Installing J-trim

[ml504]

Can anyone post pictures or point me in the right direction on installing "j-trim" around a framed opening on a steel building? My openings are 12x12 and the trim pieces are 10' sections. What is the correct way to merge the 2 pieces together to form a 12' section? Do you just **** them together? Any help would be greatly appreciated.
Thanks,
Matt

 

[Iron-Iceberg]

I cut mine with a little tongue on them and then put a single pop rivet on the face. This will keep the face aligned. Other wise they tend to not line up.