The Ductware Blog

Water-based sealants have been gaining acceptance in the HVAC industry in the last several years, displacing the once more commonly used solvent-based sealants.

Water-based sealants offer many of the same attributes without any of the potential hazards associated with solvent-based sealant.  The common misconception in the industry is that water-based sealants require an extended curing period in comparison to a solvent-based product. Although this may have been true with earlier produced water-based sealants, it does not pertain to the more advanced water-based sealants presently available. Several water-based products currently on the market can be tested within 24 hours, and fully cured within 72 hours.

Water-based sealants are classified as compounds in which the volatile vehicle, or the part of the compound that evaporates during curing, is water. As a result, water-based sealants are classified as non-hazardous waste materials allowing them to be disposed of in the regular trash or washed down the drain. Clean up is accomplished with the use of a mild soap and water, tools can be washed in any sink with the rinse water going into the drain. Water-based products do not have to be stored and accounted for as a hazardous waste and require no special disposal instructions. As a result, SMACNA has endorsed the use of water-based sealants for all ductwork systems.

The water-based sealant industry has come a long way in the past few years. Water-based sealants can match or exceed solvent-based sealant performance in all areas. Most quality water-based sealants are capable of being pressure tested after 24 hours. Water-based products are water and UV resistant, making them suitable for outdoor applications. With the exception of a few specialized applications, a water-based sealant can provide the quality, long-lasting seal required of a duct system.

Water-based sealants are an important consideration if you wish to achieve the Australian Green Star IEQ-13  credit for Volatile Organic Compounds.

Solvent-based sealants, on the other hand, have a volatile vehicle which consists of organic solvents that may include mineral spirits, hexane, heptane and toluene. These materials are considered toxic,  therefore requiring special handling and proper disposal under an approved hazardous waste program. Most common carriers charge higher fees to transport hazardous materials, as they can require special handling and permits.

The evaporation of the volatile vehicle causes heavy odour, toxic fumes and can lead to poor Indoor Air Quality (IAQ). Solvent-based sealants should not be used in or around areas that are inhabited by people as the fumes can cause headaches, nausea and eye irritation. Because of the inclusion of cancer causing chemicals, heavy fume concentrations can cause much more serious health problems as well.

On the positive side, the quick evaporation rate of the volatile vehicle allows a solvent-based sealant to cure faster than the water-based. This can be both good and bad. Although the solvents may reduce curing and installation time, they can also reduce the life of an opened container.

The same volatile component which reduces curing time of solvent-based sealants also increases its flammability, forcing contractors to either use up all of an opened container or allow the contents to completely dry before disposing of the container. Solvent based product clean up requires either mineral spirits or solvent type products. Shops that use solvent-based sealants may pay higher insurance premiums due to the high flammability and toxicity of this product.

Many Australian HVAC duct manufacturers are discovering how much time and money they can save by using Weldpins, rather than CD Pins plus Speed Clips to affix insulation to ductwork.

Using a hand held or floor mounted Gripnail Power Pinner machine allows insulation to be attached to HVAC ducts using Weldpins (resistance weld pins) rather than CD (capacity discharge) Pins and speed clips. Using Weldpins reduces the steps involved in the process - which in turn reduces the man-hours required.

Let’s compare the two processes

When using CD PINS + SPEED CLIPS to affix insulation to HVAC ducts, the steps are:

1.       Weld the CD pin to the sheetmetal

2.       Lay and pierce insulation blanket over the pins

3.       Affix speed clips.

 Compare this to using weld pins:

1.       Lay the insulation blanket on the sheet metal

2.       Affix the insulation blanket by simply piercing and welding the pin through the blanket to the sheet metal in the same step.

Not convinced? Try out Ductware’s free online calculator that allows you to calculate your possible savings.

New multi-head Gripnail technology

For even more productivity gains you need to take a look at the new Gripnail Power Pinner 50 multi head machine (see video below)

This machine makes it possible to line duct as it is run through a coil line. Weldpins are driven 4, 5 or 6 at a time while the metal is moving at up to 15 metres per minute with spacing as close as 150 mm  apart.  As the equipment fastens at coil line speed, it saves floor space by eliminating the lengthy transfer tables needed to add “gap time” with other systems which do not fasten “on the fly”. 

The automation levels of this new machine enable better labour utilisation –  The wrap brake requires only one person to unload and only one person to close the Pittsburgh (machine) because the duct is coming out in one piece instead of two AND is fully insulated. This configuration eliminates that extra step, saving time, although it does make things busy for the operator! The gap time between ducts is just enough for the operator to label the duct, place it on the floor and go back for the next piece.

An added benefit is that these machines don’t take up much space; they’re fast with a small footprint. The Gripnail machines are available from our partner, www.kleen.com.au. Ductware supplies the consumables for the Gripnail machines, along with many other HVAC parts and ductwork supplies that offer Green Star advantages

The machine in action:

Visitors to the trade nights were looking for a solution to protect the inside of ductwork from accumulating dust and dirt  – a critical consideration for HVAC applications where air contaminants need to be minimised.

Our ProGuard  ‘cling wrap for ducts’  is ideal for sealing ductwork after manufacture, protecting it during transport and storage. It offers excellent tensile strength and elongation characteristics, enabling it to resist exposure to sunlight, wind and sharp edges. It’s also highly resistant to the inevitable scuffing that occurs as duct is moved around, a characteristic not shared by competing duct wraps.

Once HVAC installation starts, our Ductcap product (think: shower cap for ducts) can be used to cover the open ends of ducts during the installation process.  This product has recently been used onsite at the new Royal Children’s Hospital project in Melbourne  – where reducing air contaminants is obviously an essential requirement.

As suppliers of HVAC components that increase productivity and offer environmental benefits, my blog aims to deliver information about:

• Changes within the HVAC industry within Australia and New Zealand
• News of events and new products
• Tips and tricks for improving the efficiency of HVAC systems and delivering Green Star compliance benefits

Best wishes

Michael Hadley

General Manager

Ductware