Note: these archives were compiled from past Parking Lot Planet Forums. The answers and opinions are those of the posters. Things may have changed since then, so be sure to get up to date information from the current Parking Lot Planet forum

 

new asphalt

From: cary
Date: 5/8/00 11:38:24 PM
How long does new asphalt need to set before striping it. I plan on using chlorinated rubber paint and putting two coats.

 

From: Bob 
Date: 5/9/00 7:11:50 AM
Cary, Regarding how long before working on asphalt. I would wait until the asphalt has had a time to cure, at least time to cool down to the surface temp is that of the other surfaces, at least 48 hours. The fed says that asphalt must set for 30 days before any paint is applied. Hope this helps. Bob

 

From: Wait a minute
Date: 5/9/00 9:01:40 AM
Please DO NOT use solvent based (such as CR or alkyd) on new asphalt. Use only latex or acrylic waterborne paints. Take it from an asphalt contractor, asphalt is made of oil and the solvents in oil based paints dissolve the light asphalt oils in new asphalt. 2 thin coats are better than 1 thick coat and you only need wait about a day or until the asphalt has fully cooled. If you can wait 3-4 days or more the new asphalt will "track" less onto the paint.

 

From: Robert Liles
Date: 5/9/00 11:15:18 PM
I’ve heard that about oilbased and new asphalt for years, but we often use CR on fresh asphalt, like when part of a shopping center is overlaid during the day and we have to stripe it that night so that it can be opened to traffic the next morning. I usually warn the owners that the paint may not appear as dense as it should, but I can show you examples where we did this and had no adverse effects. The paint may appear a little light at first, but it has held up as well or better than jobs when we were able to wait several days before striping. Don't thin the paint, don't put on more than the recommended amount, and don't use cheap, slower drying oilbased paints. One key to avoiding discoloration is to have the paint dry quickly, so that there is little time for the solvents to react with the asphalt.

 

From: Don
Date: 5/10/00 8:40:32 AM
The problem with new asphalt and oil based paint has nothing to do with the performance of the paint. The Chlorinated Rubber or oil base paint will be fine, it's the asphalt that suffers. Check back on one of those lots done the same night with a solvent paint and you will most likely find a hairline crack down either side of the stripe (or similar related defect). The recommendation about latex comes from the asphalt industry not necessarily the stripers (we do both).

 

From: Robert Liles
Date: 5/10/00 7:18:20 PM
Like I mentioned, use premium, fast-drying paints to minimize the reaction time between solvents and the fresh asphalt. Most if not all parallel cracking is caused either by paint shrinkage during drying (paint that has been thinned, or cheap low solids paint) or by the temp difference between the light colored painted area and the black, heat absorbing asphalt.

 

From: wiat a minute II
Date: 5/28/00 10:52:23 AM
I have been striping for 17 years and we only use oil base paints on new asphalt AND HAVE HAD NO PROBLEMS , its a lot more durable than latex paints.

 

From: ohio joe
Date: 5/10/00 11:20:36 PM
I have seen the articles on how long to wait before striping. However most of my asphalt paving customers do not share the "wait 30 days" precautions. I regularly follow the rollers out of the parking lot to meet their schedules: (DO IT NOW!) I use SW alkyd product 90% of the time and I do notice occasional pavement 'irregularities' a few years later. But most of my clients 1) will not wait for the blacktop to cool or cure sufficiently 2) do not pay for two coats of latex when one coat of oil will work 3) want traffic or parking delayed any longer than they determine necessary

That being said, I have never had a complaint from striping too soon, except from my workers who sink into the lot and burn their thumbs holding a chalk line.

 

New Asphalt(again)

From: broncobilly
Date: 5/18/00 9:39:33 PM
We have always used alkyd oil on new asphalt construction. However, for many reasons we have decided to switch to only waterborne(weather permitting) for all surfaces. I have seen the "cracking" which occurs with oil on new asphalt. I was very surprised to see that waterborne had the same effect on a recent job, and it had appeared by the next day, not months or years later. I applied two coats, one at a normal rate, the second a quick thin coat. We painted about an hour after the pavers had finished; the temp was about 80 degrees and no humidity, very sunny. I have always heard that latex is the way to go yet why these results? Fortunately, the paver did not notice/care or he is used to these results, because he did not mention it. However, I want to keep this from happening. Plus, I would like to stick with waterborne. I'm guessing we were too quick to follow the pavers, yet that was their choice. Any comments?

 

From: Robert Liles
Date: 5/19/00 6:30:52 AM
It was probably caused by shrinkage of the paint film as it dried. Check the solids content of the paint and compare it to other brands or types. The shrinkage is caused by evaporation of the solvents, and in general, the higher the solids content, the less shrinkage. This would apply regardless whether it's oilbase or waterbase.

 

From: broncobilly
Date: 5/19/00 7:09:33 AM
Does anyone else get these results from Sherwin Williams setfast 1952? Or could it be that my particular batch had a high solids content? Thanks - billy.

 

From: Don
Date: 5/19/00 9:42:29 AM
That’s what we use with no problems. If you have to get on the pavement while it's still warm (it's much better to come back later when it's fully cooled)do it the other way. 1st coat thin and quick... second coat a little thicker. On fresh warm pavement you can't get as thick as normal at any rate because of the rapid shrinking caused by the heat. If you don't normally thin we have also found it helps to thin a little with water in that 1st coat. SW acrylic 1952 is our "paint of choice" for new asphalt...never any problems and very long lasting.

 

From: broncobilly
Date: 5/20/00 12:08:23 AM
such a coincidence - tried it quick and thin and then back with a regular coat. I'll tell you the results on Monday. Thanks again- Billy

 

From: Don
Date: 5/19/00 9:43:21 AM
That’s what we use with no problems. If you have to get on the pavement while it's still warm (it's much better to come back later when it's fully cooled)do it the other way. 1st coat thin and quick... second coat a little thicker. On fresh warm pavement you can't get as thick as normal at any rate because of the rapid shrinking caused by the heat. If you don't normally thin we have also found it helps to thin a little with water in that 1st coat. SW acrylic 1952 is our "paint of choice" for new asphalt...never any problems and very long lasting.

 

From: Bob
Date: 5/19/00 3:53:37 PM
Robert & Don are correct in what I have read. I use SW and have not had this problem yet, Robert explanation about the paint is what has been explained to me that causes the cracking. Bob

 

From: ohio joe
Date: 5/19/00 4:17:33 PM
I use SW A300 alkyd paint on all my new asphalt jobs. But I use SW TM226 acrylic when I have to paint a blue background under my handicap stencil. The latex has a LOT more cracks and fissures than the oil paint. People tell me to switch to latex, but after seeing these results, I would still use oil and one coat, than two coats with latex.

 

From: Bookman
Date: 5/20/00 6:53:08 AM
It's always wise to DISCLAIM DISCLAIM DISCLAIM the request of the people you work for. . .just in case. Physics was never my strong point, but is there by any chance a synergism whereby the relative coolness of the paint also causes the hot pavement underneath the cool paint to cool faster than the unpainted pavement and thereby cause contraction? Could this be what attorneys refer to as a contractual relationship?

 

From: straight line
Date: 7/24/00 10:57:02 PM
I use cr from standard paint in Dallas, we paint right behind the roller and have no problems.