Under the fugging kitchen sink...some more

[JWWebster]

I gotta tell yall something percular about my mothers kitchen faucet. Yup I has been assigned to deal wif it. Their are no shut offs under the sink. My daddy built the house and lets just say he cut some corners.
A copper line goes into the faucet on both the hot and cold. The cold is fine but the hot line has come loose 3 or four times in the last few years. It happened today. The fitting is compression type. A small nut is on the faucet side and a bigger nut is on the line going in. Are any of you familiar with this type connection? What can I do to keep the line from backing out again? I got it back together and it is not leaking, I cannot help but think it is gonna back out again in the future. I am thinking I need some sort of compression sleeve?

[jumptrout51]

What you need is a plumber and a kitchen sink.

[BrntToast]

go to the local hardware store, you can buy the short prefab braided stainless hoses with the connections you will need
think its 1/2 large and 3/8 small

buy a short enough one and it'll take the place of the fitting you have now, if i am picturing what you describe

however you are probably 12 beer ahead of me, so my brain might not be as cloudy as your eyes

[JWWebster]

I might look into that, thanks

[Repair-man]

3/8" X 1/2" Water supply-

[regnursepm99]

I just replaced my copper lines under my sink in our bathroom.  I had a problem with leaking.  I replaced them with the hoses Repair-man posted and they worked like a charm.  They come in different lengths.  Use the shortest one that will work...good luck!

[chiknstik]

Uh...not so fast thar, pard.  Those SS braids are over a rubber hose.  Rubber wears out, over time (Even NASA figgered that one out, after Challanger).  Lots of rental property over 25 years tell me hard copper lines are always more trustworthy than rubbers, even with SS braid.
I'd take the time to put in stop valves while you've got the water off, and use  a copper sink supply line. I've never had one come loose, so I can't figgure why yours did.  If you go with the flex lines, I'd replace 'em eveery 5 years, and turn the water off if Mom's gonna be away for more then 24 hours. (The voice of a formerly flooded floor.)