We describe how to colour Fill-It epoxy filler to match any shade of wood. This technique can be used with any other epoxy filler (the pigments we sell will be compatible) or indeed any other filler provided that the paint grade metal oxide pigments are compatible with them (they are inert, so are very likely compatible).
The colour of the Fill-It Epoxy Filler, when cured, is an off-white that will yellow somewhat with age. Colouring epoxy filler to match the colour of wood is often desirable if clear finishes are to be used. Fill-It can easily be coloured to match any wood with our colouring kit.
Natural wood colours range from yellow to red to tan to brown to grey or black. All these shades can be obtained by various combinations of only four colour pigments: white, red, yellow and black. Dry powder pigments which are fully compatible with our products (universal liquid colour concentrates are not) are available from Make Wood Good.
Colouring Epoxy Filler
The Fill-It parts A and B should be mixed together as the product instructions recommend. Then, as each pigment is added, colour will develop with mixing. Continue mixing until no further colour change is seen with continued mixing. Only then add another colour pigment.
Add a small amount of dry white pigment, perhaps a tablespoon or two for a mixed quart. Next, a small amount of red or yellow may be added to approximate the red-yellow balance. Then add a little black to darken to the desired colour. Then, try a little more red or yellow if needed. Should the mix be too dark, add some more white to lighten the mix. The total amount of white pigment needed may be comparable to or much more than the total amount of all the other tinting pigments, as a VERY rough guide. Very dark woods will need less white, and will usually have more red than yellow.
The use of pigments to aid mixing if the filler is to be used below the waterline in boats is also recommended. That technique is described here: Mixing Fill-It Epoxy Filler for Use below the waterline