Finishing - Shellac Prevents Blotching

The best made furniture can be destroyed by a finishing disaster, one of which is blotching of stain. By blotching I mean an irregular, generally ugly discolouration of the wood after a stain has been applied.

Blotching is rarely the result of poor staining technique; rather it has everything to do with the grain and pores of wood. Different varieties of wood respond differently to staining. Some dense fine grained species take to stain beautifully whereas others seem to resent being stained.

I have been experimenting with some beech, which is a medium quality hard wood. The wood does not exhibit any figure but appears to be even grained and consistent in look. The wood is not very stable and I found it moves, twists and warps quite unpredictably.

I was given some and thought I could use it for faux panelling. The wood is relatively easy to work though hard and the panel strips came out rather well.

I decided to stain the beech panels strips (rails and stiles) as well as some very unstable Pine I had made some shelves with. The Pine was doused with heavy purple dye and there was no problem there.

Ash stains rather well

I stained some Ash and found it stains rather well. On the other hand, beech, stained with oil based Varathane stain was a complete disaster. It blotched badly and pre-treating the wood with wood conditioner (Varathane) made no difference whatsoever.

Beech prior to staining
After Stain - ugly blotches
Stained after applying one coat of Shellac
Stained after two coats of Shellac - much more uniform effect

I then applied a thin wash coat of Shellac on the wood and tried staining. It worked well; two coats of Shellac worked even better. No blotching at all!

Just proves how useful Shellac can be and the importance of testing prior to staining.

Indranil Banerjie
24 March 2015

Comments


  1. Staining can increase the value of your project. Its really a tricky job. Staining is a good solution for irregular patterned or ugly wood surfaces (if done properly). I think staining a wood is like applying makeup over a beautiful face. I love natural texture of wood grains and I never stain my projects. This information will be very helpful for those who like to stain their stuff.

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    1. You are quite right Kishore. I too do not like staining nicely figured wood. However staining can subtly change the look of a piece and bring different pieces to a similar hue.

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  2. Thanks for sharing!! The stainers I've used are from Sheenlac company. The supply a packet of color separately which is mixed to ones liking. May be next time, I'll first try without mixing the color and see results. BTW, Sheenlac has a product 'French Polish', I was told it is plain shellac.

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    1. Praveen, I have found the best way to get stains the way I want is to experiment. There are so many varieties and qualities of stain available that it is often hard to tell which ones will work. Somehow I have never come across Sheenlac products - maybe they do not market them in north India.

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