Darkening a Finished CV-coated Piece
Advice on how to add a new, darker conversion-varnish topcoat to an already varnished piece. February 19, 2006
Question
I got a call today from a client who I worked with earlier this year. As the light changes throughout the day in their living room, they are finding that the piece I did for them is lighter than they like. I told them I would take care of it, but I could use some advice. Since this is a finished piece, what would be the best way to darken it? I don't think that sanding to bare wood is really an option. That would take far too much time, and probably give inconsistent results, yes? Is a toner what I want to use or a combination of toners? Can I spray right over the CV with scuffing, then topcoat with CV again? Mil thickness shouldn't be an issue here, so I am not worried about spraying another coat. How about a glaze? Thanks for your thoughts.
Forum Responses
(Finishing Forum)
From contributor A:
To recoat CV you should always scuff with at least fine Scotch brite. You can make a toner out of the stain you used for the job but add some catalyzed sealer to it to make it stick.
From contributor B:
As contributor A said, you can use your stain and sealer. You do however have to be careful with critical film thickness. I would suggest scratching the surface a little more aggressively than with just a Scotch brite pad. I would use either 280 or 320 grit sandpaper to give a little more bite.
From the original questioner:
320 sounds good. As far as a sealer goes, I don't use it. I seal with the CV itself, and always get good results. Actually, I've never tried sealer. When I first went with SW CV some years ago, the SW folks said it wasn't necessary. That is, they told me I could use the sealer or not, and left it up to me. So, can I just mix a little stain with the CV? Do I need to do anything to the catalyst and reducer to varnish equation, or mix it as usual, but just add the stain? Provided this will work, it'll save loads not having to sand back down to bare or at the very least stained wood.
From contributor A:
If you use the CV as your toner, be sure to reduce it with xylene or some other compatible solvent about 50%. Be sure your stain is solvent based and not water.
From contributor C:
First consider, dewaxing the piece - it must be clean. Be careful with your choice of sandpaper, as scratches from the sandpaper may telegraph through the CV. Don't play with it. Get the color, clear coat it, let it cure, and quit while you’re ahead.
From the original questioner:
To contributor C: I am guessing you mean to get the color right on another sample piece, then proceed as directed above - cleaning, sanding, cleaning, shooting stain, letting cure, light scuff, top coat, let it cure then re-deliver the piece. Yes?
From contributor C:
Yes. There are more errors in finishing because we want to make it better. Instead, what happens is the more you play with it, the greater the chances are that you will cause a problem. So please, quit while you are ahead.
From the original questioner:
I understand that just fine. Oddly enough, I do a bit of journaling from time to time and one of my entries addresses just that: leaving well enough alone. I can't get to the color correction until January or February, but I am almost looking forward to it as the process sounds straight-forward enough. I think the hardest part will be getting the piece back here to the shop.
From contributor C:
You will find it easy, if you follow your samples.
