How to bleed kwila timber

Kwila, also known as Merbau, is a highly durable hardwood, that is termite resistant and ideal for outdoor use.

Below are our recommended instructions to remove the red surface tannin from the timber.

For more information on kwila - click here to read this blog article.

The lowdown

As Kwila contains a large amount of tannin (resin or sap), when the timber becomes wet it will bleed the tannin onto the surface it is sitting on. If it is not cleaned up immediately, the tannin can stain porous ground surfaces, (such as concrete) so it is advisable to accelerate this process to attempt to remove the surface tannin from the furniture.

What you will need to do in order to bleed out the tannin, is hose the timber down with clean water until the tannin has stopped coming out of the timber and then allow it to dry. Depending on the amount of tannin in the product, this process may need to be repeated several times. It should be noted that as timber is a natural product, the amount of tannin is not measurable, therefore even by following bleeding instructions, it is still possible to end up with a small amount of residual tannin which could stain a surface. So be as diligent as you can with this process. We recommend to use Timber Sealer after the bleeding to waterproof the bottom of the legs of chairs and tables to stop any tannin seeping out.

Don’t stop hosing until the run off water is clear and then use an old rag or towel to sop up any standing water on the timber, roughly going all over all of the furniture with the rag. It will take many hours for the timber to completely dry (depending on the weather), however using the rag helps to prevent water spots marking the timber while it dries.

Once your Kwila furniture is totally dry, and if you want to maintain the rich colour of your furniture, at this point it is recommended that you oil the furniture using a light decking oil, such as our Jarrah Oil.

It is important to note that you are not removing all of the tannin from the wood, just the surface tannin. This is important, because it is the tannin and the moisture within the timber that retains the tannin that helps to preserve your furniture, making it resistant to the elements.

tannin leaching

This is the tannin leaching from the timber. If no controlled bleeding is done, the tannin will come out over time and can stain clothing or flooring.

If you had a cold drink on your table, the condensation can bring the tannin to the surface, leaving you with a round mark on the table. Thus, it is important to bleed initially.

Kwila Entertainer Bar

Step by step

Assemble Furniture. If chairs have slings – do not put them on.
Put tables on their sides on a grassy area and hose the entire surface for a couple of minutes until the timbers start releasing its natural oil. You will know it is releasing by the foam residue on the ground.
Leave the tables on their sides and prop the hose up under a brick or piece of timber so that it is splashing against the table for a good 2 hours at least. This is to penetrate the thickness of the timber. Please note – the entire table back and front must be done.
Once the water is running clear remove the table to a dry area and let it air dry which would take approximately 40 minutes and then oil entire table with Furniture Oil using a lint free cloth i.e. T-Shirt Fabric. A good way to tell if the sap has removed is to wipe the table with a white cloth to check the colour.
Because the chairs are of a lesser thickness than the table, these can be done under a sprinkler hose for approximately 2 hours turning the chairs every 30 minutes. Leave in a dry area and oil. Do not install slings on the chairs until the oil is completely dry.
Tighten all bolts and repeat oiling every 6 months approximately depending on the harshness of the weather conditions. If this is not done – the Kwila timber can after 18 months to 2 years go a silvery/grey colour. This is the natural process of Kwila if not oiled but using fine sandpaper, the grey can be removed and then re-oiled to bring it back to its original condition.

kwila dining