External Redecoration of Oak Windows
I was invited to quote for the external redecoration of oak windows on a large converted coach house in rural Lincolnshire. All the oak windows had been handmade for the property during the refurbishment.
Unfortunately for me, at some point since, the windows had been painted in an unknown opaque stain. This totally concealed the grain and spoilt the natural beauty of the oak. Also the stain had failed in several places, allowing water to penetrate, which in turn discolours the oak, turning it black. I soon realised that the windows would have to be stripped back to bear wood and redecorated from scratch.
On a property of this size, a mammoth task !
After some research, I opted to use a chemical stripper called Paint Panther, In my opinion the best paint stipper on the market. This was hot, laborious work in the middle of the summer. Some of the larger windows are georgian glazed measuring 3 meters by 2 meters.
On most of the windows it took two coats of stripper to remove the old paint. The windows where then washed down with water to neutralise the chemical stripper.
If you ever use Paint Panther, read the instructions, and wear the correct PPE, it does burn the skin.
The next task was to tackle the black stains, that had occurred through water penetrating the previous coating. For this I use Oxalic acid, a chemical that will bleach wood. It was first derived from rhubarb. I buy in powder form and mix with warm water. Using a scrubbing brush I washed the affected areas many times to remove as much staining as possible.
The oak windows where left to dry thoroughly.
The next job was to sand the windows, I used my dustless sanding system. It would have been nearly impossible to hand sand the oak. Im finally ready to start painting.
I never recommend using oil on external oak windows. I would not recommend Osmo oil, Danish oil or any oil. The reason for this is, it has a 12-18 month maintenance period. That means you will have to re-paint your windows every year.
My goto product for external oak is Sadolin Ultra Clearcoat. It has UV filters, so will help keep the natural colour of the wood. Most importantly it flexes with the wood so will not crack and peel.
If applied correctly, it will have a maintenance period of 3-5 years.