# Why does scraping joint compound leave streaks??



## chandler48 (Jun 5, 2017)

Either your mud is not mixed properly, you have old mud, you are picking up trash in your mud or the surface was not clean when you started. Wipe the knife after every stroke until it smooths out. That way you are removing most of the trash from the knife's edge. Try new mud, thin it a little and mix it thoroughly before using.


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## Colbyt (Jan 27, 2014)

Least you say none of those are true, failure to scrape down the side of the bucket as the mud level drops often adds dried bits in the latter stages of bucket.


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## de-nagorg (Feb 23, 2014)

Appears to have dried parts in the mix.

There is a line with a spot on it's stop point, with a "nugget", just to the right of center of the picture. 

Are you mixing proper, using clean bucket, tools, enough water, many factors to consider. 


ED


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## JLawrence08648 (Mar 1, 2019)

Agree with everyone. You should not be working out of a bucket. You should be working from a pan scraping your knife along the top of the pan. Every time I fill the pan I scrape the bucket sides always keeping it fresh with no dry chunks. I'm very careful not to get any chunks in to the good mud. I have a small hand size piece of stiff rubber that I use for scraping the sides. I then cover immediately with saran wrap.


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## Mathlete (Nov 3, 2011)

Thanks.

Mud is brand new bucket.
Mixed it very well.
Surface is totally clean

I am not working out of a bucket.
Here is what I was doing.
I'd take JC/mud from the bucket and put into the rectangular mud pan.
I then use the knife to apply JC over the patch hole.
I would scrape the 12" knife and scrape the excess JC into the mud pan.

I never went back into the bucket.
But, this stuff dries so fast, so I think the scraping of the thin outside edges creates dried boogers within seconds.

Also, I have never added water to the JC. 
It does not say that on the directions.
But, I tried that yesterday, and I still got streaks.
So, water did not solve anything.
But, how much should you dilute the JC, in general?

Are you saying once I scrape the coat of JC,
I should throw away that entire wad of JC ?
I have never seen anyone do this in any video.
What is the point of the blade edge on the mud box
if you just throw away all joint compound you scrape?
You would basically throw away the entire can of JC very quickly.
And it would be a nightmare to dispose. Where would you store it all?
This can't possibly be the right solution.


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## Mathlete (Nov 3, 2011)

I don't understand scraping the sides of the bucket when you reload.
Doesn't that knock dried boogers into the mud?
I would think that is the worst thing you can do?
I would think you should wipe away the crud on the sides of the bucket with a towel and make sure not any bits fall into the fresh mud in the bucket that you are about the load into the portable mud pan


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## Colbyt (Jan 27, 2014)

Put less in your pan. Never return mud from the pan to the bucket.


My waste goes in the trash can though there is very little of it.


Putting too much mud in you pan may also be part of the problem.


You did dust the walls before you started top coating?


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## Mathlete (Nov 3, 2011)

Again, this happened with a brand new opened tub of mud

Yes, ceiling was cleaned. There was no dust on the ceiling.

I think it's from the scraping of the fresh mud outside of the repair. This begs the question, is it physically possible to smear on mud around the repair and ever get a clear swipe? If I smear one inch outside of the actual hole, it will build up by the time the knife gets to the actual hole.

Also, can I return mud from the knife into the pan?
I think that's the whole point of the mud pan and the metal edge it has.


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## mark sr (Jun 13, 2017)

Generally any mud reintroduced to the pan can be cleaned up [shouldn't be more than a spec or two] Squeezing the mud between the pan and knife will reveal any specs of trash. But your pic signifies more than a spec or two of trash!


What is the working temps? how long does it take you to use up the mud in your pan?


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## ClarenceBauer (Mar 4, 2005)

I am not a DRTWALL Person but look at the 10 O'clock position in the photo in Post # 7 check the dryer white area Do you do you see a lump on the surface. When that is troweled over you will pick it up & create a streak.


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## Mathlete (Nov 3, 2011)

Maybe I was working too slow. I have 90 holes I am patching so the mud in the mud pan gets old. Like 30 minutes old, maybe more. So, maybe I Am using too much in the mud pan? And it's drying out? I think the streaking started happening once the mud in the mud pan got older and dryer? Or maybe more stuff was scraped into it over time? Add less and add reload from bucket frequently ?


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## Mathlete (Nov 3, 2011)

ClarenceBauer said:


> I am not a DRTWALL Person but look at the 10 O'clock position in the photo in Post # 7 check the dryer white area Do you do you see a lump on the surface. When that is troweled over you will pick it up & create a streak.


There is no photo in post #7


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## ClarenceBauer (Mar 4, 2005)

Mathlete said:


> There is no photo in post #7


My mistake post # 1 I am getting old


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## chandler48 (Jun 5, 2017)

Can you post a picture of the bucket showing the logo? I am concerned that you may not be using the right stuff, as well as it being trashy, either in the bucket or on the ceiling.


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## Mathlete (Nov 3, 2011)

I'm using this


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## Mathlete (Nov 3, 2011)

Ok, I applied the 3rd coat today. 
I used all the tips you guys told me.

