A question I'm often asked is: "how do you seal your painted rocks." The quick answer: I use classic matte or gloss Mod Podge for sealing and protecting my painted rocks. (See my August 26, 2012 update below for a 2nd product applied over the Mod Podge to prevent "tackiness" in humidity.)
|My much-used jar of Mod Podge|
What is Mod PodgeMod Podge is a non-toxic, nonflammable, water based:
- Sealer that protects acrylic paint, decoupage, fabric, stain, etc.
- Glue that adheres, paper, fabric and other porous materials to almost any surface
- Finish that's smooth, durable and fast drying
Why I Prefer Using Mod Podge on Painted RocksThe Mod Podge formula is non-toxic, non-flammable, water based, and cleans up easily with just soap & water which makes it a great product for doing rock painting crafts with children. As an added benefit, I can also use the Mod Podge product if I wish to glue some type of porous embellishment onto the painted rock.
On the other hand, the clear, acrylic, protective finish available in a spray can (such as the Krylon brand) is toxic and care must be taken to keep the can away from heat and fire, don't puncture the can, ensure proper ventilation and avoid contact with eyes and skin.
While a sealer in a spray can might be easier to apply (especially to large painted rocks), I definitely want to use the safest product possible -- Mod Podge -- when doing my rock painting craft.
Update 5/22/2014: Learn about a low odor spray-on sealer for painted rocks.
How I use Mod Podge for Sealing Painted RocksI apply Mod Podge to all of my painted rocks (even the large outdoor garden decor and pavestone nativity sets) using a medium-to-large paint brush. Yes, it is a little more time consuming, but I love the feel of a brush in my hand and unlike the toxic alternative in a spray can, I don't have to ventilate my small painting studio.
I've used classic Mod Podge in both the matte and gloss formulas. The gloss formula is especially nice when a shiny effect is desired, such as when painting fish rocks.
Don't be alarmed when you open a jar of Mod Podge. It is white and looks like glue, however, it dries clear.
Other Mod Podge FormulasI learned about other Mod Podge formulas in the recently published book, "Mod Podge Rocks" by Amy Anderson. If you'd like to try crafting with Mod Podge, Amy's book contains 40+ projects using the various Mod Podge formulas. Note: while none of the projects are related to rock painting, there are some clever ideas for using Mod Podge.
I plan to experiment on my painted rocks with these Mod Podge formulas in the future:
- Satin - Between matte & gloss with a lustrous, soft finish
- Hard Coat - Extra protection for projects handled frequently
- Outdoor - Extra protection from moisture and elements
- Sparkle - Has a hologram glitter for a rainbow effect. Makes projects glitter
- Dimensional Magic - Thicker than other formulas, it adds extra dimension
Learn More About Mod Podge
Where to Find Mod PodgeI purchase classic matte and gloss Mod Podge at my local craft store, Hobby Lobby. It is also available in some Walmart and Jo-Ann Fabrics and Crafts stores.
Store locator from the Mod Podge manufacturer's website.
* * * Update August 26, 2012 * * *
A fellow rock painter recently faced a dilemma (or more accurately, a disaster) when she used Mod Podge on her painted rocks and stored them in a covered, plastic bin under the bed. When she opened the lid, many of her rocks were now stuck together and ruined.
It is believed that moisture and humidity do not like Mod Podge. The jar states "To eliminate tackiness apply Clear Acrylic Sealer over dried Mod Podge." Since I live in a very dry climate, I have not experienced this problem. However, I wanted to learn more about acrylic and polyurethane sealers.
Thank you, Lisa Carter, (another rock painting peer) who explained the difference between acrylic and polyurethane sealers.
"Acrylic sealer/finishes/coatings are considered single-component polymers...most are water based and provide waterproof protection on various surfaces ..they mainly enhance the color of painted surfaces and provide some durability. For the price..these work well for our painted stones ..especially those that are placed inside and will need protection as they are periodically dusted with damp cloths.
Polyurethane polymers are formed by combining two bi- or higher functional monomers. These are basically stronger and provide a more durable coating but are slightly more expensive."
|Ceramcoat Satin Exterior/Interior Varnish|
I purchased Ceramcoat Satin Exterior/Interior Varnish (the polyurethane product) and applied it over a few of my Mod Podged rocks. This is what I discovered:
- This particular Ceramcoat product was twice the price of Mod Podge
- The Ceramcoat varnish did have a slight ammonia-like odor
- The product was a thinner consistency than Mod Podge so, even though more expensive, it should last just as long if not longer than Mod Podge
- The rocks were now thinly coated with a sealer that was in between matte and gloss (which I liked)
- The product is non-toxic, water based, and cleans up with soap and water.
I was pleased to further discover from Ceramcoat's Material Safety Data Sheet that:
- Ceramcoat varnish can be used with general ventilation (no need to go outside or into the garage)
- No known hazards from inhalation, skin contact, or ingestion. However, eye contact may cause reddening and tearing.
* * * Update May 27, 2015 * * *
I have been extremely disappointed with the Delta Ceramcoat lately. It appears the company has changed hands and the sealer's formula has been altered. I now find the Delta Ceramcoat to be too thick and it has a strong odor.
My preference for a top coat sealer over the Mod Podge is Americana DuraClear Varnish.
It comes in matte, gloss and satin, has a thin consistency and low odor.
I will be adding a final coat of polyurethane to my painted rocks on top of the Mod Podge as an extra layer of protection and to avoid stickiness.
Learn about a low odor spray-on sealer I'm using for doodle, tangle, and mandala rocks designed with artists pens.
Learn how to prevent Sharpie permanent marker pens from blurring when sealed.