This waterproof silicone sealant is the best overall glue for outdoor use. It works for all my garden art projects including dish flowers that stay outside, all year-round in a cold climate.
For more adhesive recommendations, also see the Glue Resource Guide for Garden Art Projects.
Which Outdoor Adhesive Should I Use?
I get a lot of emails from people having trouble making the flat marbles or other decorations on their garden art projects stick or adhere, so I’ve written up this page with my best tips and trouble-shooting information.
This article focuses on the one adhesive I find reliable for just about everything, but there are also other options listed in the Guide to Choosing Outdoor Adhesives including E6000 and E8000.
- Best All-Round Adhesive
- Health & Safety Considerations
- Tips to Be Sure Adhesive Sticks
- Read the Label
- Frequently-Asked Questions
The Best All-Round Adhesive for Outdoor Garden Projects
I use GE Silicone II Sealant for most of my garden art projects. It is called ‘sealant’ but for my projects it works as an adhesive for aluminum, stainless steel, wood, masonry, brick, concrete, painted surfaces, vinyl and plastic. I use it mainly for glass garden art.
Keep in mind, this is just for attaching stuff together.
- It’s not a paintable caulking—it’s just a glue—so it’s cured, it’s done. You cannot paint it or glue more things to it.
But it does a fabulous job sticking stuff together permanently, holding up in crazy weather conditions for years and years.
Here’s two versions (both work fine):
Here’s what to look for when buying the adhesive:
- GE Silicone II or 100% Silicone product (same product is sold under several names)
- Waterproof (but not for use under water or in bird baths)
- Clear-drying (that’s what they say though it dries slightly opaque)
- Outdoor use
- Often marketed for gutters or flashing but exterior doors and windows is fine too
- Check the Use By date, read the product label, store it as recommended (consistent room temperature), and follow the user instructions.
Keep in mind that it is permanent. You cannot remove it once it has dried, and you cannot apply more adhesive to an existing layer once it has dried. So work thoughtfully.
It is sold in home improvement stores in the caulking section. You can buy it in a tube or a cartridge that uses a caulking dispenser. The cartridges are about half the cost of the tubes.
I make garden art items that I leave outside, year-round, through the Canadian summer heat and winter wet and cold. I do not want to have to bring them indoors for half the year so I like a product that forms a strong, long-lasting bond.
While there are other products that may work as well, I recommend this specific one because it always works for me.
If you’re new to making garden art projects like garden balls , totems, garden treasure jars, and dish flowers, these tips should help you succeed. They are all easy projects but do require the right product and technique provided in the tips here as well as the project instructions on this site.
I do not receive any compensation from GE for recommending this product – I just really like how it works – but the product links here are to my Amazon affiliates account.
You have to willing to experiment and find what works best in your climate. If you have something you like better, use it.
Health and Safety Considerations
- Before using any product, read the product label and follow the manufacturer’s health and safety guidelines.
- Most products like this one require working in a well-ventilated area.
- Know ahead of time how to clean up any leftover product, and how to remove it from your skin or eyes.
- If making a garden art project with children, only adults should handle the silicone sealant.
- As mentioned, GE Silicone II forms a permanent bond as soon as it dries and you cannot remove it so work thoughtfully-there’s no turning back.
Tips to Be Sure the Adhesive Sticks
- Use the right product. I am a fan of GE Silicone II sealant for most outdoor garden art projects.
- Make sure the product is fresh (check the Use By date on the container).
- Ensure that the product has not been stored in a hot or cold area. If it’s runny when you apply it, it’s not good and will not work.
- Make sure the surface of the globe or jar (or whatever you’re using as a base) is clean, dry, and grease-free.
- Apply the silicone sealant according to the project instructions. For most projects such as garden art balls and totems, apply it at least 1/4-inch thick.
- Press the flat marbles into the silicone sealant and allow it to smoosh around them. It will fill in the areas between the marbles appearing like an opaque grout. As it dries, it grabs the marbles, holding them in place. This tutorial shows how to make a decorative garden art ball.
- Make use of gravity. If your marbles are sliding off while you’re working, you may be working against gravity. Start at the lowest part of the base, applying one row at a time. The next row will sit on the one below and the marbles won’t shift while the silicone sealant is drying.
Read the Label
Information on the GE II Silicone Sealant Product Label
Read the label carefully before you buy! There are so many different types of sealants and caulking.
- 3-hour rain-ready and sun/freeze proof for use in gutter and flashing installations and repairs, that also provides mold-free product protection.
- Once cured (after 24 hours), is sun/freeze proof, meaning it won’t crack or crumble even when exposed to harsh weather such as heat or freezing temperatures.
- Adheres to aluminum, stainless steel, wood, masonry, brick, concrete, painted surfaces, vinyl and plastic.
- Remove dirt, grease, and moisture before applying.
- Allow at least 3 hours before exposing caulk to water.
- Not for use below the water line (i.e. not to be submerged in water ongoing).
- Application temperature: 5°C to 37°C
- Service temperature: -51°C to 204°F
- Tack-free: 30 minutes
- Water exposure: 3 hours
- Full cure: 24 hours
- Clean up (while wet only): mineral spirits
Frequently Asked Questions
1My silicone sealant says ‘clear’ on the label but it’s not clear – is something wrong?
No, you are correct. Even though they call it ‘clear-drying’, it does not dry clear, but instead has an opaque quality. If you want something that will truly dry clear, you may want to try other products.
2Can I grout over silicone sealant?
No. Nothing sticks to the dry sealant so it is not appropriate for grout or paint. If you want to do a mosaic project, you could carefully apply the sealant to the underside of the pieces only (without any oozing into the gaps), and then apply grout to the gaps. But keep in mind that if there’s any sealant showing, the grout will not stick there.
3Can I glue on top of silicone sealant?
No, not once it has dried. GE Silicone II is permanent: once it dries, you cannot remove it, you cannot add more adhesive on top of it (it will not stick), and it is nearly impossible to peel off. This is why I advise working in small sections: apply some adhesive, attach the marbles, do the next section. It works so nicely for garden art projects because it is permanent but this also means you have no second chances.
4My marbles are sliding off the globe! My marbles fell off!
I get emails asking for help with adhesive problems and it usually comes down to one of the factors listed (above, including greasy surfaces) in Tips To Be Sure The Adhesive Sticks.
5What other glues can I use?
Yes. Have a look at this Glue Resource Guide for Garden Art Projects for more recommendations.
People in really humid areas like Florida have a hard time keeping whatever product they use from becoming too warm. When adhesives and sealants get too warm, they separate into a gel-like liquid and that does not work properly.
I have not had any problems with GE Silicone II here in Canada where we have cold winters and humid summers.
~Melissa the Empress of Dirt ♛