Posted by John on May 12th, 2013
Happy Mother’s Day! Hope you had a great holiday. We pretty much hung out with our families all weekend. Good stuff. Good stuff. Ate too much.
Today I wanted to bring you a quick how-to on making concrete planters. Last week we shared the results of our attempt to make a monogrammed planter. While we didn’t get exactly what we were shooting for with the monogram, the actual planter (sans monogram) looks pretty good. We’re going to work on that monogram later, so stay tuned. We’re going to get it right.
As for the planter, the directions I followed came from Popular Mechanics. I used the exact dimensions they provided in their plans. Their procedure, however, called for some different materials, which I opted to change for convenience.
Popular Mechanics used a regular plywood board for the concrete forms that you seal or cover with aluminum foil. It may have been MDF (I dunno, I actually didn’t read the article, I just looked at the pictures, lol). So I used melamine. When I made concrete countertops, that was done using melamine for the forms. It’s what the concrete counter people recommend. If you’re not familiar with melamine boards, they are just particle boards that are laminated with a hard, smooth, typically white layer of… something. The white surface is impervious to water. Melamine is usually used for either cabinets or shelving. You can typically find it in the shelving isle at your local home improvement store. It’s not expensive. I used the 3/4″ thick stuff.
I used the 5000 psi mixture from Quikrete. You can use a regular 80 lb bag of concrete too though. Plan on one 80 lb bag of concrete per planter of the size in the article. The planter ends up being around 80 lbs when you’re done. Concrete is cheap, btw, around $5 per 80 lb bag.
Quikrete makes a colorant you can add to the concrete mixture to change the color. If you don’t color it, it will end up being the same color as a sidewalk. Nothing wrong with that, if that’s what you’re shooting for. We used a half bottle of the black colorant for our planter and it’s not that black. You add the colorant to the water before you add it to the concrete.
Tools you’ll need:
1. Drill and screws
2. Silicone caulk
3. Circular saw or table saw
To start, you cut all the melamine pieces for the form. The form pieces are listed in the article. I added the V letter to the board that’s the front of the planter. I calked it to the melamine and then caulked around the perimeter of the letter.
You basically make two planter boxes for the form, an inner and an outer. The outer is where the letter goes, if you’re adding one. As I assembled it, I applied a bead of silicone caulk to all the exposed edges of the melamine to keep the particle board from soaking it in and expanding. I also applied silicone caulk to any joint where to melamine boards met to keep any liquid concrete from running through the seams. All the boxes were joined with either nails or drywall screws.
The inner box gets mounted to a larger board.
With the smaller box mounted to the bottom board, I place the outer box over the assembly.
Before adding the concrete, I coated three small wooden dowels in vaseline. They will serve as forms for the drip holes in the bottom of the planter. You don’t need to nail them or anything. Actually, they get smushed down into the concrete after you’ve poured it and can be taken out before the concrete fully sets.
In case you were wondering, you pour this planter upside down. You need to work the concrete into the form with a stick or some other type of hand tool. A stick works fine though. Obviously, if you’re adding some sort of severe letter, you need to do a better job than I did with the concrete around the letter.
With the concrete in the form. I used a random orbital sander pressed against the form to shake the air bubbles out of the concrete.
I let the concrete cure overnight and then just started popping the sides off the form with a crow bar and a hammer. The article makes it seem like you can just pull the inner form out from the outer form. Yeah, good luck with that.
After banging all the form pieces off, you’re left with the planter.
So, lessons learned:
- The melamine boards were difficult to remove and seemed pretty firmly stuck in there. The article used a different material than melamine and talked about aluminum foil. The hardest part was removing the inner form.
- The black dye only gave us a dark grey planter. If you wanted it darker than that, use more than half the bottle per bag of concrete.
- I should’ve coated the letter with either cooking spray or vaseline.
- Don’t come into the house covered with concrete and sawdust and ask your wife for vaseline for the wooden dowels. She’ll think you’re being weird.
How much did this cost? About $35. That’s not bad though. I’m pretty sure store-bought concrete planters are expensive. Plus, if you’re able to customize the size or add some personalization, you’ll be saving buko bucks.
So what do you think… is this something you’d attempt?