Abstract: An apparatus for making a lightweight, thin wall, seamless, hollow structural profile using a simple mold. The apparatus includes a base for supporting a mandril and a two piece outer form which bolts together assembled. A mixture is poured or injected into the space between the mandril and the form to produce a profile upon hardening of the mixture of either cement, fiberglass or polymers. The hollow area of the structural profile may be filled with various materials. The base comprises a plurality of upwardly rising columns or blocks and posts around the inside perimeter of the mandril and blocks around the outside perimeter of the form for proper positioning of the mandril and the form, which are separated by a predetermined distance in accordance with the desired features and dimensions of the structural profile.