If one of the edges of your patch is against a wall, attach the other three edges first using the process described in this step. The last edge will be attached to the tack strip in the next step of the project.
Lay down the seam tape just under the seam and use the carpet iron (Image 1) to activate the seam tape and bond the edges together. Then, use a carpet tractor (Image 2) to press the carpet down onto the seam tape to reinforce the bond. Afterward, position something heavy over the area to help set the seam. Continue around the other edges of the patch in the same manner, except in the case where an edge meets a wall as mentioned above.