Fabric Wet Out: When To Use What Tool

Serrated rollers are typically metal, usually aluminum, with deep grooves in them. This means they are substantially more expensive than plastic spreaders but still reasonable. These are particularly useful epoxy resin tools when wetting out heavy fabrics, especially if you have multiple layers of heavy fabrics. The serrations help focus your downward force into a more concentrated area and the grooves allow air to escape. This allows the epoxy to penetrate deeply into thick fabrics. These can move quickly over thick fabrics but begin to skid and slide when used with thinner fabrics.

While plastic spreaders work well on thin fabrics, using alternative tools is often more efficient. Although many people treat plastic spreaders as disposable, I prefer not to buy new rollers every time I need to wet out fabric. Therefore, I find it important to keep them clean. You can do this by disassembling them and wiping them down with acetone, lacquer thinner, or denatured alcohol.

Although corner rollers are unnecessary for wetting fabric, I felt I should mention them. They are often available in a kit with other rollers and are made of metal, featuring several differently-sized wheels. Nothing gets into a corner like these, especially in hard-to-reach places like under a bench or in a cabinet. These tools primarily press pre-wetted laminates into challenging corners, ensuring that no air gaps remain. These provide the same mechanical advantage that the serrated rollers do by focusing the downward force of your arm into a small area, greatly increasing the pressure. Because these are so narrow, it would take way more time and effort to use one of these guys to wet out any considerable amount of fiberglass.

Bristle and knob rollers take that mechanical advantage and dial it up to 10. The applied force now focuses on either the points of the knobs or the tips of the bristles on several small metal strips. These typically saturate very heavy fabrics or chop strand mats. While we don’t recommend using epoxy with chop-stranded mats, this is what we would use if we did. Using a thick fiber with bristle rollers enhances application on porous surfaces. The bristles can penetrate the foam carrying the epoxy with it. This helps create a mechanical bond between the core and the laminate. However, they work well for thick fabrics and mats, and they work just as poorly on light fabrics. They don’t move the epoxy around nearly as well as a plastic spreader.

Hands are a great tool, and I’m pretty attached to my set. They are an excellent tool for lifting and manipulating fabric, which helps ensure that specific areas receive adequate wetting. Even though they don’t provide the even pressure like a roller or plastic spreader would, but they will certainly do in a pinch. They won’t penetrate as deeply as any rollers, but hey–they’re free! Finally, they won’t put fabric into the corners or corner rollers, but they are certainly better than nothing. Like all tools that aren’t disposable, you should do everything you can to protect them. When working with epoxy, wear gloves and cover any exposed skin that may get epoxy on it.