You will need one plastic can for the bottom part of the DIY pannier, and another one for the lid. They have to be cut differently. In both cases we recommend marking the cans before cutting.

Start with cutting the bottom part, because if you make a mistake, you can still use it for cutting the lid.

Marking

When marking the bottom part, leave a little bit of the inward curve on at the edge of the opening. That edge is important because it helps with the rigidity of the DIY bike pannier - the wider the edge, the more rigid it gets, but think about packing comfort, as well. You will need to curve the cut below the mouth of the can, but cut as close to it as possible because that carved space will have to be covered by the lid.

When marking the lid, place front to the front, rear to the rear. The front part will have to be cut lower to cover the space left behind the mouth of the other can.

Recommended tools for making a DIY bike bag

The best tool for cutting is a jigsaw with a blade for wood cutting, one with smaller teeth. You can start cutting from the mouths of the cans.

Warning! A jigsaw is a powertool. It is stronger than you. Use it with caution. If you are unsure, ask for help.

Other tool options

Manual jigsaw - much slower, but safe and cheap.
Angle grinder - could work, but it is more dangerous. Never use an angle grinder with a metallic circular saw disc, those are uncontrollable. If you decide to use an angle grinder, an option is to use it with worn out metal cutter disks. The smaller diameter will come handy around the corners. Metal cutting discs will grind the plastic into very tiny dust that will form a sticky spidernet-like veil around the working area and the grinder. Another option is a rugged coarse disc for universal cutting. These are more efficient for cutting plastic, and will grind the plastic into bigger pieces than a metal cutting disc, which will be less sticky, but it is still overwhelmingly dusty. Do this outside.
Heating up a normal knife - very slow and very smelly. In addition, if you cut by melting, the molten edges of the cans will keep releasing the smell of molten plastic forever.
Electric hot knife - still very smelly. If you opt for this, use one with at least 200-300 w heating power, depending on the knife thickness, otherwise it will be very slow.

Clean the burr from the cuts with a sharp knife or sandpaper.

Troubleshooting:

After cutting both pieces, try on the lid, and press down on it. See if the sides of the bottom piece bend inward, leaving a gap between the two parts. That is not terrible but it does not look good. You can try making the lid shorter. Cutting the lid shorter could help, but maybe the extra pressure comes from the corners and not from the side. You can try first carving out the corners a little bit and see if it works. Some cans will keep having the same problem until the lid becomes too short to serve its purpose, and you will need to find different cans.

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↑ video screenshot - section embedded at the bottom

Step 1: Cutting plastic cans

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You will need one plastic can for the bottom part of the DIY pannier, and another one for the lid. They have to be cut differently. In both cases we recommend marking the cans before cutting.

Start with cutting the bottom part, because if you make a mistake, you can still use it for cutting the lid.

Marking

When marking the bottom part, leave a little bit of the inward curve on at the edge of the opening. That edge is important because it helps with rigidity of the DIY bike pannier - the wider the edge, the more rigid it gets, but think about packing comfort, as well. You will need to curve the cut below the mouth of the can, but cut as close to it as possible because that carved space will have to be covered by the lid.

When marking the lid, place front to the front, rear to the rear. The front part will have to be cut lower to cover the space left behind the mouth of the other can.

Recommended tools for making a DIY bike bag

The best tool for cutting is a jigsaw with a blade for wood cutting, one with smaller teeth. You can start cutting from the mouths of the cans.

Warning! A jigsaw is a powertool. It is stronger than you. Use it with caution. If you are unsure, ask for help.

Other tool options

Manual jigsaw - much slower, but safe and cheap.
Angle grinder - could work, but it is more dangerous. Never use an angle grinder with a metallic circular saw disc, those are uncontrollable. If you decide to use an angle grinder, an option is to use it with worn out metal cutter disks. The smaller diameter will come handy around the corners. Metal cutting discs will grind the plastic into very tiny dust that will form a sticky spidernet-like veil around the working area and the grinder. Another option is a rugged coarse disc for universal cutting. These are more efficient for cutting plastic, and will grind the plastic into bigger pieces than a metal cutting disc, which will be less sticky, but it is still overwhelmingly dusty. Do this outside.
Heating up a normal knife - very slow and very smelly. In addition, if you cut by melting, the molten edges of the cans will keep releasing the smell of molten plastic forever.
Electric hot knife - still very smelly. If you opt for this, use one with at least 200-300 w heating power, depending on the knife thickness, otherwise it will be extremely slow.

Clean the burr from the cuts with a sharp knife or sandpaper.

Troubleshooting:

previous step | back to overview | next step