---
product_id: 48284394
title: "Sika Flex 521 UV, White, Polyurethane Hybrid Multi-Purpose Sealant, Adhesive Sealant for Sealing and Elastic Joints, Weatherproof, 300 ml"
brand: "sika"
price: "R934"
currency: ZAR
in_stock: true
reviews_count: 13
category: "Sika"
url: https://www.desertcart.co.za/products/48284394-sika-flex-521-uv-white-polyurethane-hybrid-multi-purpose-sealant
store_origin: ZA
region: South Africa
---

# High electrical resistance Multi-surface adhesion Weather & aging resistant Sika Flex 521 UV, White, Polyurethane Hybrid Multi-Purpose Sealant, Adhesive Sealant for Sealing and Elastic Joints, Weatherproof, 300 ml

**Brand:** sika
**Price:** R934
**Availability:** ✅ In Stock

## Summary

> 🛠️ Seal the deal with strength and style — don’t let your projects settle for less!

## Quick Answers

- **What is this?** Sika Flex 521 UV, White, Polyurethane Hybrid Multi-Purpose Sealant, Adhesive Sealant for Sealing and Elastic Joints, Weatherproof, 300 ml by sika
- **How much does it cost?** R934 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.co.za](https://www.desertcart.co.za/products/48284394-sika-flex-521-uv-white-polyurethane-hybrid-multi-purpose-sealant)

## Best For

- sika enthusiasts

## Why This Product

- Trusted sika brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Eco-Smart Formula:** Solvent, silicone, and PVC-free for a cleaner, safer workspace
- • **Versatile Surface Master:** Bonds effortlessly to wood, metal, ceramics, plastics, and painted surfaces
- • **Professional Finish Ready:** Can be sanded and painted to blend seamlessly with your project
- • **Fast & Flexible Application:** Skin forms in 30 minutes, allowing quick progress without compromising durability
- • **Ultimate Weatherproof Shield:** Keeps joints flexible and sealed through all seasons

## Overview

Sika Flex 521 UV is a premium 300 ml polyurethane hybrid sealant designed for professional-grade waterproofing and elastic joint sealing. It offers exceptional adhesion across diverse materials including wood, metals, ceramics, and plastics, while resisting weathering and aging. This solvent-free, silicone-free, and PVC-free formula ensures a durable, flexible, and paintable finish with high electrical resistance, making it the go-to choice for managers and pros who demand reliability and a flawless finish.

## Description

Sika Flex 521 UV Hybrid Sealant is specially designed for waterproofing and simple adhesives that can be used on wood, metals, primers and paints, ceramics and plastics. This Sikaflex 521 UV hybrid sealant product has very good resistance to aging and weather conditions. Among its main advantages is its excellent resistance to aging and weather conditions good adhesion on many substrates without special treatment flexible surface can be sanded and painted under non-corrosive odor high electrical resistivity without solvents or isocyanates without silicone or PVC The characteristics of the Sikaflex 521 UV hybrid sealant: density: approx. 1.4 kg/l Colour: White Application temperature: from +5 °C to +40 °C Skin formation time: approx. 30 min. Packaging: 300 ml Reference: Packaging delivered in its original packaging Tips: Application cut the nozzle to the desired gasket size. For more satisfactory results, the sealant should be applied with a suitable manual or pneumatic pump gun or unit. Use SIKA products with caution.

Review: Needed it fast. - Needed this specific product for a client task. As always the main criteria was getting the item quick as this was a urgent task. Delivery was quick and well packaged. The product worked well but as this product was a requirement by the customer I don't think it's fair to compare it to other products. It has remained flexible and provided a weatherproof seal on the component.
Review: Brilliant stuff very strong joint. - Easy to use, full size solar panel fitted to the caravan glued in 6 positions very strong joints fitted Saturday morning could not move it Sunday morning, no holes required in the caravan roof.

