant into the channel.
(d)
Put BMS 5-45 Class B sealant (or equivalent) into end of the channel and fill until sealant comes out of all other openings (Fig. 814).
(e)
Fill all slots, joggles and channels where continuity of a seal or a block-off seal is necessary.
CAUTION: MAKE SURE THERE IS SUFFICIENT SEALANT IN THE SEALING GUN
_______ FOR A FULL SEAL. IF YOU STOP AND START WHEN YOU APPLY THE SEAL, AIR BUBBLES CAN GET INTO THE SEAL AND IT WILL NOT BOND CORRECTLY.
(f)
Slowly and continuously move the sealant into the area that you apply a fillet seal.
(g)
Remove unwanted sealant with the sealant fairing tool.
(h)
Make the ends of the seal smooth.
(i)
Examine the seal for a bad bond or air bubbles.
(j)
If the seal has a bad bond or air bubbles, do the procedure again.
(k)
If it is necessary, do this task: Apply the Corrosion Resistant Finish (Topcoat) (AMM 28-11-00/701).
S 398-258
(8)
To apply a prepack seal, do these steps:
(a)
Apply a layer of BMS 5-45 Class B sealant (or equivalent) to one of the structural parts (Fig. 815).
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(b)
Use a sealant fairing tool to move the sealant such that it is in the shape of the cavity.
(c)
Make sure you apply sufficient sealant to completely fill the parts.
(d)
Assemble the parts in the sealant usable time (Fig. 804).
(e)
If it is necessary, do this task: Apply the Corrosion Resistant Finish (Topcoat) (AMM 28-11-00/701).
S 398-259
(9)
To apply a faying surface seal, do these steps:
(a)
Apply a layer of BMS 5-45 Class B sealant (or equivalent) to one faying surface with a sealing gun or spatula (Fig. 816).
(b)
Move the sealant on all of the surface to get an equal layer approximately 0.03 inch (0.76 mm) thick (Fig. 816).
(c)
Assemble the parts in the sealant usable time.
(d)
Make the extruded sealant smooth along the joint.
NOTE: You must apply sufficient sealant to make sure there is
____ continuous extruded sealant on the two sides of the joint.
(e) If it is necessary, do this task: Apply the Corrosion Resistant Finish (Topcoat) (AMM 28-11-00/701).
S 398-260
(10)
Increase the seal plane above the initial seal plane (Fig. 817).
(a)
You can replace an injection, prepack, or faying surface seal, or you can increase the seal plane to isolate a bad seal from the fuel.
NOTE: Because you add a large quantity of sealant when you
____ increase the seal plane above the initial seal plane, it is better to replace the bad seal.
(b) Examine the structure around the bad seal to find where to increase the seal plane.
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