Need helps with fixing plaster cracks please!
netrate
| Posted in Construction Techniques on
Can I paint over the plaster weld with a primer? Here are the pictures. I used the plaster-weld on the crack, waited for it to dry, and then used a CGC compound over that -waited for it to dry (24 hours), and then sanded it down and this is what I have. I am new at this, so I am probably doing something wrong. It feels smooth now (a lot of sanding).
What is next? Primer? Should I have not sanded away the CGC compound? Confused, for sure…
Replies
ne
What is a CGC compound?
Why is it pink?
Did you use no tape or mesh on this crack?
Plaster Weld is a product by Larson chemicals. It is supposed to strengthen the bond between plasters (cracks). The CGC compound is a (according to the literature) "All Purpose Drywall Compound is a excellent compound for joint finishing (taping, filling and finishing) . It's ready-mixed formulation is creamy and smooth, giving it excellent slip, bond strength and easy workability. It can be used directly from the container and requires minimal mixing and/or thinning. CGC All Purpose Drywall Compound can also be used for fasteners, bead, trim and skim coating."
I did not use mesh or tape because I really am not skilled enough. I have tried it and failed miserably, so I am going this route instead.
I understand fully the difficulty in repair and any finishing of plaster or drywall. I commend you for trying and urge you to continue. The technique doesn't just come up with the sun-practice really does make a difference.
Simple things like what tools you use-whether trowel or blade-has the possibility of making it easier for you.
I understand plasterweld and would have done the same b/4 making the repair. However, I would have used mesh or tape after first filling the voids with Durabond (not lightweight but the original) . This is not premixed and comes in timed grades from 5 minute up. I use 90 when doing most repairs, but 45 or 20 is good to have when you have a small job and want to get a couple coats on quicker.
The mesh/tape will aid in reinforcing the repair. Just filling with bucket mud might too easily crack later on the edge of the old. I use Durabond because it dries hard and has more "adhesive" than bucket mud. Your applying the plasterweld will help bond your patch.
Best of luck on a lasting repair.
Did you by any chance use the search feature here-there was some recent discussions of patching plaster in the past couple months.
And yes, you can prime over the plasterweld area when you do the same over the patch. It should look/feel as smooth as the surrounding plaster so it blends in. I usually prime these type of repairs with Bins. Keeps possible bleed through of stain to a minimum.
Again tho-why the pink-is the compound tinted so you can find the repair?
Thank you for the response. You echoes my thinking exactly. I have been working on this for over 3 weeks now - one room. I don't want to give up, but sometimes it feels like just painting over the cracks would have made my life so much easier.
Here is the issue I have come up with:
1) using the CGC compound, I was under the impression that I was supposed to feather out the compound around the crack (like an inch or more on either side). So I tried that with some success. It felt smooth (not smooth like a painted wall, but smooth enough that if I closed my eyes, I couldn't tell where it began or ended). After this, I tried painting it with Latex ...what a mess. It showed right through the paint, it started to show the seams where I had previously thought there weren't any. So live and learn.
So I sanded it all down and started again (another few days lost). I research on the internet and found out I should have used an oil-based primer on the CGC compound and it would have made it smooth (or so it claimed). I had also read that I should use Plaster Weld on the original cracks to help with stability.
So I found some plaster weld, paid $30.00 for it and started to fill in the cracks in the walls and ceilings. I let that dry and applied the CGC compound (which is premixed). I noticed that when I sanded it lightly, the CGC came off but the Plaster Weld that was dry felt bumpy and uneven - so I sanded it all down again, and that is why you see the pink in the pictures. It is sanded really well, I think, nice and smooth - but alas, there is no CGC compound anymore, just the plaster weld (and I guess whatever it bounded with).
And that is where I am at. Plaster Weld ceiling and walls. I still haven't figured out how to trowel and sand properly. I am still unsure if I am supposed to use an oil based primer or not. And I am gun-shy about painting now especially after taking days to resand everything.
Lastly, as far as taping goes - I tried on a small spot. I dug into the plaster so that it would sit evenly with the surface and used some Plaster Paper and the compound ,but alas, it is a skill that I do not have and left a mess. I am not really anxious to try again with mesh or tape, hoping instead just to use the Plaster Weld for now.
Well.............
How much area are we talking needing primer to seal the plasterweld?
If not a bunch, then there's Bins in a spray can.
If more-there's Bins sealer (not the latex if you're worried about latex) in a can-Qts-maybe 12/15 bucks. You can roll it or brush it. Brush strokes may show.
The best Bins is the original which is shellac based. Quick dry and great sealing.