## Features

- Contains Trimethoxyvinylsilane. May produce an allergic reaction.
- Safety data sheet available on request.
- Solvent-free, silicone-free and PVC-free sealant and adhesive
- SUSTAINABILITY: Weather and aging resistant
- SUPPORTS: Adheres to a variety of substrates such as wood, metals, primed and painted metals (bicomponent systems), ceramic materials and plastics
- Can be painted and can be sanded
- Elastic and high electrical resistance; It is used by experienced professionals

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B00A9UK1TQ |
| Best Sellers Rank | 32,169 in Automotive ( See Top 100 in Automotive ) 245 in Fillers, Adhesives & Sealants |
| Brand | Sika |
| Customer Reviews | 4.6 4.6 out of 5 stars (6,567) |
| Date First Available | 19 Nov. 2012 |
| Item Weight | 420 g |
| Item model number | 54864 |
| Manufacturer | Sika |
| Manufacturer part number | 54864 |
| Model | Sikaflex-521 UV (Alt) |
| Product Dimensions | 4.9 x 4.9 x 22.5 cm; 420 g |
| Special Features | BIANCO |

## Product Details

- **Brand:** Sika
- **Colour:** Weiß
- **Full cure time:** 3E+1 Minutes
- **Item weight:** 0.42 Kilograms
- **Liquid volume:** 300 Millilitres

## Images

![Sika Flex 521 UV, White, Polyurethane Hybrid Multi-Purpose Sealant, Adhesive Sealant for Sealing and Elastic Joints, Weatherproof, 300 ml - Image 1](https://m.media-amazon.com/images/I/3164D9VzyYL.jpg)
![Sika Flex 521 UV, White, Polyurethane Hybrid Multi-Purpose Sealant, Adhesive Sealant for Sealing and Elastic Joints, Weatherproof, 300 ml - Image 2](https://m.media-amazon.com/images/I/410XvliYzKL.jpg)
![Sika Flex 521 UV, White, Polyurethane Hybrid Multi-Purpose Sealant, Adhesive Sealant for Sealing and Elastic Joints, Weatherproof, 300 ml - Image 3](https://m.media-amazon.com/images/I/416nKxl0wkL.jpg)
![Sika Flex 521 UV, White, Polyurethane Hybrid Multi-Purpose Sealant, Adhesive Sealant for Sealing and Elastic Joints, Weatherproof, 300 ml - Image 4](https://m.media-amazon.com/images/I/51L-j8a-80L.jpg)
![Sika Flex 521 UV, White, Polyurethane Hybrid Multi-Purpose Sealant, Adhesive Sealant for Sealing and Elastic Joints, Weatherproof, 300 ml - Image 5](https://m.media-amazon.com/images/I/51emILCo0UL.jpg)

## Questions & Answers

**Q: Can this be over sprayed with a clear lacquer to protect from discolouration or would the lacquer just peel off in time?**
A: My answer to your question is no. Because of the way sikaflex works is that it doesn't dry totally so it remains flexible to take up movement. This leaves the seal intact and waterproof. Paint or lacquer will crack a fall off in my experience

**Q: can it be smoothed with soap water?**
A: I've just used it to seal my lockers on our caravan. Used a mastic gun. I would not personally use soap to smooth it over. Once on its better than no more nails. But like I say I used it for our caravan.. Excellent stuff

## Customer Reviews

### ⭐⭐⭐⭐⭐ Needed it fast.
*by M***L on 23 May 2025*

Needed this specific product for a client task. As always the main criteria was getting the item quick as this was a urgent task. Delivery was quick and well packaged. The product worked well but as this product was a requirement by the customer I don't think it's fair to compare it to other products. It has remained flexible and provided a weatherproof seal on the component.

### ⭐⭐⭐⭐⭐ Brilliant stuff very strong joint.
*by K***N on 11 June 2019*

Easy to use, full size solar panel fitted to the caravan glued in 6 positions very strong joints fitted Saturday morning could not move it Sunday morning, no holes required in the caravan roof.

### ⭐⭐⭐⭐⭐ Solar panals glue
*by M***T on 5 June 2021*

Great stuff used to glue solar panals on my van

## Frequently Bought Together

- Sika Flex 521 UV, White, Polyurethane Hybrid Multi-Purpose Sealant, Adhesive Sealant for Sealing and Elastic Joints, Weatherproof, 300 ml
- Sika Sikaflex-522 Caravan And Motorhome Adhesive Sealant – Weather And Mould Resistant – White – 300ml

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*Product available on Desertcart South Africa*
*Store origin: ZA*
*Last updated: 2026-02-03*