Restore Finish on Hardwood

Project Description

Restore finish on water-damaged wood parts of a staircase.

Water-damaged hardwood
Water-damaged hardwood

Damage as on the picture above occurred due to water condensation on a skylight in winter. The skylight is right above, there were occasional water droplets on a couple of boards below.

So, I have water damage in 2 places: one shown above, and also on another board, where the damage is much smaller.

Partially sanded away water damage on wood board
Partially sanded away water damage on wood board


The total area that needs re-sanding and re-finishing is probably about 3 meters long max, however, the damage is concentrated to a very few small spots, as on the picture above.

I need to re-sand the damaged boards, and then re-apply finish. Now, because the original problem why water appears here is NOT fixed, I am thinking about using oil-based finish for exterior surfaces, not water-based finish used indoors.

Eventually, I may fix the source of the water problem, by replacing skylights. This is, however, another project, which I am not ready for at the moment. To re-iterate, a few drops of water may come down on really cool nights in winter, when internal humid in-house air condensates on cool skylight surfaces.

Completion Notes

Let's start with some tools we need for the project. Here are three electric sanders.

Tools to use - electric sanders
Tools to use - electric sanders


Bosch rotating sander
Bosch rotating sander


Oscillating sanding tool
Oscillating sanding tool

The above is actually not a sander, but an multi-purpose oscillating tool. Unfortunately, I cannot recommend the Mastercraft brand, their tools are not great quality-wise, but having one of such inexpensive tools is better than nothing, especially for narrow places in between the boards like on the picture.

If you wonder what's wrong with Mastercraft - in the oscillating tool above, the electrical switch failed after approximately a couple of months of light use after purchase while I was working on hardwood floor project in my house.

Now, let's see how this renovation project was done.

1) Sand the boards with the available sanders and by hand, where sander tools cannot reach.

Sanding wood
Sanding wood


Bottom part after sanding
Bottom part after sanding


Top part after sanding
Top part after sanding


2) Apply 3 layers of oil-based wood finish allowing sufficient time to dry between the layers (overnight). Use gentle sanding between layers for smoothness.

Varathane oil based wood finish
Varathane oil based wood finish

3) Enjoy! Here is how the parts looks like after applying 3 layers of finish.

Finished job - bottom part
Finished job - bottom part


Finished job - top part
Finished job - top part

Now it looks very much better, doesn't it?

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