The Finished Part Blog

What factors are critical when choosing a deburring machine manufacturer or any supplier of surface
finishing equipment?

Most importantly, make sure that the machine manufacturer you are working with
can provide a wide range of potential solutions for your application. If the deburring machine
manufacturer only works with barrel tumblers or vibratory tumblers or high energy systems, you can be
assured that the solution is what they are selling.

Working with a company that is a polishing and deburring machine manufacturer with the options for
multiple solutions will be able to provide the optimal solution for any application. If you can, provide
samples to the machine manufacturer so that they can work with your parts to find a solution that
makes the most sense for your operation.

Achieving the finish you need is only one aspect of surface finishing. Working with the polishing and
deburring machine manufacturer to fully understand all your requirements – floor space, part
throughput, other processes happening on your production floor, required cycle times, etc. – will ensure
that you get the best overall process for you and your operation.

Both hobbyists, treasure hunters, and bulk mail houses all need a process to take cruddy, oily, or dirty coins and make them look like new. Tumbling is an easy and efficient process to accomplish this.

The coins on the left are dirty, corroded and need to be cleaned and end up with a shiny finish. The first step is the clean the corrosion. Barrel tumbling is a great process for tumbling coins (think rock tumbling). With a small Ceramic Media and a mildly acidic compound, the coins can be completely cleaned to a matte surface finish.

If a polished and shiny finish is needed, a second step with the Pegco HCW-4 Fine Premium Treated Tumbling Media will result in the beautiful, shiny finish on the right.

This process can be done in a small bench top tumbler like the MT Series or in large floor model systems like the heavy duty K Series Barrel Tumblers.

Often when the chain is exposed to the environment, it can get dirty and rusty. Cleaning the chain periodically both extends the lifetime and can be done for aesthetic purposes. The big challenge is how to clean the chain without it getting into a big ball of knots.

A vibratory tumbler is often a better process than a barrel tumbler as it will do a better job of keeping the chain expanded and not ball upon itself. The selection of media is also important, and the shape and size will depend on the size of the links in the chain. The chain on the left is rusty and dirty and needs to be cleaned. In addition to the
‘exposed’ areas, the internal areas where the links connect also need to be cleaned. The first step was to clean the chain. In this example, the chain was tumbled in a wet process using a Ceramic Cone shaped media. To get to all areas of the chain, it took about 4 hours to clean.

As this chain needed to have a polished finish, a second vibratory tumbling step was used. The Pegco GBW-3.9 Coarse Premium Treated Tumbling Media was used to polish this steel chain. This step took about 12 hours to the result on the right.

The goal in this test was to get essentially an optically clear, acrylic part. The challenge is to slightly round the edges without so much abrasiveness that an ‘orange peel’ affect occurs on the surface. This will make the polishing step nearly impossible.

The first step was to vibratory tumble with a Plastic Media for nearly 8 hours. This longer cycle time was needed because the Plastic Media is not as aggressive as something like a Ceramic Media. The wet tumbling process slowly rounded the edges and left a uniform, matte finish on the surface.

The second, dry tumbling step used Hardwood Cubes and the Hi-Glos Final Finishing Cream. This high polishing cream is very effective when coated on Hardwood Media to slowly polish the surface leaving a scratch free, totally clear result. The step was about 6 hours but can be longer depending on how the resin or plastic reacts to the tumbling process.

Tumbling flatware has been around for decades. The process can be done in either a barrel tumbler or vibratory tumbler. There are a wide variety of processes depending on how scratched the flatware is prior to any polishing and what type of metal it is.

These stainless steel spoons were tumbled in a two-step process to first remove the scratched and then polish to a mirror finish. The first wet tumbling step used a light cutting Plastic Media for about 2 hours. The second dry step used a Treated Tumbling Media to create the mirror-like surface finish. This took about 16 hours.

Often, this application is a single step using either Stainless Steel Balls or Ceramic Polishing Balls. In this case, a more aggressive first step was needed to remove the heavier scratches on the part and the equipment the customer has would not allow for the weight of the steel tumbling media.

