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Mix-In-The-Bag Expanding Polyurethane Post-Setting Foam Fast Setting 33 -fl oz Repair accessory

Ratings & Reviews for Sika Mix-In-The-Bag Expanding Polyurethane Post-Setting Foam Fast Setting 33 -fl oz Repair accessory

4.0
809
Review
 4 out of 5
813 Reviews


74% Recommend this product

Ratings may include incentivized customer reviews.

What Customers Are Saying

The product is easy and quick to use, with a fast set time, and is lightweight and mess-free compared to traditional concrete. However, it may not be as structurally strong, especially for applications requiring high stability or weight-bearing. The product works best for simple, standalone uses like mailbox posts or light-duty fencing, but users need to carefully follow the instructions to avoid issues. Overall, it can be a good option for certain light-duty post installation projects, but concrete may still be the better choice for critical structural applications.

Customer review summary generated by AI, including incentivized reviews.
813 Customer Reviews

Wish they could package it with smaller use amount

Would Recommend

It seems to be a very good strong hold.

April 30, 2026
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Definitely wear proper protective gear

Would Recommend

Very easy to use.

April 29, 2026
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Fast Setting

Would Recommend

Mix-In-The-Bag works quickly and efficiently.

April 27, 2026
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Great stuff Easy to use.

Would Recommend

Worked as expected. It really expands, I cut excess off with a pruning saw.

April 23, 2026
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Mix in the bag expanding

Would Recommend

I love the convenient and no mess. Highly recommend.

April 23, 2026
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Quick and easy

Would Recommend

Product works well. Bag will violently explode and dispense it's contents everywhere if shaken just slightly too long. User error on my part, heads up for anyone else.

April 22, 2026
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Been using it for years awesome product

Would Recommend

Great for setting up post for fence and easy. No concrete bags needed and not as heavy. Ensure that your post are level and framed.

April 21, 2026
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Make sure to mix it quickly.

Would Recommend

It worked as well as the concrete for a fence post. The biggest difference is the speed in which this sets.Once you break through to the other side make sure and mix it quickly. It says for 15 secs. Also it gets very hot so make sure to be causious when pouring this.

April 20, 2026
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It only takes a few minutes to mix in the same pou

Fast and easy to use!!

April 19, 2026
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Do not use if you have dogs

Would Not Recommend

Used this on a fence repair. Easy to use if you follow the directions and the post at least initially seems secure. However it hardens more like a flaky Styrofoam than a pumice... so it it very appealing for our dogs to dig, which they did on day 2. Makes a huge mess of what I assume is microplastic when damaged. I think neighborhood rats will also be finding it fun to chew. Going to pull and replace with concrete. This was an experiment I will not be repeating.

April 19, 2026
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Perfect product for mailbox

Super easy to use, expands A LOT, prepare as directed.

April 17, 2026
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Easy to use and directions are precise!

Would Recommend

The directions are pretty straight forward and easy to understand.

April 16, 2026
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Works perfect.

Would Recommend

It worked exactly how it’s suppose to.

April 16, 2026
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You have to act fast once once you break the seal!

Would Recommend

We coated 2 foot of the 4x4x8 with roofing cement. The bag foam works great. Sets up fast, strong and will keep the post dry for many years!

April 16, 2026
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time it took to harden

Would Not Recommend

took longer than expected to harden

April 16, 2026
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