I'm looking for a small supply (tens off) of large-ish washers, in brass or steel (solderable!). About the only critical thing is that the i/d of the thing should fit over a standard bayonet-cap lampfitting - about 29mm - o/d can be up to
50mm diameter - or even square. 2mm thick or thereabouts.
I know I can just get some brass sheet and q-max a hole in the middle (and it may yet come to that!) - but if anybody knows of an online mail-order supplier who deals in this sort of thing then that'd be great!
I found some steel ones in my local agri-co-op, but they're (predictably!) agricultural, and will need a bit of reaming / dremelling to make them fit...
I can't find those dimensions on any of the look-up tables I've been able to -erme- look up. Are you wanting to replicate something you have seen before (in which case you might try to find the engineering company that made the original product) or is this an original idea (in which case your assumption that you might have to do all the hard graft yourself could come true)?
Here's the detail.... I make stained-glass objects - mostly using the 'Tiffany' technique - where you cut the glass to size, wrap the edges with self-adhesive copper tape, and then solder.
Traditionally, lampshades are mounted to the lamp by means of a thing called a 'spider' - metal centre, three or four thin brass 'legs' and with a hole through the centre piece that mounts to the threaded section under the bayonet-cap lamp-fitting - before the lampholder is wired up.
This is all very fine, and works well for many cases.
However, I've been asked to make some smaller lampshades to fit on top of some cold-cast bronze lighthouses - these things are only about 6" tall and 3" or 4" diameter - so don't really need the traditional heavy-duty fixing. Also, it's be good for smaller lampshades, to be able to attach them in the same way as a conventional fabric shade - by means of a ring / washer fitted to the top of the bayonet lampholder, rather than to the base of the lampholder (which requires de-wiring / rewiring the lampholder.
So - there's the story. If I can find a source of 'washers' of the right size, then I can easily attach brazing-rod 'legs' to them by soldering, and everything's grand. Problem at the moment is finding a washer with a big enough internal diameter... and, if all else fails, I may have to fabricate something from thin brass sheet...
If there's a decent lampshade maker near you, they may be willing to sell you some ready made spiders. The last time I needed something like that I was in London, and the business I used has probably gone by now, unfortunately. They had a stock of "washers" with tabs on and spot welded the legs on while they were making the frames from what looked suspiciously like welding rod.
HI Bob I was hoping for a stockist of 'big washers' rather than a bespoke solution
My thought was that a brazing rod soldered to the flat part of a big washer would be stronger than if it was butt-soldered to a wire ring. Sadly, I don't do brazing / welding (though actually I could do silver-soldering... - but it's more hassle)
I can get the spiders with the 1/4" hole for mounting on the ferrule - no problem.... but fitting them to a pre-made lamp involves dismantling the lamp-holder
- which is tricky if it's somebody-else's manufacture. Also a hassle in a retail environment.... - whereas the other approach (fitting onto the bc bulbholder from above) would be easy to do...
We're out in the wilds of south-west Ireland - not aware of any lampshade manufacturers out here... which is why I was thinking 'washers'...
Google came up with a number of lampshade manufacturers with contact details in the UK, and the spider I was thinking of is one that will fit a BS bulbholder. Maybe Dublin and mail order?
Thanks for the suggestions - yes - the 'agricultural' ones I have are fairly 'meaty' (not that that's a big problem, though they'll nee more heat to solder them)
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.