Krazy Fix Fast Waterproof Glue, Fast Curing Polyurethane Singles, Repair Adhesive for Shoe Repair, Ceramic, Plastic, Jewelry, Metal, 12 Grams

Why I reached for this glue

A string of small, annoying repairs around my house—loose shoe sole, cracked ceramic planter, a wobbly address plate on brick—pushed me to try Krazy Fix Fast, a polyurethane adhesive gel sold in small single-use tubes. I typically keep cyanoacrylate super glue and a two-part epoxy on hand, but I wanted something that could bridge gaps, handle outdoors, and set faster than traditional polyurethane wood glue. After several weeks of use, this has become the adhesive I reach for when I need a strong, weatherproof bond without mixing.

What it is (and isn’t)

Krazy Fix Fast is a moisture-curing polyurethane gel, not a cyanoacrylate. It’s a light brown, slightly thixotropic gel that goes on smoothly and holds its shape. The single-use format keeps waste down—each tiny tube delivers enough for one medium repair or a couple of small ones, and then you toss it before it clogs. If you’ve ever ruined a full-size bottle of glue after one project, you’ll appreciate the format immediately.

Because it’s polyurethane, expect a few things:
- It can expand slightly as it cures, sometimes creating a subtle foaming at the squeeze-out line.
- It sets faster than typical polyurethane glues; in my tests it grabbed in minutes and was clamp-free safe much sooner than I expected.
- It cures opaque and light brown. Not the glue to choose when you need a truly invisible repair.

Setup and ease of use

The ergonomics are thoughtful. The precision tip is narrow enough to run a controlled bead, and the gel doesn’t run or drip. There’s no mixing, no pre-wetting, and no elaborate prep beyond the basics: clean, dry, and scuff glossy surfaces. My working time was roughly two to four minutes at room temperature, with an initial grab you can feel start to happen quickly. I still prefer to clamp or tape pieces together for best alignment, but I was surprised how quickly the assembly became stable enough to set aside.

Cleanup is easiest before the glue cures; a quick wipe with a rag dampened with mineral spirits handled small squeeze-out. Once cured, you’re in mechanical removal territory—careful scraping or sanding.

Real-world repairs

• Shoe sole reattachment: I re-bonded a peeling rubber sole to a leather upper. A thin, even bead on both surfaces, a quick press, and a few minutes of clamping with binder clips. After 15 minutes, the joint felt secure enough to walk around the house; after overnight cure, it’s held through wet sidewalks and daily commutes. The cured line remains flexible enough to move with the shoe, which is where this beats brittle super glues.

• Ceramic planter crack: The structural hold was excellent. The adhesive filled a small gap where the crack wasn’t perfectly tight, and the foaming sealed microvoids. Aesthetic trade-off: the cured line is visible and slightly amber/opaque. If you need an invisible ceramic repair, look elsewhere; if strength and weather resistance matter more, this works.

• Metal address plate to brick: Outdoor mounting is a good test for any glue’s bravado. I scuffed both the back of the plate and the brick high points, then applied small dabs across the contact area. It grabbed quickly and didn’t sag. After a couple of rainstorms and some hot afternoon sun, the plate hasn’t shifted, and there’s no sign of creep.

• Plastics: On an ABS toy, the bond was excellent. On a slick polypropylene bin, the first attempt failed after a light bump—no surprise, as low-surface-energy plastics are notoriously difficult. After aggressive scuffing and wiping with isopropyl alcohol, I got a serviceable hold, but I wouldn’t count on it for PP or PE without mechanical reinforcement.

• Leather patch: A loose belt loop on a leather bag reattached cleanly. The glue grabbed without soaking through the leather, and the joint remains flexible.

Performance and durability

For a polyurethane, the curing speed is impressive. I consistently saw a noticeable set within minutes and a functional bond in around 10–20 minutes, depending on material and joint fit. Full strength still benefits from an overnight cure. The slight expansion during cure helps fill tiny gaps and improves contact on porous surfaces like wood, stone, and brick.

Waterproofing is solid. I’ve soaked and rinsed test joints and left the outdoor plate to the elements. No softening or discoloration of the bond itself beyond the adhesive’s inherent light-brown color. Heat cycles from late-summer sun didn’t loosen the exterior bond, and indoor joints in a bathroom fared fine with humidity.

Where it fits among common adhesives

• Versus cyanoacrylate: Krazy Fix Fast is slower than super glue but far more forgiving on porous materials and better outdoors. It’s also a little flexible and gap-filling, which helps on imperfect joints. It’s not transparent, and you don’t get that glassy, invisible seam.

• Versus epoxy: It wins on convenience—no mixing, no worrying about resin/hardener ratios, no short pot life to manage. Epoxy still has the upper hand for crystal-clear fills, precise control over cure time, and bonding certain plastics and composites. For most household fixes where transparency isn’t crucial, the polyurethane gel is faster to deploy and plenty strong.

• Versus traditional polyurethane wood glue: This sets faster and with less mess, and the gel consistency is easier to control on vertical surfaces.

Packaging and value

The small tubes are the unsung hero here. Polyurethane glues can degrade once opened, and big bottles often go to waste. The singles solve that. Each tube dispenses cleanly, and I had no issues with partial reuse if I was careful to cap immediately and purge a tiny bit of air. That said, I still treat them as one-and-done for reliability. The overall quantity is modest, but because each fix uses so little, it’s cost-effective for targeted repairs.

One wish: a quick-reference cure chart on the packaging for different materials and temperatures. The product is straightforward, but a clear guide would help new users dial in expectations.

Tips for best results

• Prep matters: Clean surfaces thoroughly and scuff glossy plastics and metals.
• Use a thin, even bead: More glue doesn’t mean a stronger bond; it just increases squeeze-out and foaming.
• Clamp or tape for alignment: Even with fast grab, gentle pressure yields cleaner lines and stronger joints.
• Expect color change: Plan to hide the bond line or be comfortable with a visible seam.
• Mind the plastics: ABS, PC, and many nylons bond well; PP, PE, and PTFE are poor candidates without primers or mechanical fasteners.
• Safety: Wear gloves. Avoid skin contact. Use in a ventilated area. Wipe excess promptly with mineral spirits; once cured, it’s scrape-only.

Pros

• Fast initial set for a polyurethane; workable in minutes
• Strong, waterproof, and weather-resistant bonds on porous and nonporous materials
• Gel consistency resists sag and is easy to place precisely
• Single-use tubes minimize waste and clogging
• Slight expansion fills tiny gaps and irregularities

Cons

• Cures opaque/light brown; not suitable for invisible repairs
• Can foam at the edges, requiring cleanup or sanding
• Mixed results on low-surface-energy plastics
• Limited quantity per tube; partial reuse is hit-or-miss

Verdict

I recommend Krazy Fix Fast for anyone who needs a quick-setting, durable, weatherproof adhesive for everyday repairs—especially on shoes, ceramics (where appearance isn’t critical), wood, metal, stone, and outdoor fixtures. It occupies a sweet spot between super glue and epoxy: easier than epoxy, more forgiving and weatherproof than super glue, and faster than traditional polyurethane. The trade-offs are clear—the cured bond is visible and can foam—but the strength, versatility, and convenience of the single-use tubes make it a practical addition to a home repair kit. If clear, seamless joints are your priority, reach for epoxy. For most practical fixes where function outranks cosmetics, this glue earns a spot on the bench.