The wall will get tiles on you 
But the board looks a bit streaky because the concrete absorbs the oil at different rates, it seems, however it has an even and nice color now after about 2-3 days!
But the board looks a bit streaky because the concrete absorbs the oil at different rates, it seems, however it has an even and nice color now after about 2-3 days!
Hey,
I think I might have a little annoying problem.
It's like a half-white layer on top of the discs, more or less in certain places.
When you wet sand it becomes a bit milky...
It doesn't show at all when the discs are wet.
Does anyone know an easy way to get rid of this? It gradually disappears when sanding.
I think I might have a little annoying problem.
It's like a half-white layer on top of the discs, more or less in certain places.
When you wet sand it becomes a bit milky...
It doesn't show at all when the discs are wet.
Does anyone know an easy way to get rid of this? It gradually disappears when sanding.
For those of you using paraffin oil, do you find that you get a sufficiently dirt-repellent surface?
Paraffin oil never -dries-, unlike oils with drying/hardening oils/resins.
Just curious about your results, as paraffin oil is more suitable for cutting boards and such.
Since it doesn't dry, it is generally semi-impossible to polish.
Paraffin oil never -dries-, unlike oils with drying/hardening oils/resins.
Just curious about your results, as paraffin oil is more suitable for cutting boards and such.
Since it doesn't dry, it is generally semi-impossible to polish.
It becomes almost whiter when I sand it?
What is the white stuff that gets sanded off but seems to come back?
What is the white stuff that gets sanded off but seems to come back?
I have a concrete sink that I did not make myself, but it was in the apartment when I moved in. Unfortunately, during my ownership, it has gotten a couple of stains due to water being left standing. How do I remove these stains? I have oiled it with rapeseed oil, but it seems like water glass is the best solution or?
Thanks for many great posts!
Thanks for many great posts!
I have never worked with vibration-free/self-compacting concrete and therefore wonder if the result is as good as with well-vibrated "regular" concrete? Any disadvantages (besides being more expensive, I assume)?jomany said:
I googled a bit and only found self-compacting pump concrete. Feels a bit overkill if you're going to cast a countertop
Any tips on manufacturers that ship in bags?I really have no idea. I put up some walls and other stuff for some concrete workers, and they told me there is vibration-free concrete for applications where, for one reason or another, you can't vibrate. As I understood it, it shouldn't be any worse than regular concrete. But if it's possible to cast countertops with it??? Devettefan!
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SCC (self-compacting concrete) is certainly fine for casting countertops, but unfortunately, I've never seen it in a bag, and when we order it at work (via a pump truck), it's reasonably expensive per m3, and since you just need a few liters, it would be a costly affair. Regular fine concrete is good enough with just vibration, but it's best to use a smooth board in the mold so it flows together better.
Now to my question, I've never used sodium silicate before, but now I've cast my countertops. How long should I wait before applying the sodium silicate?
Regards
Now to my question, I've never used sodium silicate before, but now I've cast my countertops. How long should I wait before applying the sodium silicate?
Regards
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As for water glass, my answer is, avoid it if you don't have experience. For me, it just became a white sticky mess, which I now have to sand off somehow. Unclear what went wrong but it's not good.
I know it's an old post, but since no one else has responded to this, I will. Of course, the concrete continues to cure even if you treat it. Concrete cures even if you pour it into a plastic bag and tie it up.jawen said:
That being said, there may be other reasons to wait with the treatment. Perhaps it's good if the moisture content in the concrete is allowed to decrease before treating it, for example.
Just found this interesting thread.
I came up with an idea to try if you want a shiny and smooth surface on your cast countertop without having to sand at all. I've cast smaller items on a glass pane, and you get an extremely smooth and shiny surface. It should work for countertops too, as long as you have a sufficiently large glass pane. However, one difference is that you won't get a grainy pattern as you would by sanding. On the other hand, you can color the concrete in the desired shade. It's important to vibrate away the bubbles, as they are quite visible against the shiny surface. Personally, I think small bubbles aren't disturbing; they can actually break up the otherwise stiff surface.
It can be tricky to remove the glass; when casting against glass, a vacuum is formed that you need to release by carefully inserting a putty knife between the concrete and the glass. By the way, do not use release oil on the glass; it should be completely clean, as the slightest grease stain or dirt is visible otherwise.
I came up with an idea to try if you want a shiny and smooth surface on your cast countertop without having to sand at all. I've cast smaller items on a glass pane, and you get an extremely smooth and shiny surface. It should work for countertops too, as long as you have a sufficiently large glass pane. However, one difference is that you won't get a grainy pattern as you would by sanding. On the other hand, you can color the concrete in the desired shade. It's important to vibrate away the bubbles, as they are quite visible against the shiny surface. Personally, I think small bubbles aren't disturbing; they can actually break up the otherwise stiff surface.
It can be tricky to remove the glass; when casting against glass, a vacuum is formed that you need to release by carefully inserting a putty knife between the concrete and the glass. By the way, do not use release oil on the glass; it should be completely clean, as the slightest grease stain or dirt is visible otherwise.
On YouTube, there are of course a lot of useful tips for this as well. Search for "Fu-Tung Cheng" and you will get ideas on design and practical tips on materials. For example, using melamine boards, styropor (polystyrene), rigid plastic strips, and double-sided carpet tape to easily make molds without a single screw. Must try at some point.