Some people claim success without using tape, but I'm not
one of them. However, if you really want to avoid using tape, I'd try filling the cracks with either plaster of paris or Durabond joint compound--as Calvin mentions, the setting compound (comes dry and you mix), not the premixed. Durabond is available in with several working times. For example, Durabond 45 sets in about 45 minutes, which gives you 45 minutes to use a batch after it's been mixed. You should probably go for Durabond 90, since you're not experienced.
Are you using a sanding block to sand after you fill? Using a sanding block that rests on both sides of the filled crack should help keep you from sanding into the filling.
After sanding, prime with Zinser or a PVA primer. Then paint.
As Calvin says, "good luck". If I were doing it, I'd use Durabond, tape, and then cover with a couple of coats of all purpose joint compound feathered 10 to 12 inches on either side of the crack.
The plaster welld is to help bonding and the stabilize the weakened plaster edges.
The next step is to repair the crack with mesh taape and a plaster or Durabond.
Once that is built up and smooth it is time to sand and paint.
You can't skip taping and expect deent results
I looked it up -- CGC is simply a brand name for drywall mud, et al.
Everyone here will tell you I'm no expert, but a few points.
When you "feather out" the drywall compound, you need to go well beyond just one inch. A minimum of three inches, probably, and 4-6 if you use tape over the crack (which you probably should).
To feather the drywall compound get some wider "drywall knives" -- maybe one 6" and one 8" or 12". Work from a mud pan (like a large bread loaf pan).
Generally it helps to thin the mud (drywall compound) slightly with water. Some people put a squirt of dish detergent (eg, Ivory Liquid) into the mix. I've tried this and it seems to help a little with getting a smooth joint.
Not everyone does this, but I have a rule to never empty my mud pan back into the mud bucket. And always keep the bucket covered. Lumps of dried mud in the mix make it much harder to get a smooth joint.
Rather than using fiberglass mesh tape, you might try to find the self-stick perforated paper tape. It's thinner and thus easier to blend to a smooth joint. But note that when using either type of self-stick tape you should generally use "hot mud" -- setting type drywall compound that you must mix before using -- for the first coat.
Don't expect to get a smooth joint in one pass. Apply the tape and one THIN coat of mud, just feathering out maybe 2 inches, then come back later and apply one or two more coats, feathering out more each time. Between coats (when hardened), lightly scrape over the area with your drywall knife to knock off the loose blobs and high spots of drywall compound -- sanding is optional.
For a DIYer, the fewer passes you try to do (applying too much mud in each pass), the more passes you end up doing.
I am probably going to have to see how this is done. Can you recommend any good youtube videos?
I would paint the area with blocking primer, the can will say blocking on it, but BIN acrylic blocking primer is a good one. After the primer has cured I would then fill the are with your mud and quickly imbed a mesh or paper tape into the mud and let it dry. Then smoth the mud of excessively high spots, and apply a wider coat of mud to hide the repaired area. You would probably have to do some sanding after this dries. Apply thinned mud with a roller over the area, or do what ever you need to at least minimize the difference in texture from the existing ceiling. Then prime the entire ceiling and paint.
How To See It Done
Howdy. here is something that may help. Go to http://www.drywallschool.com where you will see all kinds of informative "how to" drywall videos. A great site for amateurs and pros...
Some of the posters are correct. You will only have limited, longer term success if you dont do the fiber-glass tape part. Its actually not too hard, once you see it done, and then practice a little.
I have done many repairs like this for customers, and one thing that helps when it comes to sanding is to use the correct material - that is, the best material for the job. As an amateur, it would be best to stay away from the screen mesh types of sanding papers, as they are tricky to work with for fine finishing. use something 120 - 150 grit, and your finish sanding will look a lot nicer.
For the primer problem, your best choice is to use something that says right on the can "Primer/Sealer." There are several good acrylic latex brands here in my area; and i am sure you will find something similar in your area.
One last tip. I am not discounting the use of the fast-set materials for your finish coats of mud, or the ready mixed stuff you are buying in the small pails. But, by far, the best you will find is drywall mud that says "Finishing Compound" on it. here, it comes in boxes, and all you do is put it in a 5 gal bucket, and mix to desired consistency. ProRoc makes a good ready-mix compound for this here. A proper finish compound will feather out and sand much easier, and will not be as hard as the fast-set stuff to work with, since you are learning...
I admire your determination! I am sure that will eventually get this job done!! Keep us posted how it's going!
Al
I only set fibreglass tape with real Durabond-I don't have confidence in either bucket/box "all purpose" or Lightweight rapid set.
net
What appears in those photo's looks like the patch area needs a roll coat to blend in the smooth sanded compound with the years of paint that preceeded it.
When I patch what you have-my compound is way wider, which makes up for the tape I embed. You feather the edge and lightly buff sand the field.
Sorry for the question but, what is a roll coat? IS that paint primer or dry wall compound?
roll coat
That finish or appearance that is very slightly bumpy-produced by a thicker nap roller. Like a very poor paintjob on a car.
