Stock Lab Rods

The RDS online store only offers our stock lab products. We only ship online orders to the US and Canada. If you need a custom rod please contact us. If you are located outside of the US please contact the distributor in your country (see link above). If we do not have a distributor in your country please contact us directly for price and availability. We can, and do, ship all over the world.

Drawdown Instructions

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SIZE SELECTION

Click a link below for the size selection chart in PDF. Because actual transfer rates are affected by coating rheology, substrate and other variables, this chart is only intended to provide a good starting point for trials. Actual transfer rates can also vary between rod types since the shape of the profile can have a significant effect on coating flow. Also note that the dry coat weight calculations assume a coating density of 1.0 g/cm3.

Lab ROD FAQ

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WHAT ARE THE BENEFITS OF FORMED RODS?

The U-shaped groove of a formed rod cleans up easier than its wire wound counterpart. Unlike wire wound rods, the diameter of a formed rod increases very little from a small groove size to a larger one. Formed rods are generally less expensive at high volumes.

WHAT EFFECT DOES ROD DIAMETER HAVE ON COATING THICKNESS?

None, the coating thickness is determined by the wire (or groove) size.

HOW DO I CHOOSE THE CORRECT WIRE SIZE?

Use the size selection chart to find an appropriate starting point. Perform a test with that size (in the lab preferably) and measure the actual film thickness. Use the actual transfer rate (wire size to film thickness) to refine your size selection.

DOES RDS OFFER RODS FOR MY COATER/DRAWDOWN MACHINE?

RDS can provide rods for nearly any coater or drawdown machine. Simply request a quote and specify the coater/machine make and model.

SHOULD THE ROD BE ALLOWED TO ROLL WHEN PERFORMING A HAND DRAWDOWN?

No, the rod should not be allowed to rotate during a drawdown. Hold the rod steady and pull the coating down the sheet with consistent speed and even pressure.

WHY IS THE FILM THICKNESS DIFFERENT FOR A WIRE WOUND VERSUS A FORMED ROD?

The cavity between wire windings is a V-shape while the formed rod has a U-shaped groove. Coating flows through the shapes differently so the actual transfer rate depends largely on coating rheology.