Have some shed doors (identical to a normal solid wood front door) that i
want to simply remain closed by the use of magnets, when coming in and out a
lot.

The neatest way i can think of is using some of those strong magnets with
holes already in them screwed to the inside door frame at the top and with a
small length of wood screwed to the top inside face of the door raising
another magnet that meets up with the one on the top frame. Hope that's
clear.

I have tried those double quite strong cupboard magnets, the kind you can
get in B and Q type stores and i thought that they would hold, surprisingly
even a small wind just blows the door open.

I can buy the Neodymium (strong type) magnets with holes with a; 1.6, 2.4,
4.8, 5.6, or 9.8 kg pull strength. Any ideas on what strength you think I
should go for? Bearing in mind we dont want the door too sticky.

john brook wrote:
Have some shed doors (identical to a normal solid wood front door) that i
want to simply remain closed by the use of magnets, when coming in and out a
lot.

The neatest way i can think of is using some of those strong magnets with
holes already in them screwed to the inside door frame at the top and with a
small length of wood screwed to the top inside face of the door raising
another magnet that meets up with the one on the top frame. Hope that's
clear.

I have tried those double quite strong cupboard magnets, the kind you can
get in B and Q type stores and i thought that they would hold, surprisingly
even a small wind just blows the door open.

I can buy the Neodymium (strong type) magnets with holes with a; 1.6, 2.4,
4.8, 5.6, or 9.8 kg pull strength. Any ideas on what strength you think I
should go for? Bearing in mind we dont want the door too sticky.


Id go for size rather than flux density.

Try a pair of buggered loudspeakers - the ferrite mags in those and the
iron parts that go with them should be nearly all you need.

You can back off the stickiness by adding a layer between the mating
surfaces..bit of fablon etc, to fine tune it

"john brook" wrote in message
...
Have some shed doors (identical to a normal solid wood front door) that i
want to simply remain closed by the use of magnets, when coming in and out
a lot.

The neatest way i can think of is using some of those strong magnets with
holes already in them screwed to the inside door frame at the top and with
a small length of wood screwed to the top inside face of the door raising
another magnet that meets up with the one on the top frame. Hope that's
clear.

I have tried those double quite strong cupboard magnets, the kind you can
get in B and Q type stores and i thought that they would hold,
surprisingly even a small wind just blows the door open.

Not surprising really, even a small pressure difference on a surface the
size of a door results in a large force.
One psi will result in a force of about 65 kg per sq foot.
The magnets used to hold security doors shut apply about 400 kg force so
that gives you the upper limit.
The size of the smallest person will give you the lower limit.
Then fit a bolt and/or a door closer.

On Apr 14, 1:36*pm, The Natural Philosopher
wrote:

Id go for size rather than flux density.

Definitely. Nd are far "harsh" is used bare, and they're too small to
use at a distance. If you did use them, I'd be inclined to add iron
poles, just to spread the flux.

Try a pair of buggered loudspeakers

Agreed. Plenty strong enough and usually a better size.

Why a pair though? One and a good polepiece. I've got a couple of
magnetic door catches like this, either speaker magnets or microwave
oven magnetrons, covered with a layer of sticky neoprene foam as a
cushion.

On Apr 14, 1:30*pm, "john brook" wrote:
Have some shed doors (identical to a normal solid wood front door) that i
want to simply remain closed by the use of magnets, when coming in and out a
lot.

The neatest way i can think of is using some of those strong magnets with
holes already in them screwed to the inside door frame at the top and with a
small length of wood screwed to the top inside face of the door raising
another magnet that meets up with the one on the top frame. Hope that's
clear.

I have tried those double quite strong cupboard magnets, the kind you can
get in B and Q type stores and i thought that they would hold, surprisingly
even a small wind just blows the door open.

I can buy the Neodymium (strong type) magnets with holes with a; 1.6, 2.4,
4.8, 5.6, or 9.8 kg pull strength. *Any ideas on what strength you think I
should go for? Bearing in mind we dont want the door too sticky.


