I don't know why this post hit me odd. I think it was the use of the word varnish in relationship to an alternative to poly. I don't know.tdoucette67 said:What is the best topcoat that I should use over a waterbased dye? I understand your supposed to seal it with shellac first but should I be using afterwards? Lacquer, varnish, poly or is the shellac enough?
You don't have to use a barrier coat with a water based dye. As long as you let the water dry you can topcoat with the protective coating of your choice. Now having said that the protective coating needs to go with the color you are doing. Finishes such as nitrocellulose lacquer, varnish and oil based polyurethane yellow over time so are not the best choice for light colored woods. On light colored woods, a cab-acrylic lacquer or a water based polyurethane will work better as they won't yellow. Any finish will work fine on darker colors however some are more water resistant than others.What is the best topcoat that I should use over a waterbased dye? I understand your supposed to seal it with shellac first but should I be using afterwards? Lacquer, varnish, poly or is the shellac enough?
No, a barrier coat is used to make a transition between two different products that are to some extent incompatable with each other or as a sealer. If for example the OP used linseed oil and then was going to put a water based polyurethane over the top then sealcoat would be a good barrier between the oil and the polyurethane which are incompatable with each other. Otherwise the linseed oil would have to thoroughly dry before using the poly over it. The sealcoat would accellerate the process as it would adhere to the linseed oil not fully cured and the poly would adhere to the sealcoat.Steve I think he's looking to wipe. Shouldn't you use a barrier coat with that method?
When you use a water based dye, the only thing you need to do is let the water dry out of it. After the water is gone you can finish the wood as though it was never stained except you need to keep from sanding through the finish in between the coats sanding. Any clear coating is compatible with it. If you wish to keep the haziness out of the finish and use lacquer as a topcoat, use a minimum of sanding sealer and build your finish with a clear gloss lacquer. Then when you think you are ready for the finished coat use the semi-gloss. The flattening agents in the lacquer is what makes it hazzy. Don't go overboard making the finish really thick. About 3 mils thick is customary. 3 mils is about the thickness of a lawn and leaf trashbag.The finish I want to apply is fairly dark I believe it is called vintage cherry from general finishes. It is a waterbased dye. I have no problem applying the dye I'm just confused about the topcoat finish, when I should sand and what grit. I'm trying to achieve a semi gloss look without any haziness. I don't know if its my spray technique with the lacquer or the fact that its an aerosol or if spraying lacquer over a WB dye is a bad idea like Julie said. Also I have an earlex spray station but I just felt wiping on a finish involved less skill since I am a very novice finisher.
To tell you the truth I've only used one water based dye and it's been some time ago. The dye I used colored the wood as well as an alcohol based aniline dye. I don't think it wouldn't have lifted with a power washer. It was about 1987 and I believe it came from Star Chemical which is no longer a company. I don't currenty have a water based dye in my shop. Could you try it and let us know if the dye you use lifts easily and let us know. You're right, there is no reason sealcoat couldn't be used and would certainly seal the dye in.Hmm
I would be worried about the pulling the dye right off as soon as it get wet. if wiping or heavy spraying. A seal coat would stop that. It doesn't hurt.
If you spray, there's no problem with the dye lifting off. You should never heavy spray. If you're brushing on the top coat, the longer you wait between dying and brushing the top coat, the less dye will be lifted. Just don't brush it over and over again on the first top coat.I would be worried about the pulling the dye right off as soon as it get wet. if wiping or heavy spraying. A seal coat would stop that. It doesn't hurt.