I will be using a water-borne finish on red oak and want the natural red colour you get when using an oil finish. How can I achieve this?
One thing to mention up front in case you're unaware, the oak itself will naturally change colour over time. All oaks (along with the majority of wood species, which are lighter or mid-coloured) are significantly lighter when new and freshly worked — the wood may be referred to as being "in the white" at this stage because of how light it appears — and will darken, sometimes dramatically, with exposure to light1 and air. In addition, red oak also ambers slightly over time2. While your oak will never be the same colour it would be if you use an oil finish it will tend towards that colouring somewhat by itself.
If you want that exact look immediately you have a few choices:
- Treat the wood with oil (BLO being the usual choice, and arguably the best) and then use waterbased finish on top, if necessary using shellac as a 'bridge' finish.
- Stain the wood, then use the waterbased finish.
- Use a coloured waterbased finish. These can be bought or homemade.
- Use an oil-modified waterbased finish. I mention this last as these darken the wood somewhat like oil-based varnishes do, but, not quite as much. So if you're fussy about the colouring this type of finish might not cut it for you.
As you can see there's a lot to pick from here and there's additional time, money and effort required in most cases. On top of that for most of these some experimentation will be required to achieve your desired result. If you're asking in relation to a one-off project then you have to ask yourself if it's really worth it (especially since you might not nail the colour first time) when you could achieve the desired end result much more directly:
- Don't go with a waterbased finish and use oil-based varnish to begin with.
Unless I had no other choice this is the option I would favour. This is partly because I get on with oil-based finishes and have lots more experience using them for wood finishing anyway, but it's also because I love how they make wood look which seems to be the case for you too. And one of the most important factors when choosing a finish is how you want the piece to end up looking. For many this is the most important aspect3 and it comes first, so there is at least one good reason to use an oil-based finish when you want that specific look.
If an oil-based varnish is not an option for you, for whatever reason(s), then the first alternative listed above would be the route I would recommend as it doesn't require experimentation, and costs least up front. An additional benefit is you'll now have BLO (and maybe shellac) in stock which will prove very useful over time, and not just in wood finishing as both have additional uses.
1 Cherry is perhaps the most famous species for this effect these days, getting significantly darker and redder (very quickly) with direct sun exposure.
2 Most woods that are slightly reddish or pink undergo similar changes. Strongly orange species like padauk will disappointingly go a much more drab brown with light and air exposure.
3 Durability should be the primary decider in some cases however.