Plantation shutters and rare earth magnets

[Dell Littlefield]

I am going to build some plantation shutters and am toying with the idea of using rare earth magnets instead of hinges to hold them in place . I figure the only time the shutters would be opened would be for cleaning and they could be easily removed and installed with just a tug. Whadda ya think? Would this work?

[Doug Shepard]

I dont think I'd personally want to trust them to hold. You'd have to get some pretty darn big ones (Kaching$) to support shutters and hope they hold up to wind gusts. Then there's your proximity to the Bermuda Triangle. Some freak event could cause your mags to go wonky.:D

[Brad Knight]

Hello... I've been a lurker around here for a few weeks...

If you'd like some very strong magnets... cheep... (who doesn't like cheep), I'd look on ebay for a lot of hard drives. People are always selling hard drives without the electronics for repair or whatever. They have tremendously strong magnets inside. It takes a little manual labor to open the cases, but if you're looking for good magnets... I can't think of a cheaper way to get them.

[Russ Filtz]

I've taken apart HD's before. At least the kind I did (western Digital) the magnets were kind of arc shaped and seemed to be bonded to a larger steel piece (or so strong I couldn't get them off!). They definitely are strong, but the shape is kind of non-useful, other than tacking something up to a wall.

[Kim Spence]

I'm curious to hear what others have to say on the topic of Rare Earth magnets. I used them in a small project (which by the way will be featured in the next issue of Woodcraft magazine) and wondered about using larger ones for various uses in woodworking.

I think it would be interesting to create a piece of furniture that uses magnets instead of mechanical fasteners/joinery. I'd do it for the novelty of it, not because its necessarily a good way to build furniture :)

The larger ones have incredible holding power. A 1" round 1/8" thick requires about 60 lbs of force to separate and can be purchased for just $2 each or even less if you buy quantity. Larger magnets can hold hundreds of pounds, but get pretty expensive, are hard to work with around cast iron machinery, and can be dangerous.

I found a good source for magnets at http://www.kjmagnetics.com. I'm not associated with them in any way, but I've ordered through them and their prices and service are good. Prices WAY lower than local woodworking sources for small magnets.

[Kyle Stiefel]

Dell,
I am not sure if you are talking about indoor plantation shutters, size etc. I have used rare earth magnets from lee valley (all different sizes) to hold covers over my panel boxes which are about 20x36 with no problem but then again there would never be a chance of wind blowing through this etc. unless there was a much bigger problem. You can get the rare earth magnets of incredible strenght, I just use epoxy to attach them to the wood. Don't know if that helps at all.

Kyle

[Dell Littlefield]

Thanks Kyle. I also have used some from Lee Valley and that is what prompted the idea. I use a 1/4 inch magnet to hold the blade changing wrench on my table saw and the two bit changing wrenches on the router table.

I think the indoor plantation shutters would be suspended using 2 or 3 on each side. The fit would have to be nearly perfect. There wouldn't be a wind problem because the windows are nearly always left closed.

Doug, Thanks for the reminder about the Bermuda triangle. Since it starts about 500 miles away, I have found it has very little influence. I get more vibes from the spicy New Orleans food. It is much closer.

[Dan Stuewe]

One thing to keep in mind with magnets is that while they can be very strong in the pulling off direction, in shear (or sliding) they are much weaker. Also, their strength diminishes greatly (exponentially?) with distance. If you want to use them as joinery, be very careful of how the item will be loaded (little kids around?). Seemingly light loads can break the magnets apart if applied in a sudden way (shock). Please don't take any of this as dismissing using magnets, just keep in mind what they can and can't do in your design.

[Dell Littlefield]

Thanks Dan, I think the rails may limit the size of the magnet too much to use in this application but I guess I hoped to be wrong in that regard. As I mentioned above the fit would have to be very good. Appreciate your comments.

[Brad Knight]

I've taken apart HD's before. At least the kind I did (western Digital) the magnets were kind of arc shaped and seemed to be bonded to a larger steel piece (or so strong I couldn't get them off!). They definitely are strong, but the shape is kind of non-useful, other than tacking something up to a wall.