Forget it, seasonal movement and vibration will make this work badly
unless you use excessive magnetic forces. Go instead for a roller
catch, which will keep it closed with the same force regardless of
these factors.


NT

On Apr 14, 1:30*pm, "john brook" wrote:
Have some shed doors (identical to a normal solid wood front door) that i
want to simply remain closed by the use of magnets, when coming in and out a
lot.

The neatest way i can think of is using some of those strong magnets with
holes already in them screwed to the inside door frame at the top and with a
small length of wood screwed to the top inside face of the door raising
another magnet that meets up with the one on the top frame. Hope that's
clear.

I have tried those double quite strong cupboard magnets, the kind you can
get in B and Q type stores and i thought that they would hold, surprisingly
even a small wind just blows the door open.

I can buy the Neodymium (strong type) magnets with holes with a; 1.6, 2.4,
4.8, 5.6, or 9.8 kg pull strength. *Any ideas on what strength you think I
should go for? Bearing in mind we dont want the door too sticky.

I'd buy the biggest. you an always mount them slightly offset to
reduce the pull.

Robert

On 14/04/2011 13:30, john brook wrote:
Have some shed doors (identical to a normal solid wood front door) that i
want to simply remain closed by the use of magnets, when coming in and out a
lot.

Fit a door closer. It will shut the door for you & hold it closed - you
can adjust the force. You can pick them up for a £10
http://www.toolstation.com/shop/Clea.../sd2599/p58488


--
Dave - The Medway Handyman www.medwayhandyman.co.uk

In message , john brook
wrote
I can buy the Neodymium (strong type) magnets with holes with a; 1.6, 2.4,
4.8, 5.6, or 9.8 kg pull strength. Any ideas on what strength you think I
should go for? Bearing in mind we dont want the door too sticky.


If you have an old computer hard disk take it apart and get the magnets

--
Alan
news2009 {at} admac {dot} myzen {dot} co {dot} uk

On Apr 14, 6:34*pm, The Medway Handyman
wrote:
On 14/04/2011 13:30, john brook wrote:

Have some shed doors (identical to a normal solid wood front door) that i
want to simply remain closed by the use of magnets, when coming in and out a
lot.

Fit a door closer. *It will shut the door for you & hold it closed - you
can adjust the force. *You can pick them up for a £10http://www.toolstation.com/shop/Clearance/Safety+Security/DoorMate+Do...

Most door closers limit door speed to such a low value that they're an
unmitigated pita when you're going through frequently. Avoid.


NT

"Tabby" wrote in message
...


Most door closers limit door speed to such a low value that they're an
unmitigated pita when you're going through frequently. Avoid.

Most door closers are adjustable, RTFM.

On Apr 14, 7:38*pm, Tabby wrote:

Most door closers limit door speed to such a low value that they're an
unmitigated pita when you're going through frequently. Avoid.

Only the top mounted ones. The cheapies that mount in the middle of
the hinge side are pure springs, no dampers, so they don't slow
closing at all.

Andy Dingley wrote:

On Apr 14, 7:38 pm, Tabby wrote:

Most door closers limit door speed to such a low value that they're an
unmitigated pita when you're going through frequently. Avoid.

Only the top mounted ones. The cheapies that mount in the middle of
the hinge side are pure springs, no dampers, so they don't slow
closing at all.

The hinges I've seen had a further advantage of being adjustable but taking
a peg out, torquing it up and reinserting peg.

The lack of dampers can be a problem though - lots of door banging unless
you set the thing on the weak side.

--
Tim Watts

On 14/04/2011 20:06, Tim Watts wrote:
Andy Dingley wrote:

On Apr 14, 7:38 pm, wrote:

Most door closers limit door speed to such a low value that they're an
unmitigated pita when you're going through frequently. Avoid.

Only the top mounted ones. The cheapies that mount in the middle of
the hinge side are pure springs, no dampers, so they don't slow
closing at all.

The hinges I've seen had a further advantage of being adjustable but taking
a peg out, torquing it up and reinserting peg.

The lack of dampers can be a problem though - lots of door banging unless
you set the thing on the weak side.



