One of my favorite hobbies is working with epoxy resin. Though the things I like to cast has changed over the years, one of my absolute favorite things to do is create costumes, lamps, tables, etc. using resin. For this tutorial we will be making a sturdy mold to hold a large pour of resin. I will eventually pour a resin led lamp in it. Before we can do that, we have to make a mold!!
One of the trickiest parts of working with resin is keeping it where you want it, since it can very easily drip out holes you didn’t even know were there, resulting in a mess that really can’t be cleaned up. (Try as you may, it’s a real bummer to clean/sand.) When cured, resin will bond to just about everything, and will ruin a table or floor very quickly. The trick is to properly seal the openings and joints in your mold.
For this DIY we will be using melamine boards. I was able to find my boards at a box store’s cull/discounted section. I really lucked out on these and they were 70% off because of water blemishes on the surface! I’ m not building a closet, so that doesn’t matter to me. What I like most about melamine material for mold making is that it’s thick to hold up from the weight of the resin without buckling, the particle board inside is coated, some molds can be reused, and you can invest in one board and make several smaller molds.
If you don’t have a budget for buying a board, you can take apart an unused melamine cabinet or shelving system. Use packing tape over the pre-drilled holes (that hold shelves) to get a flatter edge that resin won’t seep into, ruining your chances of opening the mold and retrieving your treasure. You may choose to use the smooth outside surface of a shelf on the inside your mold to keep things smooth.
For this mold I used my circular saw, and cut four pieces four-inches wide and the width of the board. This makes up the bottom, both sides and a piece to cut in half for the top and bottom. I should have used a finer blade, but I used what I had. I finer saw blade would have made a cleaner cut, but I didn’t have one.
Next I found my most square/perfectly cut piece and used that as the bottom. I mocked up one side at a time, and predrilled my holes through both pieces. If you don’t predrill your holes, you will split the boards and ruin the smooth sides of your mold. It’s not worth skipping. One side at a time, I attached the boards with one-inch screws. I made sure the bottom was flat and any pieces lined up with the bottom so that it will be stable and level while pouring resin. If you accidentally cut crooked, it’s okay, just make sure the back piece is flat on your work surface and line everything up with that. The last two pieces are attached, giving a nice rectangular space to pour a LOT of resin.
Use Silicone caulk to fill in the gaps in the boards on the inside of your mold. Squeeze it into the corners and smooth it out with your finger tip, removing any extra. I recommend using white silicone so you can see your progress. I had clear on hand, so I had to pick it up a, move it around to check the sheen and to tell where it was applied. You should apply this in all the crevices where the boards meet to keep your resin from oozing out.
As an extra precaution from leaks, I sealed the outside of the mold with packing tape. Masking tape also works. Apply tape where the seams are, on the outside of the mold. This will keep a second line of defense between resin and your table! If the inside isn’t sealed well, this will keep resin from bonding the whole thing to your work surface.
Now the mold needs to be sealed so apply a wax paste using a chip brush to the entire inside of your mold. This will be soft and easy to spread when you apply it, but will “dry” to a hazy harder coating. It is imperative that you coat the melamine entirely inside your mold with wax to seal it to keep the resin from bonding to the melamine. This makes the whole surface less porous.
Last we lightly spray mold release inside it, following the directions given. Some of these just want you to spray it, others want you to lightly brush it around, so follow the manufacture’s label. This will make it so it’s easy to get your goodies out, kind of like spraying no-stick stuff on a pan before baking.
There you have it! A great resin mold ready for your creation! All you have to do to get your creation out of the mold is to cut the tape in the creases with a utility knife and remove the screws. You can clean up the mold after using it by pealing the silicone and tape off. Screw it back together and use it again and again if you want.
Make sure your items will fit inside the mold before you cut anything.
Build the mold around your item. Like wood, beads, whatever.
Cover your work surface to protect it from drips and spills.
Clean up any sawdust before mixing resin, you don’t want dust in your project.