Any concrete stamper who has been in business for awhile has had to deal with surface crusting. This is a situation where the surface dries out before the concrete underneath. It is typically caused by a combination of wind and sun, and creates a big problem for the stamper. The problem is that with each placement of a stamp (particularly those with a deep profile) a tension crack occurs around the edges of the stamped joints, or sometimes in the middle of a stamped stone. Although these cracks are usually only cosmetic and not a structural problem, they are unsightly and can cause a customer to balk at paying for the job. It is best to avoid surface crusting in the first place by utilizing liquid evaporation retarders. These are products that when sprayed on the floated slab, form an invisible film which inhibits premature moisture evaporation. However, sometimes no matter what you try, difficult situations arise and you are left with surface cracks. There are a couple of ways to deal with these cracks. The first is to take care of them while stamping. The other is to go back another day and fill the cracks. Both procedures are acceptable and have their places. If my crew and I have time to fix them while out on the stamps, we prefer to do it that way. Sometimes, however, we are under the gun and don’t have the time to fix them while stamping. In this situation, we know we can get them later. To fix the cracks while stamping, you will need to acquire a specialized tool. This inexpensive tool can be found at any hardware or paint store. It is simply a 2 inch fuzzy paint roller and frame. You can carry it in your back pocket while stamping, and whenever a crack appears, you just use the dry roller to close it up. By rolling the fuzzy roller across the crack, you can push it back together without marring the surface. Use only enough pressure to close the crack. To fix the cracks another day, wait until you have swept the slab and washed off the excess release agent with a garden hose. Don’t worry about being too thorough, as this is not the final cleaning. When the slab is somewhat dry, mix up a slurry of color hardener and acrylic concrete fortifier. If your color hardener is too coarse, before mixing, remove the large sand particles by sifting through a piece of nylon pantyhose, cloth, or fine mesh screen. After mixing the slurry, work it into the cracks with either a sponge, small hobby paint brush, or simply a gloved finger. Use a dry rag to pat a little release agent on the patch. After the patch has set thoroughly, finish cleaning the slab and seal as normal. Using these methods, you can repair the majority of surface crusting cracks. Although some of them may still be slightly visible, they will not be open and waiting for the customer’s criticism. Steve VandeWater ArtistiCrete LLC, Noblesville IN www.4greatconcrete.com Copyright © 2005 Decosup Inc. All rights reserved. No portion of this article may be reproduced without the express consent or permission from Decosup Inc. | Home | Products Page | Decorative Concrete Gallery | Training | Technical Data | About us