This geometric concrete & copper pipe coat rack (or hat rack, or skateboard rack, whatever you prefer), looks pretty complex, but is actually really easy to do and fairly inexpensive. It doesn't require a lot of tools (you could do it with a circular saw, drill, and a cheap turkey cutter), although having a table saw is nice. The trick to it is using a cheap 3D PVC tile as the base of the form, to give the coat rack its geometric shape. You can buy any sample of one PVC tile, to customize the geometric shape of the rack how you like.
Since the big design trick for this project is using a 3D PVC tile as a concrete form, I'm entering this in the PVC contest. If you like this Instructable, I'd appreciate your vote. Thanks!
The project uses a GFRC concrete mix so that the tile can be cast at only ½” thick, and be light enough to hang on the wall. I used a new “just add water” GFRC mix, which is incredibly easy to use.
I embedded copper pipe pieces in the form and poured the concrete right around them, so that they would serve as posts for hooks. I then used more copper pipe to build hooks in interesting shapes, around the embedded posts, after the concrete cured.
This was a fun experiment, and could lead to all kinds of things that could be made using this technique for PVC tile as a concrete form.
PRODUCTS USED IN PROJECT:
AR Glass Fibers: http://www.concretecountertopsupply.com/Item/AR_G...
Concrete Sealer: http://amzn.to/2yNaF9P
3D Tile (Used for White Rack): http://amzn.to/2gCT6jb
3D Tile (Used for Grey Rack): http://amzn.to/2h7MoCb
Alternate 3D Tile Option 1: http://amzn.to/2zOwJiO
Alternate 3D Tile Option 2: http://amzn.to/2zCjUHx
Copper Pipe Cutter: http://amzn.to/2h6PztU
Spray Foam: http://amzn.to/2h7jRwq
Turkey Cutter: http://amzn.to/2gCMMrJ
Super Glue: http://amzn.to/2zCsKVU
Cake Fondant Tool for perfect edges: http://amzn.to/2w0JCVx
Quality, but reasonably priced, concrete mixer: http://amzn.to/2wcC6bZ
RZ dust mask: http://amzn.to/2wM8F1t
TOOLS USED IN PROJECT:
Dewalt Table Saw: http://amzn.to/2x4igNg
Bosch Drill and Impact Driver: http://amzn.to/2x4duEa
Step 1: Make the Base of the Form
Get a piece of foamular (aka pink insulating foam sheet), and place the 3D tile face down on the foamular, so the back side is facing up. You are going to pour concrete onto the back, which will result in the front of the concrete having the same shape as the front of the 3D tile. Make sure you have gloves on to work with the spray foam -- it is nasty stuff if you get it on your clothes.
Now you are going to fill in the gaps between the 3D tile and foamular with spray insulating foam (Great Stuff or Loctite works -- I went for Loctite because it is denser and thus provides more support.) Use the nozzle to spray foam in the spaces between the tile and the foam. Start by spraying in the middle, and work your way out. Remember that the foam expands, so you don't need too much. Before the foam hardens, press the 3D tile down so some oozes out the sides (do this a few times as the foam expands, so the tile maintains its shape).
Wait an hour or so for the foam to harden, then cut the foamular and excess spray foam away from the 3D tile, using the edges of the tile as a guide to cut it in a square. You can use a basic turkey cutter, or even an exacto knife for this. Or to speed things up, just use a table saw (be careful tho!).
Step 2: Cut the Copper Pipe for Your Posts and Insert Into the Base
Use a pipe cutter to cut your copper pipe for your posts that will be embedded in the concrete. Cut them to be the thickness of your tile, plus a couple inches (but slightly shorter than the height of the sides of your form). Clean off the copper pipe using nail polish remover. You can also cut the pieces that make up the hangers now, but this can probably wait (which is better if you design as you go, like me).
I made a mistake and didn't drill holes for copper pipe until after I had made the form. It is better to do this before putting the form together. Use a 5/8" drill bit (if you are using 1/2" copper pipe) and drill holes in the base of your form wherever you want the copper pipe posts -- location and design is up to you! Make sure to drill the holes starting from the PVC tile side through to foamular, so you don't blow out or rip the 3D tile, as this will mess up your forming surface and show in the concrete.
Step 3: Put the Rest of the Form Together
Cut out four sides from melamine. Each side should be a bit longer than the sides of the tile (exact length doesn't matter, as long as a couple inches longer than the side of the tile. The sides should be tall enough for a 1/2" on one side of your base, plus thickness of your tile/foam base, plus another inch or two to allow space for the copper pipe posts to stick out on front.
