Most objects float in resin because they’re less dense than the liquid, and the fix depends on what you’re embedding. Dried flowers, photos, lightweight charms, and wood pieces all behave differently, but a handful of reliable techniques work across nearly all of them: pouring in layers, tacking items down with adhesive, sealing porous materials, and timing your pours to catch the resin at the right stage of curing.
Why Things Float in the First Place
Cured epoxy resin has a density around 1.1 to 1.2 grams per cubic centimeter, which is slightly heavier than water. Anything lighter than that will try to rise to the surface, just like a cork in a swimming pool. Dried flowers, paper, fabric, feathers, thin wood slices, and hollow plastic pieces all fall into this category. Even items that seem heavy enough can float if they trap air underneath or inside them. Porous materials like wood and dried botanicals are especially prone to this because tiny air pockets inside them act like built-in flotation devices.
The Layered Pour Method
Pouring resin in thin layers is the single most effective way to keep inclusions where you want them. Instead of filling your mold in one go and hoping for the best, you pour a shallow base layer first, typically no more than three-quarters of an inch for standard epoxy. Place your items into that thin layer while it’s still liquid. Because there isn’t much resin beneath them, lightweight objects can only rise a tiny amount before they hit the surface.
Let that first layer cure for four to six hours until it reaches the gel stage, where it’s tacky and thick but no longer flows freely. At this point, the resin grips your items from below. Then pour your second layer over the top. If you’re using a deep-pour epoxy (mixed at a 2:1 ratio rather than the standard 1:1), you can pour up to two inches in this second pass. The tacky base acts like flypaper, holding everything in position while the fresh resin covers it.
For tall molds or thick castings, you may need three or four layers. The key is patience: each layer needs to reach that gel stage before you add the next one. Gel times vary by brand and temperature but generally fall between two and six hours.
Tacking Items Down With Adhesive
If layering feels like too much waiting, you can physically attach your items to the mold or to a cured base layer before pouring resin over them. Two adhesives work well for this.
- Super glue (cyanoacrylate): Best for small, precise applications. A tiny dot on the bottom of a charm, bead, or dried leaf will bond it to a cured resin layer in seconds. It dries clear and won’t cloud the surrounding resin if you use a minimal amount.
- UV resin: Apply a small dab of UV resin to the bottom of your inclusion, press it onto a cured base layer, and hit it with a UV light for 30 to 60 seconds. This creates an instant bond, essentially spot-welding the item in place. Then pour your regular epoxy over the top. UV resin is particularly handy for flat items like photos or printed images that catch the current of liquid resin and drift easily.
Two-part epoxy adhesive works for larger or heavier items that need a stronger hold, though it takes longer to set. Whichever adhesive you choose, the goal is the same: anchor the object so it physically cannot rise when fresh resin surrounds it.
Sealing Porous Materials
Dried flowers, wood, paper, and fabric cause a specific problem beyond buoyancy. They contain trapped air that slowly releases into the resin as tiny bubbles, and those bubbles can actually lift lightweight items toward the surface over the course of hours. Porous materials also absorb resin, which changes their appearance and can make colors bleed or paper turn translucent.
Sealing solves both problems. You have a few options:
- Spray acrylic sealer: Two or three light coats of a clear acrylic spray will seal the surface of dried flowers, paper, or photos without adding visible thickness. Let each coat dry fully before applying the next. This is the cleanest option for items where clarity matters.
- Mod Podge or similar craft sealant: Brush it on with a foam brush. It works well but can leave a slightly textured surface.
- Thin coat of mixed resin: Brush a small amount of mixed epoxy directly onto wood or flowers and let it cure completely. This is especially effective for wood slices, which can release streams of bubbles for hours if left unsealed. The brushed-on resin fills the pores and locks the air inside permanently.
For dried flowers specifically, the spray acrylic route tends to produce the best visual results because it doesn’t saturate delicate petals the way liquid sealants can.
Using Resin Viscosity to Your Advantage
Not all resins flow the same way. Coating resins (the standard 1:1 mix) are thicker and set faster, which gives lightweight items less time and less freedom to float. Deep-pour resins are much thinner, with viscosities that can be as low as 500 centipoise, similar to honey that’s been warmed up. That low viscosity is what allows deep pours without trapping heat, but it also means objects move through it more easily and have a longer window to float before the resin thickens.
A practical strategy: use a coating resin for your first layer where the inclusions sit, then switch to a deep-pour resin for the bulk fill on top. The thicker coating resin grabs and holds your items quickly, while the deep-pour resin gives you the depth and clarity you need for the final piece.
Temperature and Timing
Warmer environments speed up gel time significantly. Resin that takes six hours to gel at room temperature may reach that tacky stage in three hours at a slightly warmer temperature. This matters because the faster your base layer gels, the sooner it locks your inclusions in place and the sooner you can pour the next layer.
You can use this to your advantage by working in a warm room (75 to 85°F is a comfortable sweet spot for most epoxies) or placing a gentle heat source nearby. Don’t overdo it, though. Excessive heat can cause resin to cure too fast, which creates cracks, yellowing, or an uneven surface. The goal is a moderate bump in temperature, not a rush job.
Timing your inclusion placement also matters. If you pour a layer and immediately drop in your items, they have the full working time of the resin to drift. With most art resins, that’s about 30 to 45 minutes of open working time. Instead, wait 15 to 20 minutes after pouring so the resin has already started to thicken. Items placed into slightly viscous resin move much less than items placed into freshly mixed, water-thin resin.
Combining Techniques for Stubborn Items
Some inclusions are particularly difficult. Dried flower petals, feathers, and thin fabric pieces are so light that even a thin pour won’t fully stop them from shifting. For these, combining two or three techniques at once is the most reliable approach.
A solid workflow for something like a dried flower arrangement: seal the flowers with spray acrylic first. Pour a thin base layer of coating resin. Wait 15 to 20 minutes for it to begin thickening, then press the flowers into position. Use a toothpick or tweezers to arrange them. If any petals keep curling upward, dab a tiny spot of UV resin on the underside and cure it with a UV light to pin them down. Let the base layer reach the gel stage (four to six hours), then pour your deep-pour resin over the top to fill the mold.
For heavier items like rocks, metal charms, or glass beads, a single layered pour is usually enough. These objects are denser than the resin itself, so they’ll sink rather than float. The challenge with heavy items is the opposite problem: keeping them from settling to the very bottom and touching the mold wall. In that case, pour a base layer, let it fully cure, place the item on the hardened surface, and pour fresh resin over it.