Drywall hole repair joint compound question

Repairing 2 holes which held bathroom towel rack anchors.
Used a 3M repair screen, which fits inside the wall.
Applied standard Dap joint compound, probably about 1/2" in thickness, maybe more.
Smoothed and let dry.
It's dried almost 48 hours.

Both have big cracks. The compound also sunk in a little. The depth needing to be filled with another application is probably 1/4" thickness.

I may have used the wrong type of joint compound, as this one says for wallboard seams, etc.

Do I only need to (lightly) sand and apply another 1-2 applications?

Or... should I use a different joint compound, and apply additional coats of this on the dried compound?
I am not in a hurry, so applying a more appropriate joint compound might make more sense.

Including photos of project before applying compound, and the dried result, as well as the joint compound.

 

Too much too quick. Joint compound is not the best thing to use. Should use patch compound or plaster patch. Use thinner layers and let dry. repeat.

 

Covering existing with joint compound?
Or... should I cover existing with patch compound?

Would it make sense to pull some/ most of the compound out, and replace with the patch compound?

Thank you for your fast response.

 

Marksr is the expert on this type of repair. I think I'd rather have him give you a full blown answer. However, I think joint compound is the wrong thing to use. But I don't think its' necessary to remove what's there. Just use a plaster patch or spackling compound over it in thinner layers. I happen to like UGL 222 Lite.

Mark?

 

It's drywall compound!

Your good, it was just a thick layer and as it dried it shrank and split.

Just add additional layers and give it sufficient time to dry, no need to remove or do anything to the patch!

 

Joint compound shrinks as it dries. When applied in large amounts like this, you get this result. As Norm said, thinner layers or a different material would have worked better. Give this plenty of time to dry all the way through and the put on another layer or two as needed.

 

While a setting compound is best when using a mesh tape, I wouldn't back up and start over - just apply more joint compound [not so thick] let it dry and repeat as needed. If applied halfway decent only the final coat needs sanding.

 

Long time landlord

I always found that it was MUCH easier to cut around the existing hole to make a square hole at a standard measurement, (e.g. 9"x9" or 10"x10") then cut a square patch to fit.

Cut a "patch", a square piece of spare drywall that fits snugly into the existing hole.
Drill a small hoe in the center of the patch for threading a Molly bolt/butterfly bolt
that you will use to hold the patch in place.

Gorilla-glue 2 pieces of wood that are 2" longer than the patch horizontally on the back of the drywall patch, one towards the top and one towards the bottom, sort of like an equal sign = These "tabs" keep the front face of the patch even with the wall. (takeout chopsticks work nicely for small patches, sections of yardstick work for larger patches)

Use a can opener to cut the top off of a steel paint can or coffee can - drill a hole through the center. This will be a "backer" that spreads the force of the Molly bolt and keeps it from pulling through the patch. The "backer" shouldn't overlap the patch.

Get a scrap piece of 2 x 4 and drill a hole through it..

Assemble the "patch sandwich"
Take the bolt, slid it through-
1) the 2 x 4, 2) the drywall, and tin can lid, and spin on the moly bolt so the moly bolt is against the tin can side of the patch.
Use a dab of glue or chewing gum to keep the moly bolt from spinning.
leave plenty of slack at first

Lay out a newspaper below the patch to catch any drips of glue or drywall patch.

Turn the 2 x 4 vertical, then slide the patch into the wall horizontally, tabs on one side in, then tabs on the other side in. You can dab some glue on the exposed ends of the tabs before hand if it is a large patch,

Maneuver the patch into place, tighten the bolt until the patch is sitting flush with the wall. With the 2 x 4 is vertical, apply joint compound to the vertical joints and let dry. When the vertical joints are dry, loosen the moly bolt a bit, spin the 2 x 4 horizontal, then apply joint compound to the horizontal joints. When all the joints are dry, loosen and remove the bolt, then dab joint compound on the bolt hole.

Sand and paint as necessary.

 

Good tips. Thanks for all the advice.

I think I will purchase a spackling compound and layer it in small layers over the existing joint compound, then sand.

Not sure why I used this joint compound. I think I recognized the brand and grabbed it off the shelf. Joint compound may be good for smaller, thinner nicks and holes, which I've used it for earlier projects smoothing walls, not deeper 4-5" -sized holes. Next time, will be more careful in what I purchase.

 

It all works so just buy one and that way you wont have two tubs go bad!

 

Spackling is for minor repairs although some folks erroneously call joint compound spackle. You want j/c [what you have] Spackle is limited in how thick or thin and how large an area it can be applied to. Your original cracking/shrinking was because the j/c was applied too thick, shouldn't give you any problems going forward.