Most weeks I receive calls from people asking how to remove a sealer residue. Sealer residues occur when an impregnating sealer is incorrectly applied. Impregnating sealers (or penetrating sealers as they are sometimes known) are intended to be in or below the surface of the stone rather than ‘on’ it. So, the correct application involves applying the sealer to the surface, allowing a short time for penetration (this might be around 5 minutes, depending on both the sealer being used and the material being sealed) then any surplus sealer, remaining on the surface should be removed with something absorbent, ideally a white paper or cotton towel.All too often though, for various reasons this cleaning away of surplus, whilst still wet, does not take place. Reasons include not reading the instructions and my favourite: “I’ve been using sealers for years, always done it like this and never had a problem.”
A sealer residue can appear in a number of ways: as a dry, white powdery deposit; streaky marks or shiny spots; with some sealers, the residue can take the form of a wet or greasy coating. There are a number of ways in which the problem might be rectified, depending on the circumstances.
For example, if a solvent sealer was used, it is sometimes possible to use a little more of the actual sealer, the solvent carrier-fluid it contains can sometimes re-dissolve the residue allowing it to be wiped away with an absorbent cloth.
For other residues, we would recommend the use of a micro-abrasive cleaner like Microscrub. First apply a little water to the affected area, and then add a little Microscrub and scrub. Rinse well and dry down with paper towels. For really stubborn or thick residues that have been left for some time, a stripper may be required. In such situations, we would recommend a solvent based sealer stripper or remover, such as Strip_it applied neat and left on for a minimum of 30 minutes before scrubbing with a white nylon pad.
Apart from the last remedy (using a stripper) the others should not result in the need to re-apply more sealer afterwards. So, it need not be the end of the world if a sealer residue is left on the surface, but it is of course better to avoid the problem altogether, by applying the sealer correctly in the first place.
Copyright Ian Taylor and The Tile and Stone Blog.co.uk, 2013. See copyright notice above.
Hi, Just sounds like over application, Yes you applied 2 coats but every stone is different and this two coats is usually a guide, the stone will take in what it needs until it is saturated. Most impregnating sealers need to be applied , allowed some time (a few minutes) to soak in or penetrate, but then they should be wiped up – no wet sealer should be allowed to remain on the surface.
I think that you have just left a bit too much on the surface,
First thing to try is apply a little more – I know this sounds odd when I just said you have applied too much – but you are just using the solvent in the sealer to help remove the surplus (which has not fully dried or cured yet as it is still tacky) so, just try a little in a test area, apply a small amount of the sealer, rub it around to try to free up the sticky residue, then, buff it completely dry – so remove the now re emulsified residue.
let it dry completely then check to see if it has got rid of the problem – if it has then this is great as it means you have removed the residue without removing any sealer from within the stone and you can do the same all over.
If it does not work, then I suggest you contact your sealer supplier/manufacturer for their advice.
Hope this helps
Ian
Hi Ian,
I’ve recently sealed a area of sandstone around a pool and it has left it white in colour what could I do to fix this.I used a sandstone sealer and limestone sealer I’ve sealed other areas at a different time and have not had this problem.
Thanks mick
Hi,
Some sealers are moisture sensitive, and will turn white if exposed to too much moisture during the curing period. Others will appear white if they are applied and not adequately wiped off (the surplus that is) – as impregnating sealers are meant to be inside the stone as opposed to being left on it. With sandstone that is porous, in most cases this does not become an issue as the very porous nature of sansdstone usually means that the sealer is pulled well in to the stone and no discernible residue is left, and so many people do not feel the need to actively remove any surplus. However in some cases, sealer is left at the surface and this can dry as a white deposit.
Try applying a little more in a test patch, see if the wetting action of the fresh sealer makes the white marks translucent or disappear if so then buff it dry, allow it to dry sometimes this works as you are re emulsifying the residue then wiping it away.
If this does not work you may have to consider stripping it and starting again, if this is the case I suggest contacting the manufacturer of the sealer you used for their advice.
Hope this helps
Ian
Hi
I’ve got Basalt granite and have had hot wax from a candle pour all over it.
