Repair Hinge Seam on a Blowmolded Case





Introduction: Repair Hinge Seam on a Blowmolded Case

If you've got a toolbox that's made from HDPE (Polythene) the 'hinges' (really just a fold) will eventually wear like this, but don't worry, we can fix it!

...without any help from Robert the Construction Worker ;)

This Instructable was actually done by my friend Andy from MKMakerspace in Kiln Farm, Milton Keynes ( It's a cool place to hang out with like minded tinkerers, and we've got 3D printers, laser cutters and a whole workshop at our disposal. Pop in if you're in the area - check out the website to find out more!

Step 1:

Carefully cut down the hinge line to seperate the lid from the base.

Step 2:

Shave any loose plastic from the two halves, they will interfere with the operation of the hinges.

Step 3:

Fold the hinge flat and rest it on the lip of the case, this is so it is straight in line with the other hinge.

Step 4:

Whilst holding the hinge in place, drill a hole for the rivet.

I used a 3.5mm drill with a 4mm rivet so it will be a tight fit. place a rivet in the hole to hold the hinge in place, if the rivet will not fit into the hole use the rivet gun to push it in. once the first rivet is holding the hinge in place, drill the other hole.

Step 5:

Make sure you are happy with the placement of the hinges...

Step 6:

...and proceed to pop the rivets.

Step 7:

Make sure the clasps are closed and everything is aligned then drill the holes in the base.

Step 8:

Check to see if the rivets won't impinge on anything in the base, (they will be shorter once popped) also don't drill into any tools in the base, I was not worried about drilling into a socket but I forgot the screwdriver handle was there, so it has a tiny souvenir scratch!

Step 9:

Try to get rivets close in size to the diameter of the hinge hole, they should self-centre nicely when popped if the difference between the two is not too great.

Step 10:

Again, use the rivet gun to push the rivet in the hole, the tighter the fit the better.

Finally pop the bottom lot of rivets.

Step 11:

Tada! The finished product. Good as new; in fact better than new 'cause now we've got proper hinges that will outlast the case :)



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    If you have enough space on the inside, you can add small washers that the rivet will fit through, and the pop the rivets.

    This will sandwich the plastic and give the hinge more strength and stop the rivets coming loose over time and pulling out.

    *then* pop the rivets...

    Isn't it? All credit to my mate Andy. :)

    I've got a couple of boxes in the garage I'll need to do this for soon! Great simple fix :)