Prepare Steel for Welding

A. Finished-Project Specification

Outcome: a set of identified mild-steel coupons matching the approved coupon drawing, with verified dimensions, clean weld zones, approved edge and bevel preparation where specified, safe clamping surfaces, and a completed coupon preparation record. No arc is struck and no final cutting to length is performed in this chapter unless stock arrives pre-cut.

B. Coupon Preparation Schedule (Component Schedule)

Component	Quantity	Material	Finished Size	Preparation
Flat coupon blank	Per coupon drawing	Identified mild steel, thickness per drawing	Length and width per drawing	Clean to bright metal in weld zone; edges deburred; no bevel unless drawing specifies
Beveled joint coupon	Per coupon drawing	Identified mild steel, thickness per drawing	Length and width per drawing; bevel angle and root face per drawing	Clean to bright metal; bevel and root face prepared per drawing; deburred
Lap or T-joint coupon set	Per coupon drawing	Identified mild steel, thickness per drawing	Length and width per drawing	Clean to bright metal on all faying and weld surfaces; deburred; squareness verified

The book outline does not supply numeric dimensions, bevel angles, or root-face values for this chapter. Use the dimensions, bevel angle, and root face stated on the coupon drawing or approved welding procedure supplied by the instructor, shop, or governing project specification for the coupon set actually being prepared. Do not substitute an invented value.

C. Material Takeoff

• Base stock: identified mild-steel plate, flat bar, angle, or tube in the thickness and quantity stated on the coupon drawing, with allowance for layout waste and rejected pieces.
• Cleaning consumables: approved cleaner sufficient to degrease every coupon's weld zone and work-clamp contact area.
• Marking consumables: soapstone or approved marker sufficient to mark every coupon identifier, cut line, and bevel limit.
• Identification materials: tags, stamps, or paint markers sufficient to keep every coupon traceable through cleaning and beveling.
• Fastener and hardware schedule: not applicable. This chapter produces prepared stock, not a fastened assembly.

D. Acceptance Standards

Check	Standard
Material identification	Confirmed identified mild steel free from prohibited coatings, rust pits, lamination, cracks, bends, or previous welds before layout begins
Layout reference	All length, width, and joint-preparation marks measured from a single verified reference edge per piece
Dimensions	Length, width, and thickness match the coupon drawing within the stated tolerance
Weld-zone cleanliness	Clean to bright metal for the distance specified by the coupon drawing, extending beyond the expected weld and work-clamp area
Bevel and root face	Bevel angle and root face match the approved coupon drawing or welding procedure; no deep grinding grooves parallel to expected stress
Edge condition	Cut and beveled edges deburred; sharp corners broken only where the drawing allows
Flatness and straightness	Confirmed on the work table; minor distortion corrected only by an approved cold method
Traceability	Every coupon carries a legible identifier connecting it to the preparation record

E. Preparation — Drawing Review and Material Verification

1. Review the coupon drawing, material specification, dimensions, quantity, joint type, edge preparation, and tolerance. Confirm the drawing matches the chapter or practice sequence this coupon set will support.
2. Verify the stock is identified mild steel and free from prohibited coatings or contamination. Check the stock against its mill or supplier identification before proceeding.
3. Stop for unknown, galvanized, plated, lead-coated, heavily painted, chemically treated, or oily material until approved controls are established. Do not proceed with any piece whose identity cannot be confirmed.
4. Inspect stock for severe rust, pitting, lamination, cracks, bends, sharp edges, and previous welds. Reject pieces with defects beyond what cleaning and preparation can correct.
5. Select pieces large enough for safe clamping and the required coupon dimensions. Confirm each piece leaves adequate clamping margin beyond the finished coupon size.
6. Measure stock thickness using an approved tool. Record the measured thickness against the coupon drawing requirement.

F. Layout and Marking

1. Mark each piece with a coupon identifier that will remain traceable after cutting. Place the identifier where cleaning and beveling will not remove it.
2. Establish a clean measuring and layout surface. Confirm the table is flat and free of debris before placing stock on it.
3. Use a steel rule, square, combination square, scriber, soapstone, or approved marker. Select the marking tool appropriate to the stock surface and required precision.
4. Mark cut lines from a single reference edge. Do not mix reference edges on the same piece.
5. Verify length, width, squareness, and quantity before cutting. Recheck every mark against the coupon drawing before releasing the piece for cutting.
6. Mark bevel, root face, or joint-preparation limits only from the approved project specification. Do not mark a bevel angle or root face that is not supplied by the drawing or procedure.

G. Clamping and Cleaning

1. Secure each piece in a vise, clamp, or fixture before cleaning or edge preparation. Confirm the piece cannot shift during cleaning or grinding.
2. Remove oil and grease using an approved cleaner and ventilation procedure. Follow the cleaner manufacturer's instructions for application and required ventilation.
3. Allow flammable cleaner to evaporate fully and remove it from the hot-work area. Confirm no cleaner residue remains before any grinding or cutting begins.
4. Remove loose rust, mill scale, paint, and contamination from the weld zone using the approved method. Clean to bright metal within the zone specified by the coupon drawing.
5. Extend cleaning beyond the expected weld and work-clamp area. Confirm the clamp contact area is also clean to bright metal.
6. Use dedicated stainless brushes only when the procedure requires them; do not cross-contaminate brush types. Store carbon-steel and stainless brushes separately.
7. Inspect cleaned metal for remaining coating, rust pits, cracks, and contamination. Reclean or reject any area that does not meet the clean-to-bright standard.

H. Bevel Preparation, Deburring, and Distortion Control

1. Prepare bevels with an approved grinder, file, saw, or machining method. Use the method identified as approved for the specific joint and material thickness.
2. Maintain the specified bevel angle and root face without thinning the coupon excessively. Check the bevel against the drawing at intervals during preparation.
3. Do not create deep grinding grooves parallel to the expected stress or outside the repair allowance. Keep grinding marks controlled and within the approved area.
4. Deburr cut and beveled edges. Remove sharp burrs from every prepared edge.
5. Break sharp corners only where allowed by the drawing. Do not round a corner the drawing requires to remain square.
6. Check straightness and flatness on the work table. Place each coupon on the table and verify against a straightedge.
7. Correct minor distortion using approved cold methods before welding. Do not apply heat to correct distortion in this chapter.

I. Final Cleaning, Fixturing Check, and Documentation

1. Clean both sides of the joint and the location for the work clamp. Confirm both faces meet the clean-to-bright standard.
2. Dry the coupons completely. Confirm no cleaner or moisture remains before storage.
3. Arrange coupons by process, thickness, joint, and practice sequence. Group coupons to match the chapters that will use them.
4. Clamp a representative joint and verify access for electrode, gun, torch, filler rod, and inspection. Confirm the fixture allows full approach to the joint from the required welding position.
5. Confirm the fixture will not create an unintended current path or unstable restraint. Check that clamps contact only the intended coupon surfaces.
6. Measure final coupon dimensions and joint preparation. Record length, width, thickness, bevel angle, and root face against the drawing tolerance.
7. Photograph and document material, dimensions, edge preparation, cleanliness, and readiness. Complete the coupon preparation record for every accepted piece.
8. Reject and remake coupons that do not meet preparation requirements. Mark rejected pieces and remove them from the accepted-coupon zone.