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Dan Mages
01-26-2009, 3:45 PM
I opened a bucket of dry wall compound to patch a few holes and found the top layer was culturing a nice layer of mold. The bucket is less than 6 months old. I have never seen this happen before. Has anyone else? It was stored in the basement. Any thoughts on what I can do in the future to prevent this?

Thanks,

Dan

Tom Godley
01-26-2009, 4:00 PM
Use it. :)


I have had this happen -- I remember someone telling me to put bleach in it. But I have never tried it.

I have always found old "mud" to me lumpy -- and my skills are bad enough without help!


........moved to the powder -- it works better and if you keep it in a plastic bag it lasts.

Chris Padilla
01-26-2009, 4:09 PM
It is like cheese, Man! Scrape it off...use it! ;)

Actually, I don't really know. You could try scraping it off, add a tiny bit of water, and beat it good with a mixer. Spread some out on some scrap and see what you think.

David G Baker
01-26-2009, 4:11 PM
I had an opened bucket of drywall mud that I kept around just in case. I opened it up to do some more drywall work about three months after I closed and stored the bucket. Ever smell Limburger cheese? The mud was one of the stinkiest things I have ever smelled, I worked on a hog farm as a kid if you know what I mean. The mud was covered with mold.
I agree with Tom, either switch to powder or buy some fresh mud and toss it out if you don't use it all up on the present job.

Kev Godwin
01-26-2009, 4:23 PM
Dan,
Before longer term storage, sprinkle a light dusting of Sodium Tetraborate Decahydrate (Borax powder) over the flattened top surface of the remaining compound. Cover with a plastic grocery bag pushed tight to the top surface of the compound. Put the original lid back on bucket. Do not use (Sodium Hypochlorite) bleach! You can buy the brand name of "20 Mule Team Borax" made by Dial Corp. from any Wal-Mart or K-mart. It is in the laundry section and a 4 pound box will cost just a little more than $4.

This will last without molding for many months. It will not cause any use problems in the future. (By the way, that same additive is used in the manufacture of several building products to prevent future fungal growth and repel insects.)
Kev

Neal Clayton
01-26-2009, 4:56 PM
in addition to the setting type compound you buy in powder form being easier to store, it is chemically different.

premixed compound sets by drying, in short: it shrinks.

setting compound sets by a chemical reaction with the water, it doesn't shrink.

i might use the pre-mixed stuff on nail holes. if you need to patch a real hole, the setting compound is the way to go.

Chris Padilla
01-26-2009, 5:17 PM
My drywall/texture guy calls it mud and hot mud. Hot mud dries rather quickly (hour or two?) and mud takes like a day. He takes regular mud, sprinkles something it it, mixes it up, and lays it up. I asked him once what he sprinkled in it but that memory bank is failing me right now.

Barry Nelson
01-26-2009, 5:23 PM
you might find thats salt,common garden ,everyday variety.

Jason Roehl
01-26-2009, 5:44 PM
If you want to keep mud around for a while, I've always found that cleaning the sides of the bucket off good, then totally flattening the top of the mud will in and of itself keep the mud from molding for quite a while. You do this each time you load up a mud pan (then snap the lid back on tightly). No chunks or mold. Oh, yeah, don't ever put mud from your pan back in the bucket--throw that out.

Dan Mages
01-26-2009, 6:03 PM
Thanks to everyone for the advice so far.

Chris, I don't know if that would be the wisest move. I don't know how contaminated the bucket is and don't want to spread mold throughout the house.

Dan

David G Baker
01-26-2009, 6:21 PM
Chris,
The mud guy that I used in California used three different set up times type mud. They were powders. One had a quick set up time, one had a 45 minute set up time and the last had a 90 minute set up time. He would mix them in a manner that the mud would set up in the time and way he wanted. He did the work in two days instead of three or four days with regular slow setting mud.
I like the powder for patching as well due to the very low shrinkage and quick set times.

