Light weight mud

j120strat

Ive been wanting to try it but since I fear change I thought I'd run it by you guy's first.

Pros:
The box is so easy
to pick up.

Con's: ?

Muddauber

If your doing smooth finish walls,light mud is to soft. You will leave scratches in it when sanding,& to easily damaged by other trades. I prefer mid weight.

silverstilts

Best thing out there as long as you don't tape with it , and yes it is easy to scratch when sanding , I use a 220 grit on a porter cable and then use a fine sponge sander works great , as far as the other trades go ,that is there problem if they damage the finished sheet-rock .Usually it gets painted right away so this does protect it , if they are that careless as to damaging walls it won't matter what you have on them they will get damaged regardless.. The best lightweight mud around here is pro-form by far it mixes so smooth with no pocs and it is so easy to sand , a lot easier than the plus 3 , i guarantee if you can get your hands on some you will never want to use anything else... Happy Trails------- silverstilts aka the Rock-Doctor

Tradesman

I've been using the USG Lightweight AP (blue lid) for both taping and topping for about the past 7 or 8 years now. Initially, I was reluctant to use it because it was "lightweight". Then I talked to a USG rep at the JLC Live show and asked what the difference was and whether there was any reason not to use it in some situations. He said the main difference was in the lightweight aggregate (the solid stuff in the mud) and that it could be used as an "all-purpose" mud. On the USG website they specifically say that there is no more need to use one mud for taping and another for topping, though many guys do, and that works fine. So, I tried it, liked it and have been using it ever since. I still use the green lid regular AP for bedding No-Coat corners, as per their spec, but I use the lightweight for everything else. Never had any problems with it and I find it good to work with.

silverstilts

No disrespect Tradesman , I'm not sure even though a rep. assured you that lightweight is usable for taping , try this tape a few joints with lightweight and leave a little tail (extra length) then use some all purpose , after it is fully dried grab onto the tail and pull out and see how much bonding the lightweight has then do the same for the all-purpose and see if you can tear that away from the wall ,,, your question will be answered as to what will be the better taping mud.... Yes the light weight mud is nice in a tube or banjo for the weight but it gets to doughy and also dries to fast on the head of a bazooka and causes too much buildup causing stringing problems ... this is of coarse just my opinion and observation.....

Tradesman

Yeah, I realize that the lightweight mud is softer; that's what makes it easy to sand. I haven't found that to be a major issue. I also use the PC with 220 grit and it works fine WITH A LIGHT TOUCH.

And though I haven't done a pull-off test, I am sure that the regular mud, with more glue, would be more resistant to pulling off than the lightweight. But usually the issue is not the tape pulling off, it is resistance to shear that is important. Shear force is like if one sheet of rock slides right on the wall and the adjacent one slides left. If you take the "tail" of the tape as mentioned in the pull-off test and try to pull it out from under the mud (parallel to the board) I don't think anyone could do it unassisted because of the resistance to shear force. So I really don't think that the lightweight having less glue compromises its effectiveness at all, for practical purposes. I do agree that the regular mud has a stronger bond, I just haven't found the lightweight to be too little bond. Like I said before, I have been using it pretty much exclusively for about 8 years without a single failure or call-back. But hey, if anybody feels more comfortable with the regular for bedding the tape, I'm o.k. with that!

drywallpro

I like to tape basements with lightweight. It drys faster. I set up fans to dry it out. You can usually skim the flats out the same day. The only thing I have found lightweight doesn't work for is texture. It sets up too fast.

silverstilts

That is all i use for knock down don't know if it drys to fast , gotta put a little spring in your ass if it is , but seriously one does just have to hit it just right , also heating and humidity can cause major setting times as i am sure you are aware , I like spraying it when it is a little cooler don't have to run as fast at least not my wipe down guys , can usually spray 2500 ft in about 30 min. or less depending if everything works good.

Cyian

Light mud has Perilite used as a filler rather than Calcium Carbonate. The Perilite gives the compound much less density due to the Perlite beads displacing space within the compound which equals Lt Wt. Both are excellent products.

PROS: Easy handling, Easier sanding, Lower shrinkage, ect.....

CONS: Can re-thicken once mixed in your bucket, Can tend to pock due to surface tension ect......

My opinion regarding taping with Light Weights are old school...Conventional taping formulas have been tested and have withstood marginal conditions throughout the years. Lt Wts are still fairly new technologies which can have marginal adhesion under extreme conditions.

Hope this helps a bit.

j120strat

I just need the tape to stick long enough for the check to clear.

