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Fast 2K Fence Post Mix and Concrete Alternative and Replacement for Fence Post and Mail Post Installs. 32.8 oz Bag of Expanding Composite Footing Compound

  • Based on 1,853 reviews
Condition: New
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Availability: In Stock.
Fulfilled by Amazon

Arrives Sunday, Nov 24
Order within 1 hour and 23 minutes
Available payment plans shown during checkout

Size: 1 Pack


Style: Fence Post Mix


Features

  • SAVE YOUR BACK: Quick, lightweight patent pending technology replaces 80-100lbs of concrete with a lightweight bag that does not require messy mixing with water that requires cleanup & preparation for filling post holes
  • FAST & SECURE: Ready to build in 15 minutes, and mixes in seconds in place and in the bag. All that you need in a compact and lightweight 32.8 oz bag that mixes into a waterproof protection for your fence posts.
  • PRO TECHNOLOGY: It's the same technology used to set utility poles by the professionals. Now you can quickly and securely set your fence posts and mail posts with a minimum of fuss & mess securely.
  • EXPANDING COMPOSITE TECHNOLOGY: Fast 2K Fence Post Backfill uses an expanding composite technology which is stronger than traditional concrete. Designed to adhere to wood, Vinyl and metal posts.
  • HYDROPHOBIC TO PREVENT ROT: Unlike concrete which absorbs water which can damage metal and wood, the Fast 2K product is waterproof and hydrophobic which prevents water from getting into your posts, reducing rot, rust, deterioration and other water-related damage.

Material: Adhesive, Sealant


Brand: H.B. Fuller


Item dimensions L x W x H: 1.5 x 8.5 x 7.5 inches


Color: No Color


Item Form: Foam


Item Weight: ‎1.28 Kilograms


UPC: ‎713976908484 669602000322


Global Trade Identification Number: ‎22


Manufacturer: ‎H.B. Fuller


Part Number: ‎254-20-S


Item Weight: ‎2.82 pounds


Product Dimensions: ‎1.5 x 8.5 x 7.5 inches


Item model number: ‎254-20-S


Is Discontinued By Manufacturer: ‎No


Size: ‎1 Pack


Style: ‎Fence Post Mix


Finish: ‎Vinyl, Metal


Item Package Quantity: ‎1


Measurement System: ‎Metric


Included Components: ‎Multitool Accessory


Batteries Included?: ‎No


Batteries Required?: ‎No


Warranty Description: ‎Warranty


Date First Available: June 25, 2014


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Sunday, Nov 24

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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Top Amazon Reviews


  • Nice product
Size: 1 Pack Style: Fence Post Mix
Quick and easy. Had a hole filled 8"dia x3' deep with the post inside and filled about 3/4 of the way up to at grade. A little messy.
Reviewed in the United States on July 10, 2024 by Scott K

  • Incredible stuff
Size: 1 Pack Style: Fence Post Mix
This stuff is incredible. Easy to use and sets up quickly!!! My advice is to use it in cooler weather. I used one bag on a hot sunny day and as soon as it started to mix it expanded quicker than I could open it…..yup the bag exploded!!!!!!!!
Reviewed in the United States on June 22, 2024 by Robyn Beeler-nichols

  • Perfect for our mailbox
Size: 1 Pack Style: Fence Post Mix
This is the best I have ever used for sturdiness and ease of use. Five days after we reset and arranged our mailbox. New paint and all... it was hit by a delivery truck. The mailbox got knocked off but the post was just fine. No movement from it. Staying straight, level and strong!!
Reviewed in the United States on June 8, 2024 by Sherri

  • Decent concrete alternative
Size: 1 Pack Style: Fence Post Mix
Though it doesn’t seem as strong as concrete it works amazing for quickly getting the job done with a post. Very easy to use with the bag and your hands being all you need and certainly a LOT lighter than bags of concrete. So much easier for hard to reach areas where you can’t get a vehicle.
Reviewed in the United States on July 2, 2024 by Brock Neilson

  • It actually works!
Size: 1 Pack Style: Fence Post Mix
I was skeptical. I put my mailbox with a "drive-in" type post; however, it immediately began wobbling, even after I drove it deeper! The soil is loose and stony, so I wasn't sure anything would hold, cement had already failed. I saw this product and thought, why not give it a chance? Getting the plastic "divider" off was the most difficult part of the process! Nevertheless, I got it off and began mixing. The package began getting hot and expanding. After the prescribed mixing (30 seconds), I moved to the hole where I planned installing the new post and tore off a corner of the package. Surprise! The "foam" began spewing like a volcano! It got everywhere! My hair, arm, and all over the new post before I was able to direct it into the hole. I was able to finally direct the flow where it was supposed to go. I had just enough time to level the post before it began hardening. Within a couple of minutes the post was in and solid. I gave it overnight before shaking the new mailbox post, it is rock solid! I finally have a mailbox that is not wobbly. The "con" to this product is the price! The package says it replaces two bags of cement; however, two bags of cement is less than $10. The bottom line is that the product, although expensive, works. I am installing fence posts soon, but I doubt I'll be able to afford enough of this product for all of the posts. ... show more
Reviewed in the United States on July 11, 2023 by T Conner

