According to some embodiments, a railcar comprises an interior wall and guard strips magnetically coupled to the interior wall. Each of the guard strips comprises a cushioning material for absorbing impact. The guard strips are configured to prevent an object loaded in the railcar from contacting the interior wall. The railcar further comprises protected magnetic fastening systems coupling each of the guard strips to the interior wall. Each of the protected magnetic fastening systems comprises a magnet and a rod comprising a first end and a second end. The first end is coupled to the magnet, and the second end extends through the guard strip. The protected magnetic fastening system may further comprise a cup washer coupled to the second end of the rod and secured with a fastener. The cup washer partially surrounds the fastener to restrict objects larger than the cup washer from contacting the fastener.