Patching and Plastering - Patching old compound/mud finish

In my living room, I noticed a crack and a bulging on the wall. I chapped it away to repair. I noticed that the wall was made from 2 by 4 upright with 1" laths across and plastered with an old type compound which resembles earth. Someone told me it was called mud. This just lifted from the laths due to drying out over time and vibration of vehicles on the road. Can I use plastering compound or structurelite to do the patching. the area is about 7 feet by 18 inches wide and the thickness is about 3/8".
Please e-mail me at Caldsc@aol.com

I'd go with drywall over that large of an area.

You can float out the patch with patching plaster. Use as wide a knife or trowel as you can get. Make sure the surrounding plaster is firm. Be advised, plaster sets up fast,so you have to work fast. What most people do these days is patch holes like that with sheetrock instead.