Bevelation

Personal experience:

First off, all I have ever used is lightweight mud. For taping, I have used CGC(Synko) lite Joint and ProRoc lite taping (yellow boxes). Both seem great, but the ProRoc I find has the advantage. It glides easier running angles, doesn't set up as fast as CGC, and it smells soooooo good! Mmmmm Jalapenos.

To illustrate the strength of the ProRoc lite taping mud; If you leave a glob of ProRoc alone on the wall and it dries and you come back to it, it's better to sand it off rather than scrape it off with your knife. It will take the paper along with it. The CGC stuff won't do that, but that doesn't mean it's bad stuff, either.

I don't vouch for the all purpose stuff except for small jobs and patching where it wouldn't make sense to use a quarter bucket of joint mud and half box of filler.

As far as filling mud is concerned, I've used CGC and ProRoc, and again, they're two worlds apart. As silverstilts states, it's pretty soft stuff, but ProRoc Lite Finishing seems to be a different animal. It's definitely a harder sand compared to CGC, but it finishes wonderfully and 150 grit will suffice. Scratches won't show up behind 2 coats of paint. I know the CGC finishing we have here you need 220+ grit to make look good. Heck, you could sand the top coat off with your fingers.

CGC vs ProRoc filler comparison: (Lite finishing)

CGC is softer. Cuts easier. More water-sensitive (What I mean by that is it takes less water to thin down your mud). Airs out easily. Sands out best with 220 grit. Fisheyes and pocks galore when put through a box. I couldn't believe how bad it pocked. On finish coats it airs out quickly and you often have to dump your leftover mud after 2-3 applications and get fresh from the bucket. Joints tend to flash behind paint.

Proroc is softer right out of the box, but takes more water to mix down thinner. It's better at fighting dryness as you use it and usually I just refresh my hawk/pan without dumping any out. It glides easier. Sets harder than other lightweights. You go through more sandpaper and sponges with it, but it's worth it for the finish because it hides joints better under paint.

I think that sums it up. ProRoc is light years ahead, IMO. The only exception for filler would be Synko Classic Finish, which doesn't pock as much, but still has airing out issues with all other CGC stuff.

Hope this helps your choice.

brdn_drywall

bevelation , that was a very accurate analysis of the two products (except for the smell description) i found myself agreeing fully with you on all points, i to used synko exclusively for about 5 yrs. then made the switch to proroc mainly due to its slightly harder Finnish, the pros really outway the cons with certainteed.

Apple24

proform light blue awesome mud sand 150grit 3m paper doesn't scratch mud as bad as johnson abrasive. Tape w/ Magnum all purpose mud cause it has glue in it thats what it was made for not lightweight.

alaska123

I know what silverstilts is saying about the bonding power of lite joint compound it sucks I switched to allpurpose because I notice when I pulled on the tape in the lite mud it came to easely. didnt seem right to me.

Darren@Partners

USG guy will tell you that you can tape with +3, but never had any luck, acts same as any lite weight. The whole concept of USG +3 (I was told) was to have a single mud that would do it all but it just ain't so. I've notice almost every Topping being easier to apply but harder to sand. my .02

Drywall Tycoon

I'm with Apple on the Magnum all purpose. Take any other mud rub it between your finger and thumb. Then try it with the Magnum. The Magnum has more vinyl and the filler is ground finer. The greasiest stuff around. Even if it heavier than the light stuff.

Hey D@P, is the old Ruco / Magnum factory still running out there in KC.
.

Darren@Partners

Yes, but is out in Lenexa, a burb. Only 20 minutes from my front door. Still go there for occasional will-call. And Magnum AP is my favorite, with Lightning Red for filling and skimming. Their quickset makes an awesome hand texture(resembling plaster), but no matter what is stamped on the bag: 20, 45, 90 it all goes off like 90.

What does everyone pay for it? I'm probably spoiled on price here.

muddymen

For Magnum AP and LW I get it for $8.00 to 8.25 for a 3.5lb box. Never used there quickset but from what Darren said I don't want to because I love my 20 min.

brdn_drywall

i think most of you would agree that if you don't have to coat/sand till the next day light weight muds are better than hot/chemical setting compounds.
as far as bonding strength and hardness in light weight mud it's been a no issue for me since the switch to certainteed, would not use hot/chemical setting compounds together with light weights because of differing hardness's that would be problematic during sanding and the time saved would probably be wasted in touchups/reskimming.

Bevelation

^Bingo. Hot mud is overrated.

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