Paint viscosity increase after mixing other components.

CAUSE:

1)wrong hardener

2)wrong hardening ratio

3)over pot-life time (see technical data sheets)

4)high temperature

REMEDY:

1)change hardener

2)follow carefully technical data sheets instruction.

3)the paint is not anymore applicable.

4)add thinner to improve pot-life (use slow thinner).

Poor adhesion between wood and paint or between two coats.

CAUSE: between wood and paint

1) Main caratheristyc of the panel (paper, exotic wood, plastic laminates, etc).

2) Wrong sanding (good adhesion is also coming from physical effect) between two coats.

3) Sealer too hard because of a fast cross-linking, or because of a catalyst (too slip surfaces are not giving a good adhesion)

4) Too much time between the coats. The base-coat fully cross-linked doesn't give an easy over-coat.

REMEDY:

1)Every surface has to be carefully examined. Ask to the lab the best cycle to be used.

2)Check the sanding and control the type of sand-paper.

3)Note the cross-linking ratio reported on technical data sheets. Change sand-paper.

4)Sand between each coat in order to improve adhesion by physical effect.

During curtain application, the curtain brakes often with no paint on panel consequently.

CAUSE:

1)Too low viscosity. Paint diluted too much.

2)Silicon products presence

3)Curtain coater head to adjust.

REMEDY:

1)Add pure paint to reach the correct viscosity.

2)Check components and replace wrong product.

3)Adjust curtain coater head. In order to maintain the quantity applied, speed up the belt.

White haziness of the paint film which looses transparency.

CAUSE:

1) Strong room humidity. The problem happens more with nitro-varnishes because of a condensation of humidity on the panel. The condensation is due to a panel temperature because of a fast solvent evaporation.

2) In the polyurethane system the whitening could come from:- wrong hardener;- not compatible hardener; - too high film thickness.

3) High moisture into the wood or too much glue which is not compatible with paint.

REMEDY:

1) Use air-conditioned into the room. Use slower solvent.

2) Sand as you reach the wood (or use a remover), than re-paint the manufact.

3) The product on a surface with the right humidity. Sand as you reach wood.Before re-paint you should apply the right insulator.

When the drying time is not the desired one. The main factors are:

1)Temperature 2)quantity of applied paint 3)hardening 4)vapour solvent concentration 5)support (wrong or cold or dirty)

CAUSE:

1)Panel too cold (below 18°C)

2)Wooden moisture too high (over 14%)

3)Natural wood substances (specially in exotic wood)

4)Presence of retardant products

5)Low surface temperature

REMEDY:

1)Heat the panel

2)Dry the wood and/or apply insulator

3)Apply one or more coats of insulator.

Paint film dropping

CAUSE

1)Too much paint applied

2)Too slow thinners

3)Too low viscosity

REMEDY:

1)Reduce paint quantity

2)Use faster thinner

3)Increase air pressure in the spray-gun and pass two times with smaller quantity.

OVER-COATT (removal)

Paint film swelling due to a solvent attack.

CAUSE:

1)Sealer not fully dried

2)Sealer has not good adhesion on support

REMEDY:

1)Verify all factors playing on the drying of paint film.

2)Verify all factors playing on adhesion of sealer on the wood.

Air into the paint film due to spray application or slow solvent evaporation

CAUSE:

1)High room temperature or paint film too thick.(when the film is "closing" the upper side the solvent stay inside and creates bubbles.

2)Too high viscosity (bad solvent release)

3)Use of cheap thinner

4)Forced air after application too strong.

REMEDY:

1)Reduce paint applied. Add thinner to slow down the drying time

2)Cut viscosity with correct thinner

3)Use correct quality of thinner

4)Slow down the forced air and (if possible) use right thinner.

Paint film defect because of dust or micro air-bubbles. (easy to get after sanding the sealer or in matt-finish after drying).

CAUSE:

1)Too much paint applied in one coat. (the air cannot comes out easy).

2)Too fast drying because of thinners (fast cross-linking).

3)Using cheap thinners which contains impurities.

REMEDY:

1)Reduce quantitaty of applied paint.

2)Use slow dry thinner so the air can easy goes out.

3)Use the suggested thinners (see technical data sheets).

The paint doesn't cover properly the back of the objet durign electrostatic application.

CAUSE:

1)Bad conductivity

2)Too high conductivity

3)Solvent mix too fast (fast evaporation during spray)

4)Too high viscosity

5)Too low humidity of the objet (below 10%)

6)Too high room humidity (over 90%)

7)Bad electrostatic equipment.

REMEDY:

1)Use additives to improve conductivity

2)Change paint

3)Use retardant thinner

4)Reduce viscosity by thinner

5)Treat the wood to get the right humidity (10-40%)

6)Reduce humidity in the hair (air-condition)

7) Check with the equipment supplier.

Usually this defect appears after some days. More evident on dark wood. It involves the pores because the paint has not enough wetting properties and it appears a silver-tone near by the pores.

CAUSE:

1) Negative reaction between natural wood substances and paint (often polyester based) Silvering appears near by the pores.

2)Poor paint wetting of the pores (specially on hard wood).

3)Humidity of the pores with poor paint wetting.

REMEDY:

1) Apply an insulator in advance in ordere to have a barrier between wood and paint.

2)Apply insulator to wet the pores or change sealer.

3)Heat the panel in order to evacuate the humidity.

The paint isn't wetting the wood.

CAUSE:

1)Paint not designed on that wood type

2)Too high viscosity (spray and curtain)

REMEDY:

1)Change product

2)Dilute properly.

Texture-like, hammer tone finish.

CAUSE:

1)Wrong thinners in quantitay or quality

2)Wrong spray application; spray-gun too far from panel air pressure too high; spraygun holes too small.

REMEDY:

1)Follow technical data sheets instructions.

2)Use retardant thinners and pay attention to the application requirements.