Weatherables Fast 2k Fence Post Backfill

I used the H.B. Fuller Fast 2K Post Anchor Mix to set a 6‑foot post for a retractable hose reel, and it worked exactly the way it’s supposed to. I followed the directions — all of them — and shockingly, that seems to be the secret sauce. After reading some of the one‑star reviews, I’m convinced a few folks either skipped the instructions or probably shouldn’t be trusted with products that expand, harden, or require more than one brain cell to operate. This stuff isn’t rocket science, but it does require you to do something other than guess. Mix, pour, hold the post steady, and let it do its thing. It expanded, locked in, and cured fast. The post is solid, the hose reel doesn’t wobble, and I didn’t have to haul 80‑pound bags of concrete like a medieval laborer. If you can read and follow simple steps, this product works great. If you can’t… well, your results may vary.

Bought to set a new mailbox post, was surprised at how quickly and easily it expanded. Has been installed for 4 years and you can’t move it if you tried, quite durable. It expands to a much larger extent than i thought it would, more than filled the hole. Excess can easily but cut away.

Works beautifully! Decent price and durable. Correct size hole and depth or it overflows like bread dough! Wear clothes/shoes you don't care about as it stiffens quick. Def recommend!

It starts firming up very quickly. You want to pour it in, get as much out of the bag as possible, and without getting it on you. I used it on two 4x4 fence posts to extend our fence line a little - it was easy to mix and pour, but I wish I had one more bag, as the hole wasn't completely filled when the foam stopped expanding. It did not feel as rock-solid as concrete, but if I need to dig it out later...it'll be much easier. I also used it for a 4x4 fence post going into an older 5x5 fence gate post hole in concrete. Dig up concrete, just to pour new concrete? Try to fit new concrete in the existing hole, around the fence post? That would never work. The foam turned out to be ideal for this use case. It grabbed the existing hole and the new fence post, feels very sturdy.

Fast 2K Fence Post Mix exceeded my expectations! I was looking for an alternative to traditional concrete that would save me time and effort, and this product delivered. The setup process was incredibly simple—just mix, pour, and let it set. Within minutes, the post was firmly in place, and I didn't have to deal with heavy bags of concrete or long curing times. I also appreciate that it expands to create a strong and stable hold, making it ideal for fence posts and other outdoor projects. Plus, it's lightweight and easy to store, which is a huge bonus. If you're looking for a fast, mess-free way to secure posts without the hassle of concrete, this is the perfect solution. Highly recommended!