Cutting Plate Brass

[tallen84]

Has anyone tried cutting brass in thicknesses up to 1/4" with their shopbot? I think I should be able to as long as I take dozens of passes. Any thoughts?

*What I am trying to do is make a sign with lettering that has either a polished brass or polished chrome finish. I first tried making it out of thin brass sheet (like 0.02" thick, however, it ended up getting caught multiple times by people walking by (it is on the side of a boat in a walkway). The brass bent off the HDU foam raised backing. I am hoping that by going thicker that the brass wont be as easily caught. I attached a picture of the sign before it was damaged so you can see what I am trying to do. Thank you for the help.

13885

13884

[shoeshine]

Yup.

I cut brass all the time. I regularly cut .090" but I have done up to 3/8". Just get bits designed for non ferrous machining. I run an 1/8" 2 flute bit about .3 -.5 in/sec @ 12k rpm, .02" passes. I find a tapping lubricant to help the cut immensely.

and be sure to ramp into every (and I mean every) cut.

GL and holler back if you have any other questions.

Chris

[letterman7]

Does it need to be brass? That's just higher maintenance on a boat.. and really, you're taking a chance mounting it to HDU just with an adhesive. Why not simply gild the letters and not worry about people rubbing against it and pulling the pieces off? Or, find your local sign distributor and ask them to order in a sheet of gold anodized aluminum. It'll only be .040, but much easier to mill and less expensive to purchase. If you recess the letters a little on the sign it may make it a little less attractive to passing fabric.

[steve_g]

Would Diebond work?

Steve

[mikeacg]

I would check out some of the Rowland products. They may have an exterior product that would look like brass and be a lot easier to work with!

Mike

[tallen84]

It does not have to be brass, it needs to be a metallic finish with high reflectivity. I was also looking into some kind of chrome finish. I am definitely open to some suggestions as cutting brass that thick can be very expensive.

[letterman7]

If you finish the hdu properly, a true 23kt gild can't be beat. There isn't a true chrome (outside of the actual metal plating) that can be reliably used on anything other than metal that I'm aware of. Even some of the chrome paints - and I have some of the best - need a topcoat that dulls the finish. If you have people catching the edges as they walk by, a re-think of how this sign is created needs to be done. Methinks a flat surface with the letters and border recessed and filled would work much better and be less of a hassle to keep clean. You could easily inlay a piece of the anodized gold aluminum into either hdu or 1" pvc (my choice for marine environments) and have it look great.

[Brady Watson]

Would Diebond work?

Steve

Good question...Todd?

If you haven't checked out DiBond, it comes in all kinds of metallic shiny or brushed finishes. It cuts easy & looks great.

-B

[tallen84]

Steve / Brady,
I haven't tried Dibond, I actually do not have any experience with it.

Is there a good place to find out what finishes are available and how much it typically costs?

Rick,
I also do not have any experience with using gold leaf. All I know about it is what I have read in a few forums. I was wondering, wouldn't the seams show between the different gold pieces where you start and stop with a new gold sheet? Also, how smooth does the finish look?

[Brady Watson]

Dibond comes 4mm in 4X8' sheets and larger. Plain white is around $100. I just paid $160 for brushed AL. You could get a lot of signs out of one sheet.

-B

[steve_g]

Todd

My local supplier (Allied Plastics) will sell me any size partial sheet I need. It looks like a name change or ownership has changed since I last bought some, my samples say "Alcan Composites" while a web search seems to indicate that "3A Composites" is now the manufacture. I have used a bright brushed gold in the past, but don't see that color listed as a stock color any more.

I have used the gold as street address numbers on commercial buildings in the past. Numbers I installed 5 + years ago look like they did the day they were installed. I also used the brushed aluminum material as a trim piece on a medical device.

The polyethylene core will "emboss" if scribed or forcefully pushed on with an instrument, and of course will scratch if someone is determined to do so.

I "flame polished" the edges and was able to get a very pleasing finish on the poly part.

I don't know if sample pieces are available any more, I was supplied with a box containing 8" X 10" samples of Sintra, Gartor board, Fome-core and Diebond. Even if this isn't the product for this job these material and color samples would be nice for reference.

