drywall nightmare
 

Hello,
I recently purchased a home and I am trying to make some, what I thought were, minor cosmetic repairs. To my best estimate the original owners has applied wallpaper to just about everywhere in the house. I am trying to repair the upstairs hallway walls due to the fact that I believe the subsequent owners tried to remove the drywall and then stopped halfway through and did some spackling and then painted over it all, leaving me with something that is far from a clean slate. I sanded down the marks left from their puddy knives but I am having trouble smoothing out the wall. I am wondering if maybe I should try to strip the spackle and paint down and try to start from scratch. Any advise on how to do this would be much appreciated.

Thanks!

Do you think a skim coat would do it?
 

Usually you don't remove the "spackle", it is not really possible to cleanly separate it from the sheetrock

Usually in a case like this, either the drywall is removed, and redone
Or, if it is possible, a skim coat is used to smooth out the problem area

A "skim coat" is a thin layer of joint compound spread over the area to smooth out textures

It is not that unusual to have to skim coat a large area, such as a hallway, or bathroom
I had to skim coat a bedroom this summer
Fortunately is was not the entire surface, just mostly around the middle
If every inch of the bedroom needed to be skim coated, I would have suggested replacing the drywall

How bad is it?
Do you think a skim coat might do it?

The wall is just looks "bumpy" when you look at it from a flat angle. It's not smooth and it looks like there are dips from where I sanded down the marks from where the previous owner tried to do the repairs. I will pick up some joint compound and apply a thin layer to the dips and see if that works. I definitely do not want to replace all of the sheetrock. Thanks for your help!!

The dips may need more than one coat
Start with the deep dips, try a coat to "fill in"
Then fill in any other spots that look like they could use a "fill in with compound"
Figure that you'll do another coat or two to "smooth out" later
Those'll be thinner coats

It may never be flat, but if you can "smooth out" the surface it will look better

compound vs. vinyl
 

which do you think I should use in this situation?

Joint compound

I would suggest you use the light joint compound, you should thin it down a bit with water and mix it up real good with a drill and mixing paddle. A trick I have used for years is to add a dab of liquid dish soap to the mix, this make the mud become very smooth and creamy and will make skimming alot easier. If you try to use the compound directly out of the box or bucket it will make your job that much harder to do. If this is a large area it might be worth it to either remove the drywall & replace it or else over lay it with some 1/4" drywall, the latter option you may have to rework wood trim in the room. Good luck.