Sanding fiberglass is an extremely important step prior to painting. And for a successful sanding process, you’ve to ensure the entire surface is flat and smooth. To do that, you might have to sand it even through the primer coats.
Hence the most important thing is to ensure that you utilize the best fiberglass sandpaper. This is because different sandpapers have different grit, backing, and sizing. So, lacking to choose the right sandpaper will affect the process for sure.
Don’t worry, you’ve got it in one place!
Of course, it’s beneficial if you learn about the types and grits. But if you don’t have that scope, we’ve already covered that for you. It’s a CAREFULLY PICKED list of some of the best types of sandpapers that you can utilize for a great sanding performance on fiberglass materials.
Quick round-up table with top 5 products:
| Image | Name | Our Rating | Price | |
|---|---|---|---|---|
 |
Assorted Grit Hook & Loop Fiberglass Sandpaper |
5 out of 5 |
Check On Amazon | |
 |
Coceca – Assorted Grit Mouse Detail Sandpaper |
5 out of 5 |
Check On Amazon | |
 |
Aluminum Oxide Fiberglass Sanding Belt |
4.5 out of 5 |
Check On Amazon | |
| Super Fine 400 Grit Wet/Dry Fiberglass Sandpaper |
4.5 out of 5 |
Check On Amazon | ||
 |
Wet and Dry Waterproof Abrasive Variety Pack |
4.5 out of 5 |
Check On Amazon |
To read about our product selection procedure, visit the “About” page.
11 Best Sandpaper for Fiberglass: Reviews
Fiberglass refers to the mat of glass fibers, mainly used in reinforced plastic. It’s used in various products like cars, furniture, and boats, etc.
When it comes to sanding, a few things you should consider. Such as, for existing paint layer removal, you might start with sandpaper of 80 grits. But for some specific paint, you might need to roughen the surface using 40 girts. And, probably go down to a little bit more aggressive version (36 girts) when smoothening the glued area.
1. Assorted Grit Hook & Loop Fiberglass Sandpaper
This assortment of fiberglass sandpaper gives you several sheets with different grits. Thus, enabling you to perform various tasks. And because of being multipurpose, you can use this for different projects.
Such as, you could also fit this in as drywall sandpaper.
It comes in a great assorted pack containing 60 sanding discs of six different grits. These grit grades include; 400, 320, 240, 150, 120, and 80 grit. The different grit grades ensure you get the best grit that meets the requirement of your project.
You’ll find each grit grade on 10 units.
Each sanding disc has a diameter of 5 inches, enabling them to fit in most 5” orbital sanders. You’ll also be impressed by the hoop & loop adhesion of these discs to the sanders. This prevents them from falling off during use. Additionally, each disc has 8 pre-punched holes.
This allows for the maximum extraction of dust.
Being made with aluminum oxide abrasive material, this product is sturdy to use and durable. Besides, you can easily identify sanding discs of various grit grades. This is because the grit grade is printed at the back of every sanding disc.
Feature Highlights:
- Fits in most 5” orbital sanders
- Easy to use large batch with 60 pieces
- Easy grit identifying with printed back
- Allows maximum extraction of dust
- Ideal for multipurpose uses
- Hoop & loop adhesion
2. Hook & Loop Fiberglass Sanding Discs Sandpaper
If you’re looking for cost-effective solutions, have a look at this LotFancy hook & loop fiberglass sanding discs. Most consumers, who have used this, had many things to say about it. This is mostly why we’ve decided to bring some of its amazing features in front of you.
These are made using high-quality aluminum oxide abrasive material. In addition to being durable, aluminum oxide grains provides faster cutting. The material also has a stearate coating that enables it to resist clogging.
This coating helps in extending its durability and performance.
Additionally, the semi-open coat provides a consistent and uniform scratch pattern. On the other hand, the premium system of the resin bond provides a smooth finish. Also, they are easy to replace during the action.
Following that, it’s compatible with various reputable orbital sanders.
