Hello members,

Recently I baught in an estate sale 2 large steel planters that I plan to use to grow herbs. I dumped the potting mix, scraped off lose rust scales, brushed with a steel brush and washed out the rust powder. I will sand the inside and wash again with a solvent. I would like to know where I can find a tar based coating so I can line the interior and make it impermeable to water.I appreciate info on stores where it is available,brand names and comercial names.Thank you for the info.JM