Restoring the timber

The old cedar lining was showing some stains and it had gotten a bit water stained after sitting in my yard for months. I cleaned up the interior with oxalic acid. This is wonderful stuff for rejuvenating old timber.

Here's the interior after cleaning with oxalic acid.

I made a mixture of oxalic acid and water and applied it with a paint brush. The benches were a bit stained, but they came up like new.

Here's the finished sauna.