Metals, alloys and protective coatings
The metals and coatings AFS fabricates, how to read their designations and published ratings, an eight-step method that screens contacts and runoff before an order is placed, and the defects to look for.
4 lessons · about 40 min · 12 diagrams · 7 videos
Version 1.0.0
Builds on these modules
Lessons
0 of 4 complete
Lesson 1 · 10 min · 12 slides · 7 questions
Metals, alloys and protective coatings: principles and terminology
The three ways sheet metal resists weather, the nine AFS materials and their five families, how to read the codes printed on metal, and why heating coated metal is a hazard.
You will be able to: Name the metals and coatings AFS fabricates, say how each one protects itself or is protected, decode designations such as G90, AZ55, 3003-H14, 16 oz and 316, and state the fume boundary for coated metals.
Not startedStart →Lesson 2 · 10 min · 12 slides · 7 questions
Metals, alloys and protective coatings: materials, standards and design constraints
Which standard covers which metal, what a coating weight does and does not tell you, how galvanized, Galvalume, paint, anodizing, copper, zinc and stainless differ, and the exposure limits published for each.
You will be able to: Match each AFS metal to the standard that names it, read coating weights and film thicknesses, compare paint tiers, and say what environment and contact limits each material carries, attributing every published value.
Not startedStart →Lesson 3 · 12 min · 12 slides · 8 questions
Metals, alloys and protective coatings: methods and worked application
Read the spec, match it to the AFS material, calculate coating thickness and zinc weight, list and screen every contact and runoff path, and record storage notes and requests for information.
You will be able to: Apply an eight-step method that takes a specification line to an unambiguous, screened order, calculating coating thickness and zinc weight and recording every contact, drainage path and open question.
Not startedStart →Lesson 4 · 8 min · 11 slides · 6 questions
Metals, alloys and protective coatings: defects, verification and case study
A seven-tile inspection guide that pairs each symptom with its likely cause, an illustrative coastal case worked through to its requests for information, and the job packet that records it.
You will be able to: Diagnose the common coating and corrosion defects from what you see, name the usual cause and correction, and document evidence and open questions in a job packet.
Not startedStart →
Practical task
Build a job packet for this example specification line, then check it against the course method: "Coping on treated-wood nailers, 24 ga Kynar 500 painted steel in Charcoal, stainless screws, copper wall flashing above, near the coast." The line is a teaching example, not a real order.
Hand in
- A decoded spec line that lists the material, thickness unit, finish system and color request, with the AFS catalog material each maps to.
- The chart and printed color name for the color, with the reason: painted steel takes a McElroy chart color in AFS's register, and Charcoal also appears on a PAC-CLAD chart, so the chart must be named.
- A contact and drainage list: every metal, fastener, wood and membrane the coping touches or drains onto, each pair screened with the result (compatible, caution, avoid or not covered) and its source.
- One worked calculation: the minimum coating thickness of G90 (1.51 mil, both faces together) from GalvInfo's factor, with every input and unit written down.
- Storage and marking notes, and a list of requests for information for anything the specification leaves open.
Rubric
| Criterion | Meets the standard when |
|---|---|
| Decoding | Each part of the spec line is decoded, and nothing is assumed that the line does not state, including the base metal under the paint and the stainless grade. |
| Chart and color | The order names the chart and the printed color name, and says why a name that appears on more than one chart needs the chart named. |
| Contacts and runoff | Every contact and drain-onto material is listed. Copper above coated steel, treated wood and the fastener metal are each screened with a source, and the output is a screening result, not an approval. |
| Calculation | The G90 minimum thickness is calculated as 0.90 oz x 0.00168 in per oz = 1.51 mil with units, and is labelled as both faces together at the minimum weight. |
| RFIs and safety | Each open question is an RFI addressed to the designer or supplier, and the packet notes the fume boundary for heating coated or lead-bearing metal. |