16.4 Michigan Practical Examination: Soldering, Brazing, Assembly & Safety

16.4 Michigan Practical Examination: Soldering, Brazing, Assembly & Safety

Exam Focus: In Michigan, passing the written examination is only half of the licensing requirement. The LARA journey plumber application states that effective December 15, 2021, application for Journey Plumber is for BOTH a written examination and a practical skills examination, and you must pass both parts to achieve licensure. The PSI candidate information bulletin adds that journey applications submitted after December 15, 2021 must complete two separate examinations, and that the applicant requests the practical by emailing their name and applicant ID to LARA-BCC-Licensing@Michigan.Gov. The practical is a copper project and an isometric workbook. This section covers the trade skills that project tests: capillary soldering and brazing, mechanical joining, dimensional layout, and MIOSHA jobsite safety.

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1. Structure and Logistics of the Michigan Practical Skills Examination

What LARA Publishes About the Practical

• Components: a copper project and an isometric workbook practical.
• Who schedules it: you do, by emailing your name and the date requested to LARA-BCC-Licensing@Michigan.Gov. The written portion is scheduled separately with PSI at 1-855-579-4635, and LARA advises scheduling both examinations as soon as you receive your examination application approval.
• Deadline: the registration deadline for each practical examination date is 30 days prior to the exam date.
• Schedule and locations: LARA publishes one practical examination per day on a rotating schedule, historically at Lansing, Mason, Cadillac, and St. Ignace, with capacity of 50 to 100 candidates per date. No examinations are scheduled in December or January.
• Session time: the published session runs 10:00 a.m. to 12:30 p.m. Beginning in 2026, check-in opens at 8:00 a.m. so candidates can review tools and supplies with the proctors, and all applicants must be checked in no later than 9:45 a.m. for a prompt 10:00 start.
• Retesting: the PSI bulletin states that if you fail you may retest an unlimited number of times, and the $100 examination fee must be paid for each attempt; an examination fee expires one year after the date PSI receives it.

Verify before you go: LARA republishes the practical examination date and location table each year, and it changes. Always confirm the current dates, deadline and location on the Bureau of Construction Codes plumbing licensing page before you plan travel.

How Hands-On Copper Work Is Evaluated

The state does not publish a public rubric for the copper project. What follows is the standard evaluation framework used for hands-on copper fabrication testing across the trade, and it is a reasonable way to prepare:

1. Dimensional Accuracy: Piping sub-assemblies are expected to match the drawing dimensions closely - trade practice works to roughly $\pm 1/8\text{ inch}$ overall, so build to the line rather than to a tolerance you hope will be accepted.
2. Plumb and Level Alignment: Vertical risers must be plumb, and horizontal runs must maintain specified pitch without sagging or back-pitching.
3. Joint Cleanliness and Workmanship: Absence of excessive solder drips, burned flux, scorched surrounding wood/drywall, or distorted pipe walls.
4. Hydrostatic / Pneumatic Pressure Tightness: Fabricated assemblies are capped, filled with water or air, and subjected to a hydrostatic pressure test. Zero leakage is permitted.
5. Safety Protocol Adherence: Proper Personal Protective Equipment (PPE) is mandatory at all times. Failure to wear eye protection, proper gloves, or handling torches recklessly results in immediate disqualification.

Candidate Tools & PPE

LARA's 2026 check-in change specifically sets aside time to review tools and supplies with the proctors, which tells you that candidates bring their own. Confirm the current list with the Bureau before your date; the following is the normal working kit for a copper fabrication project:

• Personal Protective Equipment: ANSI Z87.1 approved safety glasses with side shields, leather work gloves, flame-resistant work clothing (cotton/denim, no synthetics), and sturdy steel-toe work boots.
• Hand Tools: 25-foot tape measure, torpedo level (with 45-degree vial and pitch markings), 10-inch and 12-inch adjustable wrenches, smooth-jaw spud wrench, channel-lock pliers, multi-bit screwdriver, chalk/marking pen.
• Cutting & Prepping Tools: Tubing cutters (1/4" to 2"), inner/outer reaming tools, wire tube/fitting brushes (1/2", 3/4", 1"), 120-grit emery cloth/sandcloth.
• Torquing & Joining Equipment: Calibrated no-hub torque wrench (calibrated to $60\text{ in-lbs}$), PEX crimp tool with Go/No-Go gauge (ASTM F1807) or PEX expansion tool (ASTM F1960).
• Soldering & Brazing Rig: Portable propane, MAPP/propylene, or air-acetylene torch kit with spark igniter/striker (matches and disposable lighters are prohibited), heat shield blanket, damp cotton rag.

