Have you ever had trouble figuring out the spray speed when coating the internal diameter (I.D.) of a pipe? Don’t worry, everyone has. Many perform trial run after trial run to determine the proper speed to pull back their coating tool. Here we will show you how with a couple of simple calculations and some marks on your hoses as a reference, you can be applying a consistent coating in no time.
In order to run the calculations, you must first determine the flow rate of you coating tool. Use a timer and a measuring beaker to determine the ounces after 30 seconds of spray time. Make sure your atomization air is off when doing this!
Now, using the internal diameter of your pipe, the dry film thickness you wish to achieve, the coating percent solids, your flow volume, and your flow time (30 seconds) you can determine the time it should take for your tool to travel 1 lineal foot. The equation above shows you how to calculate this manually, or you can use our I.D. Coating Speed Calculator here.
Next you should tape off markings every foot on the hose that leads to your coating tool. Now, your operator knows that he should reach each tape marking in about 1.4 seconds (using the default numbers found in on the I.D. Coating Speed Calculator page).