Could this be used to fill a plaster of Paris mold?

Not that I'm aware of, it doesn't really say on the package but it does sit up very fast and is very durable. Sorry but that's the best I can answer your question.

Could this be used to hold an 8x8 supporting a substantial weight?

I had to replace a 4x4 post for my mailbox and used this 2K Post Back Fill. I already had a deep hole in the cement, so this stuff fills up the gaps beautifully all around and keep the post solidly planted. I'm not sure about 8x8, weight is not the issue here but you would need a "solid" hole like in my case to hold to post, then this foam would then fill up any gaps. Good luck.

Can this be used to form the deck list foundation where the 8x8 post then sits on top held by a bracket anchored in the foundation?

No, Fast 2K can only be used for installing posts that are sunk into the ground. It cannot be used as a foundation material nor can any brackets be anchored into it.

Would this be good to use for posts for a horse fence strong and sturdy?

Yes, also sets up quick and should be good for a horse fence.

Fully operational. Shipping worldwide, on schedule.Duty & taxes paid at delivery

Help Track order

Account Cart

Fully operational. Shipping worldwide, on schedule.Duty & taxes paid at delivery

Help Track order

Account Cart

Fast 2K Post Anchor Mix | Expanding Composite Footing Compound (Fence, 1)

Fast 2K Post Anchor Mix | Expanding Composite Footing Compound (Fence, 1)

Product ID: 17019209

Details

Brand
H.B. Fuller
Color
Yellow
Item dimensions L x W x H
1.5 x 8.5 x
Material
Adhesive
Shape
Rectangular

⚡2.5lb replaces 80lbs concrete

⏱️Sets in 5 minutes, build in 30

🌡️-5°F to 105°F use range

Buy anything from 5,000+ international stores. One checkout price. No surprise fees. Join 2M+ shoppers on Desertcart.

$75.64

Duties & taxes included

In stock

Sold byAmazon British Virgin IslandsDelivered byDesertcartCustomer service byDesertcartReturns14 days · 30 with PRO

Buyer Protection · Full refund if your order doesn't arrive as described.

Desertcart purchases this item on your behalf and handles shipping, customs, and support to British Virgin Islands.

Secure transaction

Description

⚡ Fast, strong, and effortless—anchor your projects like a pro!

SPEED DEMON SETUP - Mix in 30 seconds, set in 5, and build on your post in just 30 minutes—time is money.
ROT RESISTANT BOND - Hydrophobic formula clings tight to prevent rot and corrosion, extending your post’s life.
ALL WEATHER WARRIOR - Reliable performance from freezing -5°F to scorching 105°F, no water or additives needed.
CODE READY STRENGTH - Meets building codes for load-bearing foundations—professional-grade peace of mind.
LIGHTWEIGHT POWERHOUSE - Ditch the heavy 80lb concrete bags—just 2.5lbs for the same strength.

H.B. Fuller Fast 2K Post Anchor Mix is a lightweight, expanding composite footing compound designed to replace traditional concrete for fence posts and similar projects. It mixes quickly without water, sets in 5 minutes, and supports construction in a wide temperature range (-5°F to 105°F). Its hydrophobic technology prevents rot and corrosion, ensuring durable, code-compliant foundations with minimal effort.

Specifications

ASIN	B00LAFUC34
Best Sellers Rank	#20,968 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #55 in Decking & Fencing Materials
Brand Name	H.B. Fuller
Color	Yellow
Customer Reviews	4.3 4.3 out of 5 stars (1,735)
Global Trade Identification Number	00669602000322
Grade Rating	Industrial
Included Components	Multitool Accessory
Item Diameter	3.05 Centimeters
Item Dimensions	1.5 x 8.5 x 7.5 inches
Item Form	Foam
Item Shape	Rectangular Prism
Item Type Name	Fast 2K 26OZ Back Fill
Item Weight	2.5 Pounds
Manufacturer	H.B. Fuller
Material	Adhesive, Sealant
Model Number	254-20-S
Number of Items	1
Part Number	254-20-S
Specification Met	True
UPC	713976908484 669602000322
Unit Count	1.0 Count
Warranty Description	Warranty

Common Questions

Are the products genuine and authentic?+

Yes, all products are sourced directly from authorized retailers in the US, UK, UAE and India. We maintain strict quality control processes and verify each product before shipping. All items come with applicable manufacturer warranties and are covered by our standard return policy.

How long does delivery take and is it reliable?+

Delivery times vary by destination country, typically ranging from 3-9 business days. Each order is fully trackable through our system. We handle all customs clearance and use reliable courier partners for last-mile delivery. You'll receive regular updates about your order status via email and our app.

What is Desertcart? Is it safe to order from?+

Desertcart is an international e-commerce platform operating since 2014. We securely process thousands of orders globally each day. Every product goes through our quality verification process before delivery, and we provide end-to-end order tracking, 24/7 customer support, and a comprehensive returns policy to ensure a safe shopping experience.

How is product pricing calculated?+

Our prices include the product cost, international shipping, import duties, customs clearance, and local delivery charges. We handle all customs and import procedures, ensuring there are no hidden fees upon delivery. PRO members receive additional benefits including free shipping.

Trustpilot

TrustScore 4.5 | 7,300+ reviews

Abdullah B.

Great price for an authentic product. Fast international shipping too!

3 weeks ago

Rajesh P.

Customer service was outstanding when I had questions about the product.

2 days ago

View all Trustpilot reviews

Shop Global, Save with Desertcart

Value for Money

Competitive prices on a vast range of products

Shop Globally

Serving millions of shoppers across more than 100 countries

Enhanced Protection

Trusted payment options loved by worldwide shoppers

Customer Assurance

Trusted payment options loved by worldwide shoppers.

Desertcart App

Shop on the go, anytime, anywhere.