Grind, Deburr, and Finish Weld Coupons

A. Finished-Project Specification

Outcome: the coupon blanks cut in Chapter 5, finished to the edge condition, bevel, weld-zone cleanliness, and dimensional tolerance stated on the coupon drawing or project specification, deburred on all handling edges, cleaned of grinding dust and debris, measured, and labeled accepted or rejected.

B. Component Schedule

Component	Quantity	Material	Finished Size	Preparation
Coupon blank	Per cut list from Chapter 5	Identified mild steel, as cut	Per coupon drawing dimensions and tolerance	Deburred handling edges; bevel and root face per drawing where required; weld zone ground to bright clean metal for the specified distance

C. Material Takeoff

• Coupon stock: the cut mild-steel blanks produced and documented in Chapter 5, matched to their identification marks.
• Abrasives: grinding wheels, flap discs, and wire wheels rated for the grinder and the identified task, in sufficient quantity for the full coupon set.
• Hand tools: files sized for final controlled deburring and correction.
• Consumables: none beyond abrasives and dust-collection media; this chapter does not consume welding consumables.
• Fastener and hardware schedule: not applicable. This chapter finishes loose coupons, not a fastened assembly.

D. Acceptance Standards

Check	Standard
Wheel/disc/brush selection	Matched to the identified task, grinder speed rating, and material; disconnected power used for every mounting change
Spark control	Spark stream directed only into the confirmed collection area; people, leads, cylinders, and combustibles kept clear
Edge and bevel dimensions	Ground edges and bevels match the coupon drawing angle, root face, and tolerance without excessive thinning
Deburring	All handling edges free of burrs and unsafe sharp corners; corners broken only within drawing tolerance
Weld-zone cleanliness	Weld zone ground to bright clean metal for the distance specified by the procedure, free of rust, scale, paint, and oil
Surface condition	Free of deep grooves, undercut edges, cracks, excessive rounding, and embedded abrasive
Final dimensions	Width, length, thickness, bevel, and flatness measured and within the coupon drawing tolerance
Documentation	Wheel type, grinder, preparation task, dimensions, defects, and final acceptance recorded for every coupon

E. Preparation — Review and Area Setup

1. Review the required coupon finish, edge condition, weld-zone cleanliness, and dimensional tolerance. Confirm the drawing or specification for each coupon before touching a grinder.
2. Inspect the hot-work and grinding area for combustible material and spark travel. Repeat the relevant portion of the Chapter 1 area check for the grinding location.
3. Install welding curtains or grinding screens as required. Confirm sightlines toward other occupied areas are blocked.
4. Select safety glasses, face shield, hearing protection, gloves, clothing, and respiratory controls. Confirm every item is inspected and in place before grinding begins.

F. Task Identification and Wheel Selection

1. Identify the task as stock removal, beveling, deburring, mill-scale removal, weld cleaning, or surface blending. Record the task for each coupon before selecting a tool.
2. Select the wheel or tool specifically approved for the task. Do not substitute a faster or more convenient wheel for one matched to the task.
3. Verify wheel diameter, arbor, speed rating, type, expiration or condition where applicable, and material compatibility. Reject any wheel that fails this check.

G. Grinder Inspection and Wheel Mounting

1. Inspect the grinder guard, handle, switch, cord, spindle, flange, and body. Remove any grinder with damage from service.
2. Disconnect power before wheel installation. Confirm the tool is fully isolated before touching the spindle.
3. Install the wheel with the proper flanges and tightening method. Follow the wheel and grinder manufacturer's mounting instructions exactly.
4. Position the guard between the wheel and operator. Confirm the guard cannot be bypassed during normal use.
5. Run the wheel at no load from a protected position. Stand clear of the wheel plane while bringing it to full speed.
6. Stop for vibration, wobble, unusual noise, cracked wheel, or loose mounting. Correct the condition before any contact with a coupon.

H. Securing the Coupon and Controlling the Spark Path

1. Secure the coupon in a vise, clamp, or fixture. Do not hold the coupon by hand during grinding.
2. Position the work so the spark stream reaches only the approved collection area. Confirm the direction of the spark stream before starting the grinder.
3. Keep leads, hoses, cylinders, windows, vehicles, and people out of the spark path. Recheck the surrounding area immediately before each grinding pass.

I. Grinding, Deburring, and Weld-Zone Preparation

1. Use both hands on the grinder. Maintain stable two-hand control for the full grinding pass.
2. Approach the material with the approved wheel angle. Match the angle to the task and the coupon drawing.
3. Use light controlled pressure rather than forcing the wheel. Let the wheel remove material at its designed rate.
4. Keep the wheel moving to avoid grooves, overheating, and local thinning. Do not dwell in one location.
5. Do not grind on the side of a cutting wheel. Use only the wheel type approved for side loading.
6. Do not use a wire wheel without checking wire condition, guard, speed, and correct direction. Confirm these items every time the wire wheel is mounted.
7. Remove burrs along all handling edges. Inspect every cut edge for a burr before moving to the next coupon.
8. Round or break sharp corners only within the drawing tolerance. Do not remove more material than the tolerance allows.
9. Grind weld zones to bright clean metal for the specified distance. Confirm the cleaned distance matches the procedure before stopping.
10. Remove rust, scale, paint, oil, and contamination without thinning the base metal. Stop grinding once bright metal is reached; do not continue removing sound base metal.
11. Prepare bevels gradually and check angle and root face frequently. Re-measure after each pass rather than grinding to a single final pass.

J. Cooling, Inspection, and Final Correction

1. Allow hot coupons to cool in the designated area. Confirm the cooling location is separated from combustibles and foot traffic.
2. Do not touch or measure hot metal with bare hands. Confirm the coupon is at a safe handling temperature before continuing.
3. Inspect finished surfaces for deep grooves, undercut edges, cracks, excessive rounding, embedded abrasive, and remaining contamination. Reject any coupon that fails this check.
4. Measure coupon width, length, thickness, bevel, and flatness. Compare each measurement against the coupon drawing tolerance.
5. Use a file or hand abrasive for final controlled correction where appropriate. Make small corrective passes rather than returning to the power grinder for minor adjustments.
6. Clean dust with approved vacuum or collection equipment. Remove metal dust and abrasive debris from the coupon and the surrounding area.
7. Inspect the area for sparks and hot particles. Confirm no smoldering material remains before leaving the coupon unattended.
8. Label accepted and rejected coupons. Mark each coupon clearly so it is not confused with an unfinished or rejected piece.
9. Record wheel type, grinder, preparation task, dimensions, defects, and final acceptance. Complete the coupon finishing log entry for every coupon produced.