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How To Cast Concrete Serving Trays
This particular serving tray was made to be used outdoors, but it works quite well inside. I came up with the idea after the hubs made a request for something to use outside. We do a lot of grilling around here, and we spend a lot of time on our patio/pool area. So, functional but also weather resistant were the requirements. (FYI – I found some amazing foil packet meals from The Campfire Call. These make easy but delicious meals for your grill.)
Since I love blending opposite elements together – i.e modern with rustic, cool and sleek with warm and textured, etc. – concrete seemed like a good idea. If you recall, I recently built a modern/rustic platform bed. I wanted to draw inspiration from that, except using concrete instead of wood. So, off to the workshop to throw this thing together.
Material Used to Cast Concrete Serving Trays
- Quikrete Countertop mix or 5000 – I used the countertop mix which is one of the more expensive versions. You can achieve the same results with one of the cheaper bags. I recommend the 5000 as a good cheap alternative.
- Plastic serving trays – these can be found at almost any party supply store. They should only cost a few dollars. I recommend buying 3-4. This is just in case you break one during the cast or if you need a replacement sometime in the future. You can also use individual containers if you prefer.
- Mixing bucket – a 5-gallon bucket is ideal for mixing.
- Mixing paddle – this will make mixing quick and easy but is not required. You can manually mix the concrete if you prefer.
- Melamine boards to create a mold form.
- 100% silicone caulk
- drywall screws or some other appropriate particle board screws.
- cooking spray
- zip ties
- latex/rubber gloves*
- protective tarp or plastic
- caster cups*
- 5-minute epoxy*
- (optional) decal – I made mine using my Cricut machine, but you can use any material that can be fully adhered to the melamine and will not absorb moisture. Do not use chipboard or wood when casting concrete, it will hold moisture at the area and the imprint can fail when the mold is removed.
- (optional) colorant – I used charcoal colorant for this project. If you want to achieve a color other than gray or dark gray, you will need to use a white concrete mix.
Tools Used for this Project
- drill/driver – you will need this if you plan to make your form or if you plan to use a mixing paddle.
- orbital sander – As an alternative, you can also use a Dremel or any other small palm sander.
Make sure you check out the full video instructions over on my Youtube channel. But first, check out the text version below to avoid missing any important details.??
Making/Adding Decals to Cast Concrete Serving Trays
The decal that I used was made on my Cricut machine. You could also use foam letters or manually cut a design into sticky vinyl. The only thing that you need to remember is that the decal or letters must be adhered backward (or mirrored).
Place the decal on the melamine form before assembling the mold. Make sure that the form is clean of any contaminants or residue that may interfere with the adhesion.
Regardless of what you use, it must be stuck to the form completely. Test to make sure that the entire surface adheres and that there are no loose edges. Any areas that lift during the curing process will not turn out clear.
Assemble the Form
You want to make sure that your cast is thick enough to remain structurally sound. To that end, it is important that the form is cut with at least 2″ allowed for each rope handle. It is also important to leave at least 1″ on all sides of the tray to provide good support and to prevent cracking.
For example, my tray insert is 16″ long x 5 1/2″ wide x 2″ tall. The interior of my form measures 20″ long x 7 1/2″ wide x 3″ tall. This left the needed 2″ on each end for the handles and a decent thickness around all the other sides and bottom. It is always better to make the form a bit too large than to make it too small.
To assemble to form, predrill holes and connect using drywall screws. Tighten just enough to get a solid contact, but do not over tighten. Over tightening could cause damage to the particle board.
Place a bead of silicone along the seams and smooth it out with your finger. You do not have to be a pro at applying caulk to get a good seam. The trick is to apply lightly. A thick layer will cause excessive caulk that will need to be removed.
If you do end up with too much caulk, don’t worry. Once the silicone dries, you can use a blade to scrape off the excess. If you end up with a slight defect in your concrete, don’t stress about it. As you can see, I didn’t worry myself with getting perfect results, and the defects just add character.
