In this instructable I will tell how I built our firewood shelf that looks like conrete but is made from MDF and covered with a concrete plaster called beton-ciré.
In retrospective it was quite an easy project but a messy one which includes lots of sanding.
I guess it took longer to clean the basement than to actually build the shelf ;-)
Sorry for the bad image quality, but a.) I worked in the evening in my basement where the light is not that good for photos and b.) I never intended to do an instructable about it, but I found this faux/real context and thought this would be a perfect project for this.
Step 1: Plans and Materials
As my local wood shop did not have thicker MDF, I planned it with 3cm MDF glued and screwed the single pieces together in order to accomplish the desired thickness of 6cm.
I attached a drawing with the single sheets, measures can of course vary depending on your needs.
The following materials were used for this project:
- Wood/MDF according to plans
- Wood glue
- gips plaster
- as concrete plaster I used a product called beton-ciré for which the following materials are used in order to process it successfully. There might be other products with oder work instructions, but this is what was available at my location:
- beton-cire powder and binder (so called Resiné)
- epoxy with hardener
- quartz sand
also, these tools were used:
- electric drill
- orbit sander
- Lots of paint rollers
Step 2: Glueing and Screwing
I glued and screwed all MDF parts together according to plan.
Afterwards I filled all gaps and holes with plaster and sanded everything down - unfortunately no photos of this additional step available...
But let me tell you that sanding MDF produces a lot of (toxic) dust, so please wear a mask!
Step 3: Epoxy and Quartz Sand
After sanding I covered everything with epoxy using a paint roller (The product I used is in an enclosed metalish bucket which you penetrate with a screwdriver. This opens an included reservoir with the hardener and you automatically have the correct epoxy/hardener ratio. You only have to mix it a little bit. The main disadvantage of this is that you have to use all material at once) and poured quartz sand over all wet surfaces. In the end it should have the haptic of sanding paper. This is important for the next step and the sand is for the concrete plaster to have a surface to stick to.
Please cover the floor and be careful with the epoxy.
Wear gloves and eye protection all the time.
Step 4: Add the Concrete Plaster
Next step is applying the conrete plaster using a spattle.
This is done twice.
The coats should not be too thick but I tried to cover all surfaces with the first coat. When dried for 45 minutes the second coat can be applied. Both layers should not be thicker than 7mm in total.
Special attention should be given to the edges. In hindsight I would have done the edges as a first step and sanded them afterwards, and only then continued with all the surfaces (this is what the salesperson told me anyway, but I thought I could do it all together and save some time - which I didn't; I ended up doing the edges anyway but at the end, which you could see if you stand close to the finished product and pay attention for details. Luckliy the shelf is quite big and it does not stand out that much).
Afterwards it needs to dry for at least 48 hours.
Then it can be sanded until the surfaces feel even and smooth. Use 80-120 sanding paper for this, according to the amount of material you need to remove.
Step 5: Primer and Finish
After sanding the primer can be applied using a paint roller.
I let it dry for 12 hours and then applied 2 coats of matt finish also using a paint roller.