Usually acheived rolling a thinned down coat of compound. This is done to blend in the finish on drywall so smooth mudded surface is the same as the slightly rough drywall paper.
Note that the repaired area will always have a different sheen vs the rest of the surface. You need to roll on some eggshell paint or some such (with a fairly nappy roller) to bring down the gloss of the repaired area. (You'd think there would be a primer especially for this, but I've never seen one, though maybe PVA comes close.)
losing the battle
Well, it seems like I am losing this game. But boy, have I tried.
I painted the ceilings today - MATTE finish latex white paint (yes, it has taken me this long to get the courage up to do it). And it wasn't what I was expecting. I thought I had sanded down all of the drywall plaster trouble spots, but I guess not. There are 4-5 spots on the ceiling that look like raised mounds of pomous or swiss cheese( trying to think of a suitable analogy for the porous look they have). I am guessing it is drywall compound that I missed. Don't know how I missed it though since I only put it on in a small area around the cracks. Didn't see it until I had already gone over the cracks. BUT I had previously painted the cracks with a AKYLD oiled based primer (althought I don't know if it did any good considering.)
So now I finished the ceiling and I am back to square one. I am going to have to sand the areas in particular and try again.
Also, the parts that have the PLASTER WELD (the pinkish red cracks) - and I have sanded it down, I covered with an oil-based primer BUT, when I painted them today (with a latex ceiling paint), the pink colour just seem to bleed through - I am guessing three coats of white ceiling paint if I am lucky.
Now you know why we don't use products that are gimicky - honestly it's painful to watch, but i'll just say that if I see a crack I scrape it with a carbide scaper to smooth out any high spots, use regular drywall compound and paper tape. Let it dry, lightly scrape with a 6" knife and apply another coat of drywall mud aiming for 1/16" coverage of the tape. Let it dry and go over it wit the 12" knife. Let that dry, lightly sand and the outter edges that form a ridge no matter how much you sand are simply sponged flat. Let dry and spray will kills stain blocking primer - 10 minutes later apply latex paiint. Add grit if you like to mimic the plaster surface, but then put a number of heavy coats of paint, or even thinned down drywall compound for the patch to blend in.
If after paint it doesn't blend in well you don't sand it off and start over - you keep feathering out the repair over a larger area - keep using a 12" knife as straight edge so you can see where it's high and where it's low - don't sand low spots and don't add to high spots! Get a light that can be pointed along the surface of the ceiling - that's basic, but allows you to better see what you're doing or else too often people might as well be working with their eyes closed - doesn't make sense does it.
Or screw it all and install acoustic tile.
Here is what it looks like :
I painted over a spot that I thought was smooth (used a palm sander) and painted over it with a latex ceiling paint. The ceiling is smooth, no water damage, hard surface - but this is what happened.
I have increased the contrast so you can see.
The rest of the ceiling is relatively good (from my standpoint), but I need to fix these areas before I can move on.
As you can see, it's not flat. There are ridges around the repair. You need to feather out the joint compound better.
You're likely discovering that a sander will preferentially remove softer material (such as joint compound) before it removes harder material (like other repair compounds). The harder you try to sand the border "smooth", the more of the softer material you remove, and the worse it gets.
Aplly anothe r skim of mud with a wide knife and feather it near smooth.
Technique takes practice.
When you sand, check by playing a light across the surface to amplify the high/low shadows soyou can see them
Listen to Piffin
Plaster weld is a bonding agent and a binding agent, nothing more.
If you are going to use a setting type compound (a powder mixed with water) to do the skim coat then you MUST use fiberglass
mesh tape. If you're using a premixed joint compound( from a bucket) then you need to use paper tape. Setting ttype
compounds set up harder and faster, they cure, instead of air drying like a pre-mixed compound.
After applying the plaster weld and letting it dry, then apply the base coat, then the correct type of tape (paper or fiberglass mesh)
then use a DRYWALL trowel, which is curved, start with a 6" flat knife, then go to a 8" or 10" drywall trowel(curved) then finish with
a 16" trowel, the curve allows the center part of the "mud assembly " to be covered and taper away without leaving a ridge or
bump where the repair area is, the wider the trowel the less conspicuous the repair.
Good Luck!
Geoff
"use regular drywall compound
"use regular drywall compound and paper tape"
Drywall mud does not stick well to real plaster. I see a lot of guys thry that, and I get to repair their repairs after 3-4 years.
None of the pink should even be showing. It is there to stabilize the plaster edges and to help the patching compound adhere.
If you have done the mud and tape patch and built up the skim over it to feather out on both sides, as should be done, the pink prep is totally covered over and cannot be seen
Don't sand more, build up thicker