# Refinishing a Rosewood veneer sideboard



## YellowShark (6 May 2009)

Hello Everyone,

I am a reseller of mid 20th century designer furniture and I buy a lot of rosewood tables, sideboards and chairs which are quite often badly bleached by sunlight. I am trying to get the experience to refinish the ones which are unsellable due to this discolouration and would like to draw on your collective experience to help me.

My first project is the top of a large (6 foot x 18 inches) sideboard. The sideboard is not worth a great deal so I can make mistakes without it being too painful on the wallet. I decided it was easier to try to match the colour and finish of the top to the rest of the piece rather that strip it all.

What I have done so far is: strip the old finish off using paint/varnish stripper and sand using an orbital sander with 240 grit - sanding may have been my first and biggest mistake as the patina built up over 40 years was probably contained in those first few microns of wood. Is there a better way to get the last few traces of the old finish off without resorting to mechanical means - stripper and 0000 wire wool perhaps.

I used two coats of water based stain but the finish was a little blotchy but not too bad. I thought that the finish coat might hide some of the blotchy areas. I then tried to apply a coat of water based acrylic varnish. This dried so quickly that I had marks everywhere as I applied it - the room temp may have been too high but I still don't think I could have covered the whole of the top without it drying in places. According to the can I could have reduced the viscocity by thinning with 10% water for the first coat. I have abandoned this varnish.

After a bit of reading, I stripped the top again using the same method and applied a washcoat of Zinsser SealCoat (de-waxed shellac) let down approx 30/70 with methylated spirit. After drying overnight I applied the stain but even with two coats the colour was not deep enough - presumably the Zinsser has filled some of the pores in the wood which would have been filled with stain first time round. Carrying on I applied an alkyd polyurethane varnish (which said it may darken the stained finish - hopefully to the same depth of colour as the rest of the piece). Although better than the acrylic varnish I still couldn't get the coat on quick enough and there were slight brushmarks in the finish. However, as the varnish dried the top looked "brighter" than it had been with just the stain - before the lines in the grain pattern were diffused but after appeared to have greater contrast between the lighter and darker lines in the wood - this is really difficult to explain without a picture. Also, the finish was much more glossy than I expected from a satin varnish which made the wet-look of the finish even more pronounced.

I stripped it again and applied the stain without a Zinsser washcoat - it's still blotchy but acceptable. That's where I'm upto.

Phew, if you're still with me then I'll ask a few questions.

Firstly, is there any way to get rid of the blotchy patches without resorting to the washcoat. Did I have too thick a washcoat.

Is the poly varnish the right finish - the "brightness" and grain contrast are so different from the original finish. Has anyone had experience of mid 20th C Danish furniture finishes - they would almost certainly be sprayed but what with? Lacquer? Is it going to be possible to get a professional finish without resorting to spraying?

Can I let down the poly varnish with methylated spirit - it doesn't say on the can. I'm thinking that by letting the varnish down I can get coats on more quickly and the reduced viscosity would help eliminate brush strokes. I could build up the finish by doing more coats of thinner varnish to get the same amount of varnish solids onto the piece.

Can I apply a coat of Zinsser over the stain to "lock-in" the diffused appearance of the grain before applying a coat of (let-down) poly - this may stop the brightening effect.

Can poly varnishes be mixed - can I add a bit of matt to the satin to reduce the gloss.

Thanks in advance,

Paul.


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## Woodfinish Man (7 May 2009)

Sealing the wood with transparent shellac will have the tendency to make the surface more equi - porous however the water stain will be prevented from penetrating into the wood properly and will therefore appear much lighter than it would have if applied to bare wood.

You could substitute the shellac for a coat of Aquacoat SP waterbased Lacquer and when dry sanded smooth with 240 abrasive paper. this could be overcoated with several coats of Aquastain which is a bound water stain.
This method should give you the evenness that you desire and control over the depth of colour by applying as many coats as required.
after staining you could consider finishing with clear Aquacoat SP. 
Many people have had great success applying this product with paint pads.

Polyurethane varnish should be thinned with white spirit.
It is possible to intermix polyurethane varnishes of differing sheens provided that they are from the same manufacturer.

Locking in the stain with shellac is do able but at the risk to some potential intercoat adhesion between the poly varnish and the shellac - you should try a test piece before committing to the whole job.
You will almost certainly achieve a better finish by spraying something like precatalysed lacquer.
These lacquers can be sprayed over precatalysed base stains or water stains.
Precatalysed base stains can be added to the lacquer to obtain tinted lacquers which give very even colouring or used to achieve shading effects.

I really hope this information helps

Ian


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