Making an epoxy resin table mold is one of the most vital parts (if not the most vital part) of making a river table. Too many times I’ve seen (and sadly experienced) epoxy resin molds not properly work – leaving the piece uneven or allowing the epoxy resin to leak out the bottom.
Here are the outlined steps to making sure you get your epoxy resin table mold right every time:
- Choose a Mold Material
- Get the Appropriate Size
- Cut and Assemble the Form
- Seal the Edges
- Make the Form Stick-Proof
While this looks simple at first glance, there is a lot of work and details that go into making sure your epoxy table mold is perfect for your project. To make this more comprehensible, I have gathered information on the most critical components and have laid out the details that you will need to consider and complete. Let’s dive in.
Choose a Mold Material
Choosing a material is a great starting point for your epoxy resin table mold project. The material you choose to use will depend on a couple of factors. After all, the material that you choose will make the difference in the quality as well as the effectiveness of the mold.
In general, there are three options that most people (myself included) go with when making an epoxy resin table mold. These include plywood, melamine, and high-density polyethylene (HDPE). Here, I’ll break down the pros and cons of each of these for you. Once you have determined what material you will make your mold from, you will need to consider the size of the project and purchase your material accordingly.
When it comes to choosing a mold material for your epoxy resin table mold, plywood is definitely the cheapest option available. If you need to save money on this project, you will likely want to go this route. However, you may find that you get what you pay for in terms of the quality of wood that you are using.
Still, plywood can be effective and is very budget-friendly. Plywood is also great because it allows you to purchase a large enough piece at a local store for just about any size epoxy resin table you could need. The convenience of this is incredibly underrated because most people are ready to jump right in once they have gathered all of their materials- including the mold material.
The cons to plywood are that it is less sturdy than the other options. This has to do with the previous statement that you will get what you pay for here in terms of quality. Also, it can be a bit more difficult to maneuver (considering its sturdiness, or lack thereof). When using plywood for your epoxy resin table mold, you will need a very level and sturdy base in order to make sure your table does not come out uneven in some areas.
Melamine is another great option for your epoxy resin table mold and is also locally available to most people. Again, we go back to the importance of having access to the material that will allow you to begin your project and recognize that this truly saves time (and potentially money, at least on shipping or travel to find other materials).
Melamine is a great in-between for saving money but still having a very sturdy option that is unlikely to allow give and cause unevenness in the epoxy resin table mold project. So, if you are looking for a sturdy option but are not willing to break the bank on a higher investment, this material can be a great choice for you.
The only real con is that it can be a risk to use melamine without tape on it. I have seen people end up in unfortunate situations where the melamine sticks to the epoxy after the pour has been completed. Personally, I will just play it safe and use tape over it, and I have never had issues with using it this way.
High-Density Polyethylene (HDPE)
If you are looking for a truly sturdy investment when choosing a mold material for your epoxy resin table, high-density polyethylene (HDPE) is the highest-quality and considered the best material used for epoxy river table forms. It comes in all sizes and thicknesses, allowing you to fully customize it to your needs.
In general, you can purchase it at ¾” thick to hold up with just about any project you could put on it. Another great benefit is that it is highly durable and is great for reusing the mold many times. Occasionally, you can find some sizes at a local hardware store, although you might need to order these high-quality materials through an online vendor.
The only real con with HDPE is that it is substantially more expensive than the other options – making it difficult to justify for everyone. However, if you are willing to make an investment in your epoxy resin table mold, this material is by far the top quality material out there for this purpose.
Get the Appropriate Size Mold
For many things in life, having more of your stash than you might need to use is a great and safe way to keep an appropriate stock. Making an epoxy resin table is no different. If you know the size of the table you want, you should always add 1” – 2” on each side.
If you are making this table for yourself or a friend and do not need the size to be 100% perfect, it is okay to only add an extra ¼” – ½” on each side. This would mean for a table that is going to be 48” long and 20” wide, you would want to make the mold about 50” long and 22” wide.
Adding extra space on the mold helps ensure that you have some wiggle room if there is an issue in the table during or after curing. Truly, it is hard to describe how important giving this extra bit of space can be in allowing your project to go more smoothly.
Issues creating an epoxy resin table can vary by project and mistake, but here are the most common ones I’ve seen or experienced:
- The table is not quite square and needs to be shaved.
