How to Sand Fibreglass

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How to Sand Fibreglass

Fibreglass is used to create surfboards, doors and some cars and boats. People interested in making repairs to these items should learn to work with fibreglass. Although learning how to sand fibreglass is challenging, it is still a skill that can be mastered with patience. To find the necessary sandpaper, fibreglass putty and other tools required to complete any repair job, dedicated beginners should visit eBay.


Steps Required to Sand Fibreglass

Before beginning any sanding project, beginners should make sure that they have the appropriate safety gear. A respirator, gloves and eye protection are essential for this project. People should also expect to wear long-sleeved shirts and pants to protect their skin as much as possible.

Preparing New Fibreglass

New fibreglass will have a thin coating of gel on its surface. Made of resin, this gel is applied to the surface of fibreglass moulds to ensure a quick release when making parts. Leaving new fibreglass in the sun for a week is the easiest way to prepare it for sanding. People who skip this step may find that the surface bubbles while it is being prepared or after it is painted.

Getting Ready to Sand Fibreglass

People should begin by cleaning the surface of any fibreglass parts with a wax and grease remover. For small jobs, a spray wax and grease remover is easy to use. However, for large projects, users should expect to buy the liquid form of this solvent and apply it with a clean cloth. Using a solvent to clean the surface is necessary even if the parts are new.

If multiple parts will be sanded and eventually refinished, the parts should be assembled and attached before sanding begins. Assembling beforehand will help ensure a uniform appearance between different pieces. It will also allow any joints to be addressed while the surrounding area is being sanded.

Sanding Fibreglass

The tools required for sanding fibreglass will depend on the item being sanded. Areas with a lot of flat surface area, like a power tools like an orbital or belt sander. However, an orbital sander should be avoided when working on areas that have lots of curves or detail, like a custom surfboard. For these items, people should expect to complete most of the sanding by hand using a sanding block and a sanding sponge.

Sanding should begin with 100-grit sandpaper. For new fibreglass, the goal should be to remove the sheen of the glossy gel topcoat. For old painted fibreglass that will be repainted, the goal is to remove the shiny finish, not all of the paint. Sanding too aggressively can create small holes in the fibreglass, which can affect the overall strength of the piece.

Making Fibreglass Repairs

Now people should look for any flaws or holes on the fibreglass that needs to be repaired. Any low spots should be filled with a fibreglass glazing putty or spot putty after the area is carefully cleaned with a dry cloth. Fibreglass filling putty should be avoided unless strength is necessary for the repair, because it is difficult to use and sand.

When applying fibreglass glazing putty, beginners should always follow the manufacturer’s instructions. Many formulas use two parts that are mixed together and then applied to any damaged areas with a putty knife. While making repairs, it’s important that a beginner applies the putty so that it is as smooth as possible to prevent any unnecessary sanding. The putty will need to cure for the manufacturer’s recommended length of time, usually at least 24 hours, before sanding resumes.

Sanding After Repairs

The repairs can be sanded with medium-grit sandpaper, but then the entire fibreglass piece should be sanded with 220-grit sandpaper. Sand the area again with 400-grit sandpaper made for wet sanding.

Once the sanding is complete, the area can be primed and painted. Beginners should keep in mind that they will have to sand in between coats of primer and paint in order to create a professional-looking surface. In most cases, professionals will continue sanding in stages, choosing a fine-grit sandpaper made for wet sanding for each pass after priming the fibreglass. They expect to progress from 400-grit sandpaper to 1500 or 2000-grit sandpaper before applying a coat of paint onto the primer.


How to Find Tools to Sand Fibreglass on eBay

Sanding fibreglass will require safety equipment, sandpaper, fibreglass putty and some other basic tools. To find electric power tools like orbital sanders, shoppers should click on “Shop by category,” which is located to the left of the eBay search bar. They should then select the Car, Truck Parts category, which is underneath the Motors category. Once they’ve navigated into the Car, Truck Parts category, they can select the Tools category to find a wide selection of orbital sanders and sanding disks. Buyers can also use the search bar to quickly find a list of auctions that have the tools they need to help them complete their next project.

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