Page 9 - Combined_3_OCR

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Spraying Operation

1. Cleanliness is a most important requirement for this process. This
includes the surface to be sprayed and the working environment as well
as the equipment.

2. Before spraying, heat both components with a heat exchanger or with
heat-traced lines, to 120°- 150°F. The materials must be in this
temperature range before they reach the gun.

3. During application, follow instructions of the gun supplier for manual
operation of gun.

4. If color shade of the foam changes markedly, c n top spraying immediately
and check metering pumps, material supply and the spray tip.

5. Do not spray solvent on the foam.

6. Use small brush to clean the tip face while operating. Vo not aAe.
m^tatttc. AoAapeA.

7. If spraying is interrupted for 10 minutes or more, remove and clean
the gun tip.

8. Caution: when replenishing material supply, make certain the ”R and
”T” components are connected to the properly identified lines of the
spray equipment. Drums of both components should be replaced simul­
taneously, in pairs.

Spraying Technique

1. For general spraying, the gun-to-work distance should be approximately
40”...36” minimum; 48” maximum. If the gun is crowded too close to
the surface of application, excessive bubbling and running will occur.

2. When filling large areas, seal joints first and use short strokes back
and forth between fillets for the most even and satisfactory results.

3. Avoid building up specific areas by dwelling in one place. Move the
spray gun at a moderate, even pace using approximately 3-4 foot strokes,
and apply spray at a uniform thickness, keeping the gun at an even
distance from the work.

4. Vo not appty thz ^oam tn a hzcwy &tngtz-paA& appttcatton as this produces
low foam densities with undesirable cell configuration. Such foams have
a tendency to shrink at low temperatures due to their relatively poor
strength properties as measured across the direction of foam rise.
Each pass of the gun should overlap 80% of the leading edge of the
previous pass.