U-Pol Body Filler Mixing Sheet

U-Pol Onion Board: The Professional's Choice for Body Filler Mixing

When it comes to body filler mixing sheets, few names carry the authority of U-Pol. As a brand with over 75 years of experience and a presence in more than 100 countries, U-Pol has engineered every element of the body repair workflow — and that commitment extends all the way to the mixing palette sitting on your workbench.

The U-Pol Onion Board (UP0737)

U-Pol's flagship mixing sheet product is the Onion Board Multi-Layered Mixing Palette (SKU: UP0737). This cleverly named board is a staple in professional bodyshops worldwide, and it's easy to see why. The Onion Board features multiple peel-off sheets stacked into a single pad — each layer tears away cleanly once your mix is done, leaving a fresh, uncontaminated surface ready for the next job. No cleaning solvents, no scraping, no wasted time.

The pad contains 100 disposable sheets, giving a full shop's worth of clean mixing surfaces in a single purchase. Each sheet provides a non-porous, stable surface that doesn't react with polyester body fillers, hardeners, or glazing compounds, ensuring your catalyst ratios remain accurate from the first stroke to the last.

Why Mixing Technique — and the Right Surface — Matters

U-Pol's own technical guides emphasize that proper filler mixing is one of the most critical steps in eliminating pinholes and air entrapment in the finished repair. The recommended figure-8 technique, pressing the filler and activator together on a flat, solid palette, works best on a surface that doesn't flex, absorb, or contaminate the mixture. The Onion Board is designed around exactly this workflow — firm enough to support the pressing action, smooth enough to keep the blend consistent.

Using a dedicated mixing sheet rather than an improvised surface helps technicians maintain the correct hardener-to-filler ratio, which directly impacts cure time, sanding ease, and long-term adhesion. This is especially important when working alongside premium U-Pol fillers like the Dolphin One Fill, FANTASTIC Ultra Lightweight Filler, or EXTRA GOLD Easy Sand Filler, all of which rely on precise catalyst mixing for optimal results.

Designed to Integrate With the Full U-Pol System

The Onion Board is consistently listed as a recommended accessory throughout U-Pol's official repair guides and product technical data sheets. Whether you're using glass fibre repair pastes, specialty flexible fillers, or standard polyester body fillers, U-Pol specifies the Onion Board as the mixing surface of choice. This tight integration across U-Pol's product ecosystem means the mixing palette isn't an afterthought — it's a tested, validated part of the professional repair process.

For shops and enthusiasts who trust U-Pol's fillers, primers, and coatings, stocking the Onion Board alongside those products is simply part of a well-run repair workflow. Explore the full range of body filler mixing sheets or browse all U-Pol products to build out a complete, professional-grade repair setup.