View Full Version : Question??

11-06-2011, 11:47 AM
Is it ok to use thickening gel or paste to gesso?I want to smooth out a surface on stone.Thankyou,Jan

11-06-2011, 02:46 PM
Certainly worth a try. I believe the thickening medium reacts with the acrylic base and I am thinking there has to be some acrylic in the gesso so it should work. No guarantees, but, it makes sense.

11-06-2011, 09:35 PM
Thankyou so much! I will give it a go! Hugz

11-06-2011, 10:52 PM
I would caution using a water-based product on stone as it is quite porous. If the stone is not sealed completely, any moisture that could absorb into it might cause the gesso mix to seperate. You may want to look into priming the stone with an oil-based primer first. Zinnser's Coverstain would be a good choice. Just something to keep in mind, especially if this is an outdoor project.

11-06-2011, 11:56 PM
Hmmm,would it be better if i seal it first with an acrylic sealer??Thanks,Jan

11-07-2011, 07:33 AM
I imagine any sealer would help, but again, an acrylic is still water-based. Most likely you won't have any issues.

the drover's dog
11-07-2011, 08:29 AM
I would suggest you seal it with a glass and tile medium or a really strong sealer like a tannin blocker. Otherwise just give it two or three coats of any good acrylic sealer. I would not seal it with an oil based sealer or your subsequent layers of acrylic paints will peel off. Water based products will not stick to oil based ones.


11-07-2011, 03:04 PM
Thankyou so much! That's what i thought about the oil base stuff.Hugz,Jan

11-07-2011, 03:40 PM
What about using a few coats of GAC-100 and then coat with gesso. You could use a heavy gesso but I don't think it is necessary with the GAC-100 undercoat. The acrylic thickener may work great with the polymer but not sure it will work well with the other ingredients in gesso. You may end up with some unwanted clumping.

11-07-2011, 04:03 PM
Oh,thats a great idea too! Do you think that would be better than the glass and tile medium?Thanks,Jan

11-07-2011, 05:08 PM
I have painted on stone and brick, concrete etc before and a couple of coats of acrylic sealer will do fine ( I was scenic artist at WB movie world Australia for 14 yrs prior to retiring )

11-07-2011, 05:31 PM
Ok,thankyou so much! Hugz,Jan

11-08-2011, 12:55 PM
I have used acrylic on stone without problems. if you want a smooth finish you you use one of the modelling pastes available.