Mechanical joining, soldering and fasteners · Lesson 1 of 4

Mechanical joining, soldering and fasteners: principles and terminology

The three ways sheets are joined, rigid against loose seams, what solder and rivets each do, the words of the trade, and the lead, flux and fire hazards that come with soldering.

You will be able to: Define rigid and loose seams, soft soldering, flux, tinning, sweating, blind rivets and grip range, explain why solder seals and rivets carry load, and state the lead, flux and fire safety boundaries.

15 min · 12 slides · 14 questions

All lessons in this module

Slide 1 of 12

Three ways to join sheet

CDA calls mechanical fasteners, such as screws, bolts and rivets, the simplest and most common joining technique.

Sheets are also joined by interlocking seams and locks, and by soft soldering. This module covers the shop side: rivets, screws, solder, flux, fastener metals and inspection.

Every value is labelled with whose it is. None is an AFS shop setting.

Sources

Copper in Architecture Design Handbook (A4050-8/24), pages 16, 25, 33 and 48 - Copper Development Association
Copper in Architecture Design Handbook - 7.2 Joints and Seams - Copper Development Association

Videos for this lesson

What this video shows: CDA shows how to make a soldered lap seam, the seam it recommends when copper is too thick for a flat lock or the shape prevents one. CDA's handbook still limits the soldered lap to copper up to 20 oz.

Video: Lap Seam, Soldered by Copper Development Association, on YouTube. Chosen from the video's published description.

Glossary

Rigid seam: A seam that is soldered or riveted and allows no movement.
Loose seam: A seam that lets the sheets slide or flex with thermal movement; it can be sealed with a flexible sealant.
Soft soldering: Joining with a lead or tin-based filler that melts below 500 F (CDA); ASTM B32 scope: joining metals below their melting points.
Flux: A chemical that lifts light oxide so solder can wet the metal; it does not remove heavy oxide.
Tinning: Coating the soldering copper, or the sheet faces, with a thin layer of solder before the seam is made.
Sweating: Drawing molten solder fully through a lap or lock by heat and capillary action.
Blind rivet: A rivet set from one side: the tool pulls a mandrel that deforms the body, then the mandrel breaks off.
Grip range: The span of total material thickness that one rivet length can clamp.
Galvanic corrosion: Corrosion where dissimilar metals are in electrical contact with moisture present.