A clay trap is a settling container plumbed under or beside a sink so that clay, glaze and plaster sink to the bottom before the water reaches your drain. Clay does not dissolve, so without a trap it builds up in pipes and septic tanks. For most home studios the best clay sink trap is the Gleco Trap System 64 oz if your cabinet has at least 15.5 inches of clearance, or a Trap-Eze 3.5 gallon bucket kit if you want more capacity for less money. This guide compares the traps US pottery suppliers sell using maker instructions and dealer listings (we did not install or test them), then covers DIY bucket traps, emptying and disposal.
Quick picks
- Best overall clay trap: Gleco Trap System 64 oz (bottle swaps in under 90 seconds without tools, per the maker)
- Best for a shallow sink cabinet: Gleco Trap System 43 oz (12.5 to 13 inch minimum clearance)
- Best value sediment trap for sink: Trap-Eze 3.5 gallon kit (big capacity, hose hookup)
- Best for heavy use: Trap-Eze 5 gallon kit (largest bucket here)
- Best bottle alternative: Trap-Eze BT Bottle Trap 64 oz (clear bottle, hard-plumbed)
- Best metal trap: Keystone Metal Plaster Trap (sight hole, 10-year warranty)
Clay sink traps compared
| Trap | Type | Capacity | Space needed | Refills | Price |
|---|---|---|---|---|---|
| Gleco 64 oz (GT64) | Bottle under P-trap | 64 oz | 15.5 in min, 17 in recommended | Replacement bottles | Check price |
| Gleco 43 oz (GT43) | Bottle under P-trap | 43 oz | 12.5 or 13 in min, 14 to 14.5 in recommended | Replacement bottles | Check price |
| Trap-Eze 3.5 gal | Sealed bucket with hoses | 3.5 gal | 11 in bucket plus 9 in gap | Disposable bucket | Check price |
| Trap-Eze 5 gal | Sealed bucket with hoses | 5 gal | 14.5 in bucket plus 9 in gap | Disposable bucket | Check price |
| Trap-Eze BT 64 oz | Bottle, hard-plumbed | 64 oz | 16 in min | Replacement bottles | Check price |
| Keystone Metal Plaster Trap | Metal canister with liners | 2.75 gal | 13.5 in tall unit | Liner bags | Check price |
Most of these traps come from dental suppliers, whose labs handle plaster waste the same way potters handle clay, and pottery suppliers resell them. They are sold mainly through pottery and dental suppliers, so the buttons may open an Amazon search. Prices below are bands from dealer listings in October 2026.
How a clay trap works
Every sink sediment trap works the same way. Waste water enters a container that is much wider than the pipe, so it slows down. Heavy particles such as clay, glaze and plaster settle to the bottom, and cleaner water leaves near the top and carries on to the drain. Buffalo Dental describes its Trap-Eze as slowing the discharge flow rate so sediment can settle out.
A clay trap does not replace the normal P-trap that blocks sewer gas. The Gleco unit screws on below the existing P-trap, and the bucket traps sit between the sink tail pipe and the drain. When the container fills with sediment, you swap the bottle, bucket or liner and throw the full one away.
Gleco Trap System 64 oz: best overall clay trap
Practicon, which sells the Gleco Trap, says it was invented by a plumber, and its main selling point is maintenance. A patented side drain lets you siphon off the standing water before you remove the bottle, so you are not carrying a full, sloshing jar of slurry across the studio. Practicon's instructions say a bottle change takes less than 90 seconds without tools.
The 64 oz package comes pre-assembled with the bottle and gasket, an 8 inch tail extension, a 90 degree elbow extension and one spare bottle. It uses 1 1/2 inch PVC fittings. You need at least 15.5 inches of vertical space under the horizontal pipe after the P-trap, and 17 inches is recommended. Krueger Pottery Supply's listing calls it the only UPC-approved sink trap made today; that is the dealer's claim, so confirm with your plumber.
- Bottle: 64 oz clear plastic
- Clearance: 15.5 in minimum, 17 in recommended
- Fittings: 1 1/2 in PVC
- Included: main unit, bottle, gasket, 8 in tail extension, 90 degree elbow, spare bottle
- Change interval: when residue is within 1 in of the top
- Refills: 64 oz bottles, six per case
- Price band: about $118 to $120 for the package at US dealers in October 2026; check the live price
Pros
- Clean, tool-free bottle swaps
- Clear bottle shows when it is full
- Compact under a normal sink
Cons
- Smaller capacity than a bucket trap
- Bottles are single use, an ongoing cost
Who should skip it: Potters who wash a lot of slurry every day and would fill a 64 oz bottle too quickly; a bucket trap suits them better.
Gleco Trap System 43 oz: best for a shallow sink cabinet
The GT43 is the same Gleco design with a shorter bottle, for vanity cabinets and utility sinks where the drain sits low. The package price is the same as the 64 oz at the dealers we checked, so choose it only when the space forces you to.
