String Theory

Feb 3 2014

Written by John Ball in Asphalt Pro Magazine

My paving crew will agree that marking out your boundaries before milling or paving is important. In this article, we’ll take a look at how to mark the job correctly so that the whole project flows more smoothly. Lining out the first pass is vital because it sets up the subsequent passes for success or failure. 

The images in this article show the APAC South crew preparing for the first pass of open-graded friction course (OGFC) for the surface course of Alexander Street, which is a new construction of full depth asphalt in Florida from the summer of 2013. There are three more passes after this one. By lining out this first pass correctly, with straight lines that start and stop where they should, the crew sets itself up to line out the next pass and the pass after that correctly as well. But if the crew makes a mistake or does sloppy work on this first pass, the mistakes will carry through the job with a domino effect.

There’s a lot to marking line that you wouldn’t think of unless you’ve done it before. You can’t send the new guy out there with a can of paint and expect him to create a flawless pattern for your paver operator to follow. In fact, the crew members in these examples have worked together for a few years now and help one another learn proper techniques. A team member who has a couple years of experience can teach a new guy how to line out a job in less than a day; then they can work together to hone the new employee’s skills.

Normally only three workers mark the lines and that is sufficient to get the job done correctly and efficiently. You’ll see in these examples that the APAC crew worked in a closed work zone and had seven workers marking lines because we had two sections of the project being marked at the same time.

Keep in mind that your company can subcontract the marking. Oftentimes, the subcontractor who will do the striping at the end of the job is asked to mark out the project as well. Only the bigger striping companies are going to have the arsenal of equipment required to do marking of lines as well as striping. These different applications require different nozzle tips and spray widths for the paint guns or walk-behind paint machines. They also use different types of paint. Striping paint will last a long time, even through rain, because it’s permanent paint. Your marking paint doesn’t need to be permanent, but it does need to be vibrant. For daytime milling or paving, I recommend red or pink paint. For nighttime milling or paving, you want  207white ground traffic paint because you can’t see the red or pink.

The brands of paint I typically recommend are Aervoe from Gardenville, Nevada, and Krylon from Solon, Ohio. They come upside down. They’re 17 ounces each. You can get paint anywhere, but this is special paint and has a special tip. It’s not for painting sideways. It’s for painting upside down. When you put the paint can into the marking stick, it has the knob on it with a trigger and it paints. Usually, the marking stick has a wheel on it, but you’re not always on a flat surface when you’re marking out a job. That’s the first thing we throwaway when we take it out of the box. I don’t know how many times I’ve been out in the field and I’ve seen guys with-out the marking stick. They just bend over and spray the line. That’s crazy. They need the marking stick to sight the line. You cannot mark a line bending over for any distance. You want to have one of these marking sticks to get a straight line and save your back.

The most difficult part of marking out the lines is going around comers. Think of the tum like a jump rope laying on the ground rather than a right angle. You have to put the string down in that u-shape for the comer for the curve. You need more than one worker to get this maneuver right. Think of it as painting a radius that’s why you have a couple of workers to help you. One worker holds his position at the beginning of the tum; one worker holds his position at the end of the tum. The third worker lays the string in the ushape- or semi-circle- between them and paints the line along the string.

Once the crew has the first pass lined out with string and paint, the team members can prepare the second, third and subsequent passes. Because they judge where the subsequent passes begin and end based off the initial measurements and lines, that first pass must be perfect. Make sure you use the right tools for the job and employ best practices to get it right for a top quality pavement. ~

 

John Ball is the proprietor of Top Quality Paving, Manchester, N.H.
For more information, contact him at
(603)493-1458 or tqpaving@yahoo.com.

 

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