I spray finished a table using Sherwin Williams dead flat black lacquer (nitro) using a 1:1 lacquer lacquer thinner mix with a little retarder. The finish went on nicely and I let it cure for a few days. At this time, it had the dead flat characteristic I was looking for. It matched a chair that I was trying to copy from Pottery Barn
I ran a dry paper towel over the surface and I find that the surface takes on a smeary characteristic. The surface varies between a satin to nearly flat variation. What am I doing to create this? Should I increase the proportion of lacquer to thinner? What am I doing wrong??? Thanks in advance. By the way, the chair that I bought does not have this problem, so it is my problem.
Replies
Most flat lacquer burnishes very easily. The paper towel is abrasive and for all intents and purposes, sort of "sands" the surface.
Further tests so far confirm what you imply about burnishing. Is lacquer more affected this way? I don't seem to notice this so much with alkyd or waterborne finishes -- at least I have not noticed it so much. This being a tabletop with a large flat surface makes it more visible and more important that I don't have this problem. I have added a flattening agent to a clear lacquer and sprayed it over the flat black. I am going to see how that behaves.
Should I try an oil based alkyd or waterborne flat finish?
When and if I get through this. what will I have learned? Lacquer based flat black is not an option for large flat surfaces? Opex from Sherwin Williams is not a product to be used for large flat surfaces? What?
All the dead flat lacquer finishes I have used have behaved this way. However, where I have used them it made no difference, like the inside of electronic equipment cabinets where I wanted the inside to "disappear". The flat I have used actually has a somewhat rough feel to it which is what makes it a dead flat finish.
It seems to me that anything the leaves a smooth surface will also leave some amount of gloss which is what you don't want.
I don't have a good answer for you. You might want to contact the finish maker and see what they suggest. Most offer good technical service.
Well, I have found a solution of sorts. It has sure cost me (butthen, every lesson in finishing HAS cost me). Using a meter measuringthe gloss/sheen at 60 degrees, my table was a sheen level of about 2with dead flat black lacquer. The chairs I was trying to match had asheen of about 5. The lacquer I ended up with was a Sherwin Williamsnitro lacquer with a sheen of about 7. This removed almost all of theburnishing I was getting. There seemed to be no way of eliminatingthe problem with this product without increasing the sheen otherwise. I THINK that a catalyzed lacquer or other catalyzed product would havehelped the situation. The chair was made in Italy. The SherwinWilliams people tell me that there is a tendancy for the Italianfinishing industry to use catalyzed polyurethane products. I guess Iwould like to have that one more lesson that showed what a catalyzedproduct would do for a dead flat surface. If anyone has furtherreflections (no pun intended) on this, please let me know.
Hi Eric,
Why did you add retarder? Slow dry thinner should do it if you need more time to get a "wet" coat. Normally on colored lacquer I put a clear top coat on...
Don Kondra - Furniture Designer/Maker
Very interesting thought, spraying a clear topcoat. My thought is that the dull flattening agent is being burnished and this might prevent this. My question is, will the clear topcoat
a: Keep the burnishing from happening?
b: Maintain the dull, flat sheen that I am looking for?
Oh, in answer to why I added retarder. I had a slight amount of striping from what I think was dryer overspray from the edges of the spray pattern. I thought that the retarder would eliminate this and it did help. I think the real problem was that I was about 12" from the surface with too much material being sprayed. I am now going to get closer and lower the amount of material being sprayed. My thinking is that the whole pattern will have a more consistant "wetness" when I am in closer. Will that help the burnishing? Don't know.
By the way, I don't think the towel imparted any residue. The burnishing seemed to telegraph from my finger pressure through the paper towel. I really think it was a burnishing type effect. The question is how can I prevent the effect if the flattening agent in the Opex flat black lacquer is burnishing?
This forum post is now archived. Commenting has been disabled