This product comes in a package of 100 sanding discs of 80 grit grade. Each disc has 8 pre-punched holes that promote the efficient extraction of dust. The discs are designed for heavy-duty removal and high-speed sanding. Thus, deliver a long-lasting and fast cut, resulting in more productivity and better surface finishes.
Besides sanding fiberglass doesn’t hesitate to wish for various other surfaces like automobiles, accessories, aluminum alloy, plastic, and painted surfaces.
Feature Highlights:
- Very effective fiberglass sandpaper
- Consistent and even scratch pattern
- Compatible with several orbital sanders
- Provides better surface finishes
- Efficient dust extraction
- Multipurpose application
3. Coceca – Assorted Grit Mouse Detail Sandpaper
Choosing a set with many sheets is a great option, especially when you’ve got a large sanding project. And this Coceca mouse sanding paper may be just the best option in such a scenario.
This product comes in a pack of 50 sheets. Moreover, you can group these sheets into 5 grit grades, each grade having 10 sanding sheets. The grit grades of this product include; 240, 180, 120, 80, and 40 grit. Each sanding paper measures 140 mm by 90 mm.
This makes it extremely versatile for various sanding tasks and compatible with most 140mm mouse sanders. You can store the remaining sheets for future uses.
They have a practical and durable hook & loop Velcro backing. The best thing about this backing is that it’s quick and easy to stick. Also, their premium quality abrasive material makes them antistatic and durable.
Each sanding sheet has 5 pre-punched holes that facilitate efficient dust extraction.
Regarding the actual sanding task, you can use these sanding sheets to polish and grind fiberglass. However, you can also use them on other materials.
Feature Highlights:
- Durable and high-quality
- Alumina abrasive material
- Ideal for both polishing & grinding
- Comes in various grades and sizes
- Ideal for various fiberglass sanding tasks
- Large batch comes with various grit options
4. High Grit Hook & Loop Fiberglass Sanding Discs
When looking for the best fiberglass sanding disc, the question that follows is; what size of discs should you choose? The 5 inch and 6-inch discs are some of the most common ones. However, we suggest that you go with this 5-inch disc from Coceca and you’ll not regret it.
These are fixed using the hook & loop method. You can use it in a similar way to the Velcro discs. This is due to the fact because they form a very strong bond.
The most unique thing about this product is that it only includes sanding discs of high grit sizes. The entire package consists of 120 sanding discs, having 5 different grit grades. Therefore, you’ll find each of these grit grades on 24 sanding discs. Grit grades include; 3000, 2000, 1500, 1200 and 1000.
As you already know, high grit grades indicate that the sandpaper has small grit particles. Such sandpapers are ideal for finish sanding. Therefore, you can use this product in polishing and grinding various surfaces including fiberglass.
Like a few others on our list, these sanding discs are also made with aluminum oxide abrasive material. Each one having a diameter of 5 inches and 8 pre-pierced holes. These holes enhance the efficient extraction of dust during use.
And luckily these sanding discs are compatible with various orbital sanders.
Feature Highlights:
- Strong adhesion
- Extremely versatile
- Very high grit range
- Durable and premium quality
- Antistatic abrasive material
- Ideal fiberglass polisher
- Hook & loop method
5. Premium Quality Aluminum Oxide Sanding Belt
If you’re looking for fiberglass sanding belts, then look no further. This special version comes from POWERTEC, well known for manufacturing premium quality machines and accessories.
It’ll enable you to realize an optimum finish on the surface. Thus committed to providing you with the ultimate value, versatility, durability, and performance. The most amazing thing about this product is that it’s compatible with most belt sanding machines. Besides fiberglass, they can also be used for other applications.
These belts are made with superior quality X-weight cloth backing. Additionally, they are made with an open coat of aluminum oxide grains and include a resin-on-resin bond. All these features ensure that the product provides durable performance.
It comes with a package of 10 sanding belts, each having an 80-grit grade.
The size of each belt is 3 by 2 inches. And because of the quality manufacturing materials, these are moisture and heat resistant. Moreover, they’ve been designed with professionally crafted seams that don’t break easily under pressure.
As a belt version, this shouldn’t really miss out on your bucket!
