Line Joining Knots

Knot tying is not just line to hook, it is also tying line to line. And when it's called for, you need a really good knot. Learn how to tie line joining knots with the following instructions.

Line joining knots tend to be popular fly fishing knots as well as critical in situations like when you have a reliable rig on 15-pound test line and you want to attach it to the 20-pound test line on your reel without having to retie the whole rig). The below knots are tested and reliable for joining two pieces of fishing line.

Double Surgeon’s Knot (Skill Level - Easy to Intermediate)

Surgeon's knots are popular fly fishing knots. Compared to the surgeon’s knot, It adds an extra twist when tying the first throw, forming a double overhand knot, thus adding friction which makes the knot more secure.

This knot makes it easy to join two lines, but one line must be short, since you have to bring the one end through the formed overhand loop. As with other lines, use a lot of overlapping line so that you can pull on all four ends to make it properly tight. Work with both lines together as you tie this, and make sure both loops are the same size to assure a strong knot. Follow these instructions to learn to tie:


A double uni-knot is two fishing knots tied back to back, then placed together to form a strong connection. Leave plenty of line at the end of the knot on each piece of line you're joining. The ends help pull the two knots into one. These line joining knots are great for attaching leader to your main line and works whether or not the lines are the same (braid to monofilament, or braid to fluorocarbon leader)

The Double uni-knot requires you to tie a uni knot with each of the two lines, with the knots facing opposite directions.

  1. Lay your main line and your leader or secondary line out in front of you so that they overlap for a good distance, start with at least a foot of overlap until you know how much you need
  2. Form a loop in the left-hand portion of the overlap that goes clockwise. You should use the line that terminates to your left for this
  3. Pass that line around the other line and through the loop five times (see uni-knot above). Snug the knot up, but don’t pull it tight
  4. With the line to your right, form a loop that goes counter clockwise
  5. Pass that line around the other line and twist it through the loop five times. If you are using a larger diameter leader you might only need three wraps
  6. Snug that knot up, but don’t pull it tight
  7. Lubricate the two lines between the two knots with saliva. Grasp both lines and pull them away from each other. The knots should slide together and pull tight
  8. Trim each tag closely. The finished knot should resemble a barrel


Albright knots are popular for tying together two lines of unequal diameter and are popular fly fishing knots. A situation when you may use this knot tying technique is when you have to tie the 15-pound test line on your rig to the 20-pound test you currently have on your reel spool or when tying monofilament backing to a fly line.

  1. Fold the leader back to form a loop, and pass the main line through the loop
  2. Wrap the main line around itself and the loop 10 times
  3. Pass the tag of the main line back through the loop
  4. Start to close the knot with light pressure on both the tag and standing portions of the main line AND the tag of the leader
  5. As the line tightens drop the tag of the leader and the tag of the main line and pull it completely tight with pressure of the line against the leader
  6. Trim closely


A blood knot (or barrel knot) is two back to back clinch knots and is most used for joining sections of monofilament nylon line of similar weight while maintaining a high portion of the line's inherent strength. Other line joining knots used for this purpose can cause a substantial loss of strength. The principal drawback to the blood knot is the dexterity required to tie it. In fly fishing, this serves to build a leader of gradually decreasing diameter with an easily cast fly line attached at the large diameter end and the fly or hook at the small diameter end.

  1. Overlap the two lines
  2. Wrap your first line around the other line about 5 times, then take the tag end back towards the center and tuck it between the lines
  3. Repeat this process on the other side, wrapping the second line around the first and bring the tag end back to the center and tucking it between the lines. A this point both tag ends should be in the center, facing opposite directions
  4. The lines are moistened and the wraps tightened by pulling on the long ends of the line

Once you have conquered knot tying, try your hand at traditional casting or fly casting.