ripples in skim

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ankers

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hi, been having few problems with ripples coming through on top coat was wondering if anyone new how to avoid them. After I put second coat on let it take for 5 then start troweling the ripples start showing through and they never trowel out. I've read a few threads where people have had the same problem, was wondering if anyone new if I'm doing anything wrong or how to trowel them out I've heard someone mention sponge float them? How would this happen?
 
Hi Ankers,

Were the ripples visible in the first coat? Are they spaced far apart or are they "wrinkles" caused by the trowel juddering across the surface when you're troweling up?
 
its streaky bacon...................Dont put it on too thick, use a new mix for laying in, dont trowel it up too much or too early..............hope this helps..............:RpS_thumbup:
 
Hi Ankers, If you put your second finishing coat on too quick without allowing your first coat to stiffen up then you can run into problems and generate 'ripples' in your work due to your finish being too thick,soft and unworkable. Try leaving your first coat to sit for a little longer and trowel it flat before applying your second coat, and mix fresh material for each coat. :RpS_thumbsup:
 
There not judder marks there more spaced out like little bumps, I spot them then go over with the trowel but they just don't push out. They always go the same was as I'm troweling. At what point should the plaster be before I start troweling. I might be troweling too early I trowel when its taken just a little bit but still quite wet. Thanks for the advice guys
 
Water to quickly will create tiger stripes and small bumps called 'blebs' as other people said peace it a little longer, flatten first coat with no water, then apply fresh second coat slightly thinner mix, flatten wait a while give first wet trowel, then second and final dry trowel just wetting you trowel
 
sounds like your far too early pal its hard to tell you when to do it but let it take up a bit more and use your initative.
also close the angle of the blade a bit so that your smoothing rather than dragging and pulling, and keeo your trowel clean dnt let the fat build up
 
ankers said:
There not judder marks there more spaced out like little bumps, I spot them then go over with the trowel but they just don't push out. They always go the same was as I'm troweling. At what point should the plaster be before I start troweling. I might be troweling too early I trowel when its taken just a little bit but still quite wet. Thanks for the advice guys
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Ankers,

This is the how I teach my students the difference between ripples and tiger stripes.

Question: What causes ripples?

Answer: Plaster that has been laid on too thick.

Reason: When you pass the trowel over a thick coat that has not pulled in yet, you end up causing some parts of the plaster to slide over itself causing ripples. Multi finish does not like to go on thick because it cannot hold its shape properly. When you approach 6mm you will notice that multi begins to sag under its own weight.

Solution: Let the plaster pull in more, and apply light pressure when laying it down. You also need to frequently discard of the excess plaster that has accumulated on the face of your trowel.

How to improve: Don't lay on thick coats, 2mm followed by 1mm is the way to proceed.


Question: What are tigers stripes?

Answer: Lines caused by a trowel that has been opened up too much when wet troweling.

Reason: When the trowel is opened up, you begin the process of scraping instead of spreading. If the trowel is opened up too much, instead of just scraping away minor lines you also end up scraping away hundredths of a mm from the surface. Even on a relatively flat surface, those hundredths of a mm will end up leaving cosmetic tiger stripes when the plaster dries (in most cases these stripes are not noticeable when the surface is painted).

Solution: Don't open the trowel too much when wet troweling and make sure the face is always wet. Only move about 12 inches at a time otherwise the water on the face of the trowel will run out and you then run the risk of tearing the plaster.

How to improve: Keep the trowel wet and work in small controlled fan shaped sweeps. Don't apply too much pressure and always overlap the previous sweep. A fast and smooth sweep is what you should be aiming for.

:-)
 
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Going on your second coat too early with too much pressure will cause this. When flattening second coat just let the trowel glide over it, it shouldn't need much pressure to get it flat. Leave the pressure for last trowels.
 
