After letting the slab cure for a few days, I sanded it today. By hand with a 125 mm diamond disc intended for an angle grinder. Nice but coarse surface that is not suitable for food.
Then I scrubbed in fine-sieved concrete. Now it needs to cure for a few days before I attempt to polish the surface.
One problem: I have yet to find a product that can protect the slab against grease stains without altering the appearance of the surface too much. Does anyone know?
After the disc cured for a few days, I sanded it today. By hand with a 125 mm diamond disc intended for an angle grinder. Nice but coarse surface that is not suitable for food.
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Then I scrubbed in finely sieved concrete. Now it should cure for a few days before I attempt to fine-sand the surface.
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One problem: I have yet to find a product that can protect the disc from grease stains without altering the appearance of the surface too much. Does anyone know?
Waterglass, which is also a requirement to get the surface completely sealed and the final high-gloss finish. Apply it after the next intermediate sanding but before the fine sanding. After finishing sanding, you can wax the surface or use hard wax oil on it for protection against grease stains.
Water glass, which is also a requirement to make the surface completely sealed and the final high-gloss finish. Apply it after the next intermediate sanding but before the fine sanding. After finishing sanding, you can wax the surface or hard wax oil it for protection against grease stains.
Yes - if I had wanted a shiny surface. The examples I've seen with water glass have all been shiny. But I want a matte and quite raw surface. However, free from visible pores & holes. I plan to finish sand the scrubbed surface in the picture with 100-grit paper. It becomes a matte and pleasantly smooth yet raw surface.
Here's what Roger Andersson writes on Betong.se:
When treating a concrete surface to achieve a more easy-to-clean surface, there are many different methods and cost levels. Water glass can be a good solution, this chemical base for surface treatment comes in a large variety and variations. The result is a less dusty surface but does not provide a hundred percent protection against oil spills, the only thing that gives full protection against oil is an oil-resistant varnish but this is a coating that changes the appearance of the finished concrete surface. In your case, I recommend a silane/siloxane impregnation which is often represented in the protection of bridge constructions.
Yes - if I wanted a shiny surface. The examples I've seen with waterglass have all been shiny. But I want a matte and quite raw surface. However, free from visible pores & holes. I plan to finish sanding the scrubbed surface in the picture with 100-grit paper. It becomes a matte and pleasantly smooth but still raw surface.
Can you sand waterglass matte? Does waterglass stand against grease/oil?
Hardened waterglass has a matte finish, so apply it as a final treatment instead if you don't want high gloss. The waterglass acts as a pore sealer/filler and provides some protection against liquids but not complete against oil. I would still recommend applying wax or hard wax oil. A completely matte hard wax oil won't change the surface significantly, it will only become slightly darker. As always, you should test both the waterglass and wax on a hidden area first to ensure you are happy with the final result.
The final sanding should be done with silicon carbide sandpaper and wet-sand with a sanding block if possible to make the paper last longer.
I can recommend Lithurin, which is applied in two steps: Lithurin 1 (hardener) and Lithurin 2 (sealer). It's very easy to apply and gives a smooth and beautiful surface. One downside is that it is sold in 5-liter containers which I believe cost almost 2000:-, which becomes quite unnecessary since only a few deciliters are needed. If you can access it in another way or if the retailer is kind enough to sell a smaller quantity, it might be an alternative.
I have personally done this treatment on both floors and on a self-cast countertop.
Can recommend Lithurin, which is applied in two steps: Lithurin 1 (hardener) and Lithurin 2 (sealer). It is very easy to apply and gives a smooth and beautiful surface. A downside is that it's sold in 5-liter jugs, which I think cost almost 2000:-, making it very unnecessary since only a few deciliters are needed. If you can get it in another way or if the dealer is kind enough to sell a smaller amount, it might be an alternative.
I have done this treatment myself on both floors and a self-cast countertop.
Lithurin is a classic two-step method with chemical water-based hardeners that react with the concrete. Lithurin 1 is regular water glass (magnesium silicate if I'm not mistaken), and Lithurin 2 is silane/siloxane-based as I recall.
If you want to do the same treatment a bit cheaper, you can first use Herdins Fuktstopp (water glass) and then Weber Concrete Impregnation (silane). The protection is better than just water glass but not completely effective against wine and grease stains.
Lithurin is a classic two-step method with chemical water-based hardeners that react with the concrete. Lithurin 1 is common water glass (magnesium silicate if I'm not mistaken) and Lithurin 2 is silane/siloxane-based as far as I remember.
If you want to do the same treatment a bit cheaper, you can first use Herdins Moisture Stop (water glass) and then Weber Concrete Impregnation (silane). The protection is better than just water glass but not completely effective against wine and grease stains.
