Magnetic Gnomon Attachment
Hello All: Two weeks ago, I attached the gnomon to my bay window stained glass sundial.In the original prototype, I had used a brass baseplate adhered to the outer protectiveglass with silicone. But this baseplate was a little ugly becauseyou could see itbehind thepainted sunnface piece in the sg panel.So instead,Iepoxied therod sheet gnomon to a 3" square piece of clear glass and then siliconed it to the outer protective pane. The edges ofthe baseplateline up with the lead came sothe baseplate isinvisible from inside the room. (you can see new photos on the SGS website). Anyway, I've been thinking that for some future project, that it would be possible to attach the gnomon to the SGS using a magnet. If a piece of stainless steel were in the stained glass design, and if the gnomon baseplate were a magnet (or vias versa), then you could secure the gnomon to the SGS without fear that it could crack the glass. If somebody bumped into the gnomon, it would simply fall off, avoiding any damage to the glass. If you have a double-paned window, you could glue the magnet to the inside or outside of the outer protective pane. Nobody has used this method, but I think it might work. (you could do the samefor atable-top analemmatic to keep the gnomon in place during high winds). John John L. CarmichaelSundial Sculptures925 E. Foothills Dr.Tucson AZ 85718-4716USATel: 520-6961709Email: [EMAIL PROTECTED] Websites:Sundial Sculptures: http://www.sundialsculptures.comStained Glass Sundials: http://www.stainedglasssundials.com
Re: Magnetic Gnomon Attachment
From: [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Tuesday, February 01, 2005 11:36 AM Subject: Re: Magnetic Gnomon Attachment John, is Stainless Steel magnetic? - Bill No, but the magnet is. And a magnet will attract it. Of course, insead of one piece of steel and one magnet, you could use two magnets for double the holding strength! What neat is that the magnet will aslo work at a distance, THROUGH the glass! In a message dated 2/1/2005 1:33:33 PM Eastern Standard Time, [EMAIL PROTECTED] writes: If a piece of stainless steel were in the stained glass design, and if the gnomon baseplate were a magnet (or vias versa), then you could secure the gnomon to the SGS without fear that it could crack the glass. -
Re: Magnetic Gnomon Attachment
John, Bill is right to query this - a magnet won't attract non-magnetic stainless steel (by definition!). I think there may be varieties of stainless whichARE ferromagnetic but the attraction may not be as strong as ordinary steel. Regards, John --John Carmichael [EMAIL PROTECTED] wrote: - Original Message - From: <[EMAIL PROTECTED]>To: <[EMAIL PROTECTED]>Sent: Tuesday, February 01, 2005 11:36 AMSubject: Re: Magnetic Gnomon Attachment John, is Stainless Steel magnetic? - BillNo, but the magnet is. And a magnet will attract it.Of course, insead of one piece of steel and one magnet, you could use two magnets for double the holding strength!What neat is that the magnet will aslo work at a distance, THROUGH the glass!Dr J R DavisFlowton DialsN52d 08m: E1d 05m
Re: Magnetic Gnomon Attachment
You learn something new every day! I didn't know about the different stainless steels, but you are right. A magnet does not stick to our kitchen sink. But you could use regular steel that's plated, anodized or pained to prevent rusting. I wonder if you can electroplate a magnet? John - Original Message - From: JOHN DAVIS To: John Carmichael ; [EMAIL PROTECTED] Cc: Sundial List Sent: Tuesday, February 01, 2005 12:02 PM Subject: Re: Magnetic Gnomon Attachment John, Bill is right to query this - a magnet won't attract non-magnetic stainless steel (by definition!). I think there may be varieties of stainless whichARE ferromagnetic but the attraction may not be as strong as ordinary steel. Regards, John --John Carmichael [EMAIL PROTECTED] wrote: - Original Message - From: <[EMAIL PROTECTED]>To: <[EMAIL PROTECTED]>Sent: Tuesday, February 01, 2005 11:36 AMSubject: Re: Magnetic Gnomon Attachment John, is Stainless Steel magnetic? - BillNo, but the magnet is. And a magnet will attract it.Of course, insead of one piece of steel and one magnet, you could use two magnets for double the holding strength!What neat is that the magnet will aslo work at a distance, THROUGH the glass!Dr J R DavisFlowton DialsN52d 08m: E1d 05m
