Choosing the right saw involves a number of factors – especially when investing in a solution that can meet the needs of today as well as tomorrow. The process involves a careful look at the material being cut and the expectations regarding the quality of that cut. Ultimately, running the saw wet or dry is part of the decision-making process.
As the vice president of development and operations at Roll-In Saw, Marcus Borman assists customers in making the choice between wet or dry sawing. Roll-In has a rich history in manufacturing saws, including the first gravity-fed bandsaw introduced in North America in 1940 – the model EF 1459. Today, the Ohio-based company is gearing up to introduce new lines of products over the next year and a half, including saws with and without coolant systems.
Narrow the Options
Borman doesn’t have an official checklist to go through with customers to determine whether they need a saw equipped with a coolant system, but he starts with some basic questions that can open up the conversation to more revealing facts. These in-depth conversations are the types that lead to effective saw selection.
First, it’s important to know how often the saw will be in use. Will it run for multiple hours a day, perhaps two shifts, or will it make a couple of cuts a day and then be shut down? This is important to know because prolonged usage commonly benefits from the inclusion of a coolant system whereas less frequent use on easy-to-manage materials does not require such a system.
Borman also asks what types of material customers are cutting presently and also what they expect to cut in the future. While the material being cut today isn’t a good candidate for wet sawing, perhaps the materials they’ll be working with in the future will require coolant or lubrication. For example, hardened or heat-treated steel, which are notorious for ruining saw blades, are excellent candidates for wet sawing.
“If you work with work-hardened material,” Borman says, “you’re going to need a lot of high pressure and low speed. Using coolant is a big benefit. If you’re cutting easier stuff and need to cut a lot of it, you can increase your band speed and keep the low pressure on it by running wet, as well. With this style of cutting, you generate more heat, and taking time between cuts or having a cooling agent helps.”
After the first few initial questions, customers open up and begin talking about jobs involving different styles of cuts or materials that they’d initially forgotten about. Borman’s goal is to cover all of the bases.
“We want to make sure they have a saw that’s going to be able to cut the size of material they have,” Borman says, “even if they only cut that size once or twice a year. I’ve found that it’s worth spending the extra bit of money for the larger size for those times when they need to bid on a job or they have to cut something for a repair in their shop.
Borman also helps make the determination about the type of saw. “If they choose a horizontal saw, we almost always recommend having the coolant system factory installed,” he says. “It’s cheaper and produces fewer headaches than trying to install it aftermarket. If they need the versatility of a stationary or gravity-fed vertical saw, then I usually recommend a chip dust blower and discuss feed and speed rates to get the most out of the saw.”
Running a saw wet, however, doesn’t necessarily serve as the best option when it comes to quality or precision of the cut, but it can help with the burrs left on the final cut when doing production style cutting, as the coolant keeps the workpiece at a stable temperature and removes chips.
“Depending on the quality of the saw,” Borman says, “you can get accurate and high-quality cuts running a saw wet or dry. However, some materials see reduced burr creation when you use a coolant while cutting.”
Another aspect of cut quality revolves around the placement of the coolant to the cut. It’s important that the liquid hits the material where the blade is entering and leaving the cut. Placement of the coolant in relation to the blade is also important.
“If you have it just pointing to the one side of the blade far away from the cutting surface,” Borman says, “you’re going to create more stress on the other side. But if you apply it in such a way that it is on the saw blade as you’re going through the cut, you’re going to get better results. You can easily move a guide arm closer to the cut, allowing the coolant to hit the blade and carry coolant through the cut.”
Because coolant can be recycled many times over before totally needing to be replaced, the cost of consumables is low. This is especially true considering that the proper use of coolants can keep the cost of the most expensive consumable at a minimum: the blade.
With blade life extended, customers can see a cost savings on blades and the added advantage of less downtime associated with making blade replacements. Borman reminds customers, though, that the proper cutting techniques extend the life of the blade while cutting – wet or dry.
“Simply choosing the right blade tooth configuration, adding a chip dust blower and cutting at the right speed and feed rate can give you equally long life out of your blades,” he says.
Mist or Flood System
It’s not unusual for customers to express concern about the cleanup associated with running wet, especially when using coolant on a vertical saw, which Borman says is “nearly impossible to keep from making a mess.” Naturally, one way to control an excess of runoff is to not go overboard on the amount of coolant being applied during use.
“A lot of customers want to err on the side of caution and say, ‘if I’m using coolant, I want to make sure it’s hitting every single spot that it needs to hit,’” Borman explains. “And so, they’ll turn it way up. We’ve found that to be overkill.”
Fortunately, if keeping the shop spic and span is a priority, a mist system can be installed. Rather than flooding the cut with liquid, one or more misters gently apply coolant to the cut area.
“The mist system doesn’t provide as many benefit as the full flood system,” he says, “but for some applications, it’s better than running it dry.”It’s not unusual for Borman to encounter a customer that purchased a saw that runs dry only to discover later that they’re running into jobs that would benefit from the use of a flood or mist system.
“Many customers buy a saw with no coolant system, but end up cutting materials they weren’t expecting and using the saw a lot more,” says Borman. “They then go through blades more quickly and the cuts don’t come out as well as expected. Fortunately, a mist system can help in some cases. It takes a little bit of engineering work to add it aftermarket, but it’s something that can be done on a lot of saws out there.”
Just because a saw is equipped with mist or flood system doesn’t mean it has to be activated with every job. When tackling smaller jobs on material that doesn’t require coolant, Borman says to simply turn the coolant system off.
Cutting fluids come in a multitude of varieties, including water-based, oil, oil-water emulsions and gels, among others. While the type of coolant or lubricant used during operation depends on the material being cut, Borman finds most customers have a personal preference. He advises them that using a water-based coolant on steel, stainless steel and aluminum as water-based coolant is more effective on those materials.
“There will be people who debate that issue and say ‘I want an oil- or synthetic-based coolant when cutting those materials,’” Borman explains. “We believe that water based is fine on stainless steel and aluminum and synthetic or oil is better for harder materials.”