Introduction: Plaster Trap

So being a cheapskate and a DIY tinkerer, I decided to make a plaster trap to put in my orthodontic office to catch the plaster that is washed down the sink on a regular basis in my lab. If enough plaster is washed down eventually it will clog the drain and could lead to costly repairs.

Now I could have just purchased one pre-made for as little as $50, but hey, that's still more than I wanted to spend for a bucket with hoses hooked to it (I think most would agree?). I found that for my application a 3 gallon bucket was the perfect fit and it is compatible with 5 gallon bucket lids. I was able to procure everything I needed for under $10.

Step 1: Supplies and Tools


3 gallon bucket. (Home Depot)

Tight fitting lid with inner rubber gasket (important because you need a watertight seal). You should identify the type of plastic the lid is made from. This is to assure that the glue will be compatible with your plastic. It appears that most lids are made from HDPE (High Density Polyethylene) (Home Depot )

Pipe Fitting (see photo). Not sure of the name. My pipes are 1 1/2" and I did have to go to a plumbing supply store to find this particular part as Home Depot and Lowes did not carry it. Alternatively you could try an aquarium bulkhead fitting and see if that works better for your application.

Any additional plumbing pipes to make your application fit properly. I had to buy a longer straight pipe to extend a few inches into the bucket lid.

Smaller inner bucket. (I just used an empty sanitizing wipe container).

Loctite Plastics Bonding System, two parts. (Must be this exact product as I found it nearly impossible via other techniques to bond anything to the polyethylene lid).



Cordless drill with hole saw attachment.

Half round file



Whatever plumbing tools you may need to loosen/tighten everything.

Step 2: Dry Fitting

First you need to figure out where the holes will go in the bucket lid to properly align with your particular plumbing arrangement. Once this is done use the part that you will attach to the bucket lid as your template for the hole that you will cut out of the lid by tracing around it with a permanent marker. Remember that when you cut out the hole it should be as perfect a fit as possible to avoid leaks. So the hole should be to just inside the marked line. I did not have a hole saw the exact dimension as the circle I needed so I used a rounded file to get to the desired width. Once the hole is close, dry fit the attachment in the hole to make sure you have the correct dimensions. It should be a snug fit. I had to file/sand down the lip of the attachment as to remove a few some lettering that was molded onto it. Now use a medium grit sandpaper to remove the plastic burs that have collected around the hole and roughen up the lid where you will be gluing it together. .

Step 3: Assembly

Now you are ready to glue everything together. Wipe off any excess plastic dust/residue from the areas you will be connecting with a damp paper towel. Allow to thoroughly dry. Dry fit one more time just to be sure it is a snug fit. N Now the glue. It is a two part system; primer and glue. Follow the directions carefully for the glue. I wore safety glasses and a mask as the fumes can be harmful. I made sure to extend the area with the applicator tip about to about 1/4" around the opening of the hole in the bucket. I went over each area a few times with this to assure full coverage with the primer. Now add the glue. It is a cyanoacrylate and will stick you fingers together pretty much instantly so be careful. I found it easiest to glue the everything together with the lid on the bucket. (not fully seated because it is a pain to remove the lid once in place) I applied the glue to the plumbing attachment not the lid. VERY important, you must make sure that the glue completely surrounds the the attachment to ensure that you will form a perfect seal once in place. Any gaps that are left will be an open door for water to escape. I pushed the attachment onto the lid and once seated turned it about an 1/8 of a turn spread the glue even more. You must do this immediately after seating it because it will bond with the lid almost instantly! Now hold it in place with pressure for about a minute. Let this set for about a day (you could probably go less but why take chances). Next use you silicone and form a nice seal around the parts just as a safety precaution. Let dry for 24 hours. In the meantime take the smaller inner bucket and glue it where the downspout pipe will enter the bucket.

Step 4: Connecting Everything

Now that everything is glued and dried, place a small bucket under the "p" trap of the plumbing and remove the trap. Now place the plaster trap bucket with firmly attached lid in place and connect everything tightly. Moment of truth. Let the faucet run for at least 15 minutes or more to ensure that there are no leaks. I ran hot water to better test the system. I also placed paper around the connections to help me detect leaks. Voila! You now have a plaster trap for under $10. When you need to empty the plaster trap simply disconnect and either dispose of the bucket and get a new one or clean it out and re-use!

Disclaimer: I am not responsible for any flooding, leaking pipes etc that you may encounter after trying to make this yourself.