Feature Highlights:
- Moisture and heat resistant material
- Compatible with most belt sanders
- Durable performance
- Extreme versatility
- Reasonable price
6. POWERTEC 60-Grit Aluminum Oxide Sanding Belt
This is another great product from POWERTEC you should probably consider when sanding fiberglass. These belts are specifically designed to provide a cost-effective pack of high-performance and durable products.
Being made with an open coat grain of aluminum oxide, they can be used for various applications. And we picked as one of our best in the list of fiberglass sandpapers.
The entire package comes including 10 sanding belts of 60 grit grade. Each one has a backing of X-weight cloth. Surprisingly, it has resin on resin bond and well-crafted seams. Thus it can provide you with durable results.
It also helps in preventing the belts from breaking when subjected to pressure. Regarding dimension, each belt measures 4 by 24 inches. Additionally, the material used to makes them is both moisture and heat resistant.
No doubt, they work well with several belt sanders. So it’s a comfortable option for various surfaces including fiberglass.
Feature Highlights:
- Compatible with most belt sanders
- Doesn’t break under pressure
- High-quality open coat grain
- Moisture and heat resistant
- Provides high performance
- Ideal for various surfaces
- Cost-effective
7. Premium Aluminum Oxide Sanding Belt Sandpaper
Aluminum oxide abrasive material has a uniquely reddish-brown color. Sanding belts made with this material are very popular. Especially it’s because of their efficiency, durability, and affordability in scrapping away various surfaces.
And these POWERTEC 110150 sanding belts are not an exception!
In addition to the open coat A/O grain, they have a superior backing of X-weight cloth. They’ve got a great resin on resin bonding which ensures durable performance.
This product comes as a set of 10 sanding belts of 240 grit grade. The 240 grit grade is ideal in delivering super fine smooth finishes on various surfaces. Each sanding belt is 36 inches long and 4 inches wide. They are joined with professionally crafted seams that don’t break under pressure.
…and are made with heat and moisture-resistant material.
Also, they can fit in with most brands’ belt sanders. Thus a worthwhile consideration when sanding fiberglass boat or whatever!
Feature Highlights:
- Durable and affordable
- Extremely versatile
- Provides long-lasting performance
- Delivers super fine smooth finishes
- Open coat A/O grain
- Superior backing cloth
8. Super Fine 400 Grit Wet/Dry Fiberglass Sandpaper
This is one of the best products that you can use to sand fiberglass surfaces for a smooth finish. It can either be used with oil or water to sand impressively.
Being made with silicon carbide abrasives, it provides quality finishes on the surface. It comes in 400 grit grades and includes an open layout that reduces clogging. Thus the sandpaper is specifically designed for dry or wet sanding between coats of primer, paint, lacquer, varnish as well as other surface finishes.
Since the synthetic abrasive mineral is sharp, it cuts smooth and fast. Still, it comes having quality fine grit. Additionally, it can be used to repair and work on surface defects.
The backing comes in 2 waterproof paper-weights. For that, you can handle the polishing task at hand. The weight includes; C-weight that levels general surfaces and A-weight that contours general surfaces.
Surprisingly it’s ideal for providing a smooth finish ion enamel, synthetic coating, varnish, and lacquer. And the pack contains 5, 400-grit sandpaper sheets. Each of these is 11 inches long and 9 inches wide. You’ll find it worthwhile for trickier sanding jobs!
Feature Highlights:
- Both dry or wet sanding
- Provides a smooth and fast cut
- Convenient sheet size
- Has open coat layout
- Reduces clogging
- Use with oil or water
9. Coarse 80 Grit Sandpaper Sheet by 3M
This is yet another great sandpaper sheet from 3M. It’s certainly among the best fiberglass sanding products in the market right now. You’ll find it ideal for repairing jobs and it’s fairly priced. It performs extremely well on regular tasks.
And it lasts longer as compared to the regular variety of aluminum oxide sandpapers.
The package includes 5 sandpaper sheets of 80-grit grade. Each of these coarse papers measures 9 inches by 3.67 inches. This product is constructed with a durable aluminum oxide abrasive material. Thus ensuring it provides the best sanding process during application.
