DeWitts Radiator builds aluminum radiators and we are one of the few companies that actually own an aluminum brazing furnace. Many companies claim to make aluminum radiators when in reality they just purchase the components and assemble radiators. Some companies may not make anything at all and just re-sell a brand made elsewhere. Aluminum Brazing requires a very high volume of nitrogen gas and if the company in question does not have an industrial grade nitrogen yard, they do not make there own cores. Here is our 3000 gallon system!