We spent days hand scraping and sanding, re-priming and -painting them, but we used indoor paint on them.

我们花了几天的时间，打磨，沙光，涂底漆，上油漆，可是我们竟然上了室内用漆。

youdao

If indoor use phenolic paint besmear to brush, time should be extended appropriately.

如果室内使用酚醛油漆涂刷，时间应适当延长。

youdao

Indoor decorative paint, plywood, shaving board, interior paint and other materials contain formaldehyde, benzene and other harmful substances.

室内装饰用的油漆、胶合板、刨花板、内墙涂料等均含有甲醛、苯等有害物质。

youdao

Niche uses, like wood stains for indoor furniture, could hit the market next year, with outdoor coatings and alternatives to latex paint a year later.

FORBES: OutFront