Will it work to seal an old rusty wheelbarrow?

Hi there, Flex Paste clings to a wide variety of surfaces including metal. For best results, we recommend applying it to a clean surface free of dirt, oil, grease, and loose rust. When you have a moment, message more information over to us at Humans@FlexSealProducts.com so we can recommend the best product for your project. We look forward to hearing from you!