- The epoxy did not cure fully along one edge.
- There is a slightly more shallow side (improper leveling).
- The end grain soaking in some epoxy or dye and needing to be cut off.
By taking a few preventative measures like adding additional space and using an appropriately-sized mold, you are well on your way to preventing at least some of these potential issues with your epoxy resin table.
Cut and Assemble the Form
When I make forms, I like to have two pieces of the material of my choice available- one that I can cut from and one that I will use as the base. You will want to cut the sides to be higher than the thickness of the table pour (to prevent overflow among other reasons). Most tables are poured between 1.5” – 3”. This means if you do a 4” side, you will not have to worry about the height of the walls for most pours you will complete while using this mold.
After you have cut the form, you will begin the assembly process. Place the walls of the mold on top of the base (meaning the base needs to accommodate an extra ¾” or however thick your material is on each side). Placing the walls on top will help mitigate leaking. It is less likely that epoxy will slip through a sealed form if it does not also have extra gravity playing a role. This will also help the base stay level.
To ensure that the form is sturdy and secured, I usually screw the walls in from underneath the base, making sure the screw heads have a divot to go into (to keep the base as level as possible). This also helps prevent any slipping later on in the project.
Seal the Edges
No matter how well you think you screwed together your form, you must seal the edges. Otherwise, you run the risk of your epoxy resin flowing out of the mold. To seal the edges, I suggest using silicone caulking, although you could use another caulking or hot glue if need be.
Make sure the form is sealed on all of the edges, and, for extra safety, seal the outside of the edges as well. I have seen many tables leaking from a single area around the mold that can ruin a project and waste tons of epoxy (not to mention time, money, and energy). A waterproof seal is vital to making a proper epoxy resin mold.
Make the Form Stick-Proof
Making your form stick-proof (as in the epoxy resin will not stick to the material when you attempt to remove the mold) is a crucial step in creating the best epoxy resin mold you can. Without this step, you could see your table absolutely ruined, or it will at least take quite a bit of work and finagling to achieve your desired result.
If you are using HDPE or Melamine, you are in luck. You can use some sort of release agent in order to keep the epoxy resin from sticking to the form. The best release agents will be silicone or waxed based.
You may have car wax lying around, which should work great if you just do a thin layer on the mold. Some sort of turtle wax will work great if you do not already have a car wax lying around. For a release spray, I suggest going with something like CRC Silicone Mold Release spray. A silicone-based spray seems to work best, but I have seen others use Pam cooking oil, and that works just fine.
If your mold is made out of wood (or sometimes melamine) you should use tape to prevent the epoxy resin from sticking. Personally, I use Shurtape sheathing tape, but another popular option is Tyvek sheathing tape. If you are in a bind, I have seen packing tape work just fine, but I would not put a 100% guarantee on this option just because it was not designed for this unique purpose. If you worry about the tape not being enough, you can always apply some wax or release spray over it to be safe.
While creating an epoxy resin table mold is far from an exact science, this guide should hopefully give you a great starting place and raise some good questions while creating your mold. Of course, you can watch a myriad of how-to videos online, but this should give you a great place to start (and to come back to) when you are planning out your next epoxy resin table project.
Here are some final tips just to ensure you have thought about the pour you are about to make and the environment it will be in for your epoxy resin table mold.
- Make sure it is level.
This may be obvious to some but not others. A non-level mold means a non-level pour and table, which could take days to fix properly (and could be disastrous if you are doing something else wrong).
- Understand what temperature variations do to epoxy.
Epoxy resin is made to be poured at warm temperatures, usually between 65 – 90 degrees Fahrenheit. If the area is colder it may have trouble curing, and if hotter it could cause the epoxy resin to overheat and smoke or crack.
- Hold the wood down with weight or clamps.
Oftentimes, I see first-time pourers forgetting to hold the wood down that they are about to pour into. The issue with this is wood is not always perfectly flat, and even when it is it has a tendency to move – allowing epoxy resin underneath it and causing unevenness and improper amounts of epoxy.
With all this said, I want to wish you happy pouring! It is an enjoyable and exciting process to create a new epoxy resin piece, and you will no doubt learn much more from the process than you will from this blog. You can do this!