Sticky lacquer even after days left to dry - help...

[CalinB]

Hello,

I am a small business owner (coffee corners).
I make most of the furniture in our coffee shops.

My newest project involves a lot of plywood with matt lacquer finish.
Even though I let the surface dry after I apply the lacquer it still feels a little sticky days after.
If I have to put an espresso machine on top, it gets stained really bad.

What am I doing wrong?

I use water based lacquer.


Thanks in advance for any tips.

[FenceFurniture]

Hello,

I am a small business owner (coffee corners).
I make most of the furniture in our coffee shops.

My newest project involves a lot of plywood with matt lacquer finish.
Even though I let the surface dry after I apply the lacquer it still feels a little sticky days after.
If I have to put an espresso machine on top, it gets stained really bad.

What am I doing wrong?

I use water based lacquer.


Thanks in advance for any tips.

Welcome to the forum Calin.

Is the lacquer fresh or old? Could there be something on or in the plywood that is interfering with the lacquer?

[CalinB]

Hi,

Lacquer is fresh and the plywood is just bought from Holver (huge wood products retail and whole seller).
One suggestion I got is that the plywood doesn't have as much absorption power as regular wood and I should both apply a thinner layer of lacquer and wait longer between layers. Still, it seems to much time to wait. Between 5 and 7 days is what I've noticed so far, from first coat until the surface is 100% dry.

Is there any other, faster solution, to finish the plywood?
I just want it to be protected, not get stained and keep it's natural look.
Oil?

[justonething]

I have no practical experience with water based lacquer. But reading some of the available product description. It says that it takes 14 days to fully cured. Which to me full hardness is not achieved for 14 days. But it shouldn't be sticky. How did you apply it? It's meant to be sprayed on only, with re-coating to be done within 2 hours.

[FenceFurniture]

..reading some of the available product description. It says that it takes 14 days to fully cured. Which to me full hardness is not achieved for 14 days.

Fully cured would just be that last little bit of hardness, not dryness.

One suggestion I got is that the plywood doesn't have as much absorption power as regular wood and I should both apply a thinner layer of lacquer and wait longer between layers.

If that was the case then then second and subsequent coats would take even longer to dry (as the surface would have much less absorption after the first coat), so to me, there is a logic flaw there.

I've used waterbased Polyurethane extensively (brushed on). It is touch dry within 4-15 minutes depending on the weather. After I have put say 3 coats on (all in the same day) and it's dry the pieces cannot be placed on top of each other for quite some days because they will stick to each other - and that would go back to the fully curing - but there's no stickiness as Calin is describing.

I can only suggest that the product may be faulty, and perhaps try another product. If that works then take the original back to the vendor (perhaps with a sample of what happens).

Water based PU would be an excellent choice - I have used it on my shed floor and it takes a beating. The drops that get in the rim of the can dry extremely hard.

[A Duke]

Hi,
What is the temperature like? I left a water based paint job to dry on top of a chest freezer over night and it did not dry at all. It was dry with in half an hour of moving it else where.
Regards

[Big Shed]

All water based coatings have a Minimum Film Forming Temperature (MFT), usually 12-15C, this is the temperature the substrate and/or the air temp. should be above

Below this the polymer in the water will not form a film (coalesce) they stay as discrete bits.

Normally manufacturers specify this MFT in their product instructions.

Considering this is being used in a commercial environment I would suggest that any water based coating won't be as hard wearing as a solvent based coating.

[FenceFurniture]

Not strictly related to this thread Fred, but if I had to apply a water based paint or lacquer, and wanted to recoat asap, could I use a hot gun gently, or is there a time requirement as well? Say on a piece that just needed the protection rather than a visual finish.

[Big Shed]

It is a time/temperature thing Brett, normally manufacturers specify a temp of, say. 15C, for 4 hours. This can be longer at high relative humidity.

Most paint manufacturers publish info on this subject, here is one from Solver Paints

https://www.google.com.au/url?sa=t&r...3v8sugpMOEeVsg

Resene has one as well.