  • Doesn't Last
Size: 1 Pack Style: Fence Post Mix
I have tried two bags of this and for me it just doesn't work. I love the idea of it and how easy it is to use. But it didn't last. I have a loose fence post. I cleared out the area around it down to where the old concrete was and poured in the mixture and watched as it rose like bread dough around the top of the hole and around the bottom of the fence. It felt secure at the end of the day. It came loose again in two days. I could move the fence post in the foam and within a week the fence was just as bad as before I tried it. Today a new bag arrived. I removed the old foam which comes off very easily. Cleaned off everything and tried again. The foam rose but didn't adhere to fence post in the hole. So now I have a loose fence post with a big yellow foam doughnut around it. Too bad. It was such a good idea. An expensive mistake - $50 for both bags and shipping and a bag of Sakrete would have cost under $20. ... show more
Reviewed in the United States on January 28, 2024 by myvureview

  • Was quite hopeful I found something good, took pictures and ended up giving up and buying regular old cement...
Size: 1 Pack Style: Fence Post Mix
UPDATE 1-10-15 Items were sent back (Amazon was superb, they provided a free shipping label to return the items and refunded the cost the day after the package was given to UPS). UPDATE 1-15-15 Amazon marked the items as 'received' and the credit still shows, major kudos to Amazon. Lousy is what this stuff was. I was excited and thought maybe their claim "Same advanced technology used to set utility poles for almost 15 years" might be a good indication but I can say categorically that claim is total non-sense. No way a utility company would ever use this, They might have TRIED it 15 years ago on one pole... So the details! (and I will upload pictures, I was VERY disappointed, so much so that I should have returned the empty containers to Amazon for a refund, but it is not Amazon's problem the products is lousy)... I had two posts I was putting up. These are to be posts to hold Just a hand railing, so they are not 'fence' posts, but a 6 foot fence post, holding a fence panel in the wind, (almost like a sail)? No way, this is an epic failure for that application. If you are 'effectively' OK with backfilling your post in with the equivalent of expanding spray foam, then this is your answer (not a good use, that is a pun)... So here is what I did exactly (pictures prove it!). I ordered 2 ($40) of the "Fast 2k Fence Post Backfill - 26 fl oz" packages from Amazon (after watching a video online and seeing someone use it). I read the instructions CAREFULLY (many times) and as you can see (from me wrapping my hand made posts in plastic wrap) I was concerned the blue foam might get on them and stick to them (I also put a bit of plastic wrap on walkway). The posts are regular 4x4 pressure treated that I have applied strips to, cut at an angle, and sanded and painted everything to end up with the posts you see. ONLY from ground level up is the entire design, below grade is regular 'fence post'... I also made a temporary bracket to hold adjustment to get the exact distance I wanted from both the stairs and edge of the walkway. I was thrilled at the idea of something 'encapsulating' the posts I had hand made (and therefore the posts lasting longer not dealing with groundwater rotting them out from below). Then wanting the posts in an exact spot I made up the temporary wooden alignment guide. Now comes the fun, after reading the instruction many times and being scared of the stuff, I CAREFULLY followed the directions. It was a 50+ degree day and I made sure the product was kept inside at the right temperature till I opened the bag. As you can see in my1st photo (that shows the post and the blue foam in the hole only) it did rise while it expanded but it never came up very far. I waited for over 30 minutes and it only 'rose' about 10" I then realized the hole might need a bit more so I prepped bag two and poured that on top (as directed). It too rose but not much (maybe 6 more inches) and you can see what that looked like in the photo that shows the step and foam and walkway edge. At this point I was out of foam and thought 'where will I get more, how much will it take" a guesstimate indicates this hole would have taken 4 bags and the other hole would have taken about 3 more. All said 7 bags at $20 a bag? How is $140 a good deal? NOW the 'epic failure' of this product. AFTER I carefully did not touch the post (It was very well supported) over and hour AFTER the second bag was poured and the surface of the foam was firm (not tacky) I tested the post. It moved a little bit and did not feel solid. I know the hole was not even half way filled so if it were totally filled with the Fast 2k stuff, maybe it would be OK. BUT if it were half filled with regular old cement that had cured there is no question the post would have been ROCK SOLID. I was bummed, I was not sure if I should 'chip' this foam 'junk' out (at this point I was very disappointed and the honeymoon was over) or what. I did not want to use cement then later find I should have removed the foam nonsense. I was NOT looking forward to trying to remove the post and then remove the foam and decided I would use REGULAR $4 a bag cement from the local home center. I went to the home center. bought 6 (50 pound) bags of quick crete and brought them home. I used a couple of bags and topped of the post that I had started using the 2k foam in, then on the other post I used only concrete. I ended up using about 5 bags total for a whopping $20. Had I used concrete from the start I would have used all 6 bags ($24). so $24 for a rock solid backfilled post or $140 for a post I would forever be worried about it getting 'wobbly'? I will NEVER use or recommend the use of this terrible product. I considered calling them and asking for help, but what can they do, it is a lousy solution for this application. I guess if it were a low fence post (that was in the middle of a run) and NOT under a lot of duress (say a short picket fence) MAYBE it might be OK, but a solid stockade fence, a corner post, an end post, or a gate post? absolutely a terrible idea! Don't get me wrong, Expanding foam is a great product and has MANY great uses but this is NOT a good application for it at all. ... show more
Reviewed in the United States on January 5, 2015 by E. Howland

  • Best to set a single post period.
Size: 1 Pack Style: Fence Post Mix
Simple to use. Dont go beyond 30 sec mixing. You'll feel bag get hot and bloat/ready to burst. I won't waste time with concrete for simple projects like this. Got 5 of my boys to buy it. For retractable water hose. Works awesome
Reviewed in the United States on June 2, 2024 by M.M

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