Dark cherry dyes and stains
1. Some say not to sand past 120 grit. We find on pigmented stained pieces that we must go to at least 180, if not 220. Your thoughts, please.
2. How do you spray dye and keep it even on complicated pieces-e.g. mantles, built-up profiles, etc? I spray very dry coats and try to build, and get okay results on flat work. Any tips?
3. It seems lately that when we put down a base dye coat on cherry, so that we can get the final color dark enough, the stain pulls the dye back out of the wood and the result is no darker than my dye. The only advantage I see is the dye gets the piece darker than stain alone, and the stain helps even out the dye. Is this how you find it, or can you add more color with the dye?
4. Tonight I dyed a sample with mixed MLC clear spray stain base, walnut dye and cordovan toner. After drying, the sample was stained with a mixture of their Gilsonite tinter, cordovan toner, cordovan stain and traditional mahogany stain. If I let it sit long enough, I reached that elusive "perfect cherry color." However, it tended to blotching and pieces with erratic grain really soaked it up. Is there a better way?
Bob Niemeyer, forum technical advisor
In a cookbook, MLC has very nice cherry recipes that will achieve exactly the color you want. I saw this at last year's IWF in Atlanta, so press your MLC rep hard to get this information for you. The cherry color you seek starts with a very vivid orange dye.
I find that adding a little de-waxed blond shellac to the dye 5% of a 2# cut mixed with 95% methanol evens out the application. Goes on more like a toner this way and is easier to control.
From the original questioner:
I'm coming to the conclusion that the dye will give my color and the stain will be used to even out the imperfections in spraying dye. As far as reducing the dye, I normally use lacquer thinner. Any problems with that?
Your assumption is not correct with respect to these multi-step finishes. Many times the color of the dye base coat is entirely different from the desired final color. At IWF, MLC had a sample door with stripes of the various finishing steps. The starting point was a bright orange dye followed by, I think, their Cordovan Wiping Stain. You seem to think that the dye and the wiping stain are the same color. This is not the case, normally. Your MLC rep should be able to provide this schedule to you.
You may need to look for another source of material. There are some dyes used by coatings companies that will come off when the wiping stain is put on them. This started happening after HAPS-compliant materials came in and you couldn't use methanol based NGR stains and dyes.
On spraying your dye, try to reduce it so it will spray medium-wet to wet. Consider putting on the wipe stain, then spraying the dye over that, to bring your color in.
What was mentioned about adding the shellac to the stain is what we commonly call 'adding a binder'. Stay away from doing that if at all possible. A binder tends to cause your stain to lay up too much on the harder parts of the wood, causing blotches.
It may also help to use a wash coat between your dye stain and wiping stain. Just reduce your sanding sealer 1:1 with lacquer thinner. The wash coat will help lock the dye into the wood before putting the wiping stain on and even out your color on the wiping stain. That depends on what solvents are in that wiping stain.
I have not used an MLC product but have had the same type of problems with other vendors' materials. How much finishing are you currently doing? If you are not that big, you might get help from Sherwin Williams, Star or Mohawk.
Continue sanding up to 180-220 grit. What type of finish are you using--lacquer, conversion varnish, etc? I am assuming that you are using a lacquer type finish.
From the original questioner:
We spray Duravar (CV) over almost all of our stain-based products. We spray probably 10 gallons of Duravar per week, on average. I know the dye after the stain will not work--I tried it once and got burned, that's how I learned--lots of mottling. Someone once noted not to spray the dye so heavy that it puddled. That helped. We probably reduce the dye at least 50% and I try to almost airbrush it on.
There's nothing wrong with 180 sanding. Some sand to 220, but I like 180. Some even stop at 150. It all depends on the sander and type of wood. You didn't say what your finish schedule really is. Do you wash coat or lay down a sanding sealer in between all those dyes and wiping stains?
When you spray a NGR (dye) stain too wet, it will puddle. You really shouldn't have to finesse the stain that much to get it to work. If you reduced it with a lacquer thinner that dries too fast, puddling will also occur. It almost sounds like there is already a binder in the stain. I have added lacquer retarder to NGR stains to help them lay down even, also. What type of wood and product are you putting this on?
1. Sand to 220? Yes; if your finish specs say okay (because of adhesion). Do you water spray to raise the grain before you white sand? 220 will reduce some blotches. Have you tried a glue sizer? Glue sizer will reduce the blotches a little more and improve adhesion.
