When using our products, shadows on porous surfaces can be avoided by ensuring the graffiti is flood coated adequately, with enough dwell time to fully dissolve the graffiti before rinsing.
For example, if you applied Bare Brick Stone & Masonry Remover as instructed but then found that an extra coat faded the graffiti more - It generally means the dwell time wasn't long enough the first time.
So always remember to FLOOD coat graffiti generously and leave it on...THE LONGER, THE WETTER,THE BETTER! Let the products do the work for you. The last thing started is always your pressure washer.
If necessary, leaving ‘Bare Brick’, Stone & Masonry Graffiti Remover or Feltpen Fadeout on overnight (especially if there are any magic marker stains) can be extremely helpful on stubborn older graffiti. On the following day, lightly coat again before rinsing with your pressure washer.
Feltpen Fadeout is extremely beneficial in removing certain spray can stains on porous masonry and concrete.
After dissolving as much graffiti as possible with Bare Brick Stone & Masonry Remover, an application of Feltpen Fadeout during or after the final rinse will eliminate any remaining pigment or stain in the surface.
This method (which is illustrated in the sequence below) can be used on a variety of spray can colors, however it is especially useful on RED spray cans and any color containing red, eg: oranges, pinks, purples and browns. These colors all contain fine red oxide pigments and are the most likely to leave a residual stain. The stain can be easily removed with a generous application of Feltpen Fadeout.
One application of Feltpen Fadeout
Final rinse with pressure washer
Once Feltpen Fadeout is applied thickly to the stain, the fading process normally takes only a few minutes to less than half an hour, but longer dwell times may be necessary. Fortunately, once you begin to see the stain disappear (even marginally) you will certainly fade the rest, so be patient with the dwell time and reapply Feltpen Fadeout if needed.
There are the occasional black or blue spray cans that can show resistance to any removal product on concrete or limestone leaving you with a threaten shadow. When this happens a solution of 1 part muriatic acid (hydrochloric acid/HCL) to 8 parts or less of water will likely fix the problem quickly.
Brush on this solution and agitate with the brush. You will see it fizz up a bit, as the solution neutralizes. Then rinse shortly after with your pressure washer. This method can be very quick and satisfying, particularly on stubborn blue or black shadows like the ones in the photos below.
The blue shadow on cinder block is a prime candidate for muriatic solution
Some slight shadows show resistance to Bare Brick Stone & Masonry Graffiti Remover
After applying muriatic solution
When using this technique it is a good idea to test out your muriatic solution first in an inconspicuous area. Stronger solutions may possibly have the effect of slightly darkening an area. If this should happen, a complete section may have to be cleaned (with the solution).Remember, your gun technique must be very even and gentle when rinsing the muriatic solution to avoid ‘tiger striping’ the area.
HOT TIP: In hot weather environments, try thoroughly wetting the wall down first, prior to applying Bare Brick Stone & Masonry Remover. Working on a DAMP wall (not dripping wet) will visibly help speed up the removal process, and slow a hot thirsty wall from slurping up and drying out the remover before it has had a chance to penetrate and encapsulate the graffiti from behind.
3 Things to Remember
1) FLOOD coat graffiti generously and leave it on...THE LONGER, THE WETTER, THE BETTER!
2) In hot weather environments, try thoroughly wetting the wall down first, prior to applying Bare Brick Stone & Masonry Remover.Working on a DAMP wall (not dripping wet) will visibly help speed upthe removal process, and slow a hot thirsty wall from slurping up anddrying out the remover before it has had a chance to penetrate andencapsulate the graffiti from behind.
3) There are the occasional black or blue spray cans that can showresistance to any removal product on concrete or limestone leaving youwith a threaten shadow. When this happens a solution of 1 part muriaticacid (hydrochloric acid/HCL) to 8 parts or less of water will likely fixthe problem quickly.