Glue tensile strength test object

Glue tensile strength test object

I designed this object for my own testing, but thought I would share it in case anyone else could benefit from it. 2 of these objects need to be printed and glued together to form 1 test item.

Background story:

I usually buy Bostik brand “Hard Plastic” glue for assembling objects printed from PLA. Due to recent severe flooding in my area, the office supplies shop which I purchase this glue from is currently closed for an unknown period for repairs. No other local shops stock this glue, and I had minimal glue remaining, so I purchased Loctite brand “Vinyl, Plastic & Fabric” glue from the local hardware warehouse as a substitute. 

I wanted to test the strength of each glue in a repeatable manner using only items I have available at home to see how they compared to each other. Keep in mind this test wasn't about getting scientifically accurate measurements, it's simply about comparing 2 glues to see if there is was any notable strength difference between them.

The test items are 10mm ID/ 20mm OD with a 6x6mm gluing area. I hung a bucket from the test object and slowly filled it with water until the glue joint failed, then measured the weight of the bucket and water on a digital scale. The bucket was only allowed to drop a distance of around 10mm to avoid water splashing out. I carried out 5 tests for each glue and compared the results.

My results aren't overly applicable unless you happen to be using these exact glues, but for context the Bostik glue failed between 12.90kg and 14.79kg across 5 tests, and the Loctite failed between 5.89kg and 9.56kg across 4 tests (1 failed so low that I didn't bother recording a result). I glue mostly printed R/C car items, so I still consider the Loctite glue to be sufficient for most of my jobs. The Loctite glue would start to yield before it failed, but the Bostik glue would fail suddenly with minimal warning.

The Bostik glue was purchased from Officeworks (Australian office supplies store conglomerate)

The Loctite glue was was purchased from Bunnings (Australian hardware store conglomerate)

I have STL files for printable nozzles for both of these glues. You can find them uploaded with all of my other models.