Under the cabinet- make a two part patch. You need two pieces of thin plywood cut to ~110% height and ~70% width of the hole. Use one side on the left, mark the pipes and cut notches maintaining overlap on the exterior of the hole. Same for the right. Now you can screw these to the back of the cabinet with an overlap. Youve covered the hole but can still access for repair. Plaster- I dont do plaster
Cons: Messy, do not wear clothes, do not get it on your skin.
Tips: Apply it in layers. Wait for first layer to expand and set, then apply next layer. Also read the instructions on the can and use your brain for your particular application.
This. Obviously, there is a hole here. With stuff in it. And at some point, you will probably have to get back inside there. So I would clean it up as square and neat as possible, and make some type of frame with a drywall cover that is easily removed when it comes time to work in there again. It's not the living room wall, so it doesn't have to be perfect.
strikt9
Under the cabinet- make a two part patch. You need two pieces of thin plywood cut to ~110% height and ~70% width of the hole. Use one side on the left, mark the pipes and cut notches maintaining overlap on the exterior of the hole. Same for the right. Now you can screw these to the back of the cabinet with an overlap. Youve covered the hole but can still access for repair. Plaster- I dont do plaster
WhiteRhino723
Great Stuff (the black can for larger holes).
Pros: It's cheap, simple and fun.
Cons: Messy, do not wear clothes, do not get it on your skin.
Tips: Apply it in layers. Wait for first layer to expand and set, then apply next layer. Also read the instructions on the can and use your brain for your particular application.
justherefortheconfession
Have you tried using ramen noodles?
Kyzyl
Ramen
tuckathanJay
And superglue.
ErindorGhostPope
That's what she said.
yesdearmetoo
conjuratio
Creative use of drywall
DecentUsernameUnavailable
This. Obviously, there is a hole here. With stuff in it. And at some point, you will probably have to get back inside there. So I would clean it up as square and neat as possible, and make some type of frame with a drywall cover that is easily removed when it comes time to work in there again. It's not the living room wall, so it doesn't have to be perfect.
minoshirokin
https://www.instructables.com/How-to-Patch-Large-Holes-in-Drywall/
sosume
You could use marshmallow fluff. I'm not saying you should, but you could.