Steve

[tallen84]

Steve / Brady,

Sounds like Dibond might be a good alternative... I put in a request for samples and hopefully they will have a finish that will work. Ideally I am looking for a polished brass (gold might work) or a polished silver chrome.

[letterman7]

Hi Todd,
Leafing isn't hard to do. You won't see any 'seam' between the leaves of gold as once it's laid you'll brush the gold "out" to get rid of any hanging particles. Those tend to get caught in any gild left open and fills the voids. Sometimes you'll need to go back and touch up areas, but not often. The finish is as smooth as you make the sign. Most times I paint with an automotive grade urethane then clear coat it and buff out any dust specks. The gold loves smooth surfaces like that: http://www.tamartedesign.com/photos/fullsizeimages/North_Hill2.jpg
I don't have any close-ups, though... never thought about taking any!

[tallen84]

Steve / Brady,
I have called every distributor I can find nearby and most of them only sell white and occasionally a brushed aluminum finish. As for their website, I am unable to locate any polished metal finishes. Do you have any suggestions where I can find them or any other options?

[letterman7]

UltraBoard is the same basic stuff, and available in polished finishes: http://www.ultraboard.com/ultraaluminum/
With a phone call they can probably hook you up with a distributor near you or even ship cut pieces UPS.

Dibond isn't available in a polished finish, by the way!

[steve_g]

Todd:

I don't see the gold color I used years ago on the 3a web site. you can either call them or, as Rick suggests, find something similar.

The major difference I see right off is that the UltraBoard has a styrene core rather than the PE core of DieBond, and I'm not sure of the ramifications.

Steve

[Brady Watson]

UltraBoard is the same basic stuff, and available in polished finishes: http://www.ultraboard.com/ultraaluminum/

Dibond isn't available in a polished finish, by the way! <---- Good to know! Thanks!

-B

[bleeth]

Ultraboard is a cool product but it's site states clearly in the tech specs that it is not suitable for exterior use.

For boat signs I strongly believe the best way to go, as suggested earlier, is carve the letters and paint or leaf them. Bottom line is for this job anything that sticks out is going to get "caught" by passers by on deck.

If this sign must be done with that look you can finish the blank with polished Sculpt Neuveau, mask it, cut the background, and paint it. Clearcoat and you should be good to go.

You can do this out of solid Brass but ask Brady how long it will take to cut!! The similar signs being sold all over now for house numbers have either glued on letters or are cast in molds with changeable letters/numbers. Note the background, if done in Brass, would probably be easier to plan on a texture then going for dead flat.

[Brady Watson]

Real brass is considered a 'semi-precious' metal. Prices are also a bit 'precious' as well, even when you get it from a true metal supplier. Buying from McMaster or MSC is convenient, but plan on paying drug store prices for the convenience. Of course, if this is for a marine application, be sure to get the correct alloy for the job. Some offer more corrosion resistance than others, and how well that alloy machines varies accordingly.

Yes, there are alternatives, and a whole host of coatings and paints you can use. Personally, these are like the diet coke of brass...and there ain't nuthin like the real thing baby...Plus, selling REAL brass has a lot more clout than the diet versions...

Routing brass can be tricky, frustrating and really push your tool and sanity to the limit, when you get into thicker more detailed designs. It most certainly CAN be done, but be patient & plan on doing your own R&D to keep things held down firmly and machined correctly with an acceptable finish.

-B

[letterman7]

Ultraboard is a cool product but it's site states clearly in the tech specs that it is not suitable for exterior use.


True, but that's mainly because of the tying poly substrate between the two aluminum skins. If the material is cut, recessed and "potted" in a reveal with a nice bed of silicone that covers the edges, there will be little issue. Even better, a coating of automotive grade clear over the entire sign will help protect the mirror coating from oxidizing over time, which it will do eventually, especially in a marine environment. If that route is chosen, then a bed of silicone won't be needed except to set the letters initially. As long as the edges are sealed you're good to go.


The other option that I just found a few days ago and will be testing is this stuff: http://plateall.com/index.php?section=content&view=30
Available in a number of finishes, that may well be the best bet short of doing real gold leaf. You can rout recessed copy and simply pour and fill the recesses with color.

[Brady Watson]

Honda dealership monument signs are made of Dibond...

-B