How to finish timber floorboards?

alizeh200011

hi! I’ve just pulled up some carpet in my 1965 home

found these floorboards underneath, I’ve been told by others they are cypress pine.
I have removed all staples left by the carpet removal, and punched in all the nails.

Questions:

What is my sequence of steps? Sanding, filling in nail holes, sealing the floor. Which order do I do these steps in?

What can I use to fill in the nail holes? Is timber mate wood filler non shrinking a good choice?
do I use the same stuff I use for the nail holes to fill in the gaps between the floor boards (pictured) as well?

When sanding- I plan on hiring a sander and edger from Bunnings- what order should I use the sand papers and different grits in? Do I use edger first and then main sander?

I like the color of the floorboards so I don’t want to stain them. Can I just seal them without staining? What sealer should I use? Do I have to sand after sealing?

And before I do any of this should I clean the floor first? Like mop it?

I also live in a town with clay soil so there’s quite a bit of movement in my house as the weather changes so the floors move if this makes a difference as to how I would do things

thank you for any advice!!!

JacobZ

Welcome to the Bunnings Workshop community @alizeh200011, it is fantastic to have you with us.

You might like to start by having a look at https://www.bunnings.com.au/diy-advice/home-improvement/flooring/how-to-sand-timber-floors for some general guidance on the process.

Before starting, check for any remaining staples, protruding nails, loose boards or deep damage. If there are loose boards or boards that seem too far gone, they may need additional fixings, or replacement.

Vacuum the floor thoroughly before sanding, but I would not mop bare floorboards immediately before sanding, as the moisture can swell the timber and raise the grain.

A typical sequence would be:

1. Punch all nails below the surface and repair any loose boards.
2. Complete the initial sanding with the drum sander first, then the edge sander.
3. Vacuum thoroughly, then fill the nail holes, cracks or defects and gaps between floorboards.
4. Allow the filler to dry and complete a second sand, vacuum, then follow up with a third fine sand to finish.
5. Vacuum carefully and wipe away any remaining fine dust.
6. Apply the selected floor coating, following the instructions from your specific coating, sanding between coats as per recommendations on packaging.

Timbermate is suitable for this application and choosing a colour close to the finished cypress pine will make the repairs less noticeable. Alternatively, you can create your own filler by mixing saw dust with PVA glue and applying it to the nail holes and between boards.

The starting grit depends on the condition of the boards. A heavily marked or coated floor might require 40 grit, whereas a floor in better condition could begin with 60 or 80 grit. In your situation, I think you'd be fine to start with 60 or 80 grit. You would then use 100–120 grit for the second finer sanding and 180-240 for your final pass.

It's generally recommended to sand the main area with the drum sander at a 45-degree angle to the boards initially. This helps to flatten the floor and remove any cupping from the floorboards. You can then do a second pass with the same grit sandpaper following along the grain of the boards. After this, then use the edging sander around the perimeter. Work through the room systematically at each sanding stage so the edges blend with the main floor rather than completing every edge before starting the centre. You can then use your filler to fill nail holes and imperfections before allowing it to dry. After applying your filler, use the 100-120 grit sandpaper, sanding parallel to the floorboards, then follow up with the edging. Vacuum up any sawdust between passes. Finish up with a final pass using 180-240 grit sandpaper, sanding parallel with the floorboards, then finishing with the edging.

Make sure you thoroughly vacuum the floorboards before you move on to coating.

You certainly do not need to stain the timber. A clear floor-grade polyurethane will protect it while allowing the natural colour and grain to remain visible, although oil-based products can add a slight amber tone. Test your chosen coating on an inconspicuous section first so you can see how it changes the colour. Cabot’s CFP Floor in a finish of your choosing would be a good option.

They recommend a light sand using 240-grit between coats of CFP, ensuring you allow adequate drying time before sanding. Again, vacuum up any dust before applying the second coat.

Check out https://www.bunnings.com.au/diy-advice/home-improvement/flooring/how-to-seal-timber-floors for some guidance on the application of your floor sealer.

Let me know what you think and if you have further questions, please don't hesitate to ask.

Jacob