How do you find the wall studs without removing the plywood?

[digimark]

I tried to install a 15"v by 30" h kitchen cabinet in my trailer this morning. After about 15 #8 1-1/2" were screwed through the back into the side wall, apparently none into the studs, I can say it's attached, but it wobbles if I pull on it and I have absolutely no confidence that it will hold any weight. On top of that, the Home Depot droid suggested I use brass screws "so it will look better". It occurs to me now that brass screws are probably a softer metal which would explain why half the screws stripped while I was installing them... (sigh).

Since I'm going to have to remove the cabinet and reinstall it properly, perhaps you can offer some advice:

1. How do you find the studs? I have a stud finder for wooden studs under drywall -- but that wouldn't work in a trailer, right? And wood drill bits would just spin when they hit the metal stud, true? I'd need a carbide bit.

2. Is there an easy way to remove a stripped screw? I have one of those reverse-grip bit kits that's supposed to be the thing for removing screws, but all they've ever done for me, after hours of work, is to grind the head down until it separates from the rest of the screw.

3. How thick is the side wall? I'm terrified of going through the outside skin. What length screws do I use? (Through the cabinet wall
and its attached ledger is just under 1".)

Thanks in advance. I thought this was going to be so easy...

Edit: Added picture. If you look closely you can see a silver screw in the plywood underneath the cabonet where, presumably, the stud is... But there is nothing similar 16" away...

[Ageless]

Can you look at the exterior and see rows of rivets that mount the skin to the stud?

[SmilinJack]

If you're trying to attach the cabinet to the front of the trailer, there are no vertical studs there. My trailer has 3 or 4 bows that form the curve you see on the front of the trailer, and they're horizontal, not vertical.

[S. Heisley]

I think I'd use a little hand-held stud finder. You can get them at a hardware store. To make sure it of what I am suggesting, I just tried using it on the enclosed wall of my trailer and it worked on that. You just pass it over the area in question and it beeps and lights up when it finds a stud.

More:
To take out a screw, if you can get hold of it with some needle nose pliers, you might be able to unscrew it that way. Or, maybe just pound it in a tad and fill over it.

If you have some calipers or can borrow some, you might be able to measure the wall thickness by the door or window. (You need an opening to do this) No calipers? Another idea is to take a large pipe wrench and screw it down very lightly to the wall, with the teeth on the inside and outside. Then, while holding the wrench in place, On the wrench, mark the spots where the jaws are. You can use a couple pieces of tape or a crayon to do this. Undo the wrench; take it off; put the jaws back to the spots you marked and measure the space between the jaws. Before you use the pipe wrench on the wall, put some painters tape or masking tape on the teeth of the jaws to help keep from marring your wall.

[S. Heisley]

Another way to measure wall thickness is to measure at the door, including the trim boards. Then, measure the thickness of the trim boards and subtract that amount from your original measurement.

[bobhenry]

I think I'd use a little hand-held stud finder. .

You vixen you ! You have a stud finder!

I tried using one and it just kept going off in my hand I don't understand.

[edcasey]

The Pace wall studs are 16" on center. The silver screw in the wall indicates where one of the wall studs is. They didn't necessarily put screws into each stud to hold the plywood in place. You can measure back toward the rear door 16 inches from the silver screw to find the next stud. In your picture, it doesn't look like any of the brass screws in your cabinet are directly over the silver screw but maybe it's just the angle of the picture.

For screws, I would use self-tapping sheet metal screws (drill point) that you can get at Home depot. That way you don't have to worry about using drill bits. That's what is used to attach the exterior aluminum skin to the wall studs. Just don't go super tight because the hat channel wall studs aren't too thick so it's not hard to strip the hole. For length, I would remove the silver screw and see how long it is and then add on for the thickness of the board on the back of the cabinet that your screwing through.

Ed

[S. Heisley]

bobhenry wrote:

I tried using one and it just kept going off in my hand I don't understand.

I love my studfinder and use it a lot. It's supposed to go 'off' in you hand. If yours is like mine, you put it to the wall in a place where you don't think there is a stud. Then, you squeeze the squeeze points and it beeps at you to tell you that it is working. While still squeezing, you move it along and it will stop beeping at you until you come to a stud, where it will beep at you again.

[Ageless]

The stud finder reacts to the metal (nails, screws, braces) in wood studs. You have all metal and it's detecting everything

[digimark]

(I've mounted the cabinet on the driver's side wall, at the top, so I'm hoping there are vertical studs.)

Sounds like a stud finder will work then. And I had assumed that there would be a screw at every stud, that explains why there was nothing 16" away.

Thank you all for the advice, I'll give it a try in the morning.

If I were to get the self-tapping metal screws of the right length, and washers to spread the holding force a bit. could I then just power screw them in without drilling a pilot hole? (Or maybe a small pilot hole so I don't split the wood.) I don't really care what the cabinet looks like on the inside...

Thanks Ed -- removing the screw there and using its length is a great idea.

[S. Heisley]

edcasey wrote:

For length, I would remove the silver screw and see how long it is and then add on for the thickness of the board on the back of the cabinet that your screwing through.

Good One!

[S. Heisley]

I'd tap the hole with a drill first. The drill bit will undoubtedly be too long and if you drill too far, you'll drill through the wall all the way. So, tape the drill bit with masking tape at the depth that you want to go in so that you can see where you want to stop.

[S. Heisley]

Ageless wrote:

The stud finder reacts to the metal (nails, screws, braces) in wood studs. You have all metal and it's detecting everything

I've heard that and it is a possibility. However, I just tried using it in an area where I know there is a stud but no nearby metal screws or nails, etc. It still found the stud. (I don't have any all-metal walls or objects to try it on or I'd try that too.) I think it might be reacting to density(?).

[edcasey]

These are the screws I was talking about. By using these, you wont need drill bits (the end of the screw has a drill tip) and you don't have to worry about drilling too deep.

I probably use 200 of these a week.


Ed

[edcasey]

Ageless wrote:

The stud finder reacts to the metal (nails, screws, braces) in wood studs. You have all metal and it's detecting everything

I've heard that and it is a possibility. However, I just tried using it in an area where I know there is a stud but no nearby metal screws or nails, etc. It still found the stud. (I don't have any all-metal walls or objects to try it on or I'd try that too.) I think it might be reacting to density(?).

There are actually 3 types of stud finders. One is magnetic and finds nails (probably would not work), another checks the density of the wall with an electric signal that measures capacitance (should work for metal studs) and the third works very much like radar but can be pretty expensive (should also work).
Ed