I’ve removed the wax but it has left a stain on the tiles.
How do i remove this?
HI,
It can be tricky.
Couple of things you can try:
Assuming the stone is not sealed, try pouring some hot water AROUND but NOT ON the stain so that this warm water can get under the stain and saturate the stone, with the aim of preventing it spreading deeper into the stone. Now, mix a high alkaline degreasing floor cleaner with warm water and apply it to the stain itself. Leave to work for a few minutes, rub with a cloth and mop up the water, uses an absorbent cloth to absorb as much moisture form the stain as possible, repeat a couple of times.
If this does not work, try using s little bit of a solvent in place of the detergent – do a test first on an inconspicuous part of the floor or a spare piece of stone to make sure it is not affected.
If the stone is sealed then you wont be able to saturate the area around and beneath the stain, but you can still try the cleaning method., just apply less off it and quickly try to absorb the cleaner up.
You can also try a poultice, again if you can pre wet the area around it then great, then take the poultice, if it is a ready mixed one, or mix a powder poultice with a degreasing detergent and water, apply the poultice to the stain, overlapping the footprint of the stain by about 20%. Cover the poultice with cling film, and leave for 24 hours. Lift the film and leave the poultice to dry out for an hour or so, then, carefully with a plastic scraper so as not to scratch the stone, lift the poultice, clean the area with water and let it dry. Inspect, if it has worked great, if it has begun to work, and pulled a large portion of the wax put the repeat.
Hope this helps
Ian
Hi Ian-
Hopefully you can lend some advice. We recently had our new limestone French pattern pool deck sealed. It happened to rain about two hours after, so that caused the sealant to bubble and not stick properly.
They came back and resealed again, and it’s just all stick and blotchy all over. Even had some pink residue as well. Now it’s just all sticky and dirt just sits in it. It comes off when I hit it with a deck brush but no matter what stays sticky and blotchy.
Do you think pressure cleaning would remove this sealant or would we need to strip it in your opinion?
Thanks Ian.
Hi Pressure cleaning may help, but I think you will at least need a little mechanical scrubbing, whether by had or by machine – a rotary scrub machine will help significantly. If you can get residue off like this then you may be able to apply a thin coat to top up, making sure to remove any residue while still wet this time and you could be fine. IF you cannot get this off using a scrubber then you will have to resort to using a proprietary stripping chemical and that will necessitate a re seal.
Hope this helps
Ian
Thanks Ian. I’ll give this a try a report back.
Hey Ian, my wife and I are just about finished with building our house. We had brick pavers (Alpha Concrete Brick Pavers) installed thoughout most of the common area of the house. The floor came out great other than we thought it had too much of a dull/matte finish. It was sealed twice with the same penetrating sealer (Omni Brand). Once before grouting, once after grouting. The floor supply place gave me a sample of high gloss sealer in the same brand. I tried it in the pantry (test spot), and it added a better shine. I went back to the floor place but they were out of the high gloss sealer. Couldn’t find it at the other local floor places either so I ended up at Lowes and I picked up their brand of high gloss sealer (Miracle). I started in the dining room which seemed to be ok. We haven’t gotten the power turned on yet so I’m going on the outside light coming in windows and a small work light. When I step away and can definitely see a shine on the floor from the reflection of the outside light coming through the window. I then started in the family room but as I got half way through, I started looking at what I had already done. That’s when I noticed that the floor looked chalky (for a lack of better words) as it was drying. Its not a residue like chalky, it’s almost like it changed the color of the brick paver giving it a cloudy appearance. It’s not ridiculously noticeable, but it’s definitely noticeable. I started doing a little research on the Internet about it and read about a couple possible problems. One site said that moisture can be a factor. Another said that using two different brands of sealer can have an affect also. Not sure if there are any other possible reasons but I wanted to get your opinion on it. Thanks in advance for your time and opinions.
Hi Mark,
OK, for sure moisture during application can be an issue with these types of sealers – it can make them go a little white/opaque. If so there is really only one remedy and that is to strip back, allow it to dry out and then re apply. Also, absolutely it is not great practice to use different products, they are very likely to have slightly different appearances to each other.