They're just that strong... all it would take would take would be a relatively small piece of steel on either side w/ the magnet between.

[Mike Forsman]

Dell,

I made and installed my own plantation shutters. Most of the ones in the house were installed using hinges. Since my garage faces the street and it has two windows in it, I made plantation shutters for those windows too. I could not use a hinge on one of the windows due to the garage door rail being in the way. So, I used magnetic door catches that can be purchased at one of the big box stores. I used two at the top and one on each side of the bottom of the window. They hold just fine and I have never had a problem with them falling off. It takes a good tug to get them loose.

I think I would consider all of the different factors about your home and everyone that might interact with the shutters. In my garage (also my shop) there is only me that uses that space much. While my children are older now, it will not be too many years until I have grandchildren in the house. I would not want one of the shutters to come down and land on top of a small child due to an tug that pulled it down on top of them. Some of the larger shutters can get quite heavy.

[Chris Schoolland]

Dell,

Some sort of orientation pins (SS lag bolts, heads cut off and rounded, for example) would line the magnets up as well as support all the weight eliminating the shear problem.

Twisting of the shutter would be something to watch out for.

A rubber layer between the magnets would be smart, because those babies chip and corrode, and whatever iron they inevitably pick up will rust.

CHRIS

[Dell Littlefield]

Good points Chris, while I was looking at the Lee Valley website, I noticed they were selling some high friction discs to go between the magnets and discs: http://www.leevalley.com/wood/page.aspx?c=2&p=32066&cat=1,42363,42348

The magnets may not be the best solution. Our thinking was to eliminate hinges and to devise some method of fitting the shutters in place by just lifting them in and out. In our application, the only time the shutters will be open is when the windows were being cleaned. Some other hardware may be more appropriate. Thanks for your input. Dell

[Scott Rader]

I'm curious to hear what others have to say on the topic of Rare Earth magnets. I used them in a small project (which by the way will be featured in the next issue of Woodcraft magazine) and wondered about using larger ones for various uses in woodworking.

I think it would be interesting to create a piece of furniture that uses magnets instead of mechanical fasteners/joinery. I'd do it for the novelty of it, not because its necessarily a good way to build furniture :)

The larger ones have incredible holding power. A 1" round 1/8" thick requires about 60 lbs of force to separate and can be purchased for just $2 each or even less if you buy quantity. Larger magnets can hold hundreds of pounds, but get pretty expensive, are hard to work with around cast iron machinery, and can be dangerous.

I found a good source for magnets at http://www.kjmagnetics.com. I'm not associated with them in any way, but I've ordered through them and their prices and service are good. Prices WAY lower than local woodworking sources for small magnets.

I used them on a recent project (chess/ backgammon and cribbage board set) that I made out of walnut and maple. They work very well.

I'll post pictures later.

[Paul Dwight]

We have plantation shutters as the indoor window treatments on a bunch of our windows. They are hinged. We swing the shutters open quite often to open and close the windows. Something you might want to think about.

[Dell Littlefield]

Now that's what I was looking for----someone with experience! I have used the magnetic cabinet latches in the past and although they have a lot of strength, I think they are considerably weaker than the rare earth magnets. The windows in this particular house are rarely opened so a lift off of some kind would be fine. I think I am going to order some and give them a try. Thanks for the information. Dell

[Tim Sproul]

I use rare earth magnets as door catches without stops....and I'm in the midst of a project doing this. No need for friction discs or such. bury the magnets in holes, then plug the hole with some wood. Lee Valley tapered plug cutters are fantastic.

For you application, you don't need much magnetic holding power. Instead, rely on some mechanical interlocking to prevent unwanted falling of the shutter and the magnets just need to keep the shutters from rattling around when a truck drives by or someone bangs into the wall.

Groove the top of the window frame. Rabbet the top of the shutter to fit in the groove. Slide shutter up into groove, drop down onto sill and let the magnets hold things together. I think this conveys the idea. There are different ways of doing this to make it even more secure such as a hidden french cleat in the groove space or making a shallow groove at the sill and a similarily shallow rabbet on the bottom of the shutter...etc.