Liquid Nails brand is a very strong adhesive that is meant to hold things permanently. Removing Liquid Nails from bricks requires extra care, because it could result in permanent damage to the brick. There are commercial adhesive removers that can be used on bricks, but there might be discolouration due to the strong chemicals in the adhesive removers. Simple and easy procedures help to remove the Liquid Nails from brick.
Scrape off the Liquid Nails adhesive with a putty knife or a chisel. If you can remove the adhesive as soon as it is applied, the adhesive will be soft and will come off easily. For dry and hard Liquid Nails, scrape gently and remove as much as you can. Do not use too much pressure while scraping, because it could crack the brick.
Apply petroleum jelly on the Liquid Nails and let it sit for three to four hours. Petroleum jelly helps to soften the dried Liquid Nails.
Use a putty knife and scrape off the softened adhesive. Do not scrape harder if the adhesive does not come off. Repeat Step 2 if necessary.
Hold a hair dryer in one hand and the putty knife on the other. Turn on the hair dryer to a high setting and aim it at the Liquid Nails on the brick. The heat should loosen the adhesive.
Check with the putty knife to see if the adhesive softens as you blow heat on it. When the adhesive gets loose, turn off the hair dryer and quickly start scraping the adhesive. Liquid Nails adhesive hardens quickly.
If you cannot remove the adhesive using the steps above, call a professional. Check with the professional to see if sandblasting or pressure washing the brick will remove the Liquid Nails. Not all types of brick tolerate these techniques.