There is one other potential issue though and that is this: most modern coating sealers (a high gloss sealer is a coating sealer) do not need a sealer beneath them, in fact using a penetrating sealer before using a coating sealer is a bad idea. If you think about it, the job of a penetrating sealer is to seal, that usually means creating a surface that will repel liquids to some degree. Problem is that these modern penetrating sealers are now so good that they also repel coatings. It is highly likely that the coating sealers (both/either of them, the brand is not important) will not be able to get a good purchase/key on the tiles because it was initially sealed with 2 coats of penetrating sealer. Instead they will be held up at the surface and this can cause them to puddle/pool i.e not lay nice and flat and so you get too much or too great a thickness and it dries in any number of incorrect ways including looking dull or patchy, chalky or not to dry correctly so they can be streaky and sticky. If there is excess moisture around then this can compound the issue as you have more residue of coating to turn white. Even if it all looked fine, the chances are the coatings you have applied will not be sufficiently well bonded as a result of the penetrating sealer, and so will not last as long as they should and can start to come off/peel, wear faster and in an uneven way. Normally the choice between penetrating or coating is down to how you want the floor to look and whether the particular floor will actually work with a coating – it is not normal to use both.
I believe you are going to have to strip back the coating sealer entirely. You will need a proprietary stripper for this either brand you mention has them. Then when you are back at the tile surface, see if you can live with the floor for a little while, this will allow it a bit of time for traffic and a few cycles of cleaning, to diminish the surface tension, and thus lessen the repelling effect of the penetrating sealer (it does not mean that floor is no longer sealed against staining by the way, just that the temporary surface effect has subdued). Then you can test the floor to see if it will now take a high gloss before going ahead with the whole thing.
There is a chance that the stripping action will diminish the surface tension enough to do this right away, and you could also go over the floor again with a scrubbing machine and a mildly alkaline liquid to try to accelerate this process – again small tests will be helpful.
Hope this helps
Ian
Hi we have a stone wall and frame around a fireplace. When the stone sealer was applied it over sprayed onto our black metal frame of our fireplace making it look oily, greasy and well ugly…any advise would be greatly appreciated, I am worried about damaging the black metal surface.
Thank you
Hi,
OK, notwithstanding the fact that I am not an expert on metal and metal finishes, I think just try a number of things, starting with the weakest, least aggressive and go up in stages from there – first though I would check with the supplier of your metal frame for their advice – just in case the black coating is sensitive to any particular cleaners/methods etc
Once you have checked that you could try:
1) Warm water and a sponge/absorbent cloth
2) if that does not work, a mild detergent – a few drops – not too many, of a washing up liquid added to the warm water – then rinse well with clean water and buff dry with soft cloth
3) After that you are looking at degreasers – alakaline cleaners but you need to be very sure they won’t damage the black coating on the metal
Hope this helps
Ian
Hi,
Our builder has recently laid riven slate in a downstairs room. The sealant was applied on Friday morning after copious cleaning. The sealant was FILA Stoneplus Colour Enhancing Stain Protector. We have been waiting since Friday for the tile to cure and dry out and it is still tacky/sticky, leaving an oily residue on your fingers. It is also quite glossy.
I was wondering if you had come across this product and if you had any ideas for how this problem can be addressed. It is the right type of sealant to try applying more of the sealant first as you suggest?
Many thanks for your help.
Hi, I have not used that exact product but what you describe is a common problem, namely over application and incorrect removal of residue.
If it is meant to be a below surface (impregnating), matt or natural finish enhancer, then it should be applied left to dwell for a few minutes then all excess should be wiped off and buffed dry.
It sounds as though your builder has just applied it and left it on to ‘soak in or dry’ He is probably used to standard non enhancing solvent based sealers – if he is used to any that is, and has got away with over application of that type of sealer in the past, more out of good luck than anything else,
Add to this the dense nature of the slate and over application just results in lots of sealer being left on the surface – taking ages to dry hence the sticky/oily and glossy finish.
Try getting an absorbent cloth (paper towel, old terry towel, microfibre cloth etc, we use a combination of scrunched up kitchen paper towels and old terry towels) and rub a test area, try to buff it absolutely dry. Keep turning the cloth until saturated – if you can get to to matt, dry condition then great.
