LID construction

I thought I’d share how I’ve made the LID.

LID

LID

BOM:

  • 180mm diameter, 3mm thick, 12″ high acrylic cylinder (ebay)
  • 180mm diameter, 5mm thick acrylic disk (ebay)
  • plastic weld glue (amazon)
  • sringe bottle (amazon).

Instructions:

I cut the cylinder down to 95mm high.  To do this, I marked 95mm from one end in a thin permanent marker pen, perhaps 20 marks around the cylinder.  I then used these markings as a guideline for applying masking tape around the perimeter as a guide for the sawing.

I used a small hack saw with the cylinder on its side, slowly rotating the cylinder as I cut; many rotations were required to ultimately separate the pieces, but this results in the critical flat cut where there are no glitches around the ring.

Then I used a sanding block and smoothed the cut’s surface, first with P120, and then P1000 sandpaper to ensure the surface is smooth and flat.  There’s good reason for this:  the glue is not actually a glue; it’s a solvent which seeps into the narrow gap between cylinder and disk, so they must have close contact all the way round.  The solvement dissolving the acrylic, and then as it evaporates, melds the two pieces of acrylic into one solid piece.

Before applying the solvent, the disk and cylinder need to be fixed firmly together; I’ve found simple masking tape works best because the solvent does not affect it.

Once the disk and cylinder are taped together, add solvent to the syringe bottle; don’t add much or it’s goes everywhere.  I’d recommend practising squirting the solvent on some spare acrylic; if you apply too much solvent, lots of permanent ‘puddles’ form – even with a lot of care, I still have some permanent “rain-drops” you can see in the photo (the major scratch you can see was there when the cylinder arrived).

Once you’re confident, place your LID, top down, onto a flat work-surface with a smaller circle just lifting it off the work-surface (cardboard will do) – the last thing you want is the dissolved acrylic to join your LID to the work-surface.

Apply the solvent to the inside connection between the disk and cylinder; speed and accuracy are critical here to avoid the puddles.  I strongly recommend doing this outdoors or in a very well ventilated room – it’s very flammable and evaporates rapidly, and not the sort of chemical you want to inhale.

Leave the LID a couple of minutes for the solvent to evaporate, and job’s done.

 

 

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