COVERAGE
Solvent-Borne Contacts
- 2 to 2.5 dry grams/square foot per surface.
- 2 dry grams/square foot = 275 to 355 square feet/gallon per surface (at 18-22% solids).
- 2.5 dry grams/square foot = 219 to 268 square feet/gallon per surface (at 18-22% solids).
Water-Borne Contacts
- 3 to 4 dry grams/square foot per surface for porous substrates.
- 2.5 to 3 dry grams/square foot on other substrates.
- 2.5 dry grams/square foot = 735 square feet/gallon per surface.
- 3 dry grams/square foot = 613 square feet/gallon per surface.
- 4 dry grams/square foot = 459 square feet/gallon per surface.
COVERAGE WEIGHT CHECK
A balance is needed (Ohaus triple beam model 750-50(approx. $65) available from Ohaus Scale Corporation, 29 Hanover Road, Florham Park, NJ 07932, Phone 201.377.9000) or any balance accurate to o.1 gram.
A. Cut out a 12" X 12" metal template (thickness 1/32" or more). Wrap with aluminum foil and tape it to the back side. Weigh it. Coat the untaped side, dry and reweigh. The difference between the second weight and the first is the coating weight.
B. Use a 1-foot-square piece of metal or HPL. Weigh it. Coat with adhesive, dry and reweigh. The difference between the second weight and the first is the coating weight.
GAP SETTING
For non-compressible materials such as wood, metal, HPL, particleboard, or sheet plastic:
Set at total thickness less 0.125".
For compressible materials such as beadboard, foamed polystyrene, or urethane foam:
Set the total thickness less 10% of the thickness of the core (foam) thickness.
Example: Metal Faces (2) are 0.020" each. Foamed polystyrene is 1" thick.
Setting: (0.020" X 2) + 1.000" - 0.100 = 0.940"
The Gap setting for honeycomb depends on the type of honeycomb involved and whether the cell edges are crushed or not. The setting will have to be determined experimentally. The aim, of course, is to make complete contact without distorting the honeycomb.
GROOVING FOR ROLL COATING
Solvent-Borne Contacts
1/2 X 10 will deposit up to 9 wet mils.
1/2 X 14 will deposit up to 6 wet mils.
Water-Borne Contacts
1/2 X 14 will work but will deposit adhesive in ridges.
1/2 X 20 is preferred for general purpose application.
1/2 X 28 is best for beadboard to deposit smooth, even coat over the entire surface and minimize distortion of bead board in the oven cycle.
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