The published clearance figures differ slightly. Practicon's installation sheet gives 12 1/2 inches minimum and 14 inches recommended for the 43 oz system; Krueger Pottery Supply's chart lists 13 inches minimum and 14.5 inches recommended. Measure from the floor of the cabinet to the horizontal pipe after your P-trap, and if you land between those numbers, ask the dealer before you order.
Source conflict: Practicon lists 12.5 in minimum clearance for the 43 oz Gleco; Krueger Pottery Supply lists 13 in. Plan for the larger figure.
- Bottle: 43 oz clear plastic
- Clearance: 12.5 in (Practicon) or 13 in (Krueger) minimum; 14 to 14.5 in recommended
- Fittings: 1 1/2 in PVC
- Kit: Krueger lists two 43 oz bottles in the GT43 kit
- Refills: 43 oz bottles, six per case
- Price band: about $118 to $120 at US dealers in October 2026; check the live price
Pros
- Fits where the 64 oz will not
- Same easy bottle change
Cons
- Fills sooner than the 64 oz
- Costs the same
Who should skip it: Anyone with 17 inches of clearance, who should buy the 64 oz instead.
Trap-Eze 3.5 Gallon Kit: best value clay trap sink kit
Buffalo Dental's Trap-Eze takes a different approach: a sealed plastic bucket that sits on the cabinet floor, connected by two flexible hoses. The Ceramic Shop lists the small kit at 3.5 gallons, 12.5 inches across and 11 inches tall, with two 1.5 inch ID hoses 20 inches long and a sewer tail pipe adapter. That is many times the capacity of a Gleco bottle, at a lower kit price.
The Ceramic Shop says no tools are needed and asks for at least 9 inches between the bottom of the sink tail pipe and the top of the bucket. Clay-King's listing describes the same kits as permanently plumbed into the drain, so plan on a proper connection either way. When it fills, you replace the whole sealed bucket. Clay-King says the kits are made in the USA. Buffalo Dental also sells a 2 gallon kit, 9.5 inches tall, for tighter spaces.
- Capacity: 3.5 gal (2 and 5 gal versions also sold)
- Bucket: 12.5 in diameter, 11 in tall
- Hoses: two, 1.5 in ID by 20 in
- Clearance: 9 in minimum from tail pipe bottom to bucket top
- Refill: sealed disposable bucket, about $30 at one US dealer
- Price band: about $66 to $85 at US dealers in October 2026; check the live price
Pros
- Large capacity for the price
- No bottle swaps for months in light use
- Tool-free hookup per The Ceramic Shop
Cons
- Takes up most of a sink cabinet floor
- A full bucket is heavy to lift out
Who should skip it: Potters with a cramped vanity cabinet; the Gleco or the 2 gallon Trap-Eze fits better.
Trap-Eze 5 Gallon Kit: best for heavy use
If several people share your sink, or you wash bats, buckets and splash pans every day, the 5 gallon Trap-Eze is the largest trap on this list. The Ceramic Shop lists the bucket at 12.5 inches across and 14.5 inches tall, with the same two 20 inch hoses and tail pipe adapter as the smaller kit. Buffalo Dental pitches it for larger labs with higher volume.
The trade-off is height and weight. With the 9 inch gap above it, you need about two feet under the sink tail pipe, which suits a freestanding utility sink better than a kitchen-style cabinet. A full 5 gallon bucket of wet sediment is heavy, so lift it with your legs or slide it out on a low dolly.
- Capacity: 5 gal
- Bucket: 12.5 in diameter, 14.5 in tall
- Hoses: two, 1.5 in ID by 20 in
- Clearance: 9 in minimum above the bucket
- Refill: sealed 5 gal bucket, about $31 at one US dealer
- Price band: about $70 to $85 at US dealers in October 2026; check the live price
Pros
- Largest capacity here
- Fewest refills
- Same simple hose hookup
Cons
- Needs a lot of vertical space
- Heavy when full
Who should skip it: Solo hobby potters who throw a few times a week; the 3.5 gallon kit lasts long enough.
Trap-Eze BT Bottle Trap 64 oz: best bottle alternative
Buffalo Dental also makes a bottle-style trap that competes with the Gleco. New Mexico Clay sells it as its under-sink clay trap and lists a pre-assembled trap body, a 64 oz clear bottle and plumbing connections in 1 1/2 inch size. It is hard-plumbed into the existing drain under the sink.
It needs a little more room than the Gleco 64 oz: New Mexico Clay gives a minimum of 16 inches from the centerline of the sewer tail pipe to the cabinet floor. Replacement bottles are sold separately. Choose it if your local supplier stocks the bottles, because refill availability matters more than the small differences between the two designs.
- Bottle: 64 oz clear plastic, replaceable
- Clearance: 16 in minimum, tail pipe centerline to cabinet floor
- Fittings: 1 1/2 in plumbing and connectors
- Install: hard-plumbed into the sanitary drain
- Price band: about $90 to $95 at US dealers in October 2026; check the live price
Pros
- Lower kit price than the Gleco
- Clear bottle shows fill level
Cons
- Needs 16 in of height
- No published tool-free claim like Gleco's
Who should skip it: Anyone with a shallow cabinet, or who wants the Gleco's siphon drain for cleaner swaps.