 

There are many factors that impact the results of a blasting process. These include the blasting pressure, the blasting angle, distance from the surface, and, most importantly, the abrasive blasting media being used.

Different blasting media will produce very different types of finishes. In the picture on the left, you can see two coupons blasted with Glass Beads. Glass Beads produce a peened surface finish. The one on the left is a 20/30 Coarse grade and the peening marks are clear. As a larger Glass Bead, the finish is also brighter. The other coupon was blasted with a 100/170 Medium-Fine grade. The finish is much smoother and also more a satin-matte finish.

The picture on the right shows the same Glass Bead – 20/30 Coarse blasted coupon next to a coupon blasted with a similar particle size Aluminum Oxide Grit – 36 Mesh. The difference is stark showing the coarsely peened finish on the left and the rough etch of the Aluminum Oxide Grit blasted surface. The hardness and angularity of the Aluminum Oxide removes much more metal to leave the rough surface finish.

When stainless steel is either machined, stamped, or molded (as in this case), the part will often have sharp edges and a dull surface finish. This part requires a soft edge with a bright, shiny finish.

The first step was to deburr the part and get a uniform matte finish. A vibratory tumbling process with a fast cutting Ceramic Media after just a few hours achieved the perfect finish ready for polishing. Due to the hardness of the metal, a more aggressive media was used for this first step.

Polishing was achieved using dry tumbling with the Pegco GBW-3.9 Coarse Premium Treated Tumbling Media. This is typically a longer cycle time, 24 hours in this case, and can produce very high polishes. This can be seen in the near-mirror finish on the finished part on the right.

Plating copper often involves very thin coatings and the metal surface needs to be prepared properly to accept the plating. This requires a smooth surface finish and slightly rounded edges the coating can tend to fail on sharp corners and edges.

Getting the proper finish can be done using either wet or dry tumbling. In this case, these parts have very small holes where smaller media can get stuck so dry tumbling was not a consideration.

A wet tumbling process using a general purpose Plastic Triangle Media produced a smooth, matte surface finish and a nicely rounded edge on the external as well as the internal holes of the part. The cycle time for this part was about 4 hours in order achieve the desired rounding and deburring on the finer features of the part.

Recovering, cleaning, and re-using brass cartridges cases is commonly done across the shooting world. After shooting, the brass might case residue from the powder, dirt from the ground, or oxidation from sitting in the outside environment.

There are many different methods to clean the brass. Many used Walnut Shell Grit or Corn Cob Grit and are effective methods. These are not always the most efficient as this is often done in smaller vibratory tumblers or barrel tumblers.

A wet process using Stainless Steel Media and a solution of Shooter’s Cartridge Juice will quickly, effectively, and efficiently clean the brass and leave a bright, shiny finish. The most commonly used media is the tried-and-true Shooter’s Mix.

 

 

 

 

Abrasive blasting can be accomplished both wet and dry. A dry process will provide maximum abrasiveness and can be done with a wide variety of media. Dry blasting can be dusty and is some situations where that is an issue, wet blasting is recommended.

Wet blasting involves using both an abrasive grit and high-pressure water. The water will aid in the blasting process and will keep the dust to a minimum. Wet blasting can be an issue if water run-off or ground contamination is of concern.

Another concern for wet blasting is flash rusting of steel surfaces after blasting. Adding a small amount of the Kramco 1510 Rust Inhibitor Liquid Compound will mitigate flash rusting and provides some longer-term protection against corrosion until the surface can be coated. Typically, about an 80:1 dilution is used (80 gallons of water to 1 gallon of Kramco 1510) in order to provide adequate protection.

 

3D printing has been around for decades with the first hobbyist printers hitting the market around 2010. While the projections of 3D printing taking over the printing market, small run manufacturing has embraced this technology.

Auto companies are using 3D Laser Beam Melting (or Selective Laser Sintering) to produce high value, highly durable and functional, small run parts for ‘hand built’ automobiles. This additive manufacturing process can build extremely complex parts that could never be machined using traditional processes.

