09Sa033o.pdf

09Sa033o

1 CONTRACT # FA8232-07-C-0007

F16 FS479 Bulkhead Bonded Repair

Mill Tool Rails Manufacturing Instructions

Applicable Engineering Dispositions Disposition Number Summary QA Signoff on Compliance

2 CONTRACT # FA8232-07-C-0007

WORK INSTRUCTIONS

STEP DESCRIPTION TECH INSP/EN

1. Purpose

2.

These procedures are for the manufacturing of the rails utilized in the groove cutting process of the FS479 bulkhead repair

3. List of Materials

4.

Tools:

• F162-200-00 Track Form Tool

• Electronic Weight Scale (for mixing polyurethane)

5.

Consumables:

• Acetone

• RenCast 6443 Polyurethane Elastomer (suppler: Graco)

• Woven Thermoplastic Mesh (McMaster P/N 9218T78)

• Tissue Wipes, Extra Low Lint

• 2 Inch Mylar Tape

• 2 Inch Aluminum Tape

• 1 Inch Teflon Release Tape

• White alumina oxide grit

3 CONTRACT # FA8232-07-C-0007

6.

WARNINGS

Provide adequate ventilation and protect skin and eyes from contact with uncured polyurethane elastomer

Wear safety goggles to protect eyes

Wear latex gloves to protect hands

If skin is exposed to direct contact with uncured polyurethane elastomer, wash with soap and warm water

Do not use solvents to clean skin

Acetone is Hazardous

Wear suitable respirator, protective latex gloves and clothing when using Acetone

Use only in a well-ventilated area, environmentally controlled for its use

7. Preliminary Preparations

8.

Rail will be manufactured on an aircraft with the vertical tail removed

4 CONTRACT # FA8232-07-C-0007

9.

Position track forming tool using tail attach bolts to locate and mark the area on the skin to which the guide rails will be manufactured

10.

Clean and degrease this area and place one layer of 2 inch mylar tape wide enough to ensure rails will not bond to aircraft surface

11.

Cover track form tool with 1 inch Teflon tape to ensure polyurethane will not bond to the track form tool

12. Assembly and Cure

13.

Cut plastic mesh 1 to 1 ½ inches wide and 2 inches longer than track form tool

Position plastic mesh on aircraft surface were rails will be manufactured and tape in place, on each end, using mylar tape

14.

Using 2 inch aluminum tape, create a “dam” around previously marked areas to keep uncured polyurethane elastomer in place during cure

15.

Mix RenCast 6443 Polyurethane Elastomer in accordance with manufacturers instructions and pour mixture in to “dam”

5 CONTRACT # FA8232-07-C-0007

16.

Place track form tool in position and apply pressure by lightly tightening the tail attach bolts and nuts

17.

Ensure “dam” is retaining uncured polyurethane

Add more aluminum tape and polyurethane mixture as necessary to keep area filled

18.

Allow mixture to cure for 24 hours before disassembly

19.

Remove track form tool and inspect rails for voids

If voids are present, mix a small amount of polyurethane elastomer, fill the voids and reinstall track form tool

Allow to cure a minimum of 12 hours before disassembly

20.

Using a sanding disk and die grinder, remove all excess material and inspect for completeness