Interior and Exterior Painter in Dunwoody. Professional Painting Company.

What is Mud Cracking

Have you ever done painting or drywall repair work and everything looked good when you were done, but upon returning the next day you were greeted with cracks (like in the picture above)?

This is called mud cracking.  It gets this name because it so closely resembles the cracking mud in a desert or dry river bed.  Ironically, the scientific cause is the same for both occurrences.

The cause for mud cracking is applying to thick a coat of paint, drywall mud, etc.  When you apply a coating at a milage rate that is thicker than for what it was designed, it causes problems as it dries.  Drying is the simple process of moisture leaving the coating.  When a coat is too thick, the outside layer that is exposed to air begins to harden as moisture is still trying to escape from the inside.  The escaping moisture causes the outside layer to expand and crack.  When the moisture get out, this outside layer contracts back to its original size, but the cracking can’t be undone.

Mud cracking is more prevalent in coatings that dry hard with little flexibility like drywall mud and enamels.

How do you avoid mud cracking?

Preventing mud cracking is the easiest strategy.  Be patient.  If the paint isn’t changing the wall color with one “normal” coat, then you are going to have to do another coat.  Trying to pile it on the wall so heavy isn’t going to magically help the paint’s hide.  It will only leave a sloppy, uneven, finish with a high probability for mud cracking.  The same goes for trying to use drywall mud to fix large, deep holes.

I know that us men don’t like reading instructions, but being a real man includes knowing when you don’t know stuff.  It’s like the old cliche` of asking for directions.  I’d rather stop, ask for help, save my time, gas, and stress instead of proving that I’m a “real man” by driving around like a moron for hours.  Also guys, I don’t care if you painted when you were in college 30 years ago.  Just like computers, phones, and cars, technology has also changed paint products.  Read the directions!

How do you fix mud cracking?

Okay.  So someone didn’t follow directions and the mud cracking has already happened.  Here’s how you fix it.

Sand it smooth and touch up where necessary.  This can be more difficult than it sounds.  Drywall mud is pretty easy because it is made to be sanded, however, if you are using an industrial enamel that is designed to be hard as metal, get your power sander ready.  Also, wear safety glasses and dust masks when you sand this stuff.  Breathing all of that crap is bad for you.

I hope that this has answered any questions you have about mud cracking.  Feel free to email us if you need any help.

By 

President of GreenWave Solutions, Atlanta painting company and Dunwoody house painters.  GreenWave Solutions offers painter services in Alpharetta, Atlanta, Decatur, Sandy Springs, Roswell, Brookhaven, Duluth, Grant Park, Inman Park, Buckhead,Milton, Midtown, and more!

CMU wall with Efflorescence.

What is Efflorescence

Efflorescence.  What a weird word.

Efflorescence – ef-flo-res-cence (ef∋ le res∋ens), 1. a change on the surface to a powdery substance upon exposure to air, as a crystalline substance through loss of water. 2. to become encrusted or covered with crystals of salt or the like through evaporation or chemical change.

In English, efflorescence is that white, powdery stuff that you see on masonry walls.  Because this isn’t a chemistry class, we are going to focus on prevention and remediation, instead of causation.

Although efflorescence is ugly and sounds scary, prevention and removal are simple and inexpensive.

How to prevent efflorescence

This is very easy.  Make sure that the masonry substrate is  at least 14 days old.  If it seems uncured or “hot”, wait another week.  Then, prime it using a masonry primers.  Sherwin Williams makes a great product called Loxon Primer.

Once you have primed, simply apply an appropriate top coat and you are done.  If you followed all of the manufacturer’s instruction, you should not have any problems with efflorescence.

How to remove efflorescence.

This is more difficult than prevention, but it isn’t a huge problem.  First off, efflorescence is a cosmetic problem.  It does not degrade the monolithic strength of the substrate.  The efflorescence on the wall pictured above is ugly, but it won’t hurt the wall.  So if you have efflorescence and it doesn’t bother you, leave it alone.  If its unsightliness does bother you, here is how you fix it.

