DEFINITION ALLIGATORING : You can almost imagine what this is by the name. If you can’t, it’s basically what happens when the paint cracks in such a way as to form a pattern that resembles alligator scales. It can sometimes just be affecting the top layer of paint and not be reaching the surface.
WHAT CAUSES IT?
There are a number of possible causes and I’ve listed them below:
You may have painted over a glossy finish and the paint wasn’t able to bond with it properly.
Using an extremely hard coating, such as oil-base enamel, (this dries very hard eventually), over a more flexible coating. The flexible coating can shift or expand and contract underneath the top-coat and cause the top-coat to crack.
The effects of extreme climates (freezing and thawing) on oil-base enamels over time.
Putting another coat of paint on before the previous one has dried. (Yes, I’m sure many of us have done that at some point!)
Using too much paint per coat.
SOLUTIONS:
By one means or another (scraping, sanding, paint remover) or a combination, get the paint down to the bare surface.
Brush or vacuum off all the dust and make sure the surface is clean and dry.
DEFINITION TANNIN: Okay, right from the start I suppose I should tell you what Tannin is. It’s something you’ve probably seen, a tan or brownish discoloration on the paint surface that the paint just won’t cover up. Here, courtesy of Wolman Wood Care Products is probably the best definition of tannin that I‘ve come across:
Tannin (or Extractive) Bleeding: Redwood, Cedar and Douglas Fir are examples of wood species that contain naturally occurring, water soluble chemicals that tend to migrate to the surface with exposure to extracting agents such as water. After rain or heavy dew, coffee or tea-colored stains may appear on the wood surface. If the wood is coated, discoloration of the coating may occur when tannin extractives are dissolved into the coating solution by water, reach the surface and remain as dark, coffee-brown stains after the water evaporates. This reddish-brown bleeding is unsightly, but not damaging to the coating.
SOLUTION:
As in many paint problems moisture is sometimes an issue and it certainly contributes to the tannin problem – - so look for and correct those. Get that surface as dry as a bone!
You can remove the existing stains with oxalic acid. Just Google oxalic acid and you’ll find information about it and products that contain it. It’s basically wood bleach.
Next you should rinse the wood off with a pressure washer. You can rent pressure washers from Home Depot’s that have Tool Rental departments.
Let the surface dry completely.
Then, I recommend using Dunn Edwards Premium E-Z Prime (W708) – Acrylic Wood Primer to prime the surface. This will really help to prevent stains from bleeding through. If the stains are severe I would suggest two coats of primer.
Final coat with high-quality paint in the finish you want.
This should handle most stain problems. However, it’s possible that some bleeding my happen within a year after you’ve painted the wood. Don’t repaint it as soon as this occurs. Wait a full year as this will let any remaining tannins to come to the surface where they will weather away naturally.
I’m sure many Do-It-Yourselfers have experienced this the first time they attempted a painting project involving the painting of walls or ceilings. You end up with areas on the wall where the paint seems to be darker than other areas, somewhat resembling the “frame” of a picture. It’s particularly noticeable when you’ve been painting the walls of a room and you’ve gone around the room and cut in the corner edges and ceiling line with a brush prior to rolling. The brushed areas can sometimes end up looking slightly darker then the rolled areas and there’s your “picture frame”.
WHAT CAUSES “PICTURE FRAMING”?
It’s most commonly a coverage problem. If you’re brushing and rolling, the brushed areas tend to have a thicker paint film than the rolled areas.
HOW DO YOU PREVENT IT?
First, make sure you’re putting on an even coat when you’re brushing and rolling as that will help keep the look uniform. Next, I would highly recommend painting one wall completely before moving on. Pick your starting wall and cut in the corner edges and ceiling line (if walls are a different color than the ceiling) with a brush and then roll the whole wall out. As an added safety I roll as close to the edge as possible with the roller leaving the minimum of brushed area showing. When that wall is done proceed to the next wall and continue around the room in this fashion. This keeps you moving from “wet to wet” as we say in the biz. That basically means the brushed areas haven’t had a chance to dry and set up before you roll the wall out.
Once again, I hope this information has been helpful and I look forward to sending you more painting tips.
Another fabulous tip from my good friend, Perry Martin, professional painter in Orange County, California. Here he gives you a full rundown on “blistering”:
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Here’s something you’ve probably seen, or even experienced yourself when trying your hand at painting – - blistering. That’s where the paint looks like it has bubbles or blisters in it. This is usually caused by heat or moisture.
CAUSES:
It can sometimes be caused by painting in direct sunlight or applying paint to a surface that is too hot.
If you’re using oil-based paint over a damp or wet surface it will also blister.
Exposure of fresh paint to high humidity, dew or rain.
Possibly moisture coming through interior walls from areas such as kitchens, bathrooms or laundries.
HOW DO YOU HANDLE IT?
There are two different ways to handle this problem depending on whether it’s caused by heat or moisture. So, the first thing you will need to do is determine which of the above is the culprit. You do this by peeling off and examining the backside and the surface of the blistered paint. If only the most recent coat of paint is blistered then it’s most likely that heat is the reason. If the peeled blister contains several coats of paint, and you’ve peeled down to the bare surface, it’s probably moisture related.