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2. Copper Joining Standards: Soldering & Brazing

Fabricating pressure-tight copper assemblies requires an intimate understanding of metallurgy, heat transfer, and capillary attraction.

                         THE MECHANICS OF CAPILLARY ACTION

     ANNULAR CLEARANCE: 0.001" to 0.005"
     +-------------------------------------------------------------+
     | FITTING SOCKET WALL                                         |
     |    .....................................................    |
     |    : SOLDER IS DRAWN IN BY CAPILLARY ATTRACTION TOWARD :    | <-- Molten solder flows
     |    : THE HIGHEST CONCENTRATION OF HEAT IN SOCKET STOP  :    |     into uniform fillet
     |    .....................................................    |
     | TUBE WALL                                        | STOP     |
     +==================================================+ SHOULDER |
                                                        +----------+

Capillary Action & Joint Mechanics

Capillary action is the physical phenomenon by which liquid solder is drawn into the narrow annular clearance ($0.001\text{ to } 0.005\text{ inches}$) between the outside diameter of the tube and the inside diameter of the fitting socket, regardless of the direction of gravity. Capillary action operates only when surfaces are chemically clean, properly fluxed, and heated to the melting point of the alloy.

The 6 Steps to Code-Compliant Soldering (Sweating)

1. Square Cutting: Cut tube squarely using a roller-type wheel cutter. An out-of-square cut reduces insertion depth into the socket and creates interior hydraulic turbulence.
2. Reaming and Deburring (MPC Section 605.14.4): Remove all internal burrs using a reamer blade, and deburr the outside edge with a file. Critical: Unreamed burrs create severe internal eddies that cause local turbulence, eroding the protective copper oxide layer and producing premature erosion corrosion (pinhole leaks).
3. Mechanical Cleaning: Polish the outside of the tube end to bare bright copper using 120-grit sandcloth for a distance slightly greater than the socket depth. Clean the inside of the fitting socket using a wire fitting brush. Wipe clean with a dry cloth—never touch cleaned metal with bare, oily fingers.
4. Flux Application (ASTM B813): Apply a thin, even coat of water-flushable (water-soluble) flux conforming to ASTM B813 to the male tube end and a very light wipe inside the fitting cup. Flux cleans away trace oxidation during heating and prevents atmospheric oxidation. Code Warning: Acid-based or petroleum pastes are strictly prohibited under the Michigan Plumbing Code because they cause green interior pitting corrosion.
5. Heating Technique: Assemble the joint until the tube seats firmly against the internal socket shoulder. Apply a neutral flame (air-acetylene or swirling MAPP) to the fitting socket—never directly onto the solder or the tube end. Heat the base of the fitting cup first, drawing the heat toward the socket entrance. When the copper reaches soldering temperature (approx. $400^\circ\text{F} - 500^\circ\text{F}$), touch the solder wire to the joint seam opposite the flame. The molten solder will melt upon contact with the copper and be drawn into the cup by capillary action.
6. Cooling & Flux Cleanup: Allow the joint to cool undisturbed until the solder solidifies (preventing crystalline fracture). Immediately wipe off excess flux residue with a damp rag while warm. Under MPC Section 605.14.3, all solder used on potable water must be lead-free (< 0.2% lead per ASTM B32), such as 95/5 tin-antimony, tin-copper, or tin-silver alloys.

