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Post cat lacquer issues9/30
I have used valspar post cat before with good results. But i recently built myself a table and sprayed the top and base with post cat from valspar, adding 5% catalyst to the lacquer before spraying. Sprayed the top and base once with no drying issues. Then did a glaze, sprayed a second coat over the glaze on the base, came back about 45-1 hour later and he finish was still VERY tacky. Never experienced this before so i figured i goofed up and didnt mix right. Proceeded to mix a stronger batch and sprayed the base. Seems fine now? But i noticed about 4-5hours after i sprayed i could scrape off the finish with my finger nail (inconspicuous spots) my question is, is that normal, and im just expecting a harder finish too soon? Or do i have some serious issues?
What do you mean you mixed up a stronger batch? Added more catalyst?
Not familiar with your Valspar product, but usually there is one ratio for the catalyst and it shouldn't be altered.
Also, is the glaze you are using designed for being put in between lacquer coats? Some glazes need to be sandwiched between two vinyl sealer coats.
The lifting off with your fingernail is concerning, it really shouldn't do that. After 45m-1h it should be pretty hard. And you would need to try to get your fingernail under the finish. Not sure if you just did a light fingernail scratch and it came up or if you really dug in.
Yes i added a tiny bit more catalyst as per something i read to try. The glaze is a valspar as well, have used it many times under pre and post cats. It wasnt really a light scrape, i had to add a little pressure. Not just a light rub of a fingernail or anything.
Almost sounds like the 2nd round wasn't catalyzed and you tried to kick it over with a batch of over catalyzed finish.
Sometimes that'll work. Other times......
Let it dry overnight and see if the fingernail test fails again. If it does it sounds like you'll need to strip and start over. If it passes then hopefully it'll stay that way. At least it's a project for yourself. You won't have to explain to a client why the finish is failing on their table.
Yep thats exactly what i was trying...no clue if it'll work, was mostly wondering what people thought about the "fingernail test" what to really expect for hardness and after how long. Yes im very happy this is for myself, still dreading the possibility that i have to strip the finish...but we live and learn i suppose. Thanks! And here's hoping !
I can't say I am a fan of Valspar,
Never use lacquer as a seal coat for glaze. use a sealer.Glaze has a terribly long setting time..and if you used Valdspar's glaze, it has a very heavy hang to it vs let's say Mohawks finishers glaze or sherwin glaze..glaze that's not fully set would/could cause lifting..specially if you use a thick layer.
I don't think it's the lacquer..but never over cat..will cause cracking and many other performance issues
Fair enough, but ive always done this process with good results. I used the glaze as a way to discolour the tinted lacquer, let it hang up a little bit in corners but for the most part i wipe 95% of it off
Fact is, sealing wood with lacquer and applying a product..stain, or glaze then Recoating with lacquer is asking for a bad result..might not be your issue..
In my expertise applying anything on top of a lacquer, like a stain, needs to be mix with a lacquer binder to help adhision between lacquer coats..
I did my antique curio in a dark cherry brown with a heavy hang VB glaze around the counters tops edge..sealed..resealed and applied a T77 F 58 lacquer topcoat x 2 and after curing for 7 days still had chipping around the glazed edge..
In truth we can push/test the limits of the products we use daily without incident..but there is always going to come a day when that push/test will cause a fail in finish
Happy Finishing and good luck in your finishing future
Valspar has a couple different catalysts each requiring a differnt percentage. Make sure the catalyst you are using is being added per the correct ratio as the TDS states. TDS are available from valsparwood.com