Don't worry about shoe glue opening; easily repair it yourself!

Shoe Sole Coming Undone? Fix It Yourself, Easy Peasy!

One of the most annoying things we deal with when wearing shoes is when the sole starts to separate. You've got a perfectly good pair of shoes, but just a tiny bit of separation, and it feels like a waste to throw them out – we're all about saving money, right? And trying to find a good repair shop is either impossible or super expensive. So today, I'm going to share some tips on how you can fix those separated soles yourself!

But first, we need to know that shoes generally fall into four main types. Because of how they're made, the way we fix them will be different.

Type 1: Vulcanized Shoes – The "Tough Guys" Baked at High Heat

You probably know vulcanized shoes well – brands like Converse, Vans, and Feiyue often use this process. Basically, the whole shoe gets baked at high temperatures (around 120 degrees Celsius) for 40-60 minutes, turning raw rubber into cured rubber. That's what makes them so durable.

In the past, most people would grab super glue (like 502) to fix these. They thought, "Super glue is so strong, it must work!" But if you've tried it, you'll know that super glue often makes both the rubber sole and the canvas incredibly stiff where it's applied. The result? When you walk and your foot bends, that spot just snaps, and your shoe is completely ruined.

So why does super glue ruin the shoe? First, it's a "small molecule" glue, meaning it's thin like water and seeps right into the canvas and rubber. Second, once it dries, it's rock-hard and has no flexibility. When something that's supposed to be flexible has hard glue seeped into it, it's bound to break when you bend it.

Type 2: Cold Cemented Shoes – The "Gentle" Adhesion for Everyday Wear

Compared to the high-heat "baking" of vulcanized shoes, cold cemented shoes are put together at much lower temperatures (around 55-70 degrees Celsius) for just 3-5 minutes. Even though it's called "cold," it's not actually freezing cold; it's just much cooler than the vulcanization process. Many everyday shoes, like Belle leather shoes (and seriously, some Belle leather shoes nowadays use such un-eco-friendly glue, the smell when you buy them is ridiculously strong!), Nike sneakers like the AJ series, Adidas, and many others, are cold cemented.

When fixing sole separation on these types of shoes, we need to consider two scenarios:

Scenario 1: New Shoe, Original Adhesive Still Works

If your shoe is relatively new and has some sole separation, it means the original adhesive (we call it an "adhesion promoter") hasn't "given up" yet. In this case, you can just use a flexible resin-based glue to fix it. But here's a crucial tip: DO NOT sand it! If you sand it, you'll remove the original factory-applied treatment layer, and then even the best resin glue won't stick properly. Many people don't understand this, and if the resin glue doesn't work, they think it's the glue's fault, when in fact, they've ruined the original "base layer."

Scenario 2: Older Shoe, Original Adhesive Has "Retired"

If your shoe has been worn for a while and the glue has aged and isn't sticking anymore, how do you know if it's aged? Take a hairdryer and blow warm air on the separated area for about 10-15 seconds. Then, touch the old glue; if it feels sticky, it means the original glue has aged.

In this situation, the first and most crucial step is to clean off all the old, aged glue. You can use a glue remover for this. Once it's clean, use sandpaper to lightly sand the opening to remove any oxidized layers. After sanding, you need to apply the correct "adhesion promoter" for the specific sole material (e.g., rubber soles get rubber adhesion promoter, EVA foam soles get EVA adhesion promoter) – getting this wrong is a no-go! Remember, there's no such thing as a "super glue" that sticks to absolutely everything; that's just sellers on Taobao trying to fool you. It's science! Each material has different surface properties, so you need the right promoter to "prime" it. Finally, use a polyurethane resin glue to fix it, and it'll be as good as new, just like it came from the factory!

Hope these little tips help you keep your beloved shoes for a bit longer, saving you money and being kind to the environment!