Fixing Drips and Runs in Paint

Some time back in Green Magazine we covered how to deal with a paint run in primer paint and promised we would look into dealing with a paint run in finish paint. Well, it’s about time we deal with that pesky run-in finish paint. This is a really small tip that will be a really big time saver. This technique will also work on primer, but we will focus on finish paint here.


We may as well admit that we like our paint glossy and free of runs. But getting that nice glossy paint is not such an easy task. If you spray too lightly, and with too much air, the paint looks dry and dull. If you paint too heavy, or with too much paint versus air from your spray gun, you end up with runs in your paint. It’s a delicate balance to spray wet enough for a nice gloss and do it without runs. Truth be told, it isn’t a question of if you will get a run, it’s a question of how many runs you will have. Runs are just part of the game, even for professionals.


This little trick will work on both sheet metal and castings. So, there you are, spraying on a second coat of paint and things are looking good until … darn, there it is, a paint run (Photo 1). You have two options now. Option one is to let the paint dry, then sand the runoff and repaint the part again which is time-consuming and expensive. The second option is to simply take care of the run before the paint dries.


The first thing to do is just relax! It works best if you let the paint “flash off”, or begin to skin over. If you are using a hardener with John Deere paint about five minutes will do the trick. Using a small artist’s paintbrush, dip the brush in John Deere paint thinner (Photo 2) and lightly brush the culprit runs.

As you lightly brush the skinned over paint run with your solvent soaked brush, the solvent will soften the paint run and surrounding paint so you can blend the run into the paint around the run (Photo 3). You need to brush lightly so you don’t expose the primer under the finish paint. Using solvent to blend the run with the surrounding paint will leave a smooth, glossy finish.


It will take a little practice to perfect this technique, but it is very easy to master and will save countless hours of sanding and repainting. If your paintbrush does not have enough solvent on it the run will not soften but will tend to smear and look rough. To correct this, wet the brush with more solvent, and lightly brush it again until your paint run blends in perfectly (Photo 4).

If you use too much solvent on your brush the solvent will soften and thin the paint to a point where it will just cause another run, or expose the primer underneath the finish paint. If you have this happen, wipe the brush to remove some, but not all of the solvent. Then try blending the run into the surrounding paint again. If you end up exposing the primer under the finish paint, simply wait a few minutes, then give the exposed primer a quick spray of paint after you have eliminated the run with your solvent and brush.


On castings, this is a very simple little trick to deal with a run in your finish paint. When working with sheet metal such as a hood or fender, this process works just as well, but your blending technique will need to be refined better than it is when dealing with a casting. Even a novice can successfully accomplish this technique with perfect results that will save countless hours and the expense of sanding the part again and repainting it.


As we said, this is a really small tip that will reap some really big benefits. If you haven’t tried this little trick yet, then you are in for a treat the first time you try this. Remember to just have a little patience when that first run occurs, and let the paint flash off, or skin over before you get started. Also, don’t wait until the paint has dried completely or this technique will not work. Until next time, enjoy your treasured iron to the fullest extent possible.