Crafco and Cimline offer electrically heated hoses. Dunn says Cimline adopted electrically heated hose technology so operators wouldn't have to handle a hose with 500-degree heat transfer oil flowing through it and in order to produce lighter hoses.

"Being on the end of the hose all day is tough work — it could be warm, noisy, it's dangerous in the traffic anyway. So we try to make the hoses and wands as light as possible," Dunn says. "We've gone to an aluminum wand, and Cimline has one of the lightest electrically heated hoses on the market, and that's for operator comfort."

An additional safety feature found on Cimline and Crafco hoses locks the wand into the port when it is recirculating material back into the tank. The wand cannot be removed, and therefore hot sealant material cannot escape from the tip, unless the safety pin is removed, which stops the recirculation. Heated hoses can tell when this recirculation is happening, and the heating mechanism slows down, saving energy.

Crafco's internal pump technology on its SuperShot melters eliminates the need for hose recirculation. The pump works only on demand, after the operator activates a switch on the wand. This pump system leads to a longer pump life and results in no pressure hoses.

"They are primarily safety related and wear parts related. When a pump's not turning, it's not wearing itself out, so it only turns on demand," Manning says. "You push the switch, the pump pumps the sealant. You turn it off, the pump stops and the sealant stops flowing, as opposed to a recirculating system where it continually pumps and all it does is redirect the sealant when you turn the handle on for the wand to apply product."

Electronic controls

More and more manufacturers are designing simplicity into their machines, and adding electronic controls is one way they're doing this.

"Early on, a lot of the kettles had no controls, and then controls were analog, sort of like turning a dial on a toaster to warmer or cooler," Dunn says. "Today, because of technology available, a lot of units have the ability to digitally measure the heat transfer oil, the material, and report that back on a digital display that tells you exactly what the temperatures are. This is nice because if you're doing state work, you can actually adjust your machine so that if an inspector used a heat gun he could actually see the material go into the crack at exactly, say 390 degrees, or exactly what the specifications called for."

These electronic controls monitor more than materials. Manning explains Crafco's SuperShot units have an engine monitoring system which operates through an onboard computer — all the operator has to do is flip switches. The control panel displays material, hot oil, and hose temperatures, and also controls the pump, agitator, heat, hose, and engine controls.

"There's nothing mechanical about it," Manning says. "The safety aspect of it has to do with not doing anything to the machine mechanically. You can stay away from it, you don't have to open lids to look inside, you don't have to turn valves that could fail, you don't have high pressure on the hoses, actually, when it's not being used there is no pressure on the applicator hoses at all."

The systems also track engine function, such as oil pressure and radiator coolant, and if there is any problem with an engine, the system shuts down.

"The biggest investment on the machine is the engine — those diesels are very expensive, but they tend to last a long time. So what this does is if there's any problem it shuts the engine down," Dunn says. "People like that, because it makes sure that if you don't have oil or something like that, you fix the problem before you wreck the engine."