How do you make parging smooth with a sponge?

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  #1  
Old 07-10-18, 02:35 PM
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How do you make parging smooth with a sponge?

I'm parging an exterior wall. I want it to look smooth. I've watched videos, bought different size trowels, and tried using a sponge. When they use a sponge in videos, it comes out perfectly. But when I use a sponge, it looks terrible. It looks worse than just leaving it the way I spread it on. It's not smooth at all. It does get rid of jagged edges and evens it out, but it ends up looking all grainy. Using a large rectangular trowel doesn't work for me at all - not even to spread the mortar on in the first place. I've watched videos of them using one of those trowels, and it looks easy, but it doesn't work when I do it. I use a triangular trowel to spread the mortar on because that works the best. Then, I tool it down using a tuck pointing trowel. That makes it look smoother than a sponge, but it takes forever, and it's still not actually smooth at all, because there are lines everywhere. It ends up looking sort of like this, but with more lines: https://farm4.static.flickr.com/3611...53248957c6.jpg

Using a sponge instead of a tuck pointing trowel, or after using the tuck pointing trowel, turns out sort of like this, only rougher: https://d12m281ylf13f0.cloudfront.ne...rge_coat_2.jpg

So what am I doing wrong? Is there a specific type of sponge you're supposed to use? I see them using regular sponges in videos so that's what I used. Are they using a mix which is only for parging? Is there a specific amount of time you're supposed to wait before wiping the parge?
 
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Old 07-10-18, 04:21 PM
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Practice... practice... practice... Like most things a video makes it look easy but it takes practice. It's not rocket science but there is definetely a "motion" to it. I think a hawk and rectangular trowel will probably end up being the best. A hawk isn't totally necessary but it does make it quicker to get the mortar onto the trowel and provides a nice edge to scrape your trowel if needed. I think a rectangular trowel is required. The straight edge allows you to uniformly smooth the material while the handle position allows your wrist to work in a strong position.
 
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Old 07-10-18, 04:33 PM
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Originally Posted by Pilot Dane View Post
Practice... practice... practice... Like most things a video makes it look easy but it takes practice. It's not rocket science but there is definetely a "motion" to it. I think a hawk and rectangular trowel will probably end up being the best. A hawk isn't totally necessary but it does make it quicker to get the mortar onto the trowel and provides a nice edge to scrape your trowel if needed. I think a rectangular trowel is required. The straight edge allows you to uniformly smooth the material while the handle position allows your wrist to work in a strong position.
But why does a sponge make it look worse no matter what I do? When I spread mortar on with a triangular trowel, it's smooth. I would just leave it like that except I want the whole thing to be smooth. Each time I spread more on beside it, I want that to be perfectly level with everything around it. I don't know how to explain this... It is smooth in that small section when you use a trowel. But only in that part. Not relative to all the other parts. They are also smooth in their sections but not relative to the last hunk of mortar you spread on beside them. A sponge is supposed to make it all smooth. But the sponge wrecks the smoothness by making it all grainy. It doesn't matter how wet the sponge is, or if I press gently with it or with more force. This is not supposed to be happening, so what am I doing wrong exactly.
 
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Old 07-10-18, 04:54 PM
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Your mortar is probably too wet. Let the water flash off (dry slightly) before you sponge it.
 
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Old 07-10-18, 05:04 PM
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Originally Posted by XSleeper View Post
Your mortar is probably too wet. Let the water flash off (dry slightly) before you sponge it.
How dry should it be? I experimented between hardly waiting at all and waiting for a few minutes, to waiting until it was almost solid, like when it's almost too late to tool it down with the tuck pointing tool. Turned out the same using each method.
 
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Old 07-10-18, 05:17 PM
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What are you using for a parge mix? Are you using a tile sponge? (Rounded edges)
 
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Old 07-10-18, 05:41 PM
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Originally Posted by XSleeper View Post
What are you using for a parge mix? Are you using a tile sponge? (Rounded edges)
Type S, 2:1:9, mixed myself with a drill. It goes on smooth. It's theoretically possible to smooth a whole section out after spreading the mortar on, but the amount of time it would take with a little tuck point tool, is too much. Using a bigger trowel doesn't work for smoothing because it messes everything up. The best I can get with a larger trowel is similar to the first picture I posted. I'm using a typical sponge as shown in videos. The bag the sponge came in says "QEP: Extra Large All-Purpose Sponge - Ideal for removing excess grout and grout haze"
 
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Old 07-10-18, 05:50 PM
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IMO you should probably be going over it with a mag once it flashes to smooth out any ribs. The mag brings the cream (Portland cement) to the surface... once it has had a few minutes to set you should be able to LIGHTLY go over it with a damp sponge. You should not be rubbing hard at all... if you are, it wasn't smooth enough to begin with.

A mag is slightly rounded and easy to use. What you are doing with the tuck pointing tool is insane. Try a mag. (Rounded magnesium float)
 
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Old 07-10-18, 06:06 PM
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Originally Posted by XSleeper View Post
IMO you should probably be going over it with a mag once it flashes to smooth out any ribs. The mag brings the cream (Portland cement) to the surface... once it has had a few minutes to set you should be able to LIGHTLY go over it with a damp sponge. You should not be rubbing hard at all... if you are, it wasn't smooth enough to begin with.

A mag is slightly rounded and easy to use. What you are doing with the tuck pointing tool is insane. Try a mag. (Rounded magnesium float)
If this: https://marshalltown.com/concrete-ha...esiumhandfloat is a mag, I have one. It doesn't work for me. Not for spreading mortar on, or for smoothing it out after. It ruins everything. I just use it with one hand to hold mortar and to catch falling mortar when I'm spreading it with a trowel in my other hand.