Didn't anyone follow the piggin link?



--
Dave - The Medway Handyman www.medwayhandyman.co.uk

Andy Dingley wrote:

On Apr 14, 7:38Â*pm, Tabby wrote:

Most door closers limit door speed to such a low value that they're an
unmitigated pita when you're going through frequently. Avoid.

Only the top mounted ones. The cheapies that mount in the middle of
the hinge side are pure springs, no dampers, so they don't slow
closing at all.

I've had these cheap ones fail in less than a year from frequent use, the
spring gradually chafes it's way through the pot metal like housing.

AJH

On Thu, 14 Apr 2011 18:48:54 +0100, Alan wrote:
In message , john brook
wrote
I can buy the Neodymium (strong type) magnets with holes with a; 1.6, 2.4,
4.8, 5.6, or 9.8 kg pull strength. Any ideas on what strength you think I
should go for? Bearing in mind we dont want the door too sticky.


If you have an old computer hard disk take it apart and get the magnets

Done that.
I used a couple to hold the kitchen door _open_
Briefly: one magnet on the body of the door handle, another on into a wooden
stop attached to the wall. Cut a piece of plastic eraser and attach
to the wooden stop above or below the magnet. Adjust the depth of the eraser
so that the magnets don't quite touch.

The only hard bit was finding an adhesive to hold the magnets in
place. Epoxy doesn't last - too brittle. Stixall is the current
goop of choice. It has a certain amount of natural flexibility
and sticks well to the ceramic magnets, the aluminium door handle
and the wooden stop.

On Apr 14, 11:26*pm, The Medway Handyman
wrote:

Didn't anyone follow the piggin link?

Yes, those top-mount Ryobi things are rubbish (see other post about
wanting Toolstation to sell better quality parts). I put four of them
in Dad's place, they all failed within a year. The damper mechanism
was OK but the joints in the arms were so badly made. The common fault
was the riveted pin working loose in the arm, which I guess I could
fix by welding.

The two that were really needed, I replaced with centre-mounted simple
spring closers.

re this thread, they were at least adjustable for closing speed.

On Apr 15, 8:49*am, root wrote:

The only hard bit was finding an adhesive to hold the magnets in
place. Epoxy doesn't last - too brittle.

I use polyurethane panel sealer (like silicone, but extra sticky). The
stuff only lasts a month once the tube is opened, so if I've had to
buy one (usually waterproofing vehicle or boat panels) it gets used
for everything afterwards. It works well as an extra-flexible glue, so
long as you don't mind a thick fillet.

On Fri, 15 Apr 2011 03:17:49 -0700 (PDT), Andy Dingley wrote:
On Apr 15, 8:49?am, root wrote:

The only hard bit was finding an adhesive to hold the magnets in
place. Epoxy doesn't last - too brittle.

I use polyurethane panel sealer (like silicone, but extra sticky). The
stuff only lasts a month once the tube is opened, so if I've had to
buy one (usually waterproofing vehicle or boat panels) it gets used
for everything afterwards. It works well as an extra-flexible glue, so
long as you don't mind a thick fillet.

I also tried PU (Gorilla glue), but that had the same drawbacks as epoxy.
There does seem to be a benefit in having a slight flexibility in the
adhesive.

On Apr 14, 1:30*pm, "john brook" wrote:
Have some shed doors (identical to a normal solid wood front door) that i
want to simply remain closed by the use of magnets, when coming in and out a
lot.

The neatest way i can think of is using some of those strong magnets with
holes already in them screwed to the inside door frame at the top and with a
small length of wood screwed to the top inside face of the door raising
another magnet that meets up with the one on the top frame. Hope that's
clear.

I have tried those double quite strong cupboard magnets, the kind you can
get in B and Q type stores and i thought that they would hold, surprisingly
even a small wind just blows the door open.

I can buy the Neodymium (strong type) magnets with holes with a; 1.6, 2.4,
4.8, 5.6, or 9.8 kg pull strength. *Any ideas on what strength you think I
should go for? Bearing in mind we dont want the door too sticky.

Velcro ?