Career
In 1878 he moved to Germany in order to study in the Grossherrzoglisch Badische Kunstschule, in Karlsruhe. There he became a pupil of Ferdinand Keller, Theodor Poeckh and Ernst Hildebrand. In 1880 Keller moved to Berlin, being followed by Weingärtner, who then enrolled in the local Academy.
In 1882 he left Germany for France, studying in the Académie Julian under Tony Robert-Fleury and William-Adolphe Bouguereau.
Then he could further his education in Rome. Thereafter for many years he divided his time between Rio de Janeiro, Porto Alegre and Rome, traveling very often and being celebrated as one of the most important Brazilian painters of his generation.
In Rio Grande do Sul he was a star. In 1920 he was back in Porto Alegre, where the remained until death.
His fame declined from 1925 on, facing competition from new painters and changing tastes in local art
He devoted all his efforts to a half-Realist half-Romantic approach to Academicism even while such styles were already being severely challenged by Modern tendencies. Major themes in his work were mythological scenes, landscapes and genre paintings focusing mainly immigrants and the gaucho, the folk type of Rio Grande do Sul people.