So the sponge should be not soaked, not almost dry, but just a bit damp?
 
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Old 07-10-18, 06:10 PM
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If it ruins everything your mix is way too wet. You should be able to drag it one direction, then again, but perpendicular to the first... this gets the surface perfectly smooth. You have to learn to handle it... as said, practice, practice, practice. Yes the sponge should be DAMP.

It might also help to mist the wall with water prior to starting. That way it doesn't suck all the water out as you apply the mix.
 
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Old 07-10-18, 06:16 PM
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Do you mean it's too watery while it's in the bucket or (still too) wet after it's been spread on, meaning I haven't waited long enough to start smoothing it out? It's probably impossible to describe but how wet/dry should the mix be? You said don't start smoothing it until it 'flashes'. I get that, but do you mean it's doomed from the start because I've mixed it too wet?

I've only been doing this for 2 days. The 1st day I parged I didn't moisten the wall and didn't attempt to use a sponge. But it stuck to the wall and was as smooth as I could make it with trowels and the tuck pointer. The 2nd time I did moisten it first and used a sponge to smooth it. The finish is worse the 2nd time.

"You should be able to drag it one direction, then again, but perpendicular to the first... this gets the surface perfectly smooth."

That's absolutely not happening, I can't even drag it once without making a mess and/or everything falling off. I only know how to use the triangular trowel that bricklayers use specifically for bricks, and the tuck pointer.
 
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Old 07-10-18, 06:21 PM
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Maybe, if it is too watery in the bucket. There should clearly be no water in the bucket after mixing. You should be able to pick some mortar up with your hand and be able to throw it at the wall and make it stick. It shouldn't run at all. It should be firm enough in the bucket to hold its shape if you draw in it with your finger. Like mud. But not watery mud.
 
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Old 07-10-18, 06:45 PM
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The consistency is pretty much as you've described. I could stick my finger in it and it'll hold its shape.

This might be important - the wall is uneven stone. It's not a flat wall I'm working on. So I might be able to use the float tool effectively IF it was a flat wall already. I want a smooth finish for cosmetic reasons but that's not all I'm trying to do. The point of this is mainly to fill in holes, gaps, missing mortar, broken stone, etc, and to make it look neat by covering over the stone. So as I'm spreading the mortar on, I'm attempting to level the wall out as much as possible. It's deep in some places and shallow in others. Then after it dries a bit I've been smoothing out the finish with the tuck pointer, with a larger rectangular trowel (that one doesn't work as good), the triangular trowel (the hawk?) and today I attempted to use a sponge.

Maybe what I'm trying to do is impossible? Or it'll need several coats and THEN I'll be able to smooth it out?
 
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Old 07-11-18, 03:26 AM
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In my limited experience, rectangular trowels left me with more lines than if I used a pool trowel like this.

https://www.homedepot.com/p/Husky-16...7512/300960487

This left me with a pretty flat surface, which I was then able to blend in with the existing wall with a green sponge.

If you have thick places, maybe a scratch coat first to even it out using Type S then follow with a Type N mortar. However I don't know if there are issue with Type S under Type N. You might have to wait a few weeks for the Type S to cure out. I just know I used Type N and the stuff was pretty easy for me to work with.

Not even sure your supposed to use a sponge with Type S mortar as I thought that was used for setting stones/block and tooled with steel??? I could be wrong though as I'm not a pro on this.
 
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Old 07-11-18, 04:47 AM
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With a rough wall it's best to Dub out the hollow bits first and then apply a stratch coat to level up the wall. The top coat can then be an even thickness ( about 6mm) which makes the floating up easier.
The coats need to be weaker as you progress. ie scratch coat could be 1/1/5 top coat 1/1/6.
 
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Old 07-11-18, 05:19 AM
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Originally Posted by stuart45 View Post
With a rough wall it's best to Dub out the hollow bits first and then apply a stratch coat to level up the wall. The top coat can then be an even thickness ( about 6mm) which makes the floating up easier.
The coats need to be weaker as you progress. ie scratch coat could be 1/1/5 top coat 1/1/6.
1/1/5 as in 1 Portland, 1 Lime, 5 Sand?
 
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Old 07-11-18, 05:36 AM
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Originally Posted by Tumble View Post
In my limited experience, rectangular trowels left me with more lines than if I used a pool trowel like this.

https://www.homedepot.com/p/Husky-16...7512/300960487

This left me with a pretty flat surface, which I was then able to blend in with the existing wall with a green sponge.

If you have thick places, maybe a scratch coat first to even it out using Type S then follow with a Type N mortar. However I don't know if there are issue with Type S under Type N. You might have to wait a few weeks for the Type S to cure out. I just know I used Type N and the stuff was pretty easy for me to work with.

Not even sure your supposed to use a sponge with Type S mortar as I thought that was used for setting stones/block and tooled with steel??? I could be wrong though as I'm not a pro on this.
In this video: https://www.youtube.com/watch?v=7giu5N9FBeE at 2:15 he says he's using 2 buckets of sand and 1 bucket of S mortar. I haven't tried that but I will, if that's what you're supposed to use. He also uses a sponge float (which probably won't be that useful to me at this stage) and a regular sponge, which he soaks. Next time I go out there I'll focus on filling in the gaps as an undercoat. I'll go back after it dries to put on a finishing coat and hopefully by then I'll have the information and tools I need to produce a smooth finish. Maybe I can find a rounded pool float with a sponge attached to it and maybe that will work better, I have no idea.
 
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Old 07-11-18, 06:03 AM
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Yes that's correct. Some plasterers might use 1/1/4 then 1/1/5. It depends on the situation and weather exposure etc.
Use a plastering sand rather than a bricklaying sand.
 
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