The more severe winter months, with days and nights getting increasingly colder, many factors can affect the overall quality of a paint finish. To ensure that a paint system performs as it was designed, PPG Automotive Refinish suggests reviewing these guidelines on storing and using paint products properly.
After a delivery, fresh stock should be put to the back of the stock shelves and also marked with the date of delivery. Although this can sometimes be a bit of a nuisance, especially for large, frequent deliveries, it saves time in the long run by ensuring that the stock is relatively "fresh."
For example, tinters that go on a stirred mixing scheme – the hand or shake stir done prior to placing on the scheme – can be a lot easier with fresh stock. Additional benefits to proper stocking include better color accuracy as a result of more thorough tinter mixing which helps to make sure jobs are done right the first time.
High solids solvent-based products are also more sensitive to lower temperatures than normal solids solvent-based products. Although they will not freeze, the products can rise dramatically in viscosity resulting in several negative effects such as:
• Paint mixing can become more time consuming
• Accurate dosing of tinters to make up colors can be slower and the temptation to over pour increases which could lead to inaccurate color matches or too much paint being mixed up
• Application becomes slower, which can increase material consumption and overloading can occur where popping and/or sagging result when baked, resulting in a complete redo
Even standing a can of clear or hardener on a cool workshop floor is enough to remove the heat from products.
Tin cans are a good conductor of heat (or cold) and this in turn will increase the viscosity. The increase of only a few degrees, i.e. 59̊F to 64̊F can make an HS product apply more like an MS one, giving better application speed, flow from the gun and wetting out – all helping in a superior final appearance. The use of a wall-mounted thermometer is by far the easiest way to check if the ambient temperature for the product you are applying is satisfactory. As always, be sure that the proper hardener and solvent is used for the temperature and the size of the repair.
Correct thinner and hardener?
As always, be sure that the proper hardener and solvent is used for the temperature and the size of the repair. During cooler conditions, your hardener and solvent choices may need to be adjusted to maximize your systems performance. As the ambient temperature decreases, a faster curing hardener and faster evaporating solvent may be required to maintain performance and productivity.
Set spray gun set
Having checked all of the above it is also essential to check that your spray gun is set up correctly for the material being applied. Whether it is a high-build primer, basecoat, solid color or clearcoat, you need to ensure that the needle and nozzle combination is correct and clean and that the fan pattern is even. Check for correct air pressure at the gun handle and not just by relying on the gauge of the wall mounted filter/regulator.