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View Full Version : Applying final coats of lacquer after a week long wait



Vespa Bob
02-22-2017, 05:38 PM
In the past, I have always managed to spray consecutive coats of lacquer a day apart, but with the inclement weather we've been having, it's been a week since my last coat. Weather looks good for the next few days, so my question is, since the time delay, do I need to prepare the instrument, apart from a wipe down and blast from my air compressor?

Bob

southcoastukes
02-22-2017, 06:41 PM
Nitro? Nothing special to worry about. A week is no problem for chemical bond - if you want a bit more mechanical bond, just a light fine sand.

Allen
02-22-2017, 08:56 PM
Here's your opportunity to really get that finish right Bob.

I always do my spraying in a couple of sessions. The first one gets the build on the instrument. 4 - 5 very thin coats. Let it dry for a week and it will really shrink back on you. Getting the solvents out......which is really important to get a finish that stays looking good after you've buffed it up.

Then I will sand it back with P800 wet. Lot's of inspection, and be absolutely certain that you don't cut through. When all passes inspection and there are no shiny spots left telling you there is a low spot, you can then spray a couple more thin coats. In the automotive trade it's called a flow coat, and if you are doing everything right it will lay out like glass.

After another week of drying, then it's nothing more than a bit of final sanding with something like P1200 up to P2000 and then a buff.

Vespa Bob
02-23-2017, 06:53 AM
Thank you for your replies, guys. It seems, Allen, that the bad weather was instrumental in me obtaining a better finish than I normally do!

Bob

spongeuke
02-23-2017, 03:16 PM
Unrelated but interesting is that fine Japan Lacquer was accomplished in a high humidity environment (boat in the harbor) that way any particle floating around in the air would latch on to a water molecule and fall out. A clean room hundreds of years BP.

sequoia
02-23-2017, 08:23 PM
When all passes inspection and there are no shiny spots left telling you there is a low spot, you can then spray a couple more thin coats. In the automotive trade it's called a flow coat, and if you are doing everything right it will lay out like glass.

Yup. This is the green light stage. Getting to that stage is the hard part. But if you want a glass finish there is no getting around it. Just when you think you are there... you see shiney spots on sand out. Bummer.. No matter how much you hope they are not there, there they are. Sigh... sand and continue. It will happen. Wet sand at 800 and check it out. Resist temptation to slather on until there are no shiney spots. Your patience is being tested. All clear? Then you can slather on, sand back and polish up. Done. I'm not finishing expert, but patience is the key.

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