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frameshop
08-01-2001, 11:06 AM
What is the best time to put on a second coat of paint to get the best bond. I am painting my Haven 12 1/2 with Interlux Brightsides, dark blue. If I wait for it to dry thououghly so it can be sanded, will it lose its ability to chemically bond. If I apply the next coat before it is completley dry I lose he ability to sand????????????????????? any good sugestions out there

dasboat
08-01-2001, 12:10 PM
On Gatsby I wait a day,then instead of overall sanding,I use a scuff pad to break the gloss without removing material.
I have not had the paint fail,although Gatsby is out in the cal.sun alot.
regards,Dasboat

Ross Faneuf
08-01-2001, 02:12 PM
For Brightside particularly I'd just follow the Interlux recommendations. You're not chemically bonding anyway, which is the main reason for scuffing between coats. The critical recoat time is mostly for 2-part finishes, and some etching undercoats. Once again, read the manufacturer's instructions carefully. You can wait years between coats, if you want, with single part polyurethanes; in that case, you sand with, say, 220 mostly to get a clean surface, and to remove any degraded finish. Note the standard Interlux instructions for recoating finishes in good condition is just to sand with 220.

I've found that Scotchbrite purple does an excellent job quickly for scuffing between coats, although it won't flatten the surface the way 220 or 320 will.

PugetSound
08-01-2001, 04:51 PM
What Ross said . . . . the bond between coats is mechanical not chemical. This is why you break the gloss. The big thing to remember is that unless the manufacturer is giving you a specific window (i.e. not less than .... not more than ...) than you are on safe ground by letting the paint cure longer than shorter. Manufacturers give recoat times based upon standard temperature and pressure (70 degrees (F) and sea level). If you are colder, then minimum recoat time will be longer. The worst thing you can do is to recoat too soon. Also, remember that minimum recoat times increase with the number of layers (due to off-gassing).