The concrete tile part of the coat rack is going to have a 1/2" thick base (with thicker parts where 3D shape sticks out). To make it 1/2" thick, put 1/2" plywood or MDF down on the table as a spacer. Then put the base on the 1/2" spacer with the tile face down (against the spacer). Now place the four sides around the base of the form, and use a hot glue gun to attach the sides to each other and to the bottom (foamular) side of the base).
Flip the form over and insert the copper pipe into the holes and press them through. Make sure the copper pipe extends above surface of 3D tile and is even or slightly below the tops of the sides of the form (so that the pipe doesn't extend past the back of the concrete, once poured)
Flip the form back over (tile facing down), and use hot glue to hold the copper pipe in place, straightening the pipes if needed while gluing.
Flip it over again (tile facing up), and caulk the form. Check out my past instructables with concrete for a detailed explanation of the caulking process for concrete forms.
Step 4: Built the Embedded French Cleat
We'll use a standard french cleat system from 3/4" plywood (or any 3/4" scrap wood) to hang the coat rack. The twist is that we'll pre-attach the coat rack side by drilling screws through half the cleat, which extend about 1/2" beyond the other side of the cleat, so that the extending part of the screws is embedded in the concrete. Use scrap wood to build a bridge that suspends the half of the french cleat above the concrete form, with the bottom of the wood cleat level with top of the form, and the screws extending to the interior of the form (so we can pour concrete around them). Use stainless steel or outdoor screws, so moisture from pour doesn't destroy the screws. Check out the pictures and video for more details on this bridge. It is simple to build, but easier shown than explained in words.
Step 5: Mix and Pour the Concrete
Check out my previous Instructables on GFRC concrete for more details on mixing. However, for this project I made it easier using Fishstone's just-add-water GFRC mix. You mix it by adding 1 gallon of water for every 50 lbs (one bag) of mix. Just adjust the ratio for the size of your tile, factoring in about 10 lbs of mix per square foot of tile (to err on the side of having more than needed). Take 30% of your mix for the whole project, and mix this first as a face coat.
When mixing the face coat (and back coat), add the concrete mix slowly to the water. E.g., add a third of the mix, then mix it up, add another third of the mix, mix it up, and so on. You can add a bit more water (but careful not too much) if you need to get it more flowable. The face coat should be like runny pancake batter. Pour the face coat in your form, and use a chip brush to spread it around and cover all surfaces as evenly as possible. There is NO need to vibrate GFRC mix.
Then mix the back coat the same way, except after it is mixed, add about 1 lb of glass fibers per 50 lb bag. Add fibers in slowly, e.g., a third at a time. Add water if needed to get the mix so you can pour it right out of the bucket into the form. Pour it in and use your hands to work it into the edges and corners, and make sure it covers everything. Again, there is no need to vibrate.
If you made your mix flowable (so it pours easily), it will self-level. Just pour it so the concrete is level with the top of the form. There is no need to screed it. If you like, you can use a trowel after it has set up a few hours, and scrape the sides of the form to level it off a bit, but this is optional.
Step 6: Demold and Seal
Now let is set for 24 hours, then demold it. Just unscrew / and pull the form apart. You may need to use an exacto knife to remove hot glue from around the copper pipes, but other than that, the sides and base of the form should come right off by hand (maybe a light tap with hammer on sides).
Optional: use a concrete sealer to seal the concrete before attaching pipes.
Step 7: Hang the Coat Rack and Create Your Copper Pipe Hooks
Attach the other half of your french cleat to the wall. Methods for this vary depending on the type of wall you have. Just search for "how to hang french cleat" and whatever type of wall you have, and you'll find an easy way to do it.
Now hang up the coat rack on the french cleat, and begin to build the copper pipe hooks. I used 1/2" copper pipe, and used straight pipe, 3-way tees, street elbows, and standard elbows. For both coat racks, I bought 10 ft of pipe, 24x 3-way tees, 24x street elbows, and 12x standard elbows. It was more than I needed, but I wanted to have options. The particular design is up to you. Just play with the pipes loosely (without soldering or gluing) until you come up with a shape you like. You can see in the pictures I tried out a bunch of different pipe layouts before arriving at one I liked.
One you finalize your layout, attach the pipes with super glue. When gluing them, you'll generally want to glue to the posts last. Build up larger groups of pieces test fit them, then glue them together unattached from posts), then glue to posts. I just used super glue to glue the pipes, and the cheap $12 pipe cutter linked to above.
For this step, the best advice I can give is to do a couple test runs (e.g., take it apart, then put it together as if you are gluing but without glue), and think through the order you'll be gluing things. Make sure you don't glue in a piece that prevents you from gluing another part of your design subsequently. If you do a couple test runs with disassembly and reassembly, it should go fine. But I'll stress, do the test runs :)
Then sit back and admire your abstract work of art embodied in a coat rack :)