Machining processes have come a long way in recent years, with fiber lasers and state-of-the-art waterjet cutters making sheet metal fabricating a fast and affordable process. No matter what machining process is used, however, parts will tend to have some amount of burr, dross, or leftover imperfections immediately after manufacturing. Trying to figure out how to deburr your parts without compromising their tolerances or final look is a challenge in and of itself, so let’s talk about the different sheet metal deburring processes available and what you should choose for your project.
Defining the processes for deburring
Fundamentally, there are two different classes that deburring systems can fall under: wet or dry.
Deburring using a dry process involves the use of an abrasive to remove dross and burr from the sharp edges of a recently laser or waterjet cut part. Dry deburring machines use a variety of abrasive materials including discs, belt heads, and brushes. Different abrasives achieve different finishings depending on their orientation in the machine and the metal they are deburring.
When deburring parts using wet systems, the parts are fed through a conveyor belt and sprayed with a lubricant and cooling solution. Wet deburring machines utilize abrasive heads or belts placed above the conveyor. The pressure on the part between the conveyor and the abrasive head holds the part in place while the abrasive head removes burr, light scratches, and performs edge rounding.
Wet and dry deburring: keeping it cool
Deburring introduces friction to an already high pressure environment, so the biggest problem deburring systems face is overheating the metal and debris during processing. This combination of friction, metal, and dust creates a highly explosive environment, especially when processing aluminum or titanium.
Wet deburring systems circumvent this problem with the addition of liquid coolant. The liquid coolant is applied to the part as it’s processed, and it prevents the metal debris from heating and igniting inside the machine. This becomes especially important when you need to deburr several different metals because the combination of certain metals in heated environments can cause a devastating explosion. (Iron oxide+aluminum oxide = thermite!)
Additional coolant benefits with wet deburring
The same coolant used to cool the machine itself prevents the actual part from warping under the intense heat. Where a part might come out of a dry process deburring machine warped from excessive heat, a wet deburring machine helps to maintain the part’s original integrity and prevent heat-related distortion. Wet deburring machines can also use a coolant that coats the part and aids in protecting it against corrosion, so your parts will stay looking well-formed and clean with the proper care.
Speaking of clean, wet deburring allows for a more consistent finish of your parts than dry deburring. A wet deburring process evenly distributes the effect of the abrasive media on your part, smoothing the surface of the part with more precision and accuracy.
Deburring machine longevity
Outside of the value wet deburring brings to a part, it’s also better for maintenance of the abrasive media than a dry deburring machine is. The lubricant and cooling used in a wet deburring machine promotes longevity in the abrasive media used, meaning you don’t have to replace the belts or brush heads nearly as often as you do for a dry deburring machine.
Minimizing the disadvantages of a wet deburring process
The biggest thing to keep in mind for any deburring process is waste disposal. This is probably one of the greatest disadvantages to wet deburring over dry deburring, because the use of liquid coolant and lubrication creates a “sludge” that has to be dried or packed in drums for disposal.
Manufacturers also have to be mindful of waste disposal with dry deburring, but since most of the debris is metal shavings and dust, it doesn’t require the same level of specialized equipment or regulation to dispose of. Unlike with a wet deburring machine, however, machine shops utilizing a dry deburring process need to be outfitted with heavy filtration equipment for the health and safety of their operators.
The environmental impact of wet deburring machines can be minimized with eco-friendly lubricant, which can be disposed of via a sewer connection. In addition, many wet deburring machines utilize a “recycling” process wherein the metal debris is filtered out of the lubricant and coolant, and run through the machine for another use. This drastically cuts down on the amount of waste a wet deburring machine produces.
Generally, while the usage of coolant is the biggest asset a wet deburring process has, it can also be its downfall if it’s not maintained properly. Because the inside of the machine is a wet environment, it’s also highly corrosive which can contribute to the degradation of its mechanics. Operators have to be trained on balancing the concentration levels of the coolant and lubricant to prevent the machine (and your parts) from deteriorating due to chemical imbalance.
Cost: initial investment and daily operation
Let’s talk cost. Purchasing and maintaining any deburring machine is no small feat, but wet deburring systems pose a greater initial investment because of the additional complexity of the machine. Depending on the manufacturer and project requirements, a deburring machine using a wet process can cost anywhere from $70k to $250k as an initial investment.
As mentioned, wet deburring machines use additional consumables that contribute greatly to its operating costs. Depending on the materials and abrasives used, it can cost roughly $2-$6 USD per hour of operation between consumables, electricity, and maintenance. This does not include labor costs.
So while a wet deburring machine may not necessarily be something you could populate your at-home machine shop with, the consistent finish and even deburring completed by wet processes make it worthwhile for a larger scale operation. Many manufacturers and fabrication businesses offer wet deburring at a reasonable rate, so outsourcing is yet another option.
Additionally, deburring with a wet process is faster than a dry process in some cases. A wet deburring machine can apply greater pressure on the part between the conveyor and the abrasive media without causing warping or introducing heat into the part. Because of this, it takes fewer passes through the wet deburring machine to achieve the desired finish. Less time on the machine means it can actually be cheaper per part to use a wet deburring process over a dry one. This is ideal for both the manufacturer and the consumer.
Conclusion: wet deburring for the win
Overall, wet processes are preferable for deburring metal parts for the clean, consistent finish it provides. While it’s not the cheapest or most feasible option for deburring in a small shop, the final results make it worthwhile.
If you’re interested in learning more about deburring, check out SendCutSend and our state of the art deburring processes. With additional services including laser and waterjet cutting, CNC routing, powder coating bending, and tapping, SendCutSend is a one-stop-shop for all your machining and fabricating needs.
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