Typically these sealers have a drying curve and the sooner you get the residue off the better. IF you cannot get it off in the manor I describe you might be able to with a white nylon scouring pad and a little water – but you may need or check with the sealer manufacturer first. Failing that you may need to strip it off with their recommended stripper and see what it is like after that.
hope that helps
Ian
Ian, thanks so much for your quick reply. I just wanted to clarify something. Is your recommendation to rub down the existing tacky surface without adding any more sealant or to add more and then rub down?
Hi Dave,
From what you said the surface is oily/greasy – if it is mobile then try wiping/buffing off as it is. The reason I sometimes suggest using more sealer is if the sealer used is a) a solvent based one and b) dry, then the idea is that a solvent may be needed to break it down, re-emulsify it, and if a normal solvent is used then it might strip out some or all of the sealer. Using the sealer itself makes use of the solvent present in the product, and at the same time you will leave sealer there where it is needed – as long as you buff off within a d=few minutes.
So, it depends if as I thought form your first post, the sealer has not yet dried, (oily ) then you should not need it. If it has dried or is very tacky then you could try using a bit more sealer as described above.
Hope that helps
Ian
Hi Ian,
I was wondering if you could spare some advice.
We had granite slabs laid down in December 2015. Just over a week ago now, we decided to seal them with Thompsons patio and drive sealant. We have two areas in the garden, one under shelter, and the other exposed to the elements ( both with granite slabs)
The under shelter sealant looks great and what it’s meant to look like when sealed, but the other area which we sealed and is exposed to rain etc looks horrible!! It’s really patchy and also has a water/ wet look mark only around the edges and not in the centre?!
Is there a way of resolving this? Or removing the sealant from the slabs back to bare granite?
The slabs had two layers of sealant and the instructions were followed very carefully when applying .
Hope you can help.
Kind Regards
Jo
Hi Jo,
Ok I think the sealer has obviously come into contact with moisture before it was fully cured/set. many sealers can react this way, where it was protected during drying it is fine. The wet look around the edges; ‘picture framing’ can be as a result of the fact that the grout joints (if they are grouted) or just the pen joints may hold even more moisture than the slab so the parts of the slab nearest that reservoir of moisture have had longer/greater exposure.
I am not sure if this is reversible It might be possible to remove, or at least partially remove (and in so doing reduce the impact of the effect) by menas of a sealer stripper. the best people to ask thought would be the sealer company, as they may recommend the most appropriate product to try.
Hope this helps
Ian
Hi I have had a problem with a sealer not being applied properly or in the wrong environment. I have tried everything to remove it and now in the process of stripping the whole floor with lithofin wax off. I would like to ask 2 questions. Firstly. How long should I leave the floor to dry before resealing? They are Moroccan encaustic tiles second. How many coats of sealer should I apply once the floor has dried??
Your expert advice would be much appreciated.
Michelle
Hi Michelle
First of all make sure you get it all off, then thoroughly rinse, more than once if you have to you do not want to leave any tace of the stipper in the tiles. Then I would leave it to dry as long as you can, certainly 24 hours or more, if you can give it a few days then that may be better but I appreciate that that is not always possible. Usually when the grout joints revert back to their light colour it is a good indicator that the moisture levels are now low.
Some sealers react badly to excessive moisture (until they are cured of course) so it is is as well to have the floor as dry as you can.
How many coats? – you don’t say what sealer it is and I can only guess at the porosity of the tiles. But I am assuming they are quite porous – maybe not quite as porous as a terracotta but more than a standard quarry tile? – In which case most sealers would most likely need 2 or 3 coats. IF an impregnator it could be 1 – 2 cots or 2-3 coats depending on the porosity, if it is a oating sealer then it can be more, depending on how quickly the desired finish is achieved.