  1. Clean the efflorescence with muriatic acid.  Be careful; hydrochloric acid is nasty stuff.  You may need to dilute depending on the molar strength.
  2. Scrape the efflorescence.
  3. Make sure you have rinsed all of the muriatic acid and allow everything to dry thoroughly.
  4. Prime and repaint using the system described above in the “prevention” section.

I hope that you were entertained while reading this riveting expose` on efflorescence.

GreenWave is also the best interior house painters, exterior house painters, and house painting company and serves Atlanta, Alpharetta, Brookhaven, Buckhead, Chamblee, Doraville, Dunwoody, Grant Park, Inman Park, Johns Creek, Duluth, Milton, Roswell, and most major suburbs.

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Tannin Stain, Painting Company, House Painters, Atlanta, Alpharetta, Sandy Springs, Dunwoody, Brookhaven, Buckhead, Roswell, Marietta, Milton, Decatur

How to Avoid Wood Tannin Bleed from Knots

We completed a project last week that gave us some trouble.  Because this isn’t the first time I’ve seen this problem, I felt that it warranted an article so others can avoid this problem.  The problem is tannin and resin bleeding through knots and “self-priming” stains and paints.

Many of the new paints and stains boast “self-priming” properties.  The selling point is that “it requires fewer coats and products to finish the job so you save time and money.”  While this sounds awesome, it is misleading.

No current product that says “paint and primer in one” or “self-priming” is going to perform as well as separate primers and paints.  For simple applications such as interior painting on previously painted substrates, these products perform fine; but when getting into applications in a more demanding environment, they fall short.

I specifically speaking about wood stains that say “self-priming to prevent tannin bleed.”  My instinct is to ignore these statements and use a stand alone alkyd wood primer or shellac primer on wood, but this time I went just with the stain.  We used package white.  The painters sprayed and back rolled the product per manufacturers’ specifications.  It looked beautiful at first and everyone went home.  When we went back the next morning, every knot on one side of the fence had bled through the stain.

To be fair, this was the side of the fence that had the sun hitting it from first thing in the morning until about 2pm.  This heat causes the tannin and resin to be more active.  However, the data sheet should have said something about this.

I told the home owner I was unhappy with the product’s performance and I wanted to prime and put another coat.  Our client obliged so it time to research.  I have heard horror stories of people applying 3, 4, and 5 coats to still have the knots bleeding through.  I didn’t want to have a story of my own so I got on the phone with technical support.  They told the “self-priming” properties are weak and that it is still advised to prime.

I went with what worked with even the most “knottiest” wood (get the pun? knotty vs. naughty).

Shellac-based primers are the best primers for sealing in stains.  Shellac comes from the lac beetle.  I don’t remember how they beetle makes it, but I am positive that all shellac comes from this little bug.

We see shellac in our everyday lives.  The easiest example is on pills.  The shiny coating on pills or the plastic parts of capsules are examples of “food-grade” shellac.  Now that I provided a visual of what shellac is, it should be simple to see why it is such an effective sealer.

When shellac primers dry, they effectively seal the stain beneath a layer of plastic.

What makes these primers such great sealers is the same thing that makes them ineffective primers for exterior house painting.  Because shellac based coatings create a solid, rigid coating, they are only specified for “spot exterior” application.  This is because of the movement that exterior substrates exhibits due to expansion and contraction from temperature fluctuations.

For this reason, we spot primed the problem knots with an aerosol primer and repainted.  If the bleeding was throughout the wood, we would have opted for an exterior alkyd primer designed for bare wood.

After everything was completed, the fence looked beautiful, our client was happy, and GreenWave Solutions did another good job.  This is why we are consistently rated the best painters in Atlanta.

 

Daniel Macris is the president of GreenWave Solutions for 8 years.  GreenWave Solutions is Atlanta’s First “Green” painting contractor.  We specialized in commercial and residential painting.  We are launching our Atlanta kitchen and bath remodeling division soon!

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