---
product_id: 58062586
title: "Sikaflex 521, White, UV Resistant Low Modulus Sealant, 300ml Cartridge"
brand: "sika"
price: "¥16957"
currency: JPY
in_stock: true
reviews_count: 4
category: "Sika"
url: https://www.desertcart.jp/products/58062586-sikaflex-521-white-uv-resistant-low-modulus-sealant-300ml-cartridge
store_origin: JP
region: Japan
---

# High Electrical Resistance Water Resistant Formula UV Resistant Sealant Sikaflex 521, White, UV Resistant Low Modulus Sealant, 300ml Cartridge

**Brand:** sika
**Price:** ¥16957
**Availability:** ✅ In Stock

## Summary

> 🔧 Seal smart, stay secure — the pro’s choice for flawless finishes!

## Quick Answers

- **What is this?** Sikaflex 521, White, UV Resistant Low Modulus Sealant, 300ml Cartridge by sika
- **How much does it cost?** ¥16957 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.jp](https://www.desertcart.jp/products/58062586-sikaflex-521-white-uv-resistant-low-modulus-sealant-300ml-cartridge)

## 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

- • **Ultimate UV Defense:** Keeps your seals flawless under harsh sunlight, perfect for outdoor projects.
- • **Compact & Easy to Use:** 300ml cartridge fits standard caulk guns for precise, mess-free application every time.
- • **Long-Lasting Adhesion:** Strong hold that stays intact even after unscrewing, ensuring durable protection.
- • **Electrically Safe Seal:** High electrical resistance ensures safe use around sensitive electronics and solar panels.
- • **Versatile Surface Compatibility:** Bonds seamlessly with aluminium, glass, wood, plastic, and ceramic for all your sealing needs.

## Overview

Sikaflex 521 is a premium white, low modulus polyurethane sealant designed for superior UV resistance and high electrical insulation. Ideal for sealing and bonding on diverse surfaces like metal, glass, wood, and plastic, it offers durable, water-resistant protection in a convenient 300ml cartridge. Trusted by professionals for outdoor and solar panel installations, it delivers strong adhesion and long-lasting performance.

## Description

NA

Review: Works great - Used this in a recent solar panel install on a van and so far seems to work great. Been through one very significant rainfall about a week after install and everything seems to be sealed tight. Along with sealing our install, it also seems to have a very strong adhesion as even when things are unscrewed, still holding on strong. Made the mistake of forgetting a caulk gun...don't do that, not too easy to apply without it.
Review: "STALE DATED SIKA 521UV" & GOT STUCK WITH A $22.00 RETURN SHIPPING FEE ???? - Stale, old expired 521UV tube !!!! Sika you should be updated on what you sell. It was a pain returning it, along with me having to shell out $22.00 for return shipping on a stale dated item which was never mentioned in the returns ? I will be following up on this. Just out of curiosity, "SIKA" are your reading this, customer reviews do carry weight. Thx.

## Features

- Safety data sheet available on request.
- High electrical resistance
- Resistant to UV radiation
- International products have separate terms, are sold from abroad and may differ from local products, including fit, age ratings, and language of product, labeling or instructions.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B005FCIB04 |
| Brand | Sika |
| Colour | White |
| Compatible Material | Aluminium, Ceramic, Plastic, Wood |
| Customer Reviews | 3.6 out of 5 stars 18 Reviews |
| Global Trade Identification Number | 07612894448689 |
| Item Dimensions | 5.1 x 5.1 x 35.6 centimetres |
| Item Form | Liquid |
| Item Type Name | Great Product |
| Item Weight | 1 Pounds |
| Item dimensions L x W x H | 5.1 x 5.1 x 35.6 centimetres |
| Item weight | 1 Pounds |
| Manufacturer | Sika |
| Manufacturer Part Number | 106096 |
| Material | Polyurethane |
| Model Number | SIKA-106096 |
| Number of Items | 1 |
| Style | Compact |
| Style Name | Compact |
| Surface Recommendation | Glass, Metal, Plastic, Wood |
| Unit Count | 10.1 millilitre |
| Water Resistance Level | Water Resistant |
| Water resistance level | Water Resistant |

## Product Details

- **Brand:** Sika
- **Item dimensions L x W x H:** 5.1 x 5.1 x 35.6 centimetres
- **Item weight:** 454 g
- **Material:** Polyurethane
- **Style:** Compact

## Images

![Sikaflex 521, White, UV Resistant Low Modulus Sealant, 300ml Cartridge - Image 1](https://m.media-amazon.com/images/I/61gUwAR32uL.jpg)

## Questions & Answers

**Q: Is this product self leveling?**
A: no but it is the ultimate for sidewall applications.  They make a self leveling silkaflex

**Q: Can i use sikaflex 521 uv under water?**
A: Not sure but I believe it needs to cure in the open air then it would be fine

## Customer Reviews

### ⭐⭐⭐⭐⭐ Works great
*by P***W on 1 May 2025*

Used this in a recent solar panel install on a van and so far seems to work great. Been through one very significant rainfall about a week after install and everything seems to be sealed tight. Along with sealing our install, it also seems to have a very strong adhesion as even when things are unscrewed, still holding on strong. Made the mistake of forgetting a caulk gun...don't do that, not too easy to apply without it.

### ⭐ "STALE DATED SIKA 521UV" & GOT STUCK WITH A $22.00 RETURN SHIPPING FEE ????
*by M***M on 13 July 2026*

Stale, old expired 521UV tube !!!! Sika you should be updated on what you sell. It was a pain returning it, along with me having to shell out $22.00 for return shipping on a stale dated item which was never mentioned in the returns ? I will be following up on this. Just out of curiosity, "SIKA" are your reading this, customer reviews do carry weight. Thx.

### ⭐⭐⭐⭐⭐ The best on the market
*by K***A on 13 April 2019*

I use this product on the desk of my yacht with excellent performance. Also use it on the exterior of my older RV while the old sealant is dry, cracking and not holding the trim in place. The UV additive and consistency makes it the best buy. I have given up on 3M 5200/4200.

## Frequently Bought Together

- Sikaflex 521, White, UV Resistant Low Modulus Sealant, 300ml Cartridge
- AP Products 017-187690 Sikaflex-715
- Sika Sikaflex-221 - Black - Multi-Purpose Polyurethane sealant/Adhesive - Creates Permanent Elastic Seal - Sandable/paintable - Non-Corrosive - 10.1 fl oz

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**Shop now:** [https://www.desertcart.jp/products/58062586-sikaflex-521-white-uv-resistant-low-modulus-sealant-300ml-cartridge](https://www.desertcart.jp/products/58062586-sikaflex-521-white-uv-resistant-low-modulus-sealant-300ml-cartridge)

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*Product available on Desertcart Japan*
*Store origin: JP*
*Last updated: 2026-08-17*