I’ve been collecting and trying various glues while crossing my fingers that they’d work long-term. I really dislike the thought of something I’ve made falling apart after I’ve sold it, so I decided I needed to test adhesives.

TESTING METHODS

I first baked test strips of five different brands of polymer clay. Then, I conditioned my bag of polymer clay scraps, cut out discs and baked them. The scraps were mainly Kato with some Fimo, Premo and a tiny bit of Soufflé.

I thought about making Kato discs to go on Kato clay, etc., but decided a mixture of different brands would make a more rigorous test.

I got new, zinc-coated, steel washers thinking they could represent bails. They looked clean, but I still washed them in hot, soapy water. I also cleaned all the washers, polymer clay discs and test strips with a Q-tip soaked in 91% rubbing alcohol. I wore nitrile gloves while doing the test.

All adhesives were purchased within a few months of testing.

I spread a thin layer of each adhesive on the back of the polymer clay discs and metal washers using a new toothpick for each. (See photo below.) I didn’t want to use too little adhesive, but I also didn’t want to use too much because it looks bad when it seeps out. I tried to find a balance.

I intentionally left the top part of the disc or washer hanging off the edge of the clay strip to allow me leverage when trying to pry them off.

I baked Kato Poly Paste and Kato Liquid Polyclay at 300˚ for 30 minutes in a preheated baking box. A baking box is two cheap aluminum pans, one inverted as a lid, with two small ceramic tiles inside. I preheat it with the lid off using an oven thermometer.

I baked Sculpey Bake & Bond and Lisa Pavelka Poly Bonder at 275˚ for 30 minutes in a preheated baking box. I realize Poly Bonder doesn’t need to be baked, but its heat-resistance is what makes it unique from other super glues.

I baked Fimo Liquid Gel and Genesis Heat-Set Oils Thick Medium at 265˚ for 30 minutes in a preheated baking box.

After the baked strips were completely cool, I applied the rest of the adhesives. I wore a vapor mask when using most of them, which is important.

I followed the directions on each bottle. Gorilla Glue needs to be shaken. Pieces that are superglued need to be pressed together for 10 seconds or more. I’ve learned from prior experience that baking Kato Poly Paste at the recommended temperature is important. It also becomes stickier if you stir it.

The adhesives I used were in this order:

Kato Poly Paste Kato Liquid Polyclay WeldBond Gorilla Super Glue Gel Sculpey Bake & Bond Lisa Pavelka Poly Bonder Zap-A-Gap 3M Super Glue Gel Fimo Liquid Gel G-S Hypo Cement G-S Hypo Fabric Cement (I tried this because it says it’s for plastics.) Liquid Fusion Genesis Heat-Set Oils Thick Medium Apoxie Sculpt Loctite Super Glue Gel Control JB Weld Steel-Reinforced Epoxy Super ‘T’ Cyanoacrylate Glue Sugru Moldable Glue Fix-It Epoxy 330 Fabri-Tac Multi-Purpose Mac Craft Glue

The liquid clays should be cured when cool. WeldBond requires more time to dry, so I let it and the rest dry for 48 hours.

Four of the five washers adhered with Lisa Pavelka Poly Bonder popped off before I could take the first photo, so I Scotch-taped them back in place. The Sugru washers popped off, too.

After the proper curing time elapsed, I tried to pry each disc and washer off by hand. I was not easy on any of them. My fingertips still hurt, hours later. One of the Premo strips broke in the process.

SANDING

When I first tested adhesives 1-17, I decided to not roughen any of the surfaces with sandpaper. I later retested adhesives 9-17 and sanded both the polymer and the metal. This made a difference in three instances:

All the polymer stuck with Fimo Gel. Previously, it didn’t stick to Kato and Premo. All the polymer stuck with Genesis Heat-Set Oils Thick Medium. Previously none of it stuck. The metal stuck with JB Weld Steel-Reinforced Epoxy, though still not the polymer.

Sanding made no difference in how well G-S Hypo Cement, G-S Hypo Fabric Cement, Liquid Fusion and Apoxie Sculpt worked.

PHOTOS BEFORE TRYING TO PRY OFF POLYMER AND METAL

PHOTOS AFTER TRYING TO PRY OFF POLYMER AND METAL

The photos above look pretty sparse. Most of the metal washers popped off very easily. The polymer clay discs were somewhat more difficult to remove.

The adhesives were all completely dry. There are circles of adhesive left on the clay strip, so it appears I had good glue coverage. Of those that popped off, many washers and had no visible glue residue. I believe this shows that the metal resisted the adhesive.

Some of these adhesives might have worked better if I’d done something differently. Many aren’t necessarily meant for use with polymer clay.

CONCLUSION

The adhesives in order of those that performed best were:

Gorilla Super Glue Gel, Loctite Super Glue Gel Control and Super ‘T’ were amazing in adhering both the polymer clay discs and the metal washers to polymer clay. Zap-A-Gap was also amazing in adhering both polymer clay and metal, except on Cernit. Kato Poly Paste and Sculpey Bake & Bond worked well for adhering polymer clay to all brands of clay tested. Fimo Liquid Gel and Genesis Heat-Set Oils Thick Medium worked well to adhere polymer clay to all brands of clay when both surfaces were sanded. Kato Liquid Polyclay worked well to adhere polymer clay to all brands of clay, except Kato. How strange. JB Weld Steel-Reinforced Epoxy worked well to adhere metal to polymer when both surfaces were sanded.

The adhesives that didn’t work well were:

Weldbond

Lisa Pavelka Poly Bonder, at least when baked

3M Super Glue Gel

G-S Hypo Cement

G-S Hypo Fabric Cement

Liquid Fusion

Apoxie Sculpt

Sugru Moldable Glue

Fix-It

Epoxy 330

Fabri-Tac

Multi-Purpose Mac Craft Glue

The clays most receptive to adhesives were:

Soufflé probably because it has a naturally textured, matte surface. Fimo Premo Kato and Cernit

Sanding

Sanding both surfaces made a positive difference in results in 3 out of 7 adhesives.

In Ginger Davis Allman’s post on adhesives, polymer clay artists have reported some adhesives deteriorating over time. I agree with Ginger’s advice on burying metal in polymer clay as the surest method. If you’re burying a wire, put a curve in it to prevent it from pulling out.

If you’re adhering polymer to polymer, I’d recommend using liquid or paste polymer rather than glue because polymer is the most compatible with polymer clay.