Using filler with an oil finish?

[paul.cleary]

Please note that I have already searched the past 10 years of Finishing threads and not found an answer, so I am posting this as a new thread.

This is a question about applying a filler to wood surfaces with small holes and cracks when the finish will be oil, e.g. Tung Oil or Danish Oil.

When I apply a filler to wood with small holes and cracks when the finish will be polyurethane, my current approach is:
1. sand the wood surface until it is smooth enough
2. apply a stain (usually a water-based pigment type)
3. apply the 1st coat of polyurethane and let it dry
4. apply a filler, tinted to match the stained wood surface. Lightly sand the filler (once it is dry) so the surface + filler is smooth.
5. apply the 2nd and 3rd coats of polyurethane, allowing the specified drying time between each coat.
- I get a good adhesion between the polyurethane and the filler with this approach.

I plan to use Penetrol for my oil finish on a rimu wood surface. The Penetrol has been tinted with Briwax rimu spirit dye so the wood surface will be stained and oiled at the same time.

Do I apply the filler before the 1st coat of oil or can I apply the filler after the 1st coat of oil and before the 2nd coat of oil?
My reason for asking is that if I can apply the filler after the 1st coat, then I can easily tint the filler to match the stained wood surface

Thanks in advance, Paul

[Fekit]

What are you using as a "filler".

[rod1949]

Try this Solarez from Amazon Aust.

[paul.cleary]

OP here - only got 2 answers to my initial question and they were not useful to me.
So here is what I did:
In a not very noticeable part of the window frame I sanded a small spot back to the bare wood and then applied the Penetrol Wood Oil to only the spot and left it for 24hours. The resulting spot gave me a colour reference for selecting the closest matching tinted filler. Go for slightly darker if you cannot get an exact match.

My procedure was then as follows:
1. sand the wood surface of the window frame until it is smooth enough - with an oil finish this is 120 grit Abranet as oil does not soak well into fine wood surfaces
2. apply the tinted filler to fill up the holes and let it dry for 1 hour. Scrape off excess and then wipe smooth with a damp rag (I used Cabots filler as it is compatible with water).
3. Lightly sand the filler area with 120grit (once it is dry) so the surface + filler is smooth. and the surrounding wood no longer shows a water stain.
4. Now apply the Penetrol Wood Oil as per the instructions on the tin

I hope this helps someone in the same situation.
Note: Resene NZ has a video on YouTube which talks about the ability of finishes on bare wood surfaces to survive the New Zealand UV sunlight.
They rate a clear polyurethane varnish as being a waste of time as its lifetime before recoating is about 1.5 to 2 years. This often requires sanding back cause of the greyed wood fibres and peeling polyurethane.
The video says mineral-based oil is OK so long as there is easy physical access to apply a "refresher coat" every 2 years. No need for any sanding, just wipe the surface with a damp microfiber cloth.
Natural oils were estimated to have a lifetime before recoating of under 1 year, unless they had loads of UV protection in them (at which stage they are not all that "natural").