Hope this helps
Ian
Hi Ian,
Can you please help. I’ve had an Indian limestone floor laid indoors. The colour was called olive but was predominantly grey with some olive tones. We chose it for greyness and were clear we didn’t want yellow. It looked great until sealed with a lithofin stain stop that was colourless. The tiles all changed to a mustard yellow and no grey remains. Also there were lots of oil looking patches. The laying of the floor, grouting and sealing was completed over 4 days. The colour change and patchiness was so bad that wax off was applied. The oily looking patches have improved but the change in colour remains. The tiles look yellow green with patches of orange. Can you suggest what has happened please. Thank you
Hi,
Hard to say what has happened. Unusual for the product you mention to have caused the stone to go yellow – not something I am aware that it does. What I do think is that 4 days start to finish including grouting and sealing – means there is more than likely still some moisture in the system and this can cause some issues (you don’t say how soon after grouting the sealing was done, was the stone sealed before grouting and again after etc),
Suspect the oily patches are just overapplication of the sealer.
If you could give me a step by step on the timeline/procedure of what you did – so ‘laid tiles on day one etc’ that might help – also can you send some pictures? – do you have any off cutrs opf stone that were not used that still look as they did before – so I can see a before and after – that might help also. Use the contact us page
Hope that helps
Ian
Hi Ian
I’ve been reading your website and am very impressed – you obviously know your stuff! Hope you can help me here – parts of my questions have been answer above but would like a definitive if you can spare the time.
I have been helping a brickie i know lay a black limestone patio at the back of our new house. We’ve been doing it in the evenings for a few hours here and there so its taken quite a long time. He was due to go on holidays a few weeks back so I though i would try and clean up the surface and seal part of the patio. I ended up using LTP grime remover to clean the stone (worked OK) and then 2 coats LTP Mattstone sealer. The stone looked fine after I sealed them but a few days later it rained and the water has dried and left very light grey marks where the water had “pooled”. I wouldn’t say its bad but it looks like the sealer has partially “evaporated” in those areas so im left with a blotchy finish.
I am of the mind to strip everything back and start over once the patio is finally completed tomorrow. How should i go about this? i contacted LTP and they suggested using LTP Power Stripper to remove – have you ever used this, if not, do you have any suggestions as to what to use? Its an impregnating sealer if that helps.
Once I strip it back I have romex/rompox Easy jointer to add and will then want to seal it and try and bring out the colour, was thinking off Romex Colour Intensifier – Sound like a good idea or not?
Thanks in Advance
Sam
Hi Lots of questions there.
First of all, best people to advise on removal of LTP product is LTP – so I would go with their advice. It could be that there was moisture in the system or that it rained before the sealer was cured – happens a lot with external stone. You really need a good few days of warm and more importantly dry weather, before during and after sealing, unfortunately we live in the UK.
I don’t know the Romex product, but most enhancers need virgin stone – i.e stone that has not yet been sealed with anything. This is because they work by penetrating to a point where they can alter the way light is reflected back out of the stone. If there are traces of old sealer there (and it is hard to remove 100% of a sealer, even if it appears completely stripped to the eye) then this can lead to a patchy inconsistent effect with a colour enhancer. So you may have missed your chance to bring out the colour.
One other issue with black limestone is that it is notoriously quick to fade – usually within the space of one season -the black colour is subject to weathering and it usually fades to a much less intense grey. It might be better to strip the LTP then reapply the sealer – or leave it off for the rest of this season, do a deep clean in the spring, when it has also weathered, and investigate the option of colour enhancing then – we have found good result a year or so later on in rejuvenating black limestone with enhancing sealers, perhaps the combination of weathering and stripping/cleaning helps to ensure adequate sealer removal prior to enhancing.
You could also contact Extensive Ltd in Alresford – and seek their advice they have a lot of experience with this type of issue
Hope that helps
Ian
Thanks Ian. Really appreciate your comments. I’ll get on to that company to see what they say
Thanks
Sam
Hi Ian. I had a patio done last year black Indian stone. It was sealed but the guy who did it, did it just after a short rain shower and the stone was not fully dry. It looked ok for. A few months but now looks dirty and grey muddy looking. Do I need to strip the sealer. Many thanks in advance
Hi my father put on Tileguard natural look sealer and it has come up white …he rang manufacture and firstly tried metho and initially it went away and then it came back ..then water power jet and that didn’t work ..we just tried your suggestion of putting more sealer on a patch and that didn’t work….he is getting rather stressed ( 85) about this ..can you help !!!
