Home » ACX vs. Marine Grade Plywood
ACX vs Marine Grade Plywood

ACX vs. Marine Grade Plywood

John K. Mayo earned a patent for plywood in 1865. Then it was forgotten.

It was reissued three years later, but Mayo never found commercial success with his product. It wasn’t until the centennial anniversary of the Lewis and Clark expedition in Portland that plywood found a home.

The Portland Manufacturing Company decided to laminate wood panels made of softwoods, using paint brushes to spread the glue.

It became their three-ply veneer work. It became such a popular product that they were producing 420 panels per day in 1907.

Plywood is highly versatile, coming with numerous benefits to consider. Before you get to work, it’s important to consider the grade you need.

ACX vs. Marine Grade Plywood

Plywood comes in four common grades: A, B, C, and D.  The highest quality products are A-grade, making them the most expensive. D-grade products have the most inferior quality and lowest prices. Some products come with an X designation that shows waterproof glue was used in its creation.

ACX plywood means the front of the product is an A-grade item. If you try to drive screws or nails through its surface, it should not split along the edges.

The top is sanded smooth, making it paintable. The product should be free of knots and repairs when you look at it.

The second letter indicates that the back is a C-grade product. It can have some discoloration and splits, but these issues don’t come to the front. There could be knotholes up to one inch in size, along with tight knots of up to 1.5 inches.

Here is a closer look at plywood grading.

Plywood GradeFeatures of This Plywood Grade
AThis plywood grade is the best available. You might find some neatly made repairs from the manufacturer on some items, but it is typically free of any visual faults. It’s usable immediately in virtually any environment, especially when it contains waterproof adhesives.
BPlywood that comes with this grade provides a solid surface that may show some signs of repair. The most common visual indicator is a football-shaped patch or the inclusion of wood filler. Some tight knots with no wood chunks missing may be present up to one inch in size.
CMore knotholes and tight knots are present in this plywood grade. It may have discoloration and some splits throughout the piece.
DThis grade has knotholes and knots of up to 2.5 inches in size. There are usually some splits, but it is unusual to see repairs with this option.
C-PluggedSome manufacturers use this alternative grading designation for plywood products that serve as a foundation for wall coverings, tile, and backing. It can handle a high-performance coating without difficulty.

What About Marine Grade Plywood?

Marine grade plywood is the best option available in the marketplace today. Most products are graded as either AAX or ABX.

Most products are made from Douglas Fir or Western Larch trees when plywood is needed for marine applications.

You can find some marine plywood graded at BBX. This product is still slightly superior to ACX-graded items in most circumstances. A direct inspection and comparison of the two products would be necessary to determine which one provides a better foundation.

Marine plywood must follow the BS1088 standard. That means the thickness of the back and face for veneers with the multi-ply construction must be a minimum of 1.3 mm and a maximum of 3.8 mm.

The veneer’s quality on marine plywood is significantly better than it is for exterior-grade products.

There should be no defects present except for sound pin knots in the face or the back. Each core layer should consist of a single piece of core veneer without having end joints.

Edge joints are permitted on marine grade plywood. There cannot be any holes or voids hidden within the inner layers.

That feature ensures it is stronger and denser than standard exterior plywood. That allows the edges to sand and cut cleaner.

How to Choose Between ACX vs. Marine Grade Plywood

When you need to choose between ACX and marine grade plywood, the answer depends on the project. If you’re building a boat, the latter product is your only option because only it gives you the water resistance and finish you need.

If you’re working on an exterior structure, an ACX product could be more suitable. Even then, if you live in a coastal environment or near a water source, it might be better to invest in an AAX or ABX marine grade plywood.

Local building codes could dictate what options you can use for the project.

One word of caution: if weight is a factor in your work, marine grade plywood weighs more than other choices. ACX is lighter while offering some water resistance, which could be helpful in some situations.

Additional factors also require consideration, including the species of the face veneer, the core species used, its construction, and the adhesive.

What Are the Benefits of Using ACX Plywood?

ACX plywood delivers durability. The higher grading ensures that you receive uniform grains that deliver strength in each direction. That allows the product to resist heavy impacts while reducing the influences of wear and tear as time passes.

When working with ACX plywood, you’ll see that it doesn’t split as easily as other wood products.