2 & 3. Always spray dyes wet. If you spray dry, and continue with a wiping stain, it will remove the dye stain. You need low pressure and high atomization to get into tight areas. Conventional spray and cup guns are only moderately suitable (depending on color depth, detail, etc.). If you spray dry, you must do almost everything you should not do, i.e. be more than 12" away from the work, turn the pressure up to about 500 pounds and spray at a low angle. This is done by people who have the dye formula too concentrated and also may be using the wrong solvents. They learn to spray dry.
When thinking about what color dye stain and what color wiping stain, imagine that the dyed wood is the new wood color (no longer white, etc.) and how the wiping stain will effect it. Therefore, if your goal is to have a blotch-free cherry finish, reduce the wiping stain concentration, then figure out what color the wood should be (DYE). That's just one approach. Then the wiping stain is used to add depth and bring back the grain.
#4. Gilsonite? Like putting gasoline on a fire at this point. I would definitely use a wash coat first.
As a refinisher, I often have color matching situations where I must use a dye/wiping stain combo.
Here's something that helps me a lot in choosing a dye and wiping stain combination for a project. I made a set of 3x5 samples on 1/2" birch ply using every combination of dye and wiping stain that I commonly use. I keep them (120 or so) in a file near the booth. They are finished clear over the stain, per my normal routine.
This helped in two ways. One, it was a great learning exercise in color interaction and using dyes. Two, when I'm looking at a project now and wondering, for example, what a dark walnut stain will look like over an orange dye, or should I try a golden wiping stain with a dark dye under it, I go to my file and there it is. It's only on one wood type, so I still have to do some experimenting on the specific project's wood, but the samples help narrow down my choices.
Back to the dark cherry thing. You've gotten some excellent advice here. I get 50-75% of my color strength needed with a dye and wiping stain combo. This would be enough for my taste, usually, but most of the dark cherry finishes I have to match will still require a pretty strong tinted coat over that.
In the past I used a fast lacquer thinner to dilute my dyes, but have now switched to denatured alcohol. I am able to spray a little more of a wet coat without so much puddling. I also used to spray them very dry when I was learning, but eventually realized it is better to cut the dye and spray a little more wet as opposed to dry-spray a more concentrated mix. Either way, low pressure around 15-20 lbs. is the deal.
From the original questioner:
My finishing schedules have varied as I've tried different things to get the perfect cherry color, which of course varies by client. The lighter colors are no problem. For the darker colors, the process needs to be as straightforward as possible with as little skill needed as possible, so that I can turn over as much of the finishing to the help as possible. I'd very much like just a stain if, dare I say it again, possible?
My finishing schedule usually is:
-- Sand to 220
Product: In this case, cherry wood on mantles, built-ins, cabinets of various kinds and degrees of detail.
Concerning spraying the dyes, I think we've been going overboard on the dry side. I just started experimenting with alcohol. We will try more of that.
On the dye, try isopropanol. It dries much slower than the lacquer thinner you're currently using. Methanol has some advantages, too. A good mix for alcohol dyes is 85% methanol, 10% butyl carbitol and 5% toluene. According to an informant, this is what most of the old (prior to HAPS) NGR stains used as their base.
Additionally, I must maintain my position of adding a small amount of shellac. This works great for me.
Adding shellac, or a binder, didn't work for us. We tried this with a dark cherry finish on oak and maple, with a conversion varnish as well on the other line N/C lacquer. There were some incompatibility problems that caused wrinkling in the conversion varnish. Also, the wiping stain had enough active solvents to still remove the NGR in places, causing blotches.
My cure for the problem was to spray a medium-wet to wet coat of NGR stain. Wash coat with the conversion varnish sealer reduced one to one with the reducer. Scuff sand 280 grit stearated. Wiping stain and fill. One wet coat of conversion varnish sealer. Scuff sand 280 stearated sandpaper. Glaze using the wiping stain to add a little more depth to the finish. Then two coats of conversion varnish with a 280 scuff sand between coats.
This was on a finishing line with different colors run with it. I had to pay special attention to my line, sometimes taking the pieces off and allowing them to dry where needed.
I have never used MLC products, so I cannot elaborate on them. But this did result in us changing vendors, as the competition had the solution for not only that problem but others we were having. This was around the time furniture manufacturers had to go to HAPS compliant materials and formulations changed and we had to relearn it all. Now NGRs that are used are a blend of ethanol and acetone and the dyes used in them are different.
Since I mentioned the issue of not puddling the dye stain (in one of the other threads), let me add that the many suggestions for you to cut your NGR with denatured alcohol are good suggestions, in my opinion.
