How to Build a Polished Concrete Desk

Step 8: Polish!

I don't have many pictures of this step since it is hard to hold the grinder, spray the hose, and take pictures simultaneously, but what you want to do is keep the polishing pads wet at all times, and slowly and evenly polish the whole surface with each pad until you reach 1500 grit. The polish pad set comes with a 3000 grit pad, but the sealer needs a small amount of roughness to adhere well. Be careful not to gouge the surface with the grinder or you will be able to tell in the shiny surface when you have finished. When it has been polished completely, apply sealer to the surface and let dry. A few coats may be desired. Buff the surface with paste wax and wipe off with a soft clean cloth or towel when dry.

Comments

[Ghost Wolf]

how heavy is the table?

[hivoltage]

 I calculated with the density of concrete and the volume of the slab that it should be about 400 pounds altogether.  ~160 ors for the smaller piece and about 240 for the larger. Makes sense, since thats close to the dry weight of the amount of sand and cement I used. not sure what it weights with the wood part, but it is in three parts also. Getting it up the stairs was quite a struggle haha.

[Ghost Wolf]

Can you make it thinner so it wont weight 400 pounds? 

[hivoltage]

well, two inches is the thinnest I recommend that you go. Thinner concrete is more prone to cracking, so it could work if you added more glass fiber or polypropylene fiber, or some other reinforcing agent. Also the support wire mesh can cause a grid type pattern on the surface if its not a thick enough slab. it will be significantly less heavy if you make a desk smaller than the one I've made, since it pretty gigantic. The smaller section by itself would make a great desk  and only weighed about 160 pounds or so.

[cfestel]

Thanks for showing the low cost polishing option.  Other wet polishers are in the $200 range and I was resigned to shelling out the money for it.   One question about the Harbor Freight air polisher:  what air compressor did you use?  I have a small compressor that has about 2.6 SCFM output at 90psi, and the Harbor Freight grinder calls for 3.0 SCFM.    

I have a friend with a bigger compressor, but I'm curious whether mine will work. 

[cfestel]

Also, did you buy the disc holder from HF?  I'm wondering if this one has the velcro backing needed to hold the diamond polishing pads.

[hivoltage]

 Hi, I used a 60 gallon compressor so i am not sure whether it would work well with your small compressor. The disc holder pad I used came with the polishing pad set I bought on ebay. One thing I think I forgot to mention about the angle grinder from harbor freight was that although it is advertised as being compatible with 5/8" arbor grinding discs, the adapter it comes with is not suitable for a backing pad with 5/8"-11 hole in it.I had to make an adapter piece to screw onto the 3/8" stud on the grinder to fit the 5/8-11 polishing pad. Its like a 5/8-11 bolt that has been cut off and had a 3/8" tapped hole drilled into it.

[trgz]

I'm rather impressed - I'll have to remember this as I'm moving into a new house soon and this might make a really interesting alternative kitchen worktop

[crasch48]

http://shop.ebay.com/?_from=R40&_trksid=p3907.m38.l1313&_nkw=polishing+pad+set&_sacat=See-All-Categories

[capt-capsaicin]

Where did you buy your polishing pads?

[hivoltage]

I bought them from urdiamondtools on ebay! they were only 30 bucks for the set. They're kinda small for doing larger surfaces though, would be easier with a larger pad size if you were doing like a whole kitchen or something