Basically, a laser is shot a load of powder, build material. The laser selectively fuses this powder, layer by layer, until the part is built. With each pass, the part is lowered and new powder is exposed to the laser beam. This is an expensive process and is designed for building one-off and very complex parts. As these are often unique parts, hand finishing rather than mass finishing is typically employed.

Autoweek.com explains this well in an article they published here.

Casting any type of material will typically leave a rough finish. When casting a resin, the surface is often also cloudy when the end result needs to be glossy or high clarity. With dice, the challenge is greater in that edge rounding needs to be minimized.

The casted resin die on the left shows a rough finish and no clarity at all. Tumbling this with an aggressive media will give a smooth surface finish that could eventually be polished to a high gloss, clear finish. Unfortunately, all those steps and all that tumbling will seriously round the edges and corners.

A better way is to use dry tumbling to first smooth out the surface and then polish the finish. These steps are long (12-24 hours each), but the light abrasiveness takes its time to provide the best of both worlds – abrasion on the surface without rounding the edges and corners.

A two-step process using, in this case, Hardwood Cubes first with the Dry Abrasive Finishing Cream produced a smooth, matte finish ready for polishing. The second step using Hardwood Media and the Hi-Glos Final Finishing Cream, resulted in the glossy, clear finish seen in the picture.

When parts are left exposed to the elements during storage or when in use, they can get oxidized due to moisture or rain. While in some cases (see: green oxidized coating on the Statue of Liberty), that oxidation can provide a protective coating while in other situations (see above), the oxidation needs to be removed to clean and re-use the part.

The pictured part here is an extreme example of a rusty, steel part. Abrasive blasting can certainly be used to remove the rust but that is often a manual, one part a time process. Vibratory tumbling a batch of will remove the rust, flush it away from the part, and leave a clean, white-metal surface finish.

This part was tumbled with Ceramic Media and the Kramco 1510 Rust Inhibitor Liquid Compound for only a couple of hours. Rinsing the part in a solution of the Kramco 1510 after cleaning will help to prevent rust formation upon storage.

Paint plugs and masks are used to cover areas of part that need to be protected from getting painted or coated. These plugs and masks are often used many times until the coating build-up becomes too much to be effective as a protectant.

It can be expensive to replace plugs at this point as they are often custom shapes and designs made specifically for a particular part. While chemical strippers can be used, this poses the problem of chemical disposal (often of a hazardous solvent). Abrasive blasting is also an option, but this only works best on hard surfaces rather than softer, rubbery parts.

Vibratory tumbling works very well to remove the paint and produce a clean-as-new plug. The process can take some time depending on how many coats of paint are on the plug. It is a single-step process using an abrasive Ceramic Media and a solution of the Kramco 1010 General Purpose Liquid Compound. After just a few hours, the parts can go from the coated ring shown to a ready-to-use plug!

When cutting out wood parts, it is common to get rough edges or even lots of excess material that does not come off cleanly (see part on left). While hand sanding will usually remove this excess material, when making lots of parts, the labor time and cost can become excessive.

The key to getting smooth edges and surfaces is choosing the right process and the right abrasive. Barrel tumbling is the most common method for this process which involves using a loose abrasive to ‘sand’ the parts. A barrel tumbler will keep the parts and media mixed to provide the optimal results.

This small part was tumbled with Hardwood Pegs and White Aluminum Oxide Grit. The Pegs were needed as this part shape is not conducive to tumbling and a media is needed to provide the soft tumbling action required. As this is lighter wood, White Aluminum Oxide Grit was used to sand the edges and surfaces. The Pegs essentially act as small sanding blocks during tumbling.

As the grit can sometimes get stuck in the pores of the wood, tumbling the parts in Corn Cob Grit after the sanding step will help to clean out the part.

 

The parts pictured here are cast bronze with some subsequent internal machining. As the part comes out of the casting and machining process, there are burrs on the threads and the surface finish is rough and dull.

A two-step process to first deburr and smooth out the finish and then to brighten the surface was used. The challenge is to identify media that will get to all areas necessary but not get stuck inside the part.

