how to install baseboard trim over uneven wall

I'm trying to post this from my smartphone, using Chrome, and see no option to attach a photo.

I'm installing baseboard trim in a room that has never had baseboard before. On one wall, a concave spot on one wall causes a large gap (almost 1/4 inch) between the wall and baseboard. Scrbing the baseboard does not seem feasble due to size of the gap. Besides, the baseboard is MDF and does not scribe well, as I see it. I can make the baseboard contact the wall by firmly pressing against it. However, I have detected a stud in the wall near the center of this gap, so regular nailing is not going to work. I am wondering whether anchor screws could be used. The idea is to countersink the screw heads in the baseboard and the probably cover them with spackling, wood filler, or caulk, and then paint over them. The only downside I see to this is that if a future owner of the house tried to remove the baseboard for any reason, they would not know about the anchor screws and could damage the drywall by trying to remove it. Your thoughts?

Edit (note on using smartphone): I'm typing this edit from my computer. When posting via computer, I can click Go Advanced button and get the option to attach a photo. Does this option not exist when using a smartphone with the Chrome browser?

 

I do not understand your concern here. Having a stud where you say would allow you to push the baseboard in against the wall and nail to the stud. What am I missing here?

 

What you're missing is the word "not". I should have said "I have not detected a stud in the wall ..."

Also, I can now post the photo since I emailed it to me from my phone and received it on my computer. It is now attached.

 

I probably should have said counterbore instead of countersink since screws that come with anchors usually have flat heads on the bottom side.

 

I would nail it through the bottom plate and caulk the top crack. You can spend hours trying to make it fit, and it never will due to the wall. It will virtually disappear once you caulk the top of it and wipe it down with a damp sponge.

 

I agree, gaps like that get caulked all the time and nobody notices once the painting is done.

 

You can also float the wall with drywall mud to make the wall just as straight as the baseboard is... but that would mean repainting the wall. Caulk will hide a lot and a sofa or table will hide the rest.

 

Very true! When there is no furniture or decorations every little defect in the wall can be noticed but once the room is filled with furniture, pics, drapes, etc. minor defects are no longer noticeable. It's rare to find a perfect wall in any house.