1) I wiped down the ceiling first. I totally think this was the issue last time. The boogers were dried nugs from the prior coat. This really prevented booger tracks.

2) I thinned mud with a dab of water (spoonful)

3) I loaded about 3 spoonfuls of mud into the pan. Way less. The mud was in the pan a lot less time now.

4) As soon as I got booger tracks, I dumped the mud out, and reloaded. I think before starting I should have wiped down the entire ceiling, not just wipe as I went along the room. That way, one less thing to remember

This all led to a much easier time. Swipe the 12" and was left with a perfect smooth finish. Tight scrape, and I will not be sanding this last coat, which was my goal. Yes, one can for sure fix holes with JC and not sand anything. 

Thanks for helping me through this project.
You guys rock.
@Yodaman
@mark sr
@mathmonger

Next step is to primer and then paint.
I will be back in Aug.


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## jeffnc (Apr 1, 2011)

de-nagorg said:


> There is a line with a spot on it's stop point, with a "nugget", just to the right of center of the picture.



Nuggets are clearly visible in the photo. OP is in a better position to figure out what they are than we are.


In general, you should be throwing away about the same amount of joint compound as you use. This stuff is cheap, don't try to save 5 cents by returning anything to the bucket, and keep the sides of the bucket and every tool perfectly clean.


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## jeffnc (Apr 1, 2011)

Mathlete said:


> Next step is to primer and then paint.
> I will be back in Aug.



Normally ceilings are painted with flat white paint, so there is not much need for a primer.


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## Mathlete (Nov 3, 2011)

I went over a few missed rough spots for a 4th coat.
I used the small knife and it was quick and no mess.

Today, I applied primer over the entire ceiling.
A few hours later, I applied flat white paint.

I can still see imperfections, but it looks 100x better than before!!

Now, it's time to paint the walls.
I don't need to primer if I'm just doing a color change, right ?
Walls are in good shape.


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## jeffnc (Apr 1, 2011)

Mathlete said:


> I don't need to primer if I'm just doing a color change, right ?



No. If you've done any patching and your paint has any sheen to it, you'll need to spot prime or at least spot first-coat the patched areas or else you'll get what's called flashing.


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## Mathlete (Nov 3, 2011)

I primered a few spots where I patched.
The rest of the paint is all clean 
Flat not gloss

So, I am going to apply 2 coats right over most of the existing clean paint.


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## bigcaddy (Jun 12, 2009)

Before I start my second coat of mud I usually drag the knife over all the joints to knock down any hangin boogers. I will sometimes use a sanding block also. 

Clean the inside of the bucket as you lower the mud level and keep the plastic wrap clean and on the top of unused mud in the bucket.


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## jeffnc (Apr 1, 2011)

Yes, maintenance of the bucket itself when storing the compound is important. I haven't found it useful or convenient to keep the plastic wrap on top, although if I'm going to store for quite awhile or an unknown time, I'll put in a shallow layer of water on top. Also, if you store it it can turn very moldy. By the way it's best to use a heavy drill and mixing paddle to mix the compound the first time you open it, to make it as smooth as possible. When doing this, I drop in a capful of bleach if I'm going to be saving the compound, which saves it from getting moldy.


When bigcaddy says to "drag the knife", it's best if you push with the sharp edge going away from you, rather than pull with the handle coming toward you, as this won't knock much off. Sanding is possible too of course, but sanding after each of 3 coats is really a messy pain. I prefer to take my time and get the coats smooth, so I don't have to sand until after the third coat.


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## Mathlete (Nov 3, 2011)

Project is done.
Ceiling looks AMAZING.
Million times better.
Cracks are all gone.
Thanks for all the advice.


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## Mathlete (Nov 3, 2011)

The room came out amazing.

I finished the ceiling.
Did a coat of primer.
Painted it with ceiling paint.

Painted the walls yellow.
No primer except on a few repairs spots.

Pulled the rug to expose hardwood floors.

Tossed the boxspring bed and got a storage bed from Ikea.

Got all new furniture. Dressers, desk, lamps,etc.
New blinds.

Whole room looks great, and the ceiling was the first step.
Thanks for all the help!


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## Mathlete (Nov 3, 2011)

Revisiting this project in a different room.

Scraped out some cracks and applied a first coat. It was a streaky mess. It also had air holes all over.
I waited 20 mins and applied a 2nd coat. Better but still awful looking.
I waited 20 mins and applied a 3rd coat. Better but still not smooth.

I will try a 4th coat tomorrow.


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## de-nagorg (Feb 23, 2014)

Mathlete said:


> Revisiting this project in a different room.
> 
> Scraped out some cracks and applied a first coat. It was a streaky mess. It also had air holes all over.
> I waited 20 mins and applied a 2nd coat. Better but still awful looking.
> ...


It is a matter of speed of application, and the moisture in the mud. 

Too dry, and it sticks to the trowel, too wet, and it is runny.

Apply too slow and it sticks, and pulls loose, too fast, and it will bubble, and pull loose.

Practice until you get it down to perfection.

Most just sand out the ridges, and bubbles though.


ED


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## Mathlete (Nov 3, 2011)

Last time, I was able to do the 4th coat smooth enough to not sand at all.


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