The first step used a small, triangular Ceramic Media in a wet tumbling step. A smaller media was used to get to the burrs and threads which are interior to the product but not get lodged in any of the holes in the part. A triangular shape was ideal to smooth out the surface finish all the way into any corners on the part. The result after this step in seen on the left.

The polishing step was dry tumbling using a Premium Treated Tumbling Media. This grit-based media is ideal as it will polish all areas of the part, even inside the threads (see part on right). This is a longer cycle time but worth the wait given the finish.

For reference, note the inevitable imperfections – divots, bubbles, small ‘channels’ – in the part caused by the casting process.

Tool steel is a hardened form of carbon steel specially made for durability when made into various types of tools. The hardening process involves heating and cooling the steel and quenching in water, oil, or air.

The part on the left was hardened using an oil quenching process. This led to enough oil getting baked onto the surface that the part could not be plated successfully. Additionally, the part needed to be lightly deburred and the edges slightly rounded to get better adhesion of the plating material.

Most times, steel is deburred with Ceramic Media as that is the most aggressive type of tumbling media. This is especially true for hardened steel. In this case, however, the parts are going to be plated. Plating is a very thin coating and will often ‘translate’ any imperfections that are on the surface prior to plating.

A Plastic Tumbling Media was used to get the finish on the right. As you can see, and with a long enough cycle time, this less aggressive media was able to round the edges, deburr the part, and leave a smooth, nearly polished surface finish ready for plating.

Quite some time ago, we posted a blog about Anchor Profile. This post explained what that is and why it is important.

The picture above clearly demonstrates the differences in anchor or etch profile using different mesh sizes of Aluminum Oxide Grit. All of these coupons are aluminum metal.

The top left was blasted with a 36 Mesh grade. This produces a rough looking and rough feeling surface finish. While all these blasted parts will look like sharp peaks and low valleys on the micro scale, on this coupon you can see that with just a simple 10x jewelry lens.

The upper right was etched with 120 Mesh. While you can still see some etching on this example, the surface feels much smoother and more uniform.

While still etched, the bottom example which was blasted with 220 Mesh has a very uniform, frosted finish. This is a finish often seen on frosted glasses, signs, and windows.

Selecting the proper grade of abrasive media is important to ensure you get the proper surface profile based on either next steps, such as a coating, or simply just an aesthetic finish.

Often when manufacturing acrylic parts, the goal is to have a part that is as clear as glass. Whether cast or ground to the necessary shape and size, the acrylic surface will obtain a matte or lightly etched finish – similar to a frosted finish.

This finish can be improved in a few different ways. Most commonly, the part is tumbled in a two-step process. The first step utilizes Plastic Media in a wet step to result in a uniform, matte finish. This step is generally needed if there are machining marks (like this part) or other deeper surface imperfections.

The second step which can sometimes be the only step needed involves dry tumbling with a Hardwood Media and the Hi-Glos Final Finishing Cream. This Cream has very fine abrasives that slowly polish the surface finish to an optically clear state. That clarity is seen in the part at the bottom of the picture. It is not uncommon to be so clear that you can read words through the part.

Both steps are best accomplished in a barrel tumbler due to the softer tumbling action and, especially with the Hardwood Media step, trapping the heat inside the barrel ‘activates’ the Cream.

 

Casting steel parts can leave a very rough surface finish and further machining or welding can produce burrs and surface imperfections that need to be addressed.

This relatively large part – about 8” tall – required a long deburring and surface finishing step to get as smooth a finish as possible. The part was tumbled with Ceramic Media for about 12 hours in a vibratory tub. You can still see some ‘bubbles’ on the surface created during the casting process that cannot be removed with tumbling.

After deburring the part, a dry tumbling step was used to take the matte, tumbled finish to the high gloss polish seen in the picture. That was also a long cycle time, but the results are excellent. This step used one of the Treated Tumbling Media.

Any time you are working with steel, it is important to be aware of potential oxidation issues. The first step was wet, so a solution of the Kramco 1510 Rust Inhibitor Liquid Compound was added to the load.

