Plastic wagon kits tend to be too light and benefit from adding a little ballast weight. The lead strip is 9mm wide which will fit under the floor and between the chassis of kits that use the Parkside Dundas 12ft wheelbase chassis or the Peco 9ft wheelbase chassis. Alternatively, fit inside kits for closed vans, or inside open wagons and then disguise with a load.
The lead strip can be cut to the desired length with a sharp knife or a pair of scissors (nail scissors are ideal). If it becomes misshapen, gently press it flat again. Peel off the adhesive backing and gently press the lead strip into place. Another piece can then be attached on top of the first, and a third piece will fit without showing under the solebar.
Make sure that the lead strip does not interfere with the wheels. Make each successive piece slightly shorter than the previous one to allow for the curvature of the wheel.
Although the adhesive backing will hold the lead strip in place, once the lead strips are added, it is advisable to put some adhesive (PVA is ideal) around them to make doubly sure that they do not fall off. Unless the lead strips will be hidden in a van or under a load, it is advisable to add a thick layer of paint to the lead strip as this protects from inadvertent contact with the lead when handling the finished model.