Making the Rope Handles
The rope handles that I made were 3/4″ thick. You can size down to 1/2″ but I wouldn’t go smaller than that. I also don’t recommend going with anything too thick because it will not be easy to grip.
To make the handles, I rolled the rope into a loop with the ends laying on top of each other. Then, I use two zip ties to hold them in place. Cut away the extra rope.
Note – make sure that the rope handles fit nicely inside the form with at least 1″ clearance on all sides. Less than 1″ of concrete surrounding the rope will not be structurally strong enough to hold up to the weight over time.
Mixing the Concrete
I mixed my concrete mix at a ratio of 5 parts concrete to 1 part water. I used a quart sized container and measure out 8 quarts of concrete. Then, I added approximately 1 1/2 quarts of water. I premixed my colorant in the water according to the instructions before adding it to the dry mix.
The mix should look and feel like a very thick milkshake. Keep extra water and dry mix close by in case you need to add one or the other to get the right consistency. I recommend making more mixture than you think you will need.
You can always keep a few small molds on standby if you have any extra mix left over. Or, you can just pour the extra mix into an old container and allow it to dry before throwing away.
Working the Mold
Once the concrete is mixed, tap and/or bounce the bucket to knock any air bubbles loose. Doing this before pouring will cut down on how much you need to do it after you get the concrete into the mold.
Air bubbles that are left behind will make tiny holes in the surface. You can see a few of these in my final outcome. Normally, you wouldn’t want to have any of these appear especially if you are casting a countertop. However, I think that they create a more rustic look when there are a tiny few, which is good since I definitely had some air bubbles in my mix.
You shouldn’t expect that you will be able to get all of the air bubbles out unless you are a professional at this. Some air bubbles will remain, but you should be able to eliminate most of them. As you pour the mixture into the mold, tap the form to further release air bubbles.
Once the form is about 3/4 of the way full, spray the bottom of the tray with the cooking spray and start working it and the rope handles into the mix. Add the remaining mixture as needed, and weigh down the tray to keep it in place.
You will need to work the top surface to get it even and smooth. It will look ugly at first, but once you start smoothing it down it will all start to take shape. The goal is to get the top as smooth as possible and make sure that everything is packed nicely into the form.
Allow it to dry overnight, but do not go beyond 24 hrs. If the temperatures are really high, the concrete may cure faster. You should check the results at the 18-hour mark and determine if it is ready or needs more time.
Removing the Forms and Tray
After the concrete has set up for the time needed, begin to remove the melamine boards by taking out the screws. Then, lightly tap the edge of the boards to make them pull away from the concrete. Be extra careful to not hit the concrete during this process.
Next, use a putty knife or blade to score around the edge of the tray to detach it from the concrete. Then carefully wedge the knife between the tray and the concrete and carefully pop it free.
Refining the Results
Use a stiff bristle brush to remove any loose material from the concrete and to clean up the rope handles. Then, use an orbital sander to knock down and sharp, thin, areas along the edge of the concrete.
The purpose of sanding the edges is to take off any concrete that is thin and could eventually chip off. Remove just enough to ensure safety. We are not trying to get a smooth finish, here.
Rinse the piece off with a water hose and allow it to cure for about 3 more days.
Adding feet to the bottom will protect both the concrete and whatever surface that it is resting on. Use the 5-minute epoxy and a few small clamps to attach the feet to the bottom. Allow it to dry for the time recommended.
Sealing Cast Concrete Serving Trays
Since this tray will be holding food, it is important to seal it. If you plan to place food items directly against the concrete, make sure that you chose a food-safe sealant. Otherwise, any sealant designed for stone can be used.
Apply a thin coat and wipe away any excess that doesn’t absorb with 60 seconds. Allow the sealant to dry thoroughly and place your plastic insert back into the concrete holder.
Now, go show off your project!
Full video build is available on my Youtube channel. Be sure to subscribe while you’re there to catch my next concrete project!