Body and Frame: Service Precautions

Welding Precautions - Steel

Material:

General Specifications - Welding Specifications:

General Equipment
3 Phase Inverter Spot Welder 254-00002
Compuspot 700F Welder 190-50080
I4 Inverter Spot Welder 254-00014
Inverter Welder with MIG Welder 254-00015

WARNING:
- Invisible ultraviolet and infrared rays emitted in welding can injure unprotected eyes and skin. Always use protection such as a Welder's helmet with dark-colored filter lenses of the correct density. Electric welding will produce intense radiation, therefore, filter plate lenses of the deepest shade providing adequate visibility are recommended. It is strongly recommended that persons working in the weld area wear flash safety goggles. Also wear protective clothing. Failure to follow these instructions may result in serious personal injury.
- Always wear protective equipment including eye protection with side shields, and a dust mask when sanding or grinding. Failure to follow these instructions may result in serious personal injury.
- On vehicles equipped with Safety Canopy (R) options, prior to carrying out any sectioning repairs near the roof line or sail panel areas of the vehicle, remove the Safety Canopy (R) module and related components. Failure to comply may result in accidental deployment or damage to the Safety Canopy (R). Refer to Restraint Systems and/or Air Bag Systems. Failure to follow these instructions may result in serious injury to technician or vehicle occupant(s).

NOTICE: Disconnect the instrument cluster module, Powertrain Control Module (PCM), Engine Control Module (ECM), fuel pump driver module (gas only), Anti-lock Brake System (ABS) module and diesel Fuel Injection Control Module (FICM), if equipped. Electronic modules and related wiring may be damaged when exposed to heat from welding procedures.

NOTE: When it is necessary to carry out weld-bonding procedures, refer to Weld-Bonding.

The correct equipment and settings must be used when welding mild or high-strength steel. Metal Inert Gas (MIG) and Squeeze-Type Resistance Spot Welding (STRW) are the preferred methods. Surfaces must be clean and free of foreign materials.

- Do not use gas welding equipment.
- Adequate ventilation must be provided to avoid accumulation of poisonous gases.
- A test weld should always be carried out on a test sample. Refer to the Weld Nugget Chart in Specifications for Ford-approved weld nugget information.
- Use cleaning brushes and abrasive grinding wheels dedicated to the type of materials being welded.
- Follow the equipment manufacturer's prescribed procedures and equipment settings for the type of welder being used. ER70S-2 or ER70S-6 wire are typically used for MIG welding steel.
- Disconnect the battery(s).
- Replace spot-welded components by spot welding where possible.
- Corrosion protection must be restored whenever bare metal repairs are made. Refer to Restoring Corrosion Protection Following Repair.
- Adequate power supply needs to be used to make sure of correct equipment performance.
- Factory spot welds may be substituted with either STRW or MIG plug welds. Spot/plug welds should equal factory welds in both location and quantity. Do not place a new spot weld directly over an original weld location. Plug weld hole should equal 8 mm (0.31 in) diameter.
- Components made of high-strength steel should not be heated to straighten or repair. If components are severely bent or kinked, new components should be installed.

When MIG or arc welding frame components, the following guidelines should be followed:

NOTICE: When welding low carbon steel side rails (35,000 psi yield strength), emphasis should be placed upon weld application techniques to avoid excessive heat affected zones that may adversely affect frame operating stresses. When welding within 100 mm (3.93 in) of any crossmember that contains rivets, remove the rivets and install new SAE grade 8 bolts/nuts.

NOTE: Do not weld on any reinforcement. Use compression type fasteners when attaching any component to the frame in the reinforcement area.

- A temperature indicating crayon calibrated below 650°C (1,200°F) should be used to avoid overheating and weakening the metal.
- Attach the ground clamp as close as possible to the work area.
- Choose welding electrodes according to the type of steel, thickness and polarity of the arc welder AC or DC.
- Do not use water or compressed air to cool welding. This can cause the metal to become brittle and weak.
- Where frame wax coating and the bracket E-coat have been removed, apply anti-corrosion coating to all affected surfaces of the frame, bracket and weld areas.
- Clean the welded areas with a wire brush.
- Use a wax and grease remover for a final cleaning of the weld areas.