Hi, hard to know exactly, don’t know the sealer or type of sealer used. It might last just one year or could still be there doping it’s job. The thing is no sealer will stop dust and dirt from settling on a floor, they are there to help prevent deep staining. What happens when the stone it wet, does it look nice then? Does it ‘wet out’ quickly, easily and evenly? If it does then it may be time to top up the sealer, you may not need to strip the old one off first. IF it does not wet out that easily then there is still sealer in there doing its job, instead try giving the stone a deep clean and rinse, let it dry then look at it again)
Hope this helps
Ian
Hi, OK the treatment you tried seemed to work but then it came back?- I am assuming that the metho? – partially wet out the sealer then when it evaporated the sealer residue was left behind – and appeared white again.
OK, clearly the solvent you used ‘does something’ my thoughts are that it is trying to break the sealer down – but it may take several goes. Try it again, in a small test area, leave the solvent on for a few minutes, but before it dries out scrub it then rinse with water and buff dry. If it looks the same or worse then it might be that the solvent has removed some of it, broken it into layers, just taken off the top etc. This often happens and it can look worse before it looks better. So, repeat the test again and even again, allowing the solvent to sit/dwell for short while, before scrubbing and rinsing away each time. see if it looks like each time some more residue comes off. If so then that is the bethjod, and it may be a slow one. It might be accelerated by hiring a mechanical scrubber machine.
Hope this helps
Ian
Hi
I have just applied a sealant to some new granite (or granite looking) slabs and now they wont dry after rain. I applied the sealant 2 days after laying, in dry conditions. They seemed to take the sealant well and looked fine. Then the following day it rained and after the shower everywhere dried up apart from the slabs which remained wet all day. Do you know what the problem may be and how I can put it right?
Hello,
If the sealant residue is of a solvent free variety does the method of applying a little more and then removing the surplus with a cloth still applicable?
Hi,
If all was well, and appeared dry (and not tacky or with patchy sticky spots) after application then it sounds like it was done ok. For only some of it to be remaining wet after seems to suggest to me that those slabs, for whatever reason, are actually the ones that have been sealed the best. When you say it stayed wet all day, I am assuming it dried up after? This could mean that there is more sealer on those slabs and it is joust holding the rain out for longer, or that part of the floor is the part at the lowest point, and all the water runs and collects there. Prior to being sealed the water may have more readily been absorbed all over the floor, now the sealer has kept the water out long enough for gravity to take over and it has all collected at the lowest pint (it does not have to be much out of level for this to happen, even if you cannot see it).
When you wet the floor does the water sit up on top, or does it darken the stone and wet out right away? If the former then my idea above may have some merit, if the latter then I am not so sure.
Hope this helps
Ian
Hi,
Most likely not. However all may not be lost first try a white nylon pad (either a proper emulsifying pad from a tile supplier or the little white ones you get attached to green sponges for dish washing). Spray a little water on the residue, and rub with the pad, buff dry with a cloth and see if it has improved. If note then I suggest you try an abrasive, search for ‘All for Stone Microscrub’ – apply some of this to the pad with a little water and scrub- this usually does the trick. Failing that you may need to get a sealer stripper.
Hope this helps
Ian
We just moved into a house where the tile floors were sealed with some type of high gloss product. The problem is the tile and grout were not cleaned (at all!) prior to the application; there are hair and fibers embedded all over the place, the grout is dirty (you can see the real color near walls), and especially in the corners there are areas where dirt and dust were not removed prior to application. My question is, how do I strip this sealant and how to clean the grout; the product is hard as a rock and does a great job as sealant, but my floors are so dirty. I’ve worked with the saturation type sealants before, like Miracle and it was nothing like this. Will I have to resort to a professional service? Thank you for any ideas you can provide.