High-Temperature Brazing Standards (AWS A5.8)

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3. Cast Iron Soil Pipe & PEX Assembly Standards

No-Hub Cast Iron Soil Pipe Joining (CISPI 301)

No-hub cast iron systems utilize a neoprene rubber elastomeric sleeve surrounded by a 300-series stainless steel corrugated shield and worm-drive clamping bands:

1. Pipe Preparation: Cut pipe square using a snap cutter (soil pipe cutter) or abrasive saw. Deburr sharp edges to prevent slicing the internal rubber center stop.
2. Gasket Placement: Slip the neoprene sleeve onto the pipe end until the pipe seats against the molded internal center stop. Fold back the other half of the sleeve, align the connecting pipe, and fold the sleeve down smoothly over both pipe ends.
3. Shield Positioning: Center the stainless steel shield over the rubber gasket.
4. Torquing Protocol: Using a calibrated T-handle no-hub torque wrench:
   • Standard Couplings (2-band): Tighten alternately between bands to $60\text{ inch-pounds}$ ($5.0\text{ ft-lbs}$) of torque. Alternate back and forth so the rubber compresses uniformly without pinching or bunching.
   • Heavy-Duty Couplings (4-band or 6-band): Tighten to $80\text{ inch-pounds}$. Tightening sequence must progress from the center bands outward to the outer bands to iron out the gasket smoothly.

PEX Mechanical Joining Standards

                      PEX JOINING INSPECTION STANDARDS

   ASTM F1807 CRIMP SYSTEM:                      ASTM F1960 COLD EXPANSION SYSTEM:
   - Copper crimp ring over brass/PPSU fitting   - PEX-a pipe with PEX expansion ring
   - Positioned 1/8" to 1/4" from cut edge       - Expanded with rotating cone head
   - MUST PASS GO/NO-GO GAUGE TEST!              - Shrinks back over fitting via shape memory

         [CRIMP RING]                                  [EXPANSION RING]
        +------------+                                +---------------+ 
   =====|   |####|   |==== PEX TUBE              =====|       |###|   |==== PEX-a TUBE
        +------------+                                +---------------+ 

1. ASTM F1807 / F2159 (Copper Crimp Ring System):
   • Cut PEX squarely using a razor shears cutter.
   • Slide the annealed copper crimp ring over the tube, positioned $1/8\text{ inch to } 1/4\text{ inch}$ from the cut end.
   • Insert the barbed fitting until fully seated against the shoulder.
   • Center the crimp tool jaws perpendicular over the ring and squeeze handles completely until the tool releases.
   • The Go/No-Go Gauge Test: Every crimped joint must be checked with a calibrated caliper gauge. The "Go" slot of the gauge must slip over the ring. The "No-Go" slot must NOT slip over the ring. If the "No-Go" slot slides over, the joint is over-crimped (crushed fitting); if the "Go" slot will not fit, the joint is under-crimped. Both conditions represent immediate practical exam failure.
2. ASTM F1960 (Cold Expansion / Uponor ProPEX System):
   • Permitted only with PEX-a (Engel method) high-density cross-linked polyethylene.
   • Slide the PEX expansion ring onto the tubing until it hits the molded stop.
   • Insert the expansion tool head into the pipe, expand fully, release, rotate the tool head $45^\circ$, and expand again. Multiple expansions with rotation prevent grooving the inside pipe wall.
   • Push the expanded tube and ring over the barbed fitting immediately. The crosslinked elastic shape memory of PEX-a shrinks the tube back down tightly over the fitting barb, creating an inseparable permanent mechanical bond.

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4. MIOSHA Part 9: Excavation, Trenching & Safety Standards

Plumbers routinely work in trenches to install building sewers, water services, and storm drains. Cave-ins are among the most lethal hazards in construction. In Michigan, trenching safety is governed by MIOSHA Safety Standard Part 9: Excavation, Trenching, and Shoring (R 408.40901 et seq.).

                      MIOSHA TRENCH SAFETY GEOMETRY

        SPOIL PILE SETBACK
        MINIMUM 2 FEET!
          /-----------\
         /  SPOIL PILE \
        /               \   2 FEET MIN
       ------------------+ <---------> +---------------------------+
                                       |                           |
                                       |   PROTECTIVE SYSTEM       |
                                       |   MANDATORY IF            |
                                       |   5 FEET OR DEEPER!       |
        LADDER EXTENDS                 |                           |
        3 FEET ABOVE                   |                           |
        LANDING!     \                 |  TRENCH BOX / SHORING     |
                      \                |                           |
                       \               |                           |
                        \              |                           |
                         \             +---------------------------+
                          \            | MAXIMUM 25 FEET TRAVEL    |
                           \           | TO REACH AN EXIT LADDER!  |
                            +----------+---------------------------+