Jason Roehl
01-26-2009, 7:51 PM
Yeah, I agree with not using it. Mud is cheap enough that it's not worth the risk of spreading mold all over your house. You'd be adding mold and water, and that could just be enough to really get a problem started that wasn't necessarily there before.

I love the quick-set mud (NOT Durabond, though that has its place) for doing patches, and I can see a pro using it in special situations on a job, but I couldn't see using it day-in, day-out in place of the ready-mix--just too much expense in the powder, and too much hassle to mix. It could work if you had the right size crew, but if you're a one-man show, that's a lot of mixing...

Denise Ohio
01-29-2009, 7:12 PM
I opened a bucket of dry wall compound to patch a few holes and found the top layer was culturing a nice layer of mold. The bucket is less than 6 months old. I have never seen this happen before. Has anyone else? It was stored in the basement. Any thoughts on what I can do in the future to prevent this?

Thanks,

Dan

Agree with lots of advice about storing the mud, though I always mix from the powder. The batch you have? Empty it out and clean the bucket for use doing things other than mixing mud.

I have four mud mixes and one 5-gallon bucket of FirstCoat with which to finish my drywall. First is the hot mud (partial of an 18# bag) that sets up in about 45-60 minutes---the house is pretty warm. It's an easy to sand product I use to fill any crevices and seams. Second is taping mud for---you guessed it, taping. I hate paper tape and paper tape hates me---We're involved in what people would call a long-term relationship. Third is all-purpose mud, to start feathering out, fourth is the topping mud, to complete featehring, and finally, a coat of FirstCoat, roll on and backrolled for smooth wall.

All USG/Beadex products.

I mix it up in clean 5-gallon buckets and warmish (not hot) water using one of those paddles in a drill. I have taping knives and trowels, but I've never used banjos and those tools.

You have to sand. Sponge sanding only kinda works. I have a book around here somewhere where the author suggests using a pole sander for everything because you can use you entire body and not just shoulder and wrist. I think that's pretty good advice and will be doing that probably in the next two weeks when I finish hanging the drywall in my studio. I'm doing a lot of bits and bobs right now, trying to gear up for the studio ceiling. it's not big, it's just a ceiling and getting those sheets up there...oy, vey, it's a job, I tell ya.

Anyway, enough about me. Mud gets moldy. Even the powder goes bad---the suppliers rotate stock for that very reason. The drywall guy who taught me said to keep the boxes in a cool, dry space, and if I open it up and it smells bad, get rid of it. The stink never goes away. He also said if I do buy the pre-mixed stuff, take a third of it out and mix up the rest with more water as the pre-mix is too thick to do a decent job with.

I've done a pretty good job with the pre-mix, but since you have to mix it up with a paddle anyway to get the water at the top down to the bottom, it's the same amount of work to mix up a batch from the powder.

Good luck with it.

Neal Clayton
02-02-2009, 2:30 AM
My drywall/texture guy calls it mud and hot mud. Hot mud dries rather quickly (hour or two?) and mud takes like a day. He takes regular mud, sprinkles something it it, mixes it up, and lays it up. I asked him once what he sprinkled in it but that memory bank is failing me right now.

there are accelerators and retarders to make it dry slower and faster, since he's quick he probably uses an accelerator to make it set faster. the stuff you buy at the borg typically has a 45 or 90 minute set time.

the plasterers i hired to do my upstairs ceilings actually used a 30 minute plaster with an accelerator added to it to get it down to about 15-20. talk about quick. what would've taken me a week and cost me another two weeks of back pain they had done by lunch time. their helper actually struggled to mix fast enough for them...

Dan Mages
02-02-2009, 8:18 AM
The bucket has been cleared out and a bag of dry mud has been purchased. I think I have all of the nicks and scratches in the walls filled. Tomorrow it is prime and possibly paint. Wish me luck!!

Dan