This benefit occurs because manufacturers use a cross-layered structure to create a dense product. That’s why you can affix hardware to it without having it split along the edges.

Additional advantages that come with ACX plywood include its availability in larger sizes, the lightweight nature of the design, and that it looks quite like real wood on its face. It can fit curved surfaces smoothly and easily.

That’s on top of the benefit that all plywood products offer, which is the eco-friendly nature of the manufacturing process. It takes less wood to make products from plywood than solid wood.

Since it has a weather-resistant design, the best uses for ACX plywood involve outdoor projects.

It works well for sheds because it delivers a durable exterior and floor. Width options range from 1/4-inch to 3/4-inch in most product lineups.

One notable ACX product is made from Radiata Pine. It’s almost always free of defects, offers a smooth surface, and creates a high-quality look. Instead of using it outside, you’ll find it used for shelving and cabinetry.

When you need to build a boat hull, marine plywood is the best option. You could use ACX for porches and decks, but CCA-treated products are just as effective – and often cheaper.

How to Cut Plywood Without Splintering

ACX and marine grade plywood is great because it’s still reasonably affordable while being easy to use. Whether you’re a beginner DIY’er or plan on building or repairing a vessel, this foundational product delivers impressive results.

The problem with plywood is that it creates splinters called “tearout.” When you cut through a thin veneer, it creates a rough and jagged edge that looks terrible.

One cut can ruin what would be a high-quality project.

The manufacturing processes for ACX and marine plywood help eliminate many of the tearout issues that happen with lower-grade products.

Two considerations must receive close attention when preparing to cut plywood. How well are the fibers supported? How intense is the impact on them?

Here are the steps to follow to have a positive outcome.

  1. Choose the right blade and correct face to cut. It would be best if you were using a fine-tooth product designed for plywood to achieve the best results. When you have more teeth per inch and a higher bevel angle, you can slice through any grade with ease. The DeWalt Circular Saw 8.25-inch 40-Tooth Blade provides consistent outcomes.
  2. When cutting the plywood, ensure that the blade enters the show face. That means you’ll place the good side down for a circular saw and flip it for a table saw.
  3. Use a zero-clearance insert when cutting any plywood grade to avoid splintering. This step is crucial if you use a miter, band, or table saw. It creates the smallest amount of open area around the blade to support the veneer fibers as much as possible.
  4. Score the cut line before attacking it with your saw or drill press. By intentionally cutting the fibers where you can control the impact, it’s much easier to avoid large, jagged lines when you shape the plywood to size. Use a sharp blade or a straight edge to complete this step.
  5. Support the veneer by placing painter’s tape over the cut line. The extra surface materials help the blade cut through the plywood smoothly. Although other tape products work, this option is easier to remove.
  6. When you need straight lines with no splintering, it helps to take a two-step process for each cut. Some production lines even use table saws with two blades so that the first pass scores the board before the second cuts it. Set the blade to about 1/16-inch above the table and make a complete pass to create a cutting channel. Flip it over to make the final cut.

Before rushing into the project, it helps to use a test board to see how your equipment performs during the cutting process. Take a few sample cuts to know what to expect before working with your ACX or marine plywood.

Best Saw to Use for Cutting Plywood

The best table saw to use for cutting plywood of any grade is the DeWalt Compact 8.25-inch Table Saw for job sites. It comes with an optional table and stand to produce several cuts, delivering 24.5 inches of rip capacity while handing OSB sheets or 4×8 plywood.

I have the DeWalt Compact 8.25-inch Table Saw at home to handle all my DIY projects. It’s helped me replace our stairs, redo the upstairs flooring, and finish repairs on the boat I’ve put off for ages.

What I like about its design is the onboard storage, offering easy access to the push stick and guarding components when I’m not using the saw.

The DeWalt table saw uses a metal roll cage to always ensure there’s stability. You can take it almost anywhere, especially if you’re operating from a generator. That means less downtime occurs since you can cut boards where you need to install them.

It incorporates rack and pinion telescoping fence rails to adjust quickly and accurately. This design works with 8.25-inch blades that can help you tackle plywood in no time at all.

When comparing ACX vs. marine grade plywood, think about the application. I used the latter for my bathroom floor foundation to ensure less water damage occurred.

Think about the need, then use the cutting principles found here to create clean edges.


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