Best 18mm and 14mm Ash Catchers: Size & Buying Guide

Ash catchers come in two standard joint sizes, 14mm and 18mm, and getting that size right matters more than any other buying decision you'll make. An 18mm ash catcher is built for larger bongs and dab rigs with wider joints, while 14mm fits most smaller and mid-size pieces. Get the size wrong and nothing else matters, it simply won't seal. Here's how to shop for each size, plus budget picks and percolator combos worth knowing about.

What Does an Ash Catcher Do?

An ash catcher is a glass attachment that sits between your bowl and your downstem, catching ash and debris before it ever reaches your bong's water chamber.

• Keep your water chamber cleaner longer. Ash and resin collect in the ash catcher instead of the main chamber.
• Adds pre-filtration. Many include their own small percolator, giving smoke an extra round of cooling before it reaches the bong's base.
• Attached externally. Not a permanent modification, it connects at the joint and can be removed or swapped independently of the bong.

The tradeoff is added height and one more joint to keep sealed, but for regular smokers, the cleaner main chamber is usually worth it.

What to Look for in an 18mm Ash Catcher

An 18mm ash catcher is the size most commonly paired with larger bongs and dab rigs, which have wider joints to accommodate.

• Percolator style. Showerhead and tree percolator styles are common here, since the larger joint has room for more elaborate percolation without restricting airflow.
• Chamber size. Precooler-style ash catchers with a wider chamber are popular too, giving smoke more room to cool before reaching the water chamber.
• Joint angle. Usually 45° or 90°. A 45° angle sits lower and closer to your bong, while 90° sits more upright and adds more height and weight up front.
• Weight and balance. Larger, percolated 18mm ash catchers add real weight to the joint, which can make a lighter or taller bong feel front-heavy on a table.

Grasscity's ash catcher and bong accessories collection can be filtered directly by 18mm joint size to see current in-stock options.

What to Look for in a 14mm Ash Catcher

A 14mm ash catcher is actually the more common size overall, fitting most smaller and mid-size bongs and bowls.

• Design simplicity. More compact designs dominate this size, since the smaller joint limits how large the percolator or chamber can be without affecting airflow.
• Percolator availability. Simpler single-chamber styles are common at 14mm, though tree and showerhead percs still show up on higher-end pieces in a more compact form.
• Fit precision. Smaller joints have less margin for error, so a slightly mismatched angle or gender is more likely to cause a weak seal than on an 18mm setup.
• Everyday practicality. Being the more common size makes replacement parts, adapters, and matching bowls easier to find later.

The same ash catcher collection covers 14mm too, worth filtering separately since the style mix skews differently at this size.

14mm vs. 18mm: Quick Comparison

If you're not sure which one your bong takes, check the product listing or manual rather than guessing from the bong's overall size, since bowl size doesn't scale predictably with height.

Best Budget Ash Catchers

You don't need to spend a lot to get a real functional upgrade. A solid cheap ash catcher still does the core job, catching ash and adding a bit of pre-filtration, even without premium glass or an elaborate percolator.

• Simple single-chamber designs are the most affordable category and still meaningfully protect your water chamber from buildup. On Grasscity, basic non-percolated styles currently start around $10 to $20 at member pricing, a reasonable entry point for testing whether an ash catcher is worth adding.
• Basic diffused downstem styles add a bit of extra filtration without the cost of a full percolator, typically at a slightly higher price than the simplest options.
• Durability matters more than features here. A simple, well-made cheap ash catcher will outlast a cheaply built one with more bells and whistles, so check glass thickness before assuming more features means better value.

Budget doesn't have to mean disposable. Prices shift with sales and stock, so check current listings rather than assuming a fixed price point.

Ash Catchers with Built-In Percolators

An ash catcher percolator combo does double duty: catching ash while breaking smoke into smaller bubbles for extra cooling before it reaches your bong.

Pairing a percolator-equipped ash catcher with a bong that already has its own percolator is a genuinely popular combo. Combining the two can add another stage of filtration on top of what your bong already does, though the airflow and smoothness you feel still depends on your setup, chamber size, and how restrictive each percolator is on its own.

It's not an automatic upgrade in every case, but for many setups it's a meaningful one. If that's what you're after, look specifically for percolator bongs and pair one with a percolator-style ash catcher rather than assuming any combination will feel the same.

Percolator-equipped ash catchers also tend to cost more than simple styles, often landing in the $30 to $50 range at member pricing based on current listings.

How to Know Your Joint Size

A mismatched fit won't seal properly no matter how good the piece is, so work through these in order:

Two more things to check: airflow and adapters. More elaborate percolators add resistance along with filtration, so on a bong that already pulls tightly, a heavily percolated ash catcher can be noticeable, especially on smaller 14mm setups. And if you want a different size than your bong's native joint, a 14mm-to-18mm adapter can bridge the gap, though it adds another seal point and some extra height.

Bottom Line

Start with joint size, 14mm for most smaller and mid-size bongs, 18mm for larger bongs and dab rigs, since nothing else matters if the fit is wrong. From there, it's about priorities. A simple design is lighter, cheaper, and easier to clean, while a percolator-equipped ash catcher adds another filtration stage many smokers find worthwhile, especially with an already-percolated bong. Neither is objectively better, it depends on whether you value simplicity or extra smoothness.