Maintaining grayed wood deck

This is a record about maintaining wood deck and what tool I needed. It took one and a half year because I tested the whole process.

Mujitushi’s wood deck

I bought a piece of wood deck at Mujirushi in November 2012.Mujirushi Wooddeck 01The piece is about 40cm x 40 cm wide, and made of Barau. (Barau maybe a name used in Japan, and I don’t know its real name. Its scientific name is Dipterocarpaceae something.)

Mujirushi Wooddeck 02By the way, this one has a crack. I returned this one and got a new one.

I just put the deck outside without any painting. As time passed, its color was grayed. I started painting in November 2013, and I didn’t know how to maintain wood deck at all.

In April 2014, I have finally understood “How to paint stain and water-based urethane varnish”, and started to restore my wood deck.

This is the 17-month-old wood deck.

Before-Sanding-01 Before-Sanding-02The surface and the back side are very different. The surface is gray. The back side doesn’t seem to get changed.

Paint I used

Because I didn’t want to change the color, I painted only varnish without stain. These are paint I used.


  1. Washin Paint “Water-based sanding sealer”
  2. Washin Paint “Water-based varnish for outside use”

Refer to “How to paint stain and water-based urethane varnish” for sanding sealer. The varnish is “all-weather-protective, uv protective and anti mold” as its label says.

How to paint

The step is almost the same as “How to paint stain and water-based urethane varnish”.

  1. Sand until the color restores
  2. Sand with 120 grit sandpaper
  3. Sand with 240 grit sandpaper
  4. Paint sanding sealer (or varnish after the 2nd time)
  5. Leave for 120 to 180 minutes (I leave 1 day)
  6. Sand with 400 grit sandpaper
  7. Paint varnish at least 2 times

Sand until the color restores

This first step is the biggest. Wood deck is made of hardwood. Mine was also hard, and didn’t change its color.

I attached 60 grit sandpaper to my electric sander.SandingThe direction I sanded varies. I didn’t pay attention to it because I didn’t even think sanding was such tough work.

The one on the left was. Because I found sanding was tough work, I tested how long it took.

The second and the third one are results after while I kept using my sander for a certin seconds like 30s (right above), 60s (right below), 90s (left above), and 120s (left below).

The rightmost one is before I worked.

By the way, this is my sander.

SanderPaint sanding sealer and varnish

All the pictures below are taken one day after the actual painting.
After painting sanding sealer.
First-Paint The color has back! Can you believe it was gray?

After painting varnish (first time)

Second-PaintThe wood deck reflects light more.

After painting varnish (second time)Ready-to-use

I can’t tell the difference, but the surface must be thicker.

8 Months Later

I checked the wood deck 8 months later. Before taking a photo, I cleaned up well with a wet rag.


We can tell the color became darker. The surface looks much better than the one without paint.

I noticed that the vessels were grayed. I could avoid this if I painted polishing powder.

I sanded with 400 grit sandpaper and painted varnish once as maintenance. I didn’t paint sanding sealer.

This is after painting varnish.


Look. The reflection looks like the one 8 months before. 😉

If you are interested in this post, check all posts of “Painting.” For example, I posted these articles.

  • How to paint stain and water-based urethane varnish
    Today I will show you how to apply polishing powder, and how to paint stain. I tried to explain the steps and points with samples as many as possible.
  • The beginner is oil-finishing with Watco
    I found Watco by chance in the store. I thought the word “oil finish” sounds like craftsman-like, and something craftsman-like would make goods better, which was a lighthearted attitude.
  • A total beginner started to learn paintings for woodworking
    As I processed Raspberry Pi cases and dimmer, I thought using wood would be a good idea because wood can be bought easily at fewer prices. Also making furniture is one of my goals. This is why I started to learn paintings.

This post is also available in: Japanese

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