Aniline dye, shellac, and mahogany

[Jake Garland]

Hello. I'm building what I consider my first "real" woodworking project in the form of a tv console for our flat-screen. I found a really nice hardwood supply store that had African Mahogany plywood which I'm using to build the carcass. I want to achieve a deep rich brown finish with a high gloss top coat. I've settled on using water-based aniline dye to achieve the brown color without losing the grain pattern. I'm considering the following:

1) a. A washcoat with Zinsser sealcoat, then lightly sanded
b. One or more layers of diluted aniline dye
c. Couple more coats of Zinsser sealcoat
d. Couple/few coats of a wiping varnish (BLO/mineral spirits/Varathane)

2) a. Dying the Zinsser with the aniline dye and applying that as the first coat or as many are necessary to achieve the proper color
b. Couple coats of clear Zinsser
c. Couple/few coats of wiping varnish

3) a. Straight to the diluted aniline dye, as many coats as necessary
b. Couple coats of clear Zinsser
c. Couple/few coats of wiping varnish

What are your recommendations? I'm leaning towards the first option, because I think the clear wash coat lightly sanded will create a nice surface to apply the dye to. I'll then lock in the dye with a couple more coats of the sealcoat shellac, and top that off with several layers of a glossy wiping varnish.

I also plan one having the dye quite diluted and slowly darkening the wood over several applications to try to obtain the most even coverage I can.

Well, I hope I've provided enough information to get some responses. Thanks in advance for any advice you might have.

[Jim Becker]

I never seal before a dye. What you absolutely need to do is go through your complete finishing regimen(s) on scrap of your project before you commit to anything. Try it both ways to see if you like the results.

BTW, if you're using alcohol soluble dye, you'll want to spray it. Wiping alcohol soluble dye on is very difficult to avoid noticeable "edges" as the alcohol flashes off so fast. Water soluble dyes are more manageable for hand application.

[Jake Garland]

Thanks Jim... that will actually make things a bit easier. I'm really looking forward to seeing how this thing turns out

So it looks like it will be several thin coats of the dye, sealed with the dewaxed shellac, and top coated with a wiping poly. I'll post some pics of my progress.

Thanks again for the quick reply.



Jake

[Prashun Patel]

Jim's the man.

I hope yr testing, though...

Veneered plywood and solid stock take color and finish quite differently, and they are notoriously hard to match. Personally, I LIKE a contrast...

As for the dye, I'd dilute it in water. It's easier to control. Start at a 1%-2%. You have to raise the grain first by sponging lightly with water, letting it dry, then lightly sanding off any fuzz. I like to apply the dye with a sponge. It allows you to move quickly and avoid lap marks. I'd also change sponges between coats. I've found that the the dye can separate in a sponge or on paper. It 'chromatographs' and the reds can separate from the browns a little. Try it by putting a drop on paper. If you put the 2nd coat on with a used sponge, you risk having sections appear slightly more red than others. DAMHIKT. It's fixable, but better avoided.

You also mentioned that you want a GLOSS topcoat. African mahogany is opengrained. You won't get a mirror gloss finish unless you fill the grain, which'll be tough with a wiping varnish alone. I've had better luck painting on a few thicker coats of shellac and then sanding most of it back before topping. Be careful not to go thru the veneer or the dye. You could also use a pore filler, but on vertical surfaces, it's not really THAT critical to get a mirror flat surface...

[ROY DICK]

I found 2 articles that might help.
1) Is in Woodsmith vol. 28 / No. 166 Pages 46 and 47. (Water Based Dyes).
2) Is in Fine WoodWorking #206 August 2009 Pagees 55 through 59.

Check at your library or on line .
I hope this helps. As the others have stated use on scrap wood as always.

Good luck with your project.

Roy

[ROY DICK]

2) Is High Gloss Finish. I could not edit.

Roy

[Jake Garland]

Thanks again for the excellent suggestions. I'm going down to Lee Valley today to pick up the dye, and I'm going to do some testing on an unseen part of the piece. I'll post some pics when I get it done.

[Chris Padilla]

I just laid down some NGR dye on some walnut. It was an interesting exercise.

One reason to lay down a seal coat is to not allow as much dye to penetrate the wood. There is nothing wrong with this as long as you understand what you are doing. If you are coloring oak, it may be a very good idea since it is so open-pored in places. If you are coloring maple, that wood is more tightly closed and so a seal coat...even very light, will keep the dye from penetrating much.

Back to my experience with walnut and NGR dye. I liked the fact that it wasn't going to raise the grain. I added some retarder to my NGR solution and didn't go above the 10% they recommended but it still dried too fast for the largish surface I was trying it out on. I first tried brushing it but that didn't go so well. Next, I used a new sponge and that went much better. As it turned out, I ended up wiping down my first coat of dye with a water-soaked rag to blend it better and remove some color and it raised the grain but a quick hit with some 400 grit from my ROS smoothed it back down but then that removed even more color...too much! haha

So I sponged more on and just let it go at that. This time, I added even more retarder and it helped it stay wet until a I had the whole section coated. Overall, it is darker than what I would have liked but it'll work.

Fun, fun, fun with aniline dye!!