RFQ : Custom Erasing Shield Wanted

[ukchris]

Hi!

I'm wondering if this is the right place to ask, I'm looking to have a custom erasing shield made. It would be a small piece of thin metal similar to this http://www.pearlpaint.com/shop~ocID~...oryID~1965.htm but with cutouts according to a template I would provide for the cutting.

The metal should not be thick in fact the thinner the better but it needs to be reasonably robust, I would want to cut around the edges or use a fine polisher "through" it using the sheet as a mask so to speak.

Overall it need only be a few inches wide.

Any tips, suggestions or people that can help would be most welcome!

Thanks,

Chris.

[NC Cams]

Pretty much anybody with a laser cutter should be able to do it for you.

Simply provide them with a DXF file of the shape you want cut, tell them to cut it out of sheets of the thinnest shim stock they have which would be 0.0015".

You might want to have it made out of something a bit thicker like 0.005" or 0.010"

[ukchris]

Thanks NC, do you have any idea how much I'd expect to pay? The image of the erasing shield I posted would be similar to what I'd need just different shapes. The overall piece would be about 4" x 3" at most and as you say, cut from thin stock.

I am waiting for a response from a commercial waterjet place but their minimum order is $75 I believe.

[NC Cams]

ANY work done by a laser shop is on a minimum amount basis. $50~$75 is about the norm PER PART NUMBER.

You'll probably be able to buy 5 or 10 for the nearly the same price as 1 as the first one is where the set-up costs get you.

We had some spring steel shims cut out of 0.015 recently. DEFINITELY use laser on the thin stuff for a cleaner, more distortion free cut.

As pricey as they are, you can't cut them our as accurately nor as quickly as the laser zapper can. Sometimes, you just have to wince and pay for the technology.

[ukchris]

Thanks for the info, I really had no clue what price range these things would be in. Maybe someone will post some specifics and I can firm things up. The actual pattern I need is less than 2" x 1" so Imay be able to have several cuts of the same thing done as I'm sure it'll wear over time.

Thanks again.

[tobyaxis]

Originally Posted by ukchris Thanks for the info, I really had no clue what price range these things would be in. Maybe someone will post some specifics and I can firm things up. The actual pattern I need is less than 2" x 1" so Imay be able to have several cuts of the same thing done as I'm sure it'll wear over time. Thanks again.

As a Draftsman I used these all the time. They have a tendancy to fold and get deformed pretty easy. How long do you plan on using them with so many CAD systems in circulation? I only say this because as it may be cheaper for you to buy these "as is" through a Drafting Supply Warehouse. $75 dollars each seems steep for something that can be replaced fairly cheap.

Unless you are going to be selling a better one yourself?

[ukchris]

Originally Posted by tobyaxis As a Draftsman I used these all the time. They have a tendancy to fold and get deformed pretty easy. How long do you plan on using them with so many CAD systems in circulation? I only say this because as it may be cheaper for you to buy these "as is" through a Drafting Supply Warehouse. $75 dollars each seems steep for something that can be replaced fairly cheap. Unless you are going to be selling a better one yourself?

I am removing the backing on a mirror in a specific design using a dremmel and an erasing shield at the moment. Piecing together my design using the shield is a pain so I thought if I had one custom made it'd be much, much easier.

Now I just need to get one cut without breaking the bank

[tobyaxis]

Originally Posted by ukchris I am removing the backing on a mirror in a specific design using a dremmel and an erasing shield at the moment. Piecing together my design using the shield is a pain so I thought if I had one custom made it'd be much, much easier. Now I just need to get one cut without breaking the bank

There are thin scrappers made for that sort of thing. They come in all different sizes and I beleave a Hardware Store could supply you with a better too than that. Try ACE, LOWES, Home Depot, and True Value websites. You won't spend $75.00 either.

[ukchris]

Originally Posted by tobyaxis There are thin scrappers made for that sort of thing. They come in all different sizes and I beleave a Hardware Store could supply you with a better too than that. Try ACE, LOWES, Home Depot, and True Value websites. You won't spend $75.00 either.

The shapes I want to etch are less than 1/4" in places, very hard to scrape. Also scraping doesn't seem to bring the mirroring off too well, it either leaves traces or scratches the glass. The polisher on a dremmel works well but it's hard to stay accurate without the shield.

Thanks for the suggestions though. I also tried paint stripper which I was told would lift the mirror coating... it didn't though.

[tobyaxis]

Originally Posted by ukchris The shapes I want to etch are less than 1/4" in places, very hard to scrape. Also scraping doesn't seem to bring the mirroring off too well, it either leaves traces or scratches the glass. The polisher on a dremmel works well but it's hard to stay accurate without the shield. Thanks for the suggestions though. I also tried paint stripper which I was told would lift the mirror coating... it didn't though.

Sorry I was thinking of something else. You have a specific application . NC Cams is right. A laser will make what you need. Though I don't have one.

Try posting this in the RFQ area of CNC Zone. Lots of talented guys will answer with quotes for you. Just not me because This Is The RFQ Sorry There seems to be a taste of feet in the mouth. YUK!

Good Luck

[Geof]

You tried paint stripper and found it did not lift the mirror coating which is to be expected; the mirror coating is either silver or aluminum. Many times it is covered with a coat of paint to protect it and all you will do is remove the paint.

However I Googled "stripping silver from mirror" and found this; "Most decent stained glass shops carry two-part mirror stripping kits, The two part chemical system consists of a paint remover that liquidizes the paint surface (which you must then remove; not always easy and very caustic process) but leaves the copper/mirror layer intact; and then a second stripper that will dissolve the two metal layers, leaving you with perfectly clear glass, no frosting like from acid or sandblasting. You can control the stripping pattern by using any masking material that is impervious to chemicals, anything from white glue to electrical tape to proper sandblast resists. That way you can selectively remove a window area in the middle of the mirror, or pinstripes, text, a pattern, whatever."

If the mirror is aluminized you should also be able to remove it chemically. Aluminum can be dissolved in an alkaline solution; Sodium Hydroxide or 'Drano'. This will also dissolve you so protective equipment is needed. A slightly less alkaline solution is ammonium hydroxide whic is often used for stripping wax from floors.

You might find a combination of chemical and mechanical methods works best. I would not suggest using your Dremel because electricty and water solutions are a bad mix but it might be worth your while looking into a high speed air grinder and using it in combination with a chemical method.

[ukchris]

Great info Geof, thanks, off to search for a Stained Glass shop near by..!!

My local craft store has widow etching stuff but nothing to remove the mirroring. Although as I think about it masking might be as big an issue as having atemplate made, the design is a bit intricate in places.

I'll definately look in to it though, thanks.