Impco's AlumiSeal is a brush-on methacrylate compound formulated for sealing porosity in aluminum parts and welds that will contain liquids or gases under pressure. AlumiSeal is designed not to alter critical surface dimensions.   

Mixing the sealant’s two components creates a VOC-free, low-viscosity, pale-blue liquid that can be applied by brush. Once mixed, AlumiSeal has a pot life of about one day, allowing multiple parts to be treated from the same kit. Curing in the absence of air, AlumiSeal is designed to form a pressure-tight seal that can withstand continuous service temperatures of up to 180° C (356° F). Parts treated with AlumiSeal have been tested leak-free at 150 psi. Cured AlumiSeal has a typical hardness of 78 Shore D (ASTM D2240) and exhibits resistance to a range of chemicals, including oils, glycol, chlorinated and fluorinated solvents, mild caustics, acid solutions and water.