MT Solar String Line Blocks Make it Easy to Align Rails and Modules

We’ve put together this string line kit for new installers to make aligning rails and modules easy. It includes two string blocks and a string line.

Watch this video to see the process in action or use the steps below.

How to Use the String Blocks

1. Start by wrapping the end of the string line around the string block so that it sits in the inner groove. There’s no need to tie it; just a few wraps are enough to hold it in place.

2. Thread the string within the channel at the top of block.

3. Hook the block on the outer edge of the rail or let it rest on the upper edge. Don’t worry if it doesn’t sit perfectly yet. The tension can be corrected when the second block is in place.

4. Get the second block ready and unroll/walk the string to the other end of the rails.

5. Take up any slack and thread the string within the channel of the second block, then wrap the line around the center to keep it in place. (It’s the same process used on the first block, just in reverse.)

6. Hook the second block on the outer edge of the rail.

7. Adjust the first block as needed until the string is taut and level. It should be tensioned so that both blocks stay put and the string line is flush across the full length of the mount.

8. Start lining up each rail by bringing the end to meet the string. Leave a slight gap so the rail doesn’t push the string forward.

9. As you get each rail lined up, you can tighten the clamp bolts. Make sure to leave the string line and blocks in place so you can continue to get the alignment just right.

10. Once you’ve got all the rails bolted, remove the blocks and wind up the string line. Keep them handy for your next solar mount installation!