Core MIOSHA Part 9 Rules for Plumbers

1. The 5-Foot Rule (R 408.40941): A protective system (sloping, benching, shoring, or trench shield/box) is mandatory in any trench $5\text{ feet}$ ($1.52\text{ m}$) or deeper, unless the excavation is made entirely in solid stable rock. If an excavation is less than 5 feet deep, a "competent person" must inspect the trench; if there is any indication of a potential cave-in, protective systems must be installed.
2. Spoil Pile Setback (R 408.40931): Excavated materials (the spoil pile), equipment, and heavy tooling must be stored at least $2\text{ feet}$ ($0.61\text{ m}$) back from the edge of the excavation. Loose rocks and soil must be retained with toe-boards or barriers to prevent them from rolling into the trench on workers.
3. Access and Egress (R 408.40933): In trenches $4\text{ feet}$ ($1.22\text{ m}$) or deeper, a stairway, ladder, or ramp must be provided:
   • Workers must not travel more than $25\text{ feet}$ of lateral distance to reach a safe exit point.
   • Exit ladders must be securely tied off and extend at least $3\text{ feet}$ ($0.91\text{ m}$) above the top surface landing.

MIOSHA Soil Classification Reference

Crucial Trade Rule: In Michigan urban plumbing installations, almost all street and yard excavations are classified as Type C soil because the ground has been previously disturbed by prior utility installations or is subject to road traffic vibrations. Plumbers must never assume soil is Type A without calibrated pocket penetrometer verification by a certified competent person.

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5. Confined Space Entry & Atmospheric Testing

Sewer manholes, lift station wet wells, underground valve vaults, and septic tanks are classified as Permit-Required Confined Spaces under MIOSHA Part 490. Atmospheric hazards in sewers are invisible, odorless, and rapidly fatal.

                      CONFINED SPACE ATMOSPHERIC TESTING

     TEST BEFORE REMOVING MANHOLE COVER & CONTINUOUSLY DURING OCCUPANCY!
     ===================================================================
     1. OXYGEN CONTENT (O₂):        19.5% to 23.5%  (Safe Breathing Range)
     2. COMBUSTIBLE GASES (LEL):    < 10% LEL       (Methane, Natural Gas)
     3. HYDROGEN SULFIDE (H₂S):     < 10 ppm        (Sewer Gas - Toxic Asphyxiant)
     4. CARBON MONOXIDE (CO):       < 35 ppm        (Combustion Engine Exhaust)

The 4-Gas Detector Parameters

Before entering any manhole or pit, the atmosphere must be sampled at the top, middle, and bottom using a calibrated direct-reading instrument in the following strict order:

1. Oxygen ($O_2$) Content: The safe breathable range is $19.5%$ to $23.5%$.
   • Below $19.5%$: Atmosphere is oxygen-deficient, causing rapid dizziness, loss of consciousness, and asphyxiation.
   • Above $23.5%$: Atmosphere is oxygen-enriched, creating extreme combustion and explosion hazard.
2. Flammable Gases and Vapors (LEL): Must be less than $10%$ of the Lower Explosive Limit (LEL). Methane ($CH_4$) produced by decomposing sewage collects in pockets and ignites from torch sparks or electric tools.
3. Hydrogen Sulfide ($H_2S$): The permissible exposure limit (PEL) ceiling is $10\text{ ppm}$.
   • $H_2S$ has a distinctive "rotten egg" odor at very low levels ($0.1\text{ ppm}$), but rapidly paralyzes the olfactory nerves at $100\text{ ppm}$. Workers lose the ability to smell the gas, leading to instant respiratory paralysis and death within minutes.
4. Carbon Monoxide ($CO$): Must be less than $35\text{ ppm}$. Often introduced into underground vaults by gas-powered pumps, trenchers, or trucks running near the excavation.

Confined Space Entry Equipment Requirements

• Continuous forced-air mechanical ventilation.
• Full-body safety harness connected to a mechanical retrieval tripod and winch operated by a trained top attendant stationed outside the space at all times.