Monday 9 July 2018
Resin can be added to your turnings either to repair defects or to add pattern and decoration. In this article I will show you a few tips on how to apply resin to your turnings effectively.
The first thing to consider is the preparation of the grooves or holes you intend to fill. For holes drilled with a precision drilling jig it is important to ensure the holes are deep enough to allow the correct shape to be achieved when turning and that they are cleanly drilled with no or as little as possible torn grain. To avoid colour seepage from the application of resin it is advisable to coat the surfaces with sanding sealer. For the example shown cellulose sanding sealer has been sprayed into the holes ensuring all internal surfaces are coated. When dry, ream out the holes with the same drill bit used to drill them; this will remove any raised fibres leaving a clean hole ready for the application of resin. You now need to mix the resin and add colour or glitter, before adding the hardener. Next, pour into the holes, overfilling them, so when the resin sets it will not sink below the surface of the hole. Tap the turning several times to remove any air bubbles and allow the resin to set before completing your turning.
The same principles can be applied to grooves cut into your timber. The use of a fluted parting tool will help to minimise the occurence of any tearout. Apply sanding sealer making sure all surfaces are coated and allow to dry, use sandpaper to remove any raised fibres and apply more sanding sealer if required. Apply the resin, again overflowing the grooves so there is room for shrinkage. Tap the turning a few times to remove any air bubbles that have built up and allow the resin to set before completing
When mixing the resin it is advisable to mix more than you think you will need; it is almost impossible to mix more resin to the same colour and consistency. One method of using the surplus mix is to have several prepared pendant blanks with pre-cut grooves and recesses which can be filled with the resin for added decoration. Another is to allow the resin to set in the cup, tear away the cup and using double-sided carpet tape, stick the flattest side of the resin to a sacrificial chucking spigot. Mount on the lathe, true up and turn a cabochon.
Prepare the timber for the application of resin; here I have drilled 12 holes into the end grain of a piece of timber being used to make a vase. Spray cellulose sanding sealer into the holes ensuring all the internal surfaces are adequately coated with the sealer
When the sealer has dried remove any torn or raised fibres by reaming with the drill bit used to drill the holes. Any debris left in the holes would show in the finished turning
Measure the required amount of resin into a paper cup; here I am using a 10ml spoon with a bent handle for ease of use. Always try to mix more than you think you will need, it is almost impossible to mix more to match if you run out. The opening shot opposite shows you a couple of ways of using the surplus mix so that none of the resin is wasted
Add your choice of colour; I have chosen green glitter but other products can be used, for example, pastel chalk powder, metal powders, acrylic paint, etc. Mix thoroughly before adding the hardener
Measure the required amount of hardener. For ease of measuring, I use a glue spatula which I have drawn a black marker pen line on. From the end of the spatula to the line is 2cm, the ratio of resin to hardener is 2-3cm of hardener to 10ml of resin – I aim for approximately 2cm length of hardener. Too much hardener and the resin will set like rock and will be very difficult to turn. Mix thoroughly ensuring there are no lumps of hardener remaining
Pour the resin into the prepared timber, the rim of the paper cup bends for easy application. Here I have filled the holes on the left-hand side with excess resin allowing it to run out of the holes and the right-hand side with just enough to fill the holes. Tap the timber several times to raise any air bubbles to the surface
This photo shows how the resin has settled once set. The resin in the holes on the right-hand side has sunk below the surface whereas the left-hand side resin remains slightly proud of the surface