First, if you reduce the NGR, you can get your color more even, without lap marks or uneven (too dark/too light) coloration. This will help when you spray complicated shapes.
Second, by using denatured alcohol (or even whole grain alcohol) to reduce your NGR, when you spray the medium wet coats suggested above, the dye stain does penetrate into the wood, but it dries almost immediately and does not penetrate very far.
Dry dusting on the dye stain is not a good technique. I learned the hard way, also using ML Campbell's Duravar (which is a catalyzed lacquer, by the way). My wiping stain also pulled up my application of dye stain. I was not happy since it was 2 am on a Monday morning and the project had to be ready for top-coating by 5 am. I had to wash everything down with lacquer thinner and start all over.
Bob Neimeyer mentioned something about controlling blotching by using pigmented wiping stains that had a higher binder content (did I get that right?). Doesn't the wash coat, sealer coat, or topcoat need to bite through the wipe stain into the wood for the purposes of good adhesion and film build? If you have a wiping stain with a high binder content, then aren't you skirting the edge of having your stain become a film-forming finish in itself? Or is the film build so minimal that this is not an issue?
Bob Neimeyer was referring to the resin content in the stain. When you have a stain with too much solvent, i.e. mineral spirits, naptha, solvent 100 or 150, etc., you get too much bite from the stain and not enough vehicle to carry the pigment. I don't know the proper chemical name for the stuff I used, other than "wiping stain oil". But it was a clear, slow-drying oil that I added in the summer or was getting too much bite from the glaze. I think it had to be some type of resin for stains. Another thing I have used is an inert pigment in a vehicle to reduce blotching, also. Either of these do not add film build, but slow the stain's drying time without taking all the body out of the stain.
I spray on dye stain for my first step, also. However, I use water-based analine dye stain (Lockwood, zero VOC), wash coat of vinyl sealer, hand sand 320, wipe on oil stain (usually Gilsonite), let dry thoroughly, full coat vinyl sealer, hand sand 320, tone with alcohol-based NGR stain mixed in with pre-cat lacquer (1 part lacquer, 4 parts thinner, splash of NGR). Follow immediately with full coat of pre-cat lacquer. After drying, hand sand 320, finish coat pre-cat lacquer. I find the water stain dries slower and is much easier to spray on.
If you use the MLC line, you can try this.
1. Mix equal parts of orange dye and cherry dye, full strength. MLC only.
2. Lower the pressure on the gun just enough for proper atomization. Keep the gun 8 to 10 inches from the surface so that your fan pattern is about 6-8 wide and overlap the past run about 1 inch. Immediately apply a light second coat, reversing the sequence. In other words, if you spray flat and you work from out, you would reverse that and spray back towards you immediately.
3. When you spray the first coat of Duravar, use a tone coat. The tone coat is full strength cherry dye mixed in the Duravar after catalyzed and reduction of about 1.5 ounces to the gallon of finish or about 1.2 or 1 to 3 quarts of finish.
3. Reduce this 1st coat after catalyzing with a slower reducer at about 6-8 percent. Then completely mix the dye in with the finish, stirring for at least 3 minutes.
4. Apply the finish a good wet 3.5 to 4 mill wet.
5. Scuff with 320 and apply an untoned 2nd coat at 4 mill, reduced about 5 percent.
If you sand cherry, you can sand to 150 on end grain only if you are using high solids finishes. You can sand all of it 150, but you must change paper frequently. I use 120 on the cherry and will do the final sanding with a PL type of paper, which does a beautiful job. We sand the end grain of the raised panels prior to assembly with the 150 PL paper.
If you build the thing, make sure you like it, dismantle it, sand it, tape off anything that needs to be glued, finish it and the reassemble it, you may find that works better. It does for us.
Specifically what is PL sandpaper? Is this the Klingspor PL35 or PL35W silicon carbide paper or something else?
I don't have the sandpaper in front of me, but it is the Klingspor paper. We use that paper for the absolute final sanding immediately prior to finishing. The finishing paper will load fast (silicon carbide), but does an outstanding job for final sanding. We also use and have great results with the Mirka and 3M papers.
The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).
Comment from contributor A:
1. Sand wood to 180.
2. Dye stain, lacquer thinner base. Mix 15% cherry dye (Ilva PF series) and 10% precat lacquer. Pressure just high enough to atomize. Two box coats at 8-10" away.
3. Wipe stain. Mix two parts burnt umber, with one part raw umber.
4. Seal, then proceed with desired finish coats.
This finish schedule produces a rich red brown color that is sought after when finishing cherry.
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