Author Topic: lumpy mud  (Read 13277 times)

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Offline truck90278

  • Posts: 104
lumpy mud
« on: April 25, 2014, 01:27 PM »
First off, my son and i are not dry well experts - have only small DIY experience, we're doing repairs in dry wall and mixing our mud in small amounts (not bucktes). However we are getting a lot of lumps, also tried a small mixer with an electric drill, smaller lumps but still some lumps.  Needless to say, when we put it on the areas we are working, the lumps put i, perfections in the surface.  What are we doing wrong?  Any suggestions would be appreciated.

CT22, CT26, Midi, TS55, MFT3 x 2, Domino 500, DTS 400, RO 125, RO 90, ETS 125, OF1010, CXS, Boom arm, Trion, parallel guides, LR32 system, shop cleaning set, T-18 +3, Kapex

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Offline Paul G

  • Posts: 1986
Re: lumpy mud
« Reply #1 on: April 25, 2014, 01:53 PM »
Are you using the powdered stuff? If so what set time?

I use the longest setting type I can find simply because I don't work that fast. I do small batches also and use a mixing bit on a drill but there always seems to be some chunks on the sides and bottom so I mix with the drill then use a knife to scrape the entire container edges and bottom to work the chunks loose and then mix again. Also I try not to mix it too wet initially, adding more powder in to thicken has resulted in chunks for me so I progressively add a little more water until its right. I got to the point of having a set of containers that are perfect measures of powder and water, its a large yogurt bowl and a trenta starbucks cup lol, but it works. I should measure their volumes sometime in case I lose them.
+1

Offline tjbnwi

  • Posts: 6132
  • Cedar Tucky Indiana
Re: lumpy mud
« Reply #2 on: April 25, 2014, 02:07 PM »
You're not adding enough water for the amount you're mixing.

Mix in a small pail, 1 gallon size is a good size. Two working pans (about 1 pan full) at a time is a good amount for a novice to mix.

Always add the powder to the liquid, not the liquid to the powder.

If you need to add water hold a wet sponge over the mix and gently squeeze, this allows you to add small amounts of water at a time.

Use a beater from a hand mixer or a propeller type mixer in a cordless drill.

Mix time is about 2 minutes.

You should have no lumps. Consistency should be that of chilled mayonnaise.

Once you get it, it is easy.

Tom  

Offline jmbfestool

  • Posts: 6628
Re: lumpy mud
« Reply #3 on: April 25, 2014, 02:09 PM »
Are you adding the powder to the water?

If you are mixing less than a bucket it is little more difficult to get it smooth and creamy.

Half a bucket is the smallest amount I have mixed using a corded drill.  

While mixing just adding the powder to water.   Then every so often with a bucket trowel scrape the sides and then carry on mixing bobing up and down.  

You shouldn't get any lumps.

Jmb
« Last Edit: April 25, 2014, 03:19 PM by jmbfestool »
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Offline Dan Clark

  • Posts: 545
    • talkFestool
Re: lumpy mud
« Reply #4 on: April 25, 2014, 02:25 PM »
First off, my son and i are not dry well experts - have only small DIY experience, we're doing repairs in dry wall and mixing our mud in small amounts (not bucktes). However we are getting a lot of lumps, also tried a small mixer with an electric drill, smaller lumps but still some lumps.  Needless to say, when we put it on the areas we are working, the lumps put i, perfections in the surface.  What are we doing wrong?  Any suggestions would be appreciated.
Presumably, you're using hot mud.   For hot mud...

Because I'm an expert (i.e. I made LOTS of mistakes), I recommend a good mud pan (http://www.all-wall.com/Categories/Mud-Pans/Sheetrock-Classic-Mud-Pan.html) and a 3/4" joint knife (http://www.all-wall.com/Categories/Joint-Knives/Hyde-Plastic-Handle-Knife.html) to mix the mud.   

Add a small amount of dry mix to the pan, add a bit of water to the mix, and stoke the knife gently back and forth in the pan to mix.  If you see a lump, smush it with the knife.   If all the mud is not wet, add a bit more water, and mix again gently.    When it's at the consistency you want, mix gently a few more times and then STOP!  Do not over mix.

As Paul mentioned, try to get at least 90 minute mud to start of with.  I've used 90, 45, and 20 minute mud.   20 minute mud is for quick patches.   

Also, not all brands of mud are created equal.  Try getting another brand.  Go to a drywall supplier if necessary.  They will typically carry more brands than the big box stored.

Regards,

Dan.

P.s. if you are using drying type mud, I recommend that you use premix mud.   

Offline Paul G

  • Posts: 1986
Re: lumpy mud
« Reply #5 on: April 25, 2014, 02:52 PM »
Always add the powder to the liquid, not the liquid to the powder.

