I’ve used this method successfully for several biplane models. Music wire stays arrow-straight in short sections. Choose a guitar string that will add strength but not too much dimension — an E or B is perfect.

It is easier to leave the strut mounted on the sprue. Place a section of vinyl tape along the back side of the model strut to hold the wire in position. (The tape can be removed easily later.)

The wire is positioned against the strut and held by the tape. Run a bead of thin super glue along the seam between the wire and strut. Allow it to dry without kicker; the kicker can pucker up the glue and make finishing harder. Remove the tape and run an additional bead of thin super glue along the seam on both sides. Repeat until the gap is filled and the joint becomes flush. Light sanding is all that is needed to prepare for paint. The ends of the wire may be rounded with a motor tool if desired. This method provides needed strength to struts while allowing for some flexibility. Coupled with support wires, the resulting structure is very strong without altering the appearance drastically.