Its abrasive material is tough, versatile, and resists loading.
It’s suitable for the 3M 03149 sanding block. However, they can either be used for machines or hand sanding. And you can either use this for dry/wet sanding. In fine, I must mention that it has a few other great applications including – stripping paint as well as sanding and shaping body filler.
So that way, number 9 is totally good!
Feature Highlights:
- Durable and tough abrasive material
- Lasts longer in comparison to others
- Ideal for various applications
- Perfect for both dry & wet sanding
- Ideal for repairing fiberglass
- Tough abrasive material
- Resists loading
10. Wet and Dry Waterproof Abrasive Variety Pack
The last package comes with several grit grades. This will enable you to handle various sanding applications including polishing and buffing fiberglass surfaces. It includes 12 wet dry sandpaper sheets of different grit grades. You’ll find grit grade 2500, 1500, 1000, and 600 on at least one sandpaper sheet. On the other hand, you’ll find grit grades 400, 320, 220, and 120 on 2 sheets each.
This provides you with an extensive selection of sandpapers, ranging from fine to coarse grits. And you’ll always have the right grit grades at your disposal. You can easily identify sandpaper sheets of various grit grades since they’re labeled on their back.
The sheets are made with premium quality silicon carbide abrasive material.
Due to that, it provides good effect, high efficiency as well as abrasion resistance. Additionally, these abrasives feature an electro-coated technology. And that ensures the grits are uniformly distributed on the sandpaper. So they don’t fall off during use since they’re firmly attached.
Unlike most products on this list, this one includes a hand sander. The sander is made with ABS and includes a screw clamp that holds the sandpaper sheets firmly. It’s lightweight and has a comfortable grip.
Their backing paper is both flexible and tear-resistant.
The dimension of each sandpaper sheet is 3.6 by 9 inches. For that, it’s extremely easy to use as it covers a large surface area. As per the sheet size, a hand sander would totally worth it!
Feature Highlights:
- Tear-resistant
- Includes a hand sander
- Extremely flexible and sturdy
- Waterproof & high-quality abrasive material
- Extensive selection of sandpapers
- Flexible backing paper
11. Paxcoo – Assorted High Grit Wet & Dry Sandpaper
If you’re after one that can handle both dry/wet fiberglass sanding, you might also consider this. And what makes our last pick a great consideration?
Let’s dive right in and go through some of its amazing features.
This product comes included with 24 sandpaper sheets of various grit grades. You’ll find 2 sheets per grit grade for 12 different grit grades. These grit sizes include; 7000, 5000, 3000, 2000, 1500, 1000, 800, 600, 400, 320, 240 and 120. Therefore, you’ll definitely find a grit grade that will fit most of your sanding needs within this pack.
Another great thing is that you can either use it for dry or wet applications. This is because the sheets are made with waterproof silicon carbide abrasive material. They also have excellent quality backing material that is tear-resistant. This prevents the sandpaper sheets from crumbling or falling apart during use.
Moreover, these sheets feature the nano-sand planting technique that makes the grains extremely uniform and fine on their surface. Each sandpaper sheet measures 3.6 by 9 inches. For that, you can use them with a sanding block or even on their own.
And they have printed grit size indicators on the back for convenient use. Additionally, the soft backing allows fitting in your hand perfectly. And highly resists slippage during use. Ranging from superfine to rough grit, you can use this sandpaper for various applications.
Feature Highlights:
- Used for dry & wet applications
- Waterproof silicon carbide abrasive
- Excellent quality backing material
- Includes a wide range of grit grades
- Tear-resistant backing material
Fiberglass Sandpaper Buying Guide
When sanding the fiberglass surface, you should consider certain factors. Such as, if you want to remove previous materials like gel coat; start sanding the surface using 150 grit sandpaper or lower. To help you make a decision, we’ve published an exclusive guide specifically on selecting the right sandpaper type for undertaking your project.
Go ahead and check that and you’ll love that for sure…!
Other than those major concerns, there’re some other minor factors (listed below).