I do the opposite (old habit from baking probably), but maybe that's why I get so much junk that I need to scrape off the bottom and remix. Will experiment next time.
+1

Offline truck90278

  • Posts: 104
Re: lumpy mud
« Reply #6 on: April 25, 2014, 03:16 PM »
thanks everyone for your comments, been using the fast set 20. so we will go with somthing longer and will try adding the powder to the water technique
CT22, CT26, Midi, TS55, MFT3 x 2, Domino 500, DTS 400, RO 125, RO 90, ETS 125, OF1010, CXS, Boom arm, Trion, parallel guides, LR32 system, shop cleaning set, T-18 +3, Kapex

Offline Dan Clark

  • Posts: 545
    • talkFestool
Re: lumpy mud
« Reply #7 on: April 25, 2014, 04:00 PM »
thanks everyone for your comments, been using the fast set 20. so we will go with somthing longer and will try adding the powder to the water technique
Just curious...  Why not use premix, drying type mud?   It's much easier to use.

Regards,

Dan.

Offline Paul G

  • Posts: 1986
Re: lumpy mud
« Reply #8 on: April 25, 2014, 04:07 PM »
thanks everyone for your comments, been using the fast set 20. so we will go with somthing longer and will try adding the powder to the water technique
Just curious...  Why not use premix, drying type mud?   It's much easier to use.

Regards,

Dan.

Speaking for myself, I like hot mud for most jobs due to low shrink and seems to be a harder product when dry. Also can apply it much thicker when needed and won't crack when curing/drying. My experience is limited to the stuff I get at home depot, other products may perform differently. I'll go with premix when the project is so large that I'll waste too much time mixing hot mud. YMMV
+1

Offline Dan Clark

  • Posts: 545
    • talkFestool
Re: lumpy mud
« Reply #9 on: April 25, 2014, 04:15 PM »
thanks everyone for your comments, been using the fast set 20. so we will go with somthing longer and will try adding the powder to the water technique
Just curious...  Why not use premix, drying type mud?   It's much easier to use.

Regards,

Dan.

Speaking for myself, I like hot mud for most jobs due to low shrink and seems to be a harder product when dry. Also can apply it much thicker when needed and won't crack when curing/drying. My experience is limited to the stuff I get at home depot, other products may perform differently. I'll go with premix when the project is so large that I'll waste too much time mixing hot mud. YMMV
Paul,

I agree mostly.    I've used hot mud for almost everything including skim coating in moist areas (like above a tub or shower).   For skim coating other areas, I found drying type mud easier to work with - especially sanding.  When hot mud starts setting, you have to move fast with the sanding.   OTOH, YMMV.   [smile]

Dan.

Offline tjbnwi

  • Posts: 6132
  • Cedar Tucky Indiana
Re: lumpy mud
« Reply #10 on: April 25, 2014, 08:29 PM »
A Shurform (cheese grater) is great for shaping hot mud.

Paul G, I enjoy baking also.

Tom

Offline Saskataper

  • Posts: 278
Re: lumpy mud
« Reply #11 on: April 25, 2014, 08:30 PM »
First off using 20 min mud is crazy, I tape for a living and rarely touch the stuff unless I'm doing a very small patch job that needs to be done in a day. 20 min is the set time not the working time, you have maybe 10 min after you start mixing to use it then it'll start flaking.
If you have to use hotmud go with 90 then you have a bit of time to work, water first then powder.
I would recommend going with a good all purpose mud and try and find some fibafuse drywall tape, not fiba tape. It's easy to use and dries faster. If your using mesh then you have to use hotmud  it mesh is junk.

Offline Bikeboy80

  • Posts: 467
    • Drumm Design Remodel
Re: lumpy mud
« Reply #12 on: April 26, 2014, 07:17 AM »
Ditto, water then powder. If I am mixing a pan at a time I put about 1/2" of water in the bottom of the pan, then fill with powder, then add a bit of water on top. Then I let it sit for 60 seconds or so, then mix with a square trowel and add water as needed. It helps with the lumps and dry spots at the bottom of the pan. Most of the time I use 45min also with the fibrafuse tape. Also it is usually only when the project is time sensitive and I need to get another coat on that day. [wink]

By the way, less is more with the hot set. I try to never sand the stuff because it just doesn't sand all that well, thin coat and scrape with a knife before the next coat. And always finish with a coat of lightweight premix for easy sanding.
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Offline truck90278

  • Posts: 104
Re: lumpy mud
« Reply #13 on: May 01, 2014, 04:48 PM »
Changed from the 20 to 90 and from adding water to the powder to adding powder to the water.  Big improvement.  Thanks
CT22, CT26, Midi, TS55, MFT3 x 2, Domino 500, DTS 400, RO 125, RO 90, ETS 125, OF1010, CXS, Boom arm, Trion, parallel guides, LR32 system, shop cleaning set, T-18 +3, Kapex