House Painters Pro Tips: Filling Gaps, Cracks, Nail Holes

Jeremy Holderness

One of the signs of a great paint job is a seamless finish.  In a previous article we discussed Defined Levels of Surface Prep required to achieve various grades of finishes.  But exactly which filling products do you use to fill gaps, cracks, and nail holes to get the results you're looking for?

In this post we'll discuss those specific products, along with when and where to use them.  Follow these tips and you can get a quality finish that can make many professional house painters jealous.

Filling Gaps

There are many places where you may need to fill gaps before you paint.  

On an interior paint job you could find them where walls meet ceilings, on inside corners of walls, where wood trim meets walls, on inside corners where wood trim meets other wood trim (i.e. on door/window frames and baseboards), etc.  

On an exterior paint job you could find them where trim meets the siding or body of the house, the butt-joints on longer runs of siding, inside corners, etc.

Regardless of inside or outside, there are more of these areas that will need to be filled than any other kind.  So the product you will need more of than any other will be caulking -- specifically painters' caulk.  This is why most painting crews carry at least a couple of cases of the stuff with them all the time...because they use a LOT of it.

Luckily painters' caulk is so cheap, right?  I mean you can get a tube of basic paintable latex caulking that says '25 Year' right on the side for a little over $1.  And as long as you don't care if it actually lasts for more than a few months then you're good to go.  I suppose in a perfectly controlled environment where there is no movement or change in temperature and humidity it might hold-up a long time, but in the real world it will often begin to pull away from the sides of the joint pretty quickly.

Just like with paint -- probably even more so than paint -- there is an enormous difference in quality and life-span of caulkings.  In fact, I typically purchase the most expensive caulking on the shelf for both interior and exterior painting projects because they flex more, shrink less, and resist cracking better than the others.  I could go into a a long, boring, technical explanation about shrink coefficients but I doubt anyone cares that much about caulking, so I'll just say you should buy the most expensive appropriate product for your project that you can justify because they are absolutely worth every penny.  The brand isn't terribly important.  There are lots of different manufacturers of high-quality caulking that are widely available, such as DAP, GE, Tremco, Sherwin-Williams, etc.  Just make sure it's paintable if you're planning to paint over top of it.

*TIP* If you want to make sure your expensive caulking doesn't fail on you, be certain to prime any bare substrate surfaces before you apply caulking to them.


Filling Cracks

On interior wall surfaces like drywall and plaster, the material that gives the most inconspicuous repair is joint compound.  Joint compound comes in pre-mixed "mud", as it is referred to, that comes in 1 gallon and 5 gallon buckets.  It is also available in powder form that can be mixed in the quantity that is needed for your particular size of crack repair.

The benefit of joint compound in powder form is that it can be purchased in a variety of fast-drying versions (20 minute, 45 minute, 90 minute) depending on how quickly you can effectively work before your mix starts to set up.

On interior door, window frame, and trim surfaces which are usually wood, the material that works best is wood filler.  Quality wood fillers dry hard like the surrounding wood; they don't shrink; and they can be sanded, drilled, painted, or stained.  This is a perfect solution for miter joints in trim because once it's been sanded smooth you often can't tell that there's been any filling done.

On most exterior surfaces a high quality caulking tends to work well because it can move and flex as changing weather conditions stress the surrounding substrates.  If you want a more seamless repair on wood you may need to get into some wood replacement.  And stucco can be seamlessly repaired if you have the right materials, tools, and skill-set.


Filling Nail Holes

Nail holes in interior walls can generally be filled with shrink-free spackling by overfilling the hole slightly, then s

anding smooth once it's dry.  Holes in wood trim are best filled with wood filler.

Nail holes in exterior surfaces, just as with cracks or gaps, can be dealt with using a good caulking.

Take the time before you apply any paint on your next project to fill all of the gaps, cracks, and nail holes.  Sure it takes some extra time and money spent buying additional products, but it will absolutely take your paint job from looking good to looking great.

If you need assistance with your painting project, please give us a call at (813) 570-8800 or visit our Contact Us page to schedule a free consultation and quote, or simply click on the button below to have us call you.

photo by: Jens karlsson / CC BY 2.0

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