 

It is that time of the year where Section 179 of the Federal Government tax code for investment and depreciation credits a purchase of new equipment from Kramer Industries. Here’s your opportunity to upgrade today!

Link: www.section179.org/section_179_deduction.html

What is the Section 179 Deduction?

Most people think the Section 179 deduction is some mysterious or complicated tax code. It really isn’t, as you will see below.

Essentially, Section 179 of the IRS tax code allows businesses to deduct the full purchase price of qualifying equipment and/or software purchased or financed during the tax year. That means that if you buy (or lease) a piece of qualifying equipment, you can deduct the FULL PURCHASE PRICE from your gross income. It’s an incentive created by the U.S. government to encourage businesses to buy equipment and invest in themselves.

Several years ago, Section 179 was often referred to as the “SUV Tax Loophole” or the “Hummer Deduction” because many businesses have used this tax code to write-off the purchase of qualifying vehicles at the time (like SUV’s and Hummers). But that particular benefit of Section 179 has been severely reduced in recent years (see ‘Vehicles & Section 179‘ for current limits on business vehicles.)

However, despite the SUV deduction lessened, Section 179 is more beneficial to small businesses than ever. Today, Section 179 is one of the few government incentives available to small businesses and has been included in many of the recent Stimulus Acts and Congressional Tax Bills. Although large businesses also benefit from Section 179 or Bonus Depreciation, the original target of this legislation was much needed tax relief for small businesses – and millions of small businesses are actually taking action and getting real benefits.

Here’s How Section 179 works:

In years past, when your business bought qualifying equipment, it typically wrote it off a little at a time through depreciation. In other words, if your company spends $50,000 on a machine, it gets to write off (say) $10,000 a year for five years (these numbers are only meant to give you an example).

Now, while it’s true that this is better than no write-off at all, most business owners would really prefer to write off the entire equipment purchase price for the year they buy it.

And that’s exactly what Section 179 does – it allows your business to write off the entire purchase price of qualifying equipment for the current tax year.

This has made a big difference for many companies (and the economy in general.) Businesses have used Section 179 to purchase needed equipment right now, instead of waiting. For most small businesses, the entire cost of qualifying equipment can be written-off on the 2020 tax return (up to $1,040,000).

Limits of Section 179

Section 179 does come with limits – there are caps to the total amount written off ($1,040,000 for 2020), and limits to the total amount of the equipment purchased ($2,590,000 in 2020). The deduction begins to phase out on a dollar-for-dollar basis after $2,590,000 is spent by a given business (thus, the entire deduction goes away once $3,630,000 in purchases is reached), so this makes it a true small and medium-sized business deduction.

Who Qualifies for Section 179?

All businesses that purchase, finance, and/or lease new or used business equipment during tax year 2020 should qualify for the Section 179 Deduction (assuming they spend less than $3,630,000).

Most tangible goods used by American businesses, including “off-the-shelf” software and business-use vehicles (restrictions apply), qualify for the Section 179 Deduction.

For basic guidelines on what property is covered under the Section 179 tax code, please refer to this list of qualifying equipment. Also, to qualify for the Section 179 Deduction, the equipment and/or software purchased or financed must be placed into service between January 1, 2020 and December 31, 2020.

For 2020, $1,040,000 of assets can be expensed; that amount phases out dollar for dollar when $2,590,000 of qualified assets are placed in service.

What’s the difference between Section 179 and Bonus Depreciation?

Bonus depreciation is offered some years, and some years it isn’t. Right now in 2020, it’s being offered at 100%.

The most important difference is both new and used equipment qualify for the Section 179 Deduction (as long as the used equipment is “new to you”), while Bonus Depreciation has only covered new equipment only until the most recent tax law passed. In a switch from recent years, the bonus depreciation now includes used equipment.

Bonus Depreciation is useful to very large businesses spending more than the Section 179 Spending Cap (currently $2,590,000) on new capital equipment. Also, businesses with a net loss are still qualified to deduct some of the cost of new equipment and carry-forward the loss.

When applying these provisions, Section 179 is generally taken first, followed by Bonus Depreciation – unless the business had no taxable profit, because the unprofitable business is allowed to carry the loss forward to future years.