This is a bit like the how long is a peace of string question.To me the answer is simple ,you have to work with the plaster, not all sets are the same ,some take early ,some take ages to go. Its all about experiance and good skill with the trowel. I have found that the multi finish has changed so much in the last 12 months it now requires no water or a very little to trowel up , i have even gone back to using an old carbon steel trowel that i have had for bloody years to trowel up with as i find it gives a better finish. Don't put on more than you can handle, keep each coat as neat as poss ,dont lay in when the first coat is to wet ,and don't put on to thick. when you start the first trowel you will know straight away what is required so adjust your method from there.
 
surely the difference is obvious one is on a big cat that wants to eat you and the other is a tasty chocolaty snack:RpS_unsure:
 
Minh said:
Only move about 12 inches at a time otherwise the water on the face of the trowel will run out and you then run the risk of tearing the plaster.
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CeeVee said:
Eh????????
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I'm surprised you guys are reading my beginners guide: it was intended for Ankers to read.

Since you appear to be disagreement, I assume you prefer to wet the wall instead of wetting the trowel? There's nothing wrong with either method but I prefer the latter and I have no doubt whatsoever that during the process of wet troweling, if there isn't sufficient water to lubricate the trowel the plaster will tear :-)
 
KevRM said:
I think he was referring to the 12 inches at a time
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You could probably get away with 18 or 24 inches but the principle is the same. Why run the risk of tearing the plaster? It only takes 2 secs to re-wet the trowel whereas it will take longer to repair a tear :-)
 
wtf would you advise anyone to be troweling up 12 inches at a time ? when troweling up you make the strokes as long as possible.
 
KevRM said:
wtf would you advise anyone to be troweling up 12 inches at a time ? when troweling up you make the strokes as long as possible.
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As long as possible for wet troweling? I disagree.
Yes, for laying down lines and dry troweling, but not for wet troweling :-)
 
KevRM said:
Then you've been taught wrong
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KevRM said:
and you're also teaching it wrong
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I'm not a swimming instructor. Obviously, you prefer the method of flicking water onto the wall. Fair enough, there's nothing wrong with that. However, I've seen people who flick so much water on the wall that I could literally swim it in. Then they use long strokes and chase the fat all over the wall. It makes a real mess with water dripping all over the place. Are you saying my preferred method of wetting the trowel is wrong? :-)
 
and if you do the job right in the first place you shouldn't be getting fat to "chase" as you put it
 
well what you do is












from your starting position be it top of wall or bottom move your hand & arm for as far as it will go in one smooth action
 
whether you use a splash brush or wet the trowel you should use minimum amount of water when troweling
 
KevRM said:
well what you do is from your starting position be it top of wall or bottom move your hand & arm for as far as it will go in one smooth action
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Either you're using some super refined pure water because I have never known water to last the width of my arm :-)
 
My first wet trowel I flick it on the wall and trowel horizontal from right to left then vertical with one pass of the brush over my trowel, about a m2 at a time then clean trowel and repeat, I find this method closes it in fast enough to only need to wet the trowel on all other trowels, 12" at a time :RpS_confused: in the real world you don't have that much time with it to do 12" at a time
 
SpankySouthport said:
My first wet trowel I flick it on the wall and trowel horizontal from right to left then vertical with one pass of the brush over my trowel, about a m2 at a time then clean trowel and repeat, I find this method closes it in fast enough to only need to wet the trowel on all other trowels, 12" at a time :RpS_confused: in the real world you don't have that much time with it to do 12" at a time
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No offence intended Spanky but I already know the different techniques for wet troweling and I prefer to wet the trowel.

Have you seen the speed that I re-wet the trowel? Each stroke takes less than 2 seconds: it doesn't take long to cover the whole wall at that speed :-)
 
So by your method of troweling for each say 8ft high wall you pass over the length 8 times ?

On each wet trowel
 
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KevRM said:
So by your method of troweling for each say 8ft high wall you pass over the length 8 times ?

On each wet trowel
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If the wall was 8ft x 8ft and it takes 8 strokes in each direction, at 2 seconds a stroke I would cover the wall in less than 3 minutes :-)
 
in each direction ? so not only do you do too short a stroke you trowel up 4 times in the wrong direction ?
 
KevRM said:
in each direction ? so not only do you do too short a stroke you trowel up 4 times in the wrong direction ?
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8ft x 8ft. Assuming my trowel is 1ft long (or slightly longer), it takes 8 strokes in each direction. 8 x 8 is 64 strokes in total. 64 x 2 seconds is 128 seconds in total :-)
 
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