Re: Magnetic Gnomon Attachment
John Carmichael commented; Anyway, I've been thinking that for some future project, that it would be possible to attach the gnomon to the SGS using a magnet. Perhaps you should consider using the new 'rare earth magnets'. These are available in a variety of sizes but the tiny discs have phenomenal attractive power. A pair face to face are extremely difficult to separate with fingers. They are not expensive and are worth buying just to experience their astonishing attractive force as plaything/curiosities. http://www.rare-earth-magnets.com/ has some details but a Google search will give lots of info. Tony Moss. -
ENC: Magnetic Gnomon Attachment
Dear All, I was thinking about the effect of high temperature on the magnet. I know that very high temperatures can destroy the magnetic power, but what about temperatures around 35 or 40ºC, day after day? Vanderlei Borsari 23.5 S 46.5 W -Mensagem original- De: JOHN DAVIS [mailto:[EMAIL PROTECTED] Enviada em: terça-feira, 1 de fevereiro de 2005 16:03 Para: John Carmichael; [EMAIL PROTECTED] Cc: Sundial List Assunto: Re: Magnetic Gnomon Attachment John, Bill is right to query this - a magnet won't attract non-magnetic stainless steel (by definition!). I think there may be varieties of stainless which ARE ferromagnetic but the attraction may not be as strong as ordinary steel. Regards, John -- John Carmichael [EMAIL PROTECTED] wrote: - Original Message - From: To: Sent: Tuesday, February 01, 2005 11:36 AM Subject: Re: Magnetic Gnomon Attachment John, is Stainless Steel magnetic? - Bill No, but the magnet is. And a magnet will attract it. Of course, insead of one piece of steel and one magnet, you could use two magnets for double the holding strength! What neat is that the magnet will aslo work at a distance, THROUGH the glass! Dr J R Davis Flowton Dials N52d 08m: E1d 05m -
Re: ENC: Magnetic Gnomon Attachment
The temperature above which demagnetization occurs is called the Curie point. This is listed for many materials. For example, it can be as low as 25 deg C for monel (nickel copper alloys) to as high as 1121 C for cobalt. Nickel-iron alloys are in the range 300-500 C; iron is 770 C. I think that temperatures well under the Curie point will not demagnetize even after long periods. Gordon At 12:19 2/1/05, Vanderlei Borsari wrote: Dear All, I was thinking about the effect of high temperature on the magnet. I know that very high temperatures can destroy the magnetic power, but what about temperatures around 35 or 40ºC, day after day? Vanderlei Borsari 23.5 S 46.5 W -
Re: Magnetic Gnomon Attachment
ferromagnetic and would not provide much attractive force to a magnet; when they are cold-worked, as in rolled sheet, they are only slightly ferromagnetic but would still not provide sufficient magnetic attractive force for this approach to be successful. Some 400-series stainless steels are ferromagnetic, but those that are also rust slightly and are not what you would call stainless. Another approach would be to place a painted steel plate on the inside of the glass. If you then use a coated (anti-corrosion) rare-earth magnet on the gnomon, there would still be significant attractive force through the glass. Neodymium-iron-boron magnets give you the best attractive force for the cost; samarium-colbalt magnets can be stronger but cost substantially more due to the limited availability of cobalt (not the samarium). Or, the magnet could be on the inside and the steel plate on the outside. Larry McDavid John Carmichael wrote: snip Anyway, I've been thinking that for some future project, that it would be possible to attach the gnomon to the SGS using a magnet. If a piece of stainless steel were in the stained glass design, and if the gnomon baseplate were a magnet (or vias versa), then you could secure the gnomon to the SGS without fear that it could crack the glass. If somebody bumped into the gnomon, it would simply fall off, avoiding any damage to the glass. -- Best wishes, Larry McDavid W6FUB Anaheim, CA (20 miles southeast of Los Angeles, near Disneyland) -