My house has black Welsh slate countertops in the kitchen, installed by the previous owner, which are really nice but constantly get cloudy white watermarks. I am guessing that some sort of wax finish has been applied to that is not appropriate for a kitchen surface. The watermarks can be scrubbed off with mild abrasive and effort, but is there a better way to remove all the wax finish and then just have the bare slate or some more appropriate treatment? Thanks very much for your advice.
Hi,
OK, you are going to have to strip this for sure. Best bet would be to contact the maker of the particular sealant they are usually the best people to advise on what to use and how to use it. Failing that, a proprietary sealer stripper,depending on the exact nature of your sealer, you may need a stronger solvent. It is not rocket science so unless you are nor feeling up tot he task, you should be able to do it yourself, however it can be a bit messy and is best doe with proper equipment (like scrubbing machines and wet vacs for extraction etc). you apear to be in FL, I can recommend that you contact the tech services team at Mapei USA – based in Deerfield Beech, they have a good range of products and are knowledgeable.
Regarding the grout, you may find that some if not all of the grout dirt comes off in the process of stripping he sealer, if not then again it would be good to consult with the guys I just mentioned. – However, a grout haze removal product may be helpful
Hope this helps
Ian
OK,
Is it the actual ‘wax finish’ that is turning cloudy as a result of the water? or is it just white marks being left on the surface?
The latter could simply be water marks: Welsh Slate is EXTREMELY dense with very low water permeability, to the point that even unsealed, the stone does not really absorb much in the way of moisture, (it will show oily/greasy marks but this may have more to do with ADsorption, rather than ABsorption – it just sticks to the surface). With a sealer of some kind this may be even more so. IN which case the white marks are normal and to be expected, especially in hard water areas; basically as the water (which may be full of impurities and minerals like calcium) dries off the impurities get left behind, the dense and or sealed nature of the slate keep the water at the surface, so all the impurities get deposited on the top – hence white water marks. IF this is the case then scrubbing is the answer, a mild acidic cleaner may help though.
If it is the former, then it could well be a wax, one that is just sitting on the surface, and has not really been designed to go hard – some coatings/sealers/ finishes like this will turn white with water. If this is the case then you could try a high alkaline cleaner to degrease the entire surface, then look to see if A) you need a treatment at all, or B) some kind of impregnating sealer – just to add some additional stain protection.
Hope this helps
Ian
Thank you, that’s very helpful. I think it is wax because the surface just seems waxier than it does on our hearth made of similar slate. The marks are very like what one would get if something wet was left on top of finished wood. I will look for a high alkaline cleanser to try as you suggest.
Hi Ian
I am in the process of taking up a very old, worn parquet veneer flooring in our hall. I have revealed a flagstone floor underneath but there was obviously a latex screed put down first on top of the flagstones. Parts of the slate that I can see are white and powdery, almost like cement and very uneven. Is it worth trying to remove the latex or will the flagstones just be too damaged? If so, how on earth do I remove the latex without damaging the slate?
HI I would first try to remove the white powdery material, that does not sound like slate, more like cement, salt/efflorescence or lime mortar bed that the slate was installed on – if there is a lot of this visible then maybe there is some slate missing anyway?
Only way to see is to to try I am afraid, if the slate is old and laid in lime mortar it might be in poor condition and also not stuck well to the subfloor, which could even be plain earth. Removing leveler? – not easy, depends on how in tact it is and how well stuck to the slate it is, if it is stuck really well, then it may well cause more damage to the slate by removing it.
Try scraping it off with a metal scraper, chemicals won’t be much help unless all you are dealing with is the traces or ‘stains’ of levelling compound. To do an entire floor you may need to hire a rotary machine with a tinex (steel) brush head or even abrasive pads – it could be quite a job.
Hope this helps
Ian
Hi last saturday 24th Sep we used Lithofin intensifier w on our sawn sandstone patio which was laid 7 1/2 weeks ago. We applied it as instructed on a dry patio and it looked good afterwards, we were relieved we had managed to get it done before the bad weather sets in. On Sunday we had a light shower and afterwards there were grey mottled marks over the patio. They are still there and I am wondering if the rain affected the curing as in the lithofin details it does say curing can take upto 14 days. Intensified colour does not seem to have happened at all. What can we do to get rid of the grey mottled appearance?
