Rare Earth Magnets as Inset Door Catches

Tips on using magnets as hidden door catches. October 27, 2009

Question
I'd like to try using some Rare Earth magnets for door catches on my flush inset cabinets. It's a paint job and I'd like to use them in the top and bottom of the door and the inside of the face frame, then bondo over them. I did some looking, and apparently, there are a zillion magnet sizes and strengths available. What's worked for you?

Forum Responses
(Cabinetmaking Forum)
From contributor P:
I've used them a couple of times. Lots of work, compared to regular magnet catches. 3/8 x 3/8 cylinder should work, depending on the size of the door. You want the neodymium magnets.

Use a magnet on the door, and a screw-in "cup" that's countersunk into the face frame. Make sure you get the polarity correct. Never tried the bondo idea. Might work.



From contributor U:
Don't use bondo. Anything you put between them will decrease their holding power. Just drill a tight hole and use silicone to hold them in place, but be careful with the silicone if you put them in before you paint. If you get the polarity wrong this will take a long time to correct. I put one in the bottom of the stile and one in the face frame. You also have to make small stops for the doors. On bigger doors you need to use more. The biggest problem is if any of your doors are bowed they will not give you any kind of holding power. All adjustments have to be made at the hinge. Install the magnets in your shop to make sure you get them in the right way or you might look like a dummy in front of your customer. Yes, this happened to me. No matter how careful you are, you will most likely get the polarity wrong. When this happens, drill a small hole in the bottom of the face frame and insert a small finish nail and tap it out. Using magnets takes a lot longer to install. I suggest doing a sample door and time it and adjust your price for the extra time. Using a template to mark the holes will speed up the process. They have a very nice fill and if installed right they will never fail.


From the original questioner:
Thanks. Have either of you ever tried using a conventional steel catch embedded in the door and having the magnet (perhaps a stronger one) just in the frame? Might solve the polarity problem. Just wondering.



From contributor A:
Lee Valley has been selling all kinds of magnets for years. They are super strong and cheap. Technically regular cabinet hinges are not too strong.

I doubt you would need top and bottom. I would think one placed on the bottom corner of the knob side, maybe 1 1/2 from the stile of your face frame. (Gives you enough room to get your cordless drill in there with running the chuck into the stile.)

You would only need 1/16 of an inch of bondo. I would drill a 1/4" whole then use a countersink to give the bondo some wood to grab onto besides the magnet. That plan would use a 1/4D x 3/4" long Rare Earth. You could screw a steel flat head screw flush on the bottom of the door.



From contributor U:
Yes, I have used a screw, and I even used a drywall nail, and they will hold the door in place. I did not like how the door held, though - it dos not give the same holding power that two magnets do. I suggest trying it to see how you think it feels. I think you will feel the difference I am talking about. I have tried drilling the hole deeper and then I put a small piece of wood over it to hide it, and the holding power was less than using either the nail or the screw. I did not try bondo so I can not give you any input on this matter. My reveal was never greater than 1/8 between the door and the face frame.

If you are trying to do this on the cheap, then only use one magnet. I think this is something that only you can tell by trying for yourself and then deciding what kind of a cabinet you want to sell to your customer. Holding the two magnets as close together as possible will give you the strongest holding power. It is a soft hold to begin with.

I'm guessing that the idea of using bondo over the magnet is so you can paint it. I have never tried to paint a magnet, but I'm sure that if you use the right primer it would hold paint just fine. If you are using a hinge with a self-closing spring, the magnet will be a waste of time, but I'm sure you already know this. I have used magnets on cabinets that had a clear finish so you could see them and did not mind how they looked at all. The customer liked it so much that they had me do this on all their cabinets. I did this on over 80 doors and in nine years I have never had any problems. And yes, I still talk to them. I ran short when I was installing them and bought some other magnets that were not Rare Earth. I thought this would not make that big of a difference, but I was wrong.

The stronger the magnet, the better the hold. There is a big difference, so make sure when you buy them you get the right ones and make sure that when you drill the hole it is a tight fit. If there is any wiggle, the magnet will not stay in. I tried different sizes and found that the 4 millimeter worked just fine.