Silicone caulking extruded from a caulking gun

Marine use

Wooden ship caulking

The tools of traditional wooden ship caulking; caulking mallet, caulker's seat, caulking irons, cotton and oakum.

Modern marine sealants are frequently used now in place of the pitch, or even to supplant the oakum and cotton itself.

Iron or steel ship caulking

In riveted steel or iron ship construction, caulking was a process of rendering seams watertight by driving a thick, blunt chisel-like tool into the plating adjacent to the seam. This had the effect of displacing the metal into a close fit with the adjoining piece.^[1] Originally done by hand much like wooden vessel caulking, pneumatic tools were later employed. With the advent of electric-arc welding for ship construction, steel ship caulking is truly a lost art.

Boiler use

The same technique described above for making riveted steel or iron ships watertight was also used to make riveted boilers, such as steam locomotive boilers, watertight and steamtight.^[2]

Building construction

Man putting caulk on baseboard

This is mostly done with ready-mixed construction chemicals sold as caulk such as silicone, polyurethane, polysulfide, sylil-terminated-polyether or polyurethane and acrylic sealant. Unlike construction caulk, which is applied where no building movement is expected, a sealant is made of elastomeric materials that typically allow movement of 25% to 50% of the width of the joint. Silicone sealants form a durable, water-tight seal, but are not typically paintable. Some silicone sealants are made to be paintable with certain types of paint such as water or oil-based paints. Other sealants are paintable.

One-component sealants are commonly sold in cartridges which are loaded into a pistol-like caulking gun (opening at the side) or barrel gun (opening at the end) for application. During the tool-working time, which varies by chemistry, the bead can be pressed into the joint so that it can bond with the materials on both sides, and also be smoothed. The time it takes for a chemical sealant to become a rubber is known as the curing time and varies by temperature and humidity. Issues of technique that may not be obvious to first-time users:

• The nozzle must be chopped short to match the intended size of the bead. If the opening in the nozzle is too small, the bead is liable to bunch and is difficult to keep even.
• Common tools are a pointing tool, shaped wood, wet finger or a spoon. Detergent should not be added to the moisture for tooling since it may drip onto the bond surface causing a loss of adhesion.
• For neat work, the worker may apply painter's masking tape beforehand, taping off the areas on each side of the joint to catch any surplus, and remove the tape again before the tooling time has expired.
• To prevent three-sided adhesion or to avoid sag in wide, deep joints, a backer rod made of plastic foam can be pressed into the gap before caulking.

Backer rod can also be used to fill cracks in sidewalks, and masonry before caulking. It is composed of a foam roll that is generally about 1/4 inch to 1 1/2 inch thick. The material is stuffed into the cracks to be sealed and then caulked over.

Energy Efficiency

According to the Consumer Federation of America, sealing unwanted leaks around homes is an excellent way to cut home energy costs and decrease the household carbon footprint.

Also, sealing cracks and crevices around homes puts less strain on home appliances and can save time, money and hassle by preventing major repairs. Additionally, increasing the lifetime of homes and appliances also puts less waste and pollution into landfills.

References

1. ↑ U.S. Coast Guard: Navigation and Vessel Inspection Circular Number 7-01: Procedures for hull inspection and repair on vessels built of riveted construction. Issued 2001-10-09.
2. ↑

External links

• Standards Association of New Zealand, Glossary of Building Terminology, 1979. ISBN 0-473-00035-0
• Recommendations for Selecting and Using Caulks and Sealants in Pest Management (PDF)
• Consumer Federation of America http://www.consumerfed.org/releases2.cfm?filename=Pepcoratedc.txt

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