We are so dissaponted after trying many different samples for this to happen.
Hello Ian, years ago we decided on white slate floor tiles for our new kitchen. It has been hard to maintain as dirt settled in the tiles very quickly leaving the floor more grey than white ! Recently we decided on sealing the floor with Lithofin slate seal. We have scrubbed the floor thoroughly with bleach, rinsing well with water. After the floor was dry, we applied the sealant 1 coat and after few hours another coat. Now patches are appearing, like not enough sealant was applied in certain places and as we walk bare feet , flakes residue stick to our feet ( which I’m assuming are sealant from the patches). Have we applied too much sealant ? How to fix the problem. Scrub or remove the sealant with wax off from lithofin?
Your advise will be greatly appreciated especially as we need to finish the room .
OK, I am not 100% sure if rain would affect that product but it may well have done. The actual intensifying can give variable results on different stones. Sometimes an additional application can improve that aspect. However I fear you may have to strip back a little to get rid of the grey spots. I am going to suggest you contact the manufacturer, or at least the UK distributor for specific advice on this one
Hope this helps
Ian
OK it does sound like the sealer has been over applied in a few places, also it does not sound like it is bonding very well. I am wondering if your rinsing and subsequent drying, despite your obvious best efforts, was not quite enough.
I would do a test strip using wax off, in a small area strip it back, rinse well and leave it a couple of days if you can to dry. Then, re seal those areas with more sparing coats. See if it makes a difference. Then scale this up across the whole floor
Hope this helps
Ian
Hi Ian, we had our garden tiled last year and employed someone to seal the porcelain tiles this year but it hasn’t “taken” and all attempts to clean and remove the sealant have left all areas covered white marks and patches, it’s a mess to be honest and I’m at the end of my tether. The guy says we asked for it to be applied at the wrong time of year. I just want the tiles back to their best. Any help would be appreciated.
Hi hope you can help I’ve laid black Indian lime stone on my patio seals it thinking it was clean enough but it wasent.is there anyway of getting the dealer of.thank you.
OK, well first of all, you may have asked a the wrong time of year, but they are supposed to be the ‘professionals’ – to be honest, it should be up to them to tell you they cannot do it if they are concerned about anything. Plus most comments like this pertain to moisture issues, as many sealers used outside have to be applied in a period of dry weather – which means the summer, which we have only just finished anyway?
However, the other thing I note is that this is porcelain – it may well be that your porcelain does not need and should not have been sealed (again I would expect a pro company to be able to do a test and determine this for you). The whole point of a porcelain is that is ‘should not ‘ require sealing, but in reality these days that is not always the case, as some are not as good as the original concept of porcelain.
The problem arises as good porcelain is so dense and practically impervious, that a sealer simply will not be able to penetrate and ‘get into’ where it is needed. So it will just sit on top and form a sticky, or shiny, or white, dull and blotchy coating that will over time, start to wear off or blister etc. I suspect that this is what happened in so far as it ‘did not take’ the sealer just dried on the surface, and it has a good grip of the surface texture.
Have you tried a solvent based stripper?
I would contact the supplier of the sealer for their suggestion on what product to use to break down and remove the dried residue,. it will be a solvent of some kind. IF you have a large area, I would consider hiring a rotary scrubbing machine with a brush head, apply the stripper, let it dwell for a time (this can be anywhere from 10 minutes to an hour) keep it wet with more stripper and agitate with the scrubber. Then squeegee and powerwash it all off, make sure you leave now residue on the tile surface to dry. See what it is like and repeat if necessary.
Hope this helps
Ian
Hi
OK, most likely you are going to need a solvent based sealer stripper. My first port of call would be the supplier where you got the sealer from, if not them, then call the manufacturer of the sealer and ask their tech support what they recommended as they most likely have a product designed for the job.
Hope this helps
Ian
Wonderful, thank you very much.
Hiya
I was advised by a local supplier to use Fila stone plus on a grotesque patio we had laid. The guy instructed us to apply with a brush or even a roller before we grouted the slabs. We have done this but has left a sticky surface. Help how can I rectify this problem. If instructed by the supplier properly would never be in this mess.