Ever seen this on a Granite Counter Top?

[Mikey P]

brand new and un sealed..

slightly unpolished inch thick lines every 4 to 5 inches.

 

[Out of Character - 0]

In a office building we built a few years back we had ordered counter tops for the reception areas in each suite. They sat outside for along time in the weather. I think it was rain that caused it but the stuff that they had separating the counters left a dull pattern.

 

[rwcarpet]

It could have sat in direct sunlight with some type of plastic wrapping on it. My Daughters granite grave monument (black) and polished, has images baked into the finish from the plastic clings that we used to put on the stone. I tried every type of compound to rub them out, but the image still remains. I would have to probably have the whole front of the stone ground down and refinished to remove the marks.

 

[Chads]

Probally is from the sunlight, red is the first color to fade from uv rays, they probally had some type of tape or straps on it that blocked some of the light, causing the the difference in color shade.

 

[Stone Dude]

It is wear from mechanical abrasion. Likely some sort of cover was rubbing on it when transported. Its not from straps, there are too many marks, I have never seen straps that close together.

it is a minor issue, it can be polished out when done properly, and fairly risk-free. There are a few ways of doing it, all but 1 require a good amount of experience. MB20 from MBstone.com is fairly easy to use.

I usually stress to never attempt this type of work if you dont have experience, but the top isnt that bad and wont require any mechanical abrasives.

and to clarify about the sun; sometimes stones will fade in direct sunlight. More often than not, it is actually the resin they use to treat the slabs being effected, not the minerals in the stone themselves. Our slabyard is outside, and we experience this from time to time. 99% of the time it is easily reversible. Marble doesnt really fade, unless its been a VERY long time, 20+years. and then its usually some sort of spalling of the crystals. in this case it can be refinished and brought back to new.

 

[John LaBarbera]

It is wear from mechanical abrasion. Likely some sort of cover was rubbing on it when transported. Its not from straps, there are too many marks, I have never seen straps that close together.

it is a minor issue, it can be polished out when done properly, and fairly risk-free. There are a few ways of doing it, all but 1 require a good amount of experience. MB20 from MBstone.com is fairly easy to use.

I usually stress to never attempt this type of work if you dont have experience, but the top isnt that bad and wont require any mechanical abrasives.

and to clarify about the sun; sometimes stones will fade in direct sunlight. More often than not, it is actually the resin they use to treat the slabs being effected, not the minerals in the stone themselves. Our slabyard is outside, and we experience this from time to time. 99% of the time it is easily reversible. Marble doesnt really fade, unless its been a VERY long time, 20+years. and then its usually some sort of spalling of the crystals. in this case it can be refinished and brought back to new.

Wow! Good post. I learned a lot. Thanks.

 

[alazo1]

I'd try a mild stripper to make sure they did not wax it.

I have some of the mb20 that Stone Dude (Cameron) is reffering to. Let me know and I'll send it to you. You'll need some black oxide as well.

In reality though, I'd have them call the fabricator back since it's new and their issue.

Albert

 

[Stone Dude]

I'd try a mild stripper to make sure they did not wax it.

I have some of the mb20 that Stone Dude (Cameron) is reffering to. Let me know and I'll send it to you. You'll need some black oxide as well.

In reality though, I'd have them call the fabricator back since it's new and their issue.

Albert

This isnt a bad idea, but I can save you some time. Being around stone long enough you can immediately identify a topical. There isnt one in this case. Its hard to explain but its basically the way the sun glares from the surface. if there was a topical it would look different.

 

[Mikey P]

No topical for sure. The bar slab next to it has the same line running down the length of it. All the other slabs are fine.
Cameron, are slabs given the final polish with an automatic laith like machine or by hand with a Makita type hand tool?

 

[rwcarpet]

It is wear from mechanical abrasion. Likely some sort of cover was rubbing on it when transported. Its not from straps, there are too many marks, I have never seen straps that close together.

it is a minor issue, it can be polished out when done properly, and fairly risk-free. There are a few ways of doing it, all but 1 require a good amount of experience. MB20 from MBstone.com is fairly easy to use.

I usually stress to never attempt this type of work if you dont have experience, but the top isnt that bad and wont require any mechanical abrasives.

and to clarify about the sun; sometimes stones will fade in direct sunlight. More often than not, it is actually the resin they use to treat the slabs being effected, not the minerals in the stone themselves. Our slabyard is outside, and we experience this from time to time. 99% of the time it is easily reversible. Marble doesnt really fade, unless its been a VERY long time, 20+years. and then its usually some sort of spalling of the crystals. in this case it can be refinished and brought back to new.

Hey, Stone dude.....I described the mis-coloration of my Daughters grave marker in an above post. It was caused by plastic window clings applied to the black granite stone polished front, and they were left there for months in direct sunlight. Can you tell me what caused it? And any product to remove the marks? Or are they permanent?

RW

 

[Dolly Llama]

are slabs given the final polish with an automatic laith like machine or by hand with a Makita type hand tool?

I know nothing about stone, and I'll prove it by saying it looked like a problem with a roller/cylinder type finishing gizmo at the stone factory
Like they use for S2S hardwood lumber at the mills

and I don't know what a "laith" is either..but it sounds like "lathe" and they make square lumber round...like a rolling pin....or bludgeon ...that Mr Phiff will use to BEAT YOUR BRAINS OUT if you jack up her counter tops more than they are now with your Mosquita angle buffer .... :shock:


..L.T.A.

 

[Mikey P]

I refused to touch/seal them until either they were fixed or the owners signed off on all responsibility on my part.


and your wainscoting is still ugly as hell even if you do know your way around a workshop.

 

[Stone Dude]

the final polish, as well as the entire process is done with a bridge polisher. It is like a bridge saw, but a horizontal head. they do all the abrasive passes then finish with a wool head of some sort.

like this, but they switch heads, or send it through a polishing line. EXTREME amounts of pressure and friction

http://www.youtube.com/watch?v=f0TvupBJvn4


as far as the black stone headstone goes. Black granite is notorious for etching and/or losing color. Many countries that process black granite introduce a dye to give its black color that can be slightly removed. OR, when rain water and untreated water get on the slabs it is held there by the plastic. it will slightly etch the pattern into the stone.

if it is etched, it can be repaired rather easily, like with MB20. If it is color loss, it is more difficult. the two easiest options are to etch the whole thing so it is consistent, or re-dye it with something like Tenax Uniblack or Tepox V black.

 

[Mikey P]

0]http://www.youtube.com/watch?v=2g8ZrcHHx8o0]

 

[Stone Dude]

there you go. different countries use different machines, but its all the same principal.

in the field, its impossible to duplicate this procedure, so other methods have been developed to hone and polish granite with small pads. This process is very physically demanding and can only be done a few hours a day. MB20 has eliminated a couple of steps from the process, and significatnly reduced the effort needed.

many, included myself, have speculated that MB20 was an artificial polish, a wax of some sort. I have stabbed, scraped, burned with acid, heated with a torch etc. only to have no effect on the surface. I am convinced its a legit polish and have been using it a lot more for a while now. My point is the process is fairly easy, user-friendly and almost risk free. It can be used in a situation like the one originally brought up in this post. It does have some acidic compounds in it, so the surrounding areas should be taped off. other than that there isnt much more to do but practice.