Detectors On Galvanised Steel Window Frames

[hensoa]

Does anyone have any sugestion as to the best way to fix magnetic switches and shock sensors to galvanised steel (Crittal) window frames.

There is little depth to accept a self tapper and this would damage the integrity of the galvanising. Drilling, tapping and bolting would take an awful long time. I am thinking of thouroughly cleaning switch and frame and glueing with araldite.

Thanks

[Guest old-hand]

Does anyone have any sugestion as to the best way to fix magnetic switches and shock sensors to galvanised steel (Crittal) window frames.

There is little depth to accept a self tapper and this would damage the integrity of the galvanising. Drilling, tapping and bolting would take an awful long time. I am thinking of thouroughly cleaning switch and frame and glueing with araldite.

Thanks

Being a fully trained locksmith as well as an alarm installer and maintainer your problem simply isnt one.

Drill and use the appropriate self tapping screws, if needed use a galvanise spray to cover the exit points.

As for "glueing" what are you sticking it to, paint or the "galv" either way its only as strong as the adhesion of the covering material.

As for drilling and bolting through, this might stop the closure of the windows/doors, as you have realised they are not the best medium to work with.

Personally drill and self tappers are the way.

[Fred555]

I have done this before - it is not too bad a little fiddly though.

Self tapping screws are the way to go - use some engine oil on the drill bit tip while drilling it generally speeds things up then a little on the screw thread - if that then gets stuck use a new self tapping screw and generally you will be able to cut the thread relatively easily - if the head snaps off the screw clamp a drill chuck onto the remaining part of the screw and undo it with that then use another screw.

Obviously do not try and screw into the thickest part of the frame (ie where the metal profile edge turns through 90 degrees on a corner if you see what I mean) and also get a box of the smallest suitable (6ga. I think I used) screws plus a brand new cobalt HSS drill bit speeds things up greatly. Center punch first then drill - stops sliding.

[spider]

Just reminded me of a nightmare job, 330 contacts, we could not drill as the client was a leaseholder and at the end of tenancy everything had to be returned to prior ocupation standard.

We used an epoxy adhesive, using IPA wipes to degrease the surface first, you must ensure that you use aluminium shims or other non ferrious material beneath the magnet otherwise you might end up with poor contact performance or worse residual magantism in the frame and the contact fails to operate!

Where possible we fitted the contacts inside 16 x16 trunking as it made the job very neat, especially when finished with decorators chalking, vipers were mounted parallel to the trunking, again bonded to the frame.

Good luck

[Fred555]

We used an epoxy adhesive, using IPA wipes to degrease the surface first, you must ensure that you use aluminium shims or other non ferrious material beneath the magnet otherwise you might end up with poor contact performance or worse residual magantism in the frame and the contact fails to operate!

Good point - put a shim under the reed as well in case the frame gets magnetised.

[james.wilson]

just use g3 contacts and it wont be an issue

[Fred555]

De-rate reed operating gap by 50% for all ferrous mounting surfaces ie steel