Product Information Bulletin:
Use of LT-5 Lacquer Retarder
& Flash-Off Control (IBIB)
The primary reason for using nitrocellulose lacquers and sanding sealers is that they provide tough, clear protection with a very rapid dry time. Many of the application problems encountered when using these products revolve around this rapid dry and may be eliminated or counteracted by use of LT-5 Lacquer Retarder.
Nitrocellulose lacquers and sanding sealers dry by evaporation. This process means that the first dry will occur at the surface; the lacquer will skin-over. Under conditions of high humidity water vapor may enter the drying film by the atomizing air from the spray gun or it may condense into the film due to the chilling effect the rapidly evaporating solvents have on the ambient air. Cold, damp air will present a greater problem than warm, damp air for this reason. Under conditions of high heat the same surface skin will form very quickly and, possibly, to such an extent that it will be too thick to allow the evaporating solvents below to break the surface.
Moisture Blush will appear variously as a cloudy or milky film; it may have an iridescent rainbow sheen, or the film may be flat, regardless of the specified gloss rating. Heat-bubbling will appear as many thousands of closely packed bubbles that are so small that they may not be visible to the naked eye. Some of these bubbles may have partially broken the surface to yield a pebbly texture and appearance. Both problems will be more severe in those areas of greater coating concentration such as edges and tight moldings.
The best method of control for these problems is prevention.
Under the conditions mentioned above, when problems are likely, the addition of two fluid ounces of LT-5 Lacquer Retarder per gallon of reduced lacquer will prevent either problem from occurring. In extreme conditions, this ratio may be increased to four fluid ounces per gallon, however, at this level, the drying time will be noticeably slower and may affect production schedules.
When moisture blushing or heat bubbling has unexpectedly occurred, one of two methods may be employed to correct the problem. On the piece where more coats of lacquer or sealer are to be applied the addition to the next coat, of four fluid ounces of LT-5 Lacquer Retarder per gallon of coating , as above, will effectively remove the blush or bubbles from the lower coat(s). On pieces where finishing has been completed, a mixture of 75°- LT-3 Lacquer Thinner and 25% LT-5 Lacquer Retarder applied as a mist coat will, likewise, eliminate the problem. The above mixtures may also be used to abate minor orangepeeling problems.
DO NOT use more than 6 fluid Oz.
DO NOT use more
Wood Finish Supply
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