Using Shellac to Solve Bleed-through Issues While Painting (Plus to How to Tell if Shellac is Expired)

One of the many wonderful things about Jolie Paint is that for most projects, there is no need to sand or prime prior to painting. However, there are always exceptions to any rule, and one issue that can come up from time to time is bleed-through.

What is bleed-through?

Bleed-through often appears as paint dries, creating orange or pinkish spots in the finish. It is typically caused by tannins bleeding out of open-grained wood into fresh paint, although stains can also be caused by oils seeping out of wood filler or previous oily spills. Bleed-through issues can be difficult to predict, but in general, the most likely offenders are open-grained woods like oak, pine and mahogany, vintage furniture pieces with cherry colored stain, items repaired with wood-filler, or water-damaged furniture.

While there is no guarantee whether these types of pieces will experience bleed-through issues, you may choose to be proactive and take steps to ensure that you don’t run into any problems later on. If you are already painting and begin to experience bleed-through, don’t panic! While it can be frustrating to see your beautiful finish marked with stubborn stains, there is a fairly quick and easy solution.

Stopping bleed-through with Shellac

The best way to handle bleed-through is to apply a product called shellac, a non-toxic sealer found in most hardware and paint stores under the Zinnser brand. Shellac seals in stains, and once dry (in a matter of minutes), you can then paint or repaint the area with Jolie Paint.

The easiest way to apply shellac is to simply dip a cloth into the can and wipe it across the stained areas. Be sure to wear gloves! If you use a brush to apply shellac, clean it with either denatured alcohol or ammonia.

PRO TIP: In addition to preventing stains, shellac is also helpful for sealing in unwanted odors (smoke, mustiness, etc.) on older pieces of furniture.

How to check whether shellac is expired

In our experience, shellac has a shelf-life of around one year and is not effective if exposed to warm temperatures. Before purchasing shellac, you want to be sure you are buying a fresh can, otherwise, the shellac may crack under your paint finish, and you will be forced to sand down to the bare wood.

Zinnser, the most widely sold brand of pre-mixed shellac in North America, used to clearly mark their cans with a manufacture date so that you could easily judge whether a can was safe to use. However, this is no longer the case– instead, cans are now stamped with a series of letters and numbers that likely won’t mean much to you at first glance. However, there is a trick to reading the stamp, and it can be used to decipher the production date of the shellac. In general, we recommend using shellac that is no more than 1 year old. If the production date is within the last year, then it should be okay to use.

To start, find the stamp on the lid of the can– it should contain a series of 6 letters and numbers. The first and last letters in the series are codes for the factory location and batch number, which are not important for the purposes of figuring out the production date. Instead, you’ll want to focus on numbers 2-5, which indicate the year, month, and day that the shellac was packaged.

Here is how you would read the following date stamp: S3310B

S: factory code

3: last digit of the year

3: month (note: October, November, December use O, N or D instead of a number)

1: day (first digit)

0: day (second digit)

B: batch code

So according to this stamp, the shellac was packaged on March 10, 2023, and would likely be okay to use within a year of that date.

We hope you find this to be a helpful resource in the event you are experiencing bleed-through issues with your project. As always, please contact us if you need further advice or assistance!

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