An Overview of the Teardown Procedure of Cans & the Common Tools Needed

In commercial manufacturing facilities, they need to tear down cans and examine double seams at specific intervals. They should also perform a teardown procedure after shutting down their plant.

Homeowners are not obligated to these regulations and are not expected to perform the procedure in every use of the can sealing machine. But, they need to perform some adjustments when they are going to change the machine’s seaming chuck to accommodate other can diameters. They need to re-adjust the space between the chuck and the seaming rollers.

Tearing up one can in every re-adjustment is recommended to make sure that the succeeding seams produced are reliable. Here, you will get an overview of the teardown procedure and some of the important tools needed.

The Teardown Procedure
Tearing up a can helps in the accurate measurement of the seam formed by the can seamer. In commercial packaging lines, they use a special seam saw to cut and clean the cans faster for examination. Homeowners will commonly use available tools like hacksaws, files, or handheld tools which we will discuss later.

Below is an overview of the teardown process which homeowners can follow.
  1. Removal of the can cover’s center part.
  2. Cutting the part of the can’s body to expose the double seam’s cross-section.
  3. Examination of the double seam.

But, do take note that you need to measure the seam’s thickness, width, and countersink depth first before tearing the can down.

Tools For Cutting the Center Part of the Can Lid

#1 Can Openers
When we say can openers, we do not mean those that you usually use in your household. Because these can openers will deform the double seam, making the measurements not accurate. Use a seam opener that can cut the lid’s center part without deforming the seam.

#2 Aviation Snips
You can use other tools, like aviation snips, to cut the lid’s center part but make sure that you will not damage the seam. Make a hole in the can’s lid first before cutting it out using an aviation snip.

Tools For Exposing the Double Seam
After the removal of the can cover’s center part, the next step of a teardown procedure is to cut through the seam. Homeowners can use either a file, hacksaw or a rotary tool.

#1 File
This method will cause a small problem because the cut will not be perfectly clean. The shavings can fill the seam’s gaps and obstruct your view during the inspection process. You need to find a file with one smooth surface and which will not obstruct the seam. This method is easier though. This is because you can use one of your hands to grip the can and the other to cut it using the file.

#2 Hacksaw
Cutting through a seam with a hacksaw will be hard even if you choose one with a very fine blade. Unless you have a means to strongly support your can. But, you will need a large pipe holding instrument or a vise for this purpose.

#3 Rotary Tool

A rotary tool with a cut-off disc makes clean cuts so it will not obstruct the can’s seam, unlike files. You will find many grinders and rotary tools that can do the task. But, it is important to take note that rotary tools are power tools so you need to consider your safety. Secure the can properly and wear goggles and gloves.

Other Useful Tools
#1 Canning Vacuum Gauge

Canning vacuum gauges are used for checking the vacuum formed after sealing a can. The bottom of the gauge has a steel needle which you will use to pierce the can’s lid. The rubber gasket around the needle will help in maintaining an airtight seam while you do your measurements.

#2 Jeweler’s Loupe
Homeowners do not necessarily need to invest a huge amount of money for computerized seam projectors. They can simply use a more affordable jeweler’s loupe to enlarge the can seam’s details.

#3 Nippers
You can use nippers to tear down the can’s seams. We recommend using #5 nippers.

Common Defects Observed During the Teardown Procedure
Below are the common defects you can observe visually without any special magnification tool during the teardown inspection.

  • False seam
  • Insufficient overlap
  • Short body hook
  • Short cover hook
  • Lone body hook
  • Long cover hook

You can find the definitions of the above-mentioned can defects along with other defects in Double Seam Troubleshooting Guide’s website.

Bonus Tip: How to Check if Your Can Sealer Needs Re-Adjustment
You should check your can sealer before you use it to make sure that they are properly adjusted to create reliable seals.

You can follow the steps below for a simple method you can use to test your can sealer.
Fill an empty can with water.

Seal the can and then drop it in hot water. Make sure that the whole can is covered by the water. 

Use a can lifter to keep the can submerged.

If you notice bubbles coming up around the can’s lid, the double seam is not airtight so you need to adjust your can sealer.

You can perform a teardown procedure and inspection for your cans even in your own homes. You do not need expensive inspection tools before you can examine the seam produced by your can sealer. The tools we have mentioned here are common instruments so you can easily acquire them. Hopefully, this short guide was able to help you gain enough knowledge for your own teardown procedure.

By the way, if you are looking for customizable can sealing machines, you can go to Levapack’s website: Levapack is a manufacturer of various packaging machines in China.

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