spooky pentimento

Bongo

Well-known member
Messages
1,405
I gessoed up a 48" x 32" panel for a painting... and today I noticed these random bluish marks showing through the gesso. The panel is hardboard (masonite-like) which I lightly sanded and cleaned with alcohol before I applied two coats of gesso - which I applied in vertical and horizontal strokes - no random pattern. This morning there are these very noticeable marks all over it. For it to show up in a photo, I had to massively adjust the exposure and contrast - but to the eye, they are quite prominent. You can't appreciate it from the photo, but this will give you an idea. Any thoughts on what might have caused this?

0


just in time for Halloween.


Reply
Like
More
 
If it starts oozing blood, well...

Gesso is water based, right? Masonite is not waterproof, so the gesso will soak in some in a blotchy way. I suggest letting it dry, sand it, and seal it again with a white-pigmented shellac sealer (found in house paint stores). My opinion because I've done some house painting and furniture refinishing. JMHO :)
 
what you say is logical -- however, I've gessoed many hundreds of "masonite" panels with the same water-based gesso and never had any problems. The random pattern is bizarre it's not blotchy but marked with lines as if someone scribbled all over it. Thank you though for the input.

I just put another coat of gesso on and it seems to have covered it up.
 
Sorry...
Wonder if it's a fault of that run in the manufacturing process. Which doesn't help you. I wonder if oil based gesso would help? Or Kilz?
 
what you say is logical -- however, I've gessoed many hundreds of "masonite" panels with the same water-based gesso and never had any problems. The random pattern is bizarre it's not blotchy but marked with lines as if someone scribbled all over it. Thank you though for the input.

I just put another coat of gesso on and it seems to have covered it up.
Good, glad to hear it's working normally again. (y)
 
GHOST BUSTED

After much thought, I think residual paint on the brush is the most likely answer. Blue has notorious staining power, so a little bit on the brush could account for all the marks. Also looking at the marks, although they seem random, they all have vertical trajectories - which is consistent with how I apply gesso alternating between horizontal and vertical applications. The exception is the long horizontal mark at the bottom of the panel - often after applying vertical strokes, I'll run the brush along the bottom of the panel to even out "ends" of the strokes and make sure coverage goes to the very edge of the panel.

I finished gessoing that night and left the panel on the floor to dry. The next morning I picked it up and hung it on the wall. That's when I noticed the blue marks - when I stood back under proper lighting and closely examined the panel.
 
Back
Top