Good tips! Good because it is practically usable. Product names & packaging that can be bought by an amateur. For example, I have found Lithurin but it applies to 200-liter barrels. On the other hand, it will probably take a day or two to find where I can purchase water glass & silane.
95% of all tips I've found online are unusable because the place of purchase & product names are missing. For example, I needed plasticizer for the casting. Impossible to buy for an amateur, but luckily I have an acquaintance who worked in construction. He could beg for the centiliters I needed.
A very unexpected problem is that it has proven nearly impossible to obtain sandpaper suitable for wet sanding concrete. They are not sold by Bauhaus/K-Rauta/Hornbach/Biltema/etc. I have Googled several manufacturers who can deliver if I order 100s of square meters. The only store I have found online that has 125 mm sanding discs of grit 100 is toolab.se. But it turned out they can only deliver individual sheets because their supplier, Bosch, cannot deliver. At Lantmännen in Brösarp they had a package with 5 sheets. So far I've managed with diamond cutting discs from Biltema, but next week I’ll have to spend a day calling the Lantmännen stores in Skåne, local stone workshops, etc. Sigh!
Regarding sandpaper, they don't need to be specifically for concrete but just need to have silicon carbide instead of aluminum oxide. Most black wet sandpapers are silicon carbide.
Bosch has a series of sandpaper for angle, orbital, delta, and hand sanding called "Best for Stone" that most hardware and building supply stores can stock. But maybe those were the ones you meant above? Here is one for orbital sanding, for example: http://www.nords.se/sv/verktyg-och-...h-best-for-stone-125-mm-8-halat-k320-5-p.html
Regarding sandpaper, it doesn't need to be specifically for concrete but should be silicon carbide instead of aluminum oxide. Most black wet sandpapers are silicon carbide.
Thanks! Great info again!
Biltema has silicon carbide paper. It's 120 instead of the 80-100 I wanted, but it'll have to do in the absence of anything else. I'll keep googling.
And yes, it was Bosch "Best for Stone" I was after. The 15 discs with grit 100 I got provided exactly the surface I wanted. Just a bit short-lived. Doesn't handle water well.
And one cries when reading the site http://www.toolocity.com/ . Why isn't there such a supplier in Sweden? On the other hand, it could have been possible to find something similar within the EU if I had realized from the start that sandpaper was an issue.
"3M Hook-it 618" could be an alternative. If one can find someone selling it....
Lithurin does not cost 2000kr for 5l. I treated my 100m2 garage floor a few months ago and bought 10-15l of both step1 and step2. I paid under 2000kr for everything.
Lithurin does not cost 2000kr for 5l. I treated my 100m2 garage floor a few months ago and bought 10-15l of both step1 and step2. I paid under 2000kr for everything.
Sounds alright for 100 m2. But me with my 4 m2?
If it works, maybe I'm willing to pay up. Where did you buy? How large are the packages?
(Now I'm envious again. I also want a 100 m2 garage. )
In a few hours, I will brush the surface with a float. After two days, I will do a rough grind and fill with fine concrete sifted to an aggregate size of 0 - 1 mm. Two days later, I will remove the mold, sand again, and rub in fine concrete sifted to about 0 - 0.3 mm. Then the slab will cure for a few days after which I will remove the protective plastic, let the slab dry for a few days, and then sand it to the finish I want.
Stay tuned. More photos to come.
It looks like it's going to be really nice.
I assume it will be a built-in hob and then a built-in oven underneath, if so, how will you place the hob? Will it end up over the concrete edge or will it be slightly lower?
Today I have dismantled the mold. Will keep the slab moist for a couple more days. Planning to do the final sanding on Wednesday. Toolab.se has now gotten hold of sandpaper that will hopefully be with me by then. Unless the snowstorm blocks the transports here to Österlen.
maglag said:
I assume it will be a built-in hob and then a built-in oven below, if so, how do you place the hob?
Will it end up over the concrete edge or will it be slightly lower?
As shown in the picture above, I have a freestanding 60 cm stove.
Sounds completely OK for 100 m2. But me with my 4 m2?
If it works, I might be ready to fork out. Where did you buy it? How large are the packages?
(Now I'm jealous again. I also want a 100 m2 garage. )
I bought it from my local Beijer dealer, the smallest I believe are 5l packages, which are enough for many countertops. The concrete surface becomes much more resistant but not sealed, oil/water can penetrate the surface if left for a while. The biggest advantage is that the concrete doesn't dust and becomes very easy to clean, especially if you have a mirror-smooth surface on the concrete before treatment.
100m2 garage is a luxury I could afford when we design and build on our own