But from my own perspective, I won’t compromise with these if the major concerns are putting the hands-off. And more importantly, if you follow any of the top 11 fiberglass sandpapers above, you don’t need to worry. Cause we’ve already done the work for you. But for your own practice, let’s get to know about those minors:
1. Reviews
This is a fact of trust. If you are concerned about customer satisfaction with a particular product then you can look at the sales report. It will include how many times the product has been sold and how satisfied the consumers were…!
2. Brand
It’s a similar kind of fact in relation to reviews. The famous the brand is, the more trusted products you get.
3. Prices
If you find the same type of sanding paper with two different prices that could be due to its quality. But this factor is not something you should be worried about. Because prices don’t really differ a lot. Rather considering the major concerns would swap away any difficulties with this factor.
Fiberglass Sanding Tips
1. Clean the Surface
To aim for successful fiberglass sanding, ensure the surface is clean. Remove any adhesives and stickers and then wash them off using water and soap. Once dried, you can start sanding the surface using medium grit sandpapers.
2. Put on Safety Equipment
Fiberglass strands may irritate your eyes, throat, and skin. Sanding fiberglass releases certain particles and dust into the air. Therefore, you should cover your nose and mouth with a dust mask to protect yourself from those particles. Additionally, put on goggles and gloves to prevent eye and skin irritations.
3. Start Using Medium-grit
Sanding fiberglass helps to remove the exterior gloss finish, enabling the paint to adhere properly. For small fiberglass pieces, use a sanding block or 120-180 grit sandpapers. Move them back and forth until their glossy finish comes off.
4. Use Power Sanders for Large Area
Use power sanders when covering a large surface area. This helps to speed up the sanding process. However, you should still use medium-grit (120-180) sandpapers. Or, you might decrease a little bit towards the coarser grit for glued areas.
5. Stop if Fibers are Visible
If you start seeing any fibers or strands after removing the gloss layer, you have reached the fiberglass. In such a scenario, stop sanding that area immediately.
6. Fill any Fiberglass Breaks with Resin
If you’ve exposed the fibers or strands when sanding, repair those spots using a hardener, cloth matting, and fiberglass resin. Mix the hardener and resin, then brush it on the surfaces using the cloth matting. Once the resin dries, carefully sand the area again without penetrating through the surface layer.
7. Remove any Dust after Sanding
Sanding fiberglass tends to leave dust and residue behind. You can clean off the surface by using a rag dampened with mineral spirits. This will pick up any dust and residue conveniently. Once you’ve cleaned the surface completely, you can now proceed to prime, and then paint it.
Conclusion
Hopefully, that clarifies the fact of choosing your best sandpaper for fiberglass. And now you should make your own decision. As you can see there’re several types coming with specific benefits. And choosing one will entirely depend on your own preference based on your available working tools.
FAQs
1. Can fiberglass be sanded? Is that dangerous?
Answer: Being a useful building material, fiberglass can certainly be sanded. However, sanding fiberglass poses several dangers to the user. This is because the process of sanding fiberglass releases certain particles into the air. The particles can affect your respiratory system, skin, and eyes. Additionally, they might cause nausea, weakness, dizziness, and fatigue. For this reason, ensure that always wear goggles, gloves, and dust mask when sanding fiberglass.
2. How do you smooth out fiberglass surfaces?
Answer: To smooth out the fiberglass surface, use the WEST system or other epoxy. This will help you to build up any low part of the fiberglass. Then thicken it with additives and sand it down up to a smooth finish.
3. Do I need to sand between layers of fiberglass?
Answer: You don’t have to sand between fiberglass layers. Once the layer of mat cures, fibers will be sticking up. If you don’t knock down these fibers with coarse paper, they create air bubbles when you apply the next layer.
4. How do you get scratches out of a fiberglass boat?
Answer: Start out to dry sand the boat fiberglass with 180 grit abrasive paper. When the scratch starts to disappear, shift to the 320 grit sandpaper. When 90% of the scratch disappears, bump up to 400/ 600 grit. Then start wet sanding up to the 1000-grit sandpaper.
