How to Clean Up Oak Beams

If you’re like us and love a little bit of timber (oak doors, porch, sleepers above fireplaces, sleepers as flower beds, furniture etc) you’ll know that the beauty in a lot of these items is that it’s okay if the wood isn’t ‘perfect’. In fact you’ll have probably told yourself that all of those marks just give your item ‘character’, and whilst this is certainly true in many cases, often wood can get some blemishes that aren’t as charismatic as others.

By the time our new porch  had been built, assembled on site, transported to us and then built again it had picked up a few of these blemishes:

You can see some of the water marks in the above photo as well as quite a lot of black dirty marks at the bottom of that top beam.

The news is that it’s really easy to fix these so I’m sharing the steps in this post. If you’ve got timber that has been painted or varnished then this probably isn’t the process for you. You’ll probably need something more intensive that involves paint strippers, but if you’re looking to remove machining marks (including stains caused where the metal machinery has come into contact with wood) or water marks caused by tannins in the wood then this is a really easy way to get some brilliant results.

The first thing you’ll need is Oxalic acid. You can get this quite easily and cheaply (we got ours here from eBay). It comes in powdered for, and you just need to dilute with water in a 1:6 ratio.

Using it is quite literally as simple as brushing it on. You might need to do this more than once, or really work the product into areas that are badly stained, but it literally is as easy as it sounds.

You can see how the wood looks after being treated here:

We were pleasantly surprised with how well the wood came up. The official advice is to rinse off the acid but we were worried this would cause futher water marks so we left it as it was.

We then wanted to protect it to stop any more water marks and to UV protect the wood (to stop it from going grey as it ages). If you’re looking into this you may consider varnishing timber but we prefer oiling it. Not only do we prefer the look of oil, but varnish eventually cracks and blisters which means water can get under the varnish (and turns black). To reapply coats you’d need to strip back varnish, whereas oil coats just need a quick sand before reapplying.

The product we use repeatedly is Osmo oil. For this particular job we use UV protection in ‘clear’, but it is available in other stains. It’s worth being aware that there is an internal and external variation. The external oil contains biocides which protect against fungal attack of the wood, but these aren’t recommended for use internally in a confined space.

We used the internal oil for the inside of our front door, and the external for the outside and the porch.  Again, it’s really easy to apply – we just brush it on and make sure to catch any drips:

Once dry, this is the finish we end up with (and I apologise for the Christmas spam in July! It’s the best close up I have of the door!):

This has been on the door for well over twelve months now and we’re really happy with it.We’d really reccomend this as a process because it’s really simple and you get such good results. If anyone’s ever tried similar products it would be great to hear how you got on in the comments below…