Volume 29, Issue 3 - Fall 2015

Metal Matters

Care of Architectural Aluminum
Pitfalls and Preventative Actions of Material Handling on a Project
by Dean Lewis


Aluminum is famously strong structurally, but its varied and attractive anodized and organic finishes—while durable against the onslaughts of nature—are highly susceptible to damage. The damage can come from improper handling, storage, physical impact and contamination from many of the chemicals commonly used in the construction process. Anyone working with aluminum on a project should be aware of these pitfalls and available preventive actions to ensure that the materials safely transit the entire manufacturing, finishing, fabrication, delivery and installation phases.

AAMA CW-10-15, Care and Handling of Architectural Aluminum from Shop to Site, identifies several stages in the value chain as material flows from extruder to fenestration product fabricator to the project in which the finished product is installed.

Mill Fabrication and Packing

During processing, the extruder must take care to stack metal in appropriate configurations and add spacers to prevent contact between exposed surfaces, sliding and excessive weight build-up. Saw chips that can collect between layers must be removed. Unfinished aluminum should be handled with clean gloves, since acids from skin contact can cause finger or hand prints to emerge after anodic finishing.

Unloading and Storage Prior to Fabrication

Because less handling reduces the chance of damage, both unloading and storage should be organized to minimize material handling. Every precaution should be taken to prevent parts from striking each other or striking other hard or sharp objects and to distribute weight evenly to prevent distortion, slippage or damage. All pieces should be stored so that withdrawing will not cause scuffing or abrasion.

Prolonged contact with wet wrapping or interleaving material—particularly those containing dyes or printing inks—could cause staining or discoloration.


Aluminum can be susceptible to damage and requires care from all involved in a given project—from fabrication, to installation, to maintenance.



Fabrication of the Fenestration Product

Handling and intra-plant transport of “in process” components and sub-assemblies should employ rubber wheeled carts or dollies. Wood, corrugated paper or plastic spacers should be used between pieces to protect the material surfaces from scuffing, marring and abrasion.

The principal contributor to the abrasion of painted surfaces is the accumulation of aluminum waste during sawing and machine operations. Frequent removal of chips, borings and slugs by brushing or with pressurized air is recommended.

Packaging and Shipping of the Finished Product

Packing the finished product properly is one of the most important steps the fabricator can take to help ensure that the product will arrive at the job site undamaged. Packaging techniques include nesting, interleaving, banding, wrapping, boxing and crating.

Jobsite conditions should be determined in advance so that packing can be compatible with the equipment available, storage conditions and the labor to be used.

Unloading and On-Site Storage Prior to Installation

Unloading and storage should be scheduled to avoid premature delivery and ensure that materials receive minimum handling and storage time at the construction site.

Products should be stacked properly to avoid distortion, allow for air circulation and protect against abrasion.

Assemblies should be stored in a clean, dry location, preferably indoors.

During Installation

Damage to finishes is extremely difficult, if not virtually impossible, to fix in the field. For this reason, foremen, installers and workers of all trades should be instructed in the proper handling of aluminum.

In many instances, additional protection against physical damage can be provided by using temporary wood frames around the heads, jambs, and sill sections of doors and windows and other exposed parts where traffic damage could be extensive.

A major source of damage to in-place aluminum architectural components comes from adjacent or overhead masonry work. Any mortar, plaster, concrete, or other wet preparations that inadvertently splash upon the aluminum must be immediately wiped clean before they dry and the area washed liberally with water.

In-Service Maintenance and Cleaning

AAMA 609 and 610-15, Cleaning and Maintenance Guide for Architecturally Finished Aluminum, is published as one document; it picks up where CW-10-15 leaves off. Intended for use with anodized or painted architectural products, it outlines methods, equipment, and materials for cleaning and periodic maintenance of finished aluminum after construction. In general, always correctly identify the aluminum finish to be cleaned when selecting an appropriate cleaning method. Never use aggressive alkaline or acid cleaners on aluminum finishes. Test-clean a small area first and do not mix different cleaners.

Periodic maintenance inhibits long-term accumulation of soil which, under certain conditions, can accelerate weathering of the finish. The more frequently aluminum is cleaned, the easier and less costly succeeding maintenance will be.

AGG

Dean Lewis is the educational and technical information manager for the American Architectural Manufacturers Association in Schaumburg, Ill.

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