Keystone Metal Plaster Trap: best metal trap
Keystone Industries builds this trap as a metal canister with disposable liner bags, sold to dental labs and resold by Sheffield Pottery. A dental dealer lists it at 2 3/4 gallons, 13.5 inches high and 10.75 inches in diameter, with a sight hole that shows when the liner is full. Three liners and installation tubing are included, and replacement liners come in packs.
The appeal is durability. A metal body will not crack if you knock it with a bucket, and that dealer lists a 10-year maker warranty, the longest here. It costs the most up front, but liners are cheaper than whole buckets or bottles, so running costs are lower over time.
- Capacity: 2 3/4 gal
- Size: 13.5 in high, 10.75 in diameter
- Body: metal with sight hole
- Included: three disposable liners and installation tubing
- Warranty: 10 years, per dealer listing
- Price band: about $200 at a US dental supplier in October 2026; check the live price
Pros
- Metal body
- Cheap liners
- Sight hole for fill level
Cons
- Highest up-front price
- Changing a liner is messier than swapping a sealed bucket
Who should skip it: Beginners who are not sure how much they will use the sink; start with a Trap-Eze kit.
DIY clay traps: the bucket method
Many potters build their own trap from buckets or a plastic tote. Ceramics Monthly and Ceramic Arts Network have published several designs. The common idea is two or three containers in a row: water enters the first, sediment drops out, and the overflow passes to the next before it leaves through an outlet set lower than the inlet. One published design uses square buckets because flat sides make pipe connections easier to seal, and clear containers so you can see the sludge level. Another author placed the trap beside the sink, not under it, so it is easy to open and clean.
A DIY trap can hold far more than any bought one, which suits a busy garage pottery studio. The weak point is the connection to your drain. Leaks under a sink rot cabinets and floors, and drain work has to meet local plumbing code. The triple-stage design article itself recommends a professional plumber for connecting the trap to existing plumbing.
Any trap that ties into your drain line should follow the maker's instructions and local plumbing code. Gleco's instructions say the user is responsible for meeting all applicable plumbing codes and warn against overtightening PVC fittings. If you are not sure, have a licensed plumber install it.
No-plumbing option: the rinse bucket routine
The cheapest clay trap is a habit. Wash hands, tools and sponges in a bucket of water first, not in the sink. Let it stand overnight, pour the clear water off, and reclaim or bin the sludge. Many potters use two or three rinse buckets so the last rinse is nearly clean. See how to reclaim clay to reuse what settles.
How to choose a clay sink trap
Measure the space first
Clearance is the deciding spec. Open the cabinet and measure from the floor to the horizontal pipe after the P-trap. Under 15.5 inches points you to the Gleco 43 oz or the 2 gallon Trap-Eze. Between 15.5 and about 20 inches suits the Gleco 64 oz or the Trap-Eze BT. A freestanding utility sink with open space below takes the bucket kits.
Match capacity to how you work
A hobby potter who throws twice a week and uses a rinse bucket sends far less clay to the sink than a shared studio. Small bottles fill faster but are easy to change. Buckets last longer but are heavier to replace. If you are unsure, start smaller and keep using a rinse bucket. Bucket kits also need a clear patch of cabinet floor, so empty the cabinet and check where the shut-off valves and any other pipes sit before you order.
Count the running cost
Every design has a consumable: bottles, sealed buckets or liners. Check that your local pottery supplier stocks the refills before you choose, because shipping a case of empty bottles costs more than the bottles. Our pottery supplies guide lists where US potters buy studio items like these.
Septic systems
Clay is a fine, heavy solid that settles in a septic tank and adds to the sludge layer. If your home is on septic, a trap plus a rinse bucket routine matters even more. The triple-stage trap article was written by a potter protecting a septic tank.
Emptying and disposal
Change a Gleco bottle when sediment is within 1 inch of the top, and replace a bucket or liner when the clear view or sight hole shows it is full. Gleco's instructions say to cap the full bottle and discard it in line with applicable regulations, and not to reuse it. Ask your local waste authority how they want trap waste handled, especially if you rinse glaze in the sink, and never tip it into a storm drain or garden bed.
Dried trap sludge is clay and glaze dust, which contains crystalline silica. Keep it wet or sealed, never let it dry out and get swept, and clean spills with a wet sponge or mop. More in clay dust safety.
A trap is one part of a clean studio setup. Our home pottery studio setup guide covers where the sink fits, and the short answer on whether clay can go down a household sink is on our start pottery at home page.
Sources: Practicon Gleco Trap page and Gleco Trap System installation instructions; Krueger Pottery Supply Gleco Trap Kit listing; The Ceramic Shop sink trap category and Trap-Eze 2 gallon, small (3.5 gallon) and large (5 gallon) kit listings; Clay-King Buffalo Dental Trap-Eze listing and sink trap category; Sheffield Pottery sink trap collection; New Mexico Clay Trap-Eze BT 64 oz listing; American Dental Accessories Keystone Metal Plaster Trap listing; Ceramic Arts Network articles on a homemade sink trap and a triple-stage clay trap. Specs checked October 2026.