How to Rivet Plexiglass to Steel

 Riveting Acrylic Sheet to Steel Without Cracking it!

In this post I’m covering how to successfully rivet acrylic sheet to steel without cracking it.  Of coarse, the same principles apply to joining acrylic to other metals but steel is more widespread and cheaper so I will stick with it.  

First of all, because we are joining two very dissimilar materials, it goes without mentioning that they will experience differences in expansion and contraction in different temperatures.  Acrylic, unlike mild steel, is strong but not tough and can easily stress crack.  For this reason I highly recommend drilling a hole slightly larger than the rivet being used.  Preferably 1/64 inch to 1/32 inch larger to allow for slight movement without stress.  I cover how to do that in my other post “Drill Perfect Holes in Plexiglass Every Time!”  The steel, on the other hand, should have a hole exactly the same diameter as the rivet. This will provide a firm grip on the rivet holding it in place.  

Another thing you’ll need is a nylon washer.  This is a firm plastic that won’t deform excessively like rubber but will absorb the tremendous force created by the rivet gun pulling the mandrel through.  Below ¼ inch nylon washers will come typically with number sizes to match screws of the same diameter.  The number 10 nylon washer works well with a ³⁄₁₆ inch and #8 washer should be close enough for the ⅛ inch diameter rivets.  Here is a close up of the Plexiglass bonded to a steel tube.  If you look closely you can see the nylon washer nicely sitting there.