BLISTERING DUE TO HEAT:
Scrape and/or sand the blisters down to the underlying, sound coats of paint or primer.
Repaint the surface with a high-quality paint, in the desired finish (see Volume 2 for advice on types of sheen) and make sure the surface temperature is below 90 degrees.
BLISTERING DUE TO MOISTURE:
Do what you can to improve the room ventilation if it tends to be a moisture trap. Re-caulk any areas you suspect moisture may be entering from, as necessary, to prevent future moisture from getting in.
Scrape and/or sand the blisters down to the bare surface.
Prime and repaint with desired finish.
Voila! That should pretty much handle it!
Once again, I hope this information has been helpful and I look forward to sending you more painting tips.
Perry Martin
Professional Painter – Orange County, California
Perry’s email: perry801@hotmail.com
Here’s a very informative description of the various types of sheens available when selecting your paint. Professional painter, Perry Martin, in Orange County, California has done a fabulous job in outlining these options.
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High-Quality Residential Interior and Exterior Painting
In this volume we’re going to explore the various finishes paint comes in, where they are most commonly used and the pluses and minuses of them.
What Is Sheen?
I’m sure you’ve heard the term “sheen” before. Quite simply it refers to the shininess, or lack of, of the various paint finishes. There are five basic sheens that paint comes in, although different paint companies tend to vary these sheens somewhat. (Wish they wouldn’t do that!). They are Flat, Eggshell, Satin, Semi-Gloss and Gloss – - or High-Gloss as it is sometimes called. There are practical reasons for the various sheens, as well as aesthetic. In recent years the aesthetic has sometimes won out over the practical, particularly when someone is going after a certain “look”. I’m not saying this is right or wrong but, as you’ll discover in this article, there are definite advantages to keeping the practical aspect in mind. Okay, let’s have a look at these finishes.
FLAT:
As its name would suggest this finish has a smooth, dull, non-shiny appearance. It’s commonly used interiorly on ceilings, bedroom and living room walls, closet interiors, entryways and hallways. On an exterior it can be used on wood and stucco and there are surface specific products that come in this finish. It’s not recommended for use on metal, however. The advantages of this finish are that it is better at hiding surface imperfections, touches up well, is non-reflective (which can be more desirable in a living room or den where you want a more relaxing, muted surface finish) and is generally easier to apply than semi-gloss and gloss finishes, which can be a little tricky. The main disadvantage is that it is not washable, which is why it’s just as well that it touches up easily.
EGGSHELL:
Eggshell is sometimes mistakenly thought to be a color when, in fact, it refers to the finish which is somewhat like an eggshell which tends to have a slight sheen to it, sometimes called a “side-sheen”, which means the sheen is more noticeable if you stand alongside a wall and look down it’s length. It gives the smooth look of a flat while providing a bit more protection and a more washable surface. It can be used pretty much anywhere you would use a flat paint.
SATIN:
This is the next step up in sheens and, while not as shiny as semi-gloss, does have a more noticeable sheen. It is scrubbable and particularly useful in children’s bedrooms, high traffic areas and can be used in kitchens and powder rooms. It’s not generally recommended for use in bathrooms but, and here is where the aesthetic clashes with the practical, some people are not big fans of the “shiny” look and are willing to sacrifice protection and longevity for the lower sheen appearance of a satin. Satin is available in exterior products, too, and can be used on stucco and wood. It’s not the most ideal product to use on metal surfaces but, provided the surface has been properly prepared and primed, it can be used.
SEMI-GLOSS:
This is the finish most companies recommend for kitchens, bathrooms, laundries or any room or area that is subject to moisture and condensation on a regular basis. It’s protective qualities are excellent and it is very scrubbable. It is also commonly used on doors, cabinets, baseboards and other interior trim. On an exterior I like to use it on fascia boards, (as they are continually exposed to the elements), exterior doors, window trim (metal or wood) etc.
GLOSS:
The shiniest of them all it is rarely used inside (it’s just so dang shiny!) but, sometimes used on front doors, exterior metal or trim, it dries the hardest of all the sheens and offers excellent protection. Nevertheless, some people like the ultra-shiny look and sometimes use it on interior doors and cabinetry. At this point it’s just a matter of personal preference.
As I mentioned earlier, the aesthetic sometimes wins out over the practical and I have, at the customer’s request (or sometimes the interior decorator’s) painted kitchens and bathrooms using a flat, because that’s the “look” they were going for. On the other side of the coin, practical over aesthetic, I have also done a whole house in semi-gloss (although I tried to talk the customer out of it) because he didn’t care how it looked, he just wanted it to be washable. In the end, achieving a balance between practical and aesthetic is probably the best – - if you can do it. The various finishes were developed for specific reasons to be the most optimum for the surface they are being applied and the rooms they are being used in.
Okay, that’s it for this week. I hope you found this information helpful and remember, when all else fails, call a Pro – - namely me!
Perry Martin
Professional Painter – Orange County, California
Perry’s email: perry801@hotmail.com