Section 179’s “More Than 50 Percent Business-Use” Requirement

The equipment, vehicle(s), and/or software must be used for business purposes more than 50% of the time to qualify for the Section 179 Deduction. Simply multiply the cost of the equipment, vehicle(s), and/or software by the percentage of business-use to arrive at the monetary amount eligible for Section 179.

Large vibratory bowls like our EVB Series can be used for a wide variety of surface finishing applications. If properly designed, a vibratory system can be used both for wet and dry processes. This only increases the utility and value of the unit.

Most commonly, large bowls are used for large batches of smaller parts for deburring and polishing applications. Bowls provide for reduced impingement (part-to-part interaction) relative to vibratory tubs and barrel tumblers. Not only does the load tumble around the diameter of the channel, it also moves around the toroidal section of the bowl. Keeping parts separated provides for better finishes in shorter periods of time.

Systems like the EVB Series can be used with a variety of media including Ceramic, Plastic, and dry media like Hardwood. Many systems can also be upgraded to handle the load weight of Steel Tumbling Media.

This media versatility allows for many different types of materials to be tumbled including hard metals like steel and titanium to softer metals such as aluminum and brass. A wide variety of plastics can also be deburred, deflashed, and polished in large bowls.

When looking for the proper tumbler for your application, make sure you consider the support being offered by the company with whom you purchase. The source of the equipment and where it is manufactured can tell you a lot about the quality of the engineering and the potential results you will get with your parts.

Not sure what you need, we are here to help you Right From The Start!

As part of our new product roll-out, we are happy to release the EVB Large Bowl Vibratory Tumbler Series. This line of Made in the USA vibes is engineered for heavy duty usage and made to last.

The EVB Series is available in capacities from 3 cubic feet up to 92 cubic feet. As with most of our other lines of equipment, we have designed these systems to be fully customized as it relates to size/capacity and a whole series of options and upgrades.

Every model in the EVB Series can be modified to include a separating screen deck, compound metering system, sound cover, variable speed drive, settling tank, and many other options. A heavy-duty motor and solid metal construction is, of course, engineered into each and every unit.

While typically used with a wet process, these systems can be used dry as well. Check out the specifics on the web page and give us a call to discuss the details of your application. We can’t wait to hear from you!

As we mentioned in last week’s post, Kramer Industries has been working hard on new and innovative products. The G-100 model is our most compact and economical vibe bowl to date.

The G-100 Little Big Red Vibratory Tumbler has a capacity of 3 quarts and maximum load weight of about 10 pounds. The 1/8 HP motor is significantly more powerful than the 1/20 HP motor found in most retail ‘18 pound’ tumblers. This results in a more energetic and more durable system.

Given the 10” diameter bowl, parts as large as 4” can be tumbled. The system is designed to be used wet or dry (most retail vibes are only designed for dry tumbling). Little Big Red also has an adjustable weight to allow for variable amplitude providing even more flexibility and utility.

If you are looking for a bundle of vibratory energy, the G-100 Little Big Red Vibratory Tumbler is the system you need! We look forward to talking with you about this new addition to the family!

The Kramer Industries’ product development team has been busy working on a number of new projects during these crazy, pandemic times.

We are pleased to introduce the G Class Vibratory Bowl Tumblers. These Made in the USA bench model vibes come in a series of sizes and capacities. The smallest, model G-100, is a 3 quart capacity and is perfect for small batch finishing and R&D environments.

The G-330 model has a capacity of 10 quarts. This heavy-duty system is ideal for a DIY environment or industrial area that needs a small, well-engineered system. Imagine a basic ‘18 pound’ vibe on steroids. The G-660 and G-1300 models are 20 quart and 1.3 cubic foot capacities, respectively.

All of the models are supplied with adjustable amplitude, sound cover, flow-through drains, and durable springs and motors. Options include a stand, filter system, and compound recirculating system.

If you are looking for a bench model, heavy-duty vibratory bowl tumbler, the G Series is the system you need. Call us to discuss!