Stand-In for a bronze monument plaque

[John Jackson]

An organization my son works for had a dilemma last month. They were honoring a community member by naming a hiking trail after him for all his years of service. All was set - friends and family of the honoree were invited, press, dignitaries, the caterer had snacks to deliver, a canopy to keep the elements off the guest speakers. A podium and PA system were all arranged.

The date was a Saturday, but on the Wednesday evening they realized the cast brass plaque that was ordered was going to be ready about two weeks after the unveiling ceremony was scheduled.

They were trying to find a recovery plan when my son volonteered me to help out.

I had the PDF proof from the foundry with dimensions. I imported the PDF into VCarve Pro and traced the vectors. I then used some gold - on - black Rowmark engraving plastic and rotary engraved away the gold around the letters. The final result turned out great if you stood a few feet away, and since this was outdoors fastened to a large rock and the audience was 20-25 feet back seated on chairs. The event came off without a hitch or a comment, and two weeks later the plastic decoy was quietly switched for the real brass plaque.

The organization took a side by side photo during the switch-out. The brass plaque is on the left, mine is on the right.

John Jackson
Russell, ON

[Mike Null]

John

Great work and idea. Thanks for posting.

[Richard Rumancik]

John, I understand that this was just meant for a temporary plaque and your solution looked great. But I've often wondered whether it would be cost effective to actually machine bronze using a program like V-carve. I realize it is a lot of material removal but the depth isn't that great, and it's not like you need to watch it. With all the steps required to make a mold for sandcasting and finishing, it just makes me wonder if it would not be possible to competitively machine plaques in their entirety, and perhaps have even better turn-around than a foundry. With V-carve you could generate a textured background to imitate the pebble finish (or whatever) of a cast plaque. A patina could be applied after machining and the tops of the characters sanded to expose the bronze just like a cast plaque is made.

Of course you still need the bronze blank - I'm not sure of the availability of bronze plate.

Any thoughts?

[John Jackson]

I have two rotary engravers and a small CNC machine. I can tell you I would not attempt brass or bronze on this scale with the engravers. The plastic version took 6 hours to cut and I was only removing 0.012"!

It would be possible with the CNC, but with the item from the foundry costing $600 all in, I cannot see doing it cheaper if I count my time. For someone on a budget, however, I can see making this out of SignFoam or MDO and applying something like sculpt nouveau. I have not used sculpt nouveau yet because it is a bit harder to get in Canada, but from what I hear this would be a good application of it.

[Mike Null]

John

I'm only guessing at the size but a bronze here would be less than $150 in the size I think that is.

[John Jackson]

Mike,

I have no previous experience with bronze but $600 was what the client was paying.

Hijacking my own thread - I see you have a CE5000-60. How do you like it? I am about to order one in about 3 hours...

[Richard Rumancik]

John, what size was the bronze plaque?

At $600 there may be room for "improvement" in pricing using alternate techniques, but if it can be purchased at $150 as Mike suggests there probably isn't much opportunity here.

Some customers might be okay with a polymer plaque with a metallic-looking coating, if it comes in at 30%-50% of the cost, but I was trying to decide if machining plate was at all viable. You are saying "no" but it still puzzles me. I am not a machinist but for a 10" x 12" plaque (for example) you would probably only be removing a couple cubic inches of metal so it doesn't seem insurmountable. I realize that to cut the characters you need a small bit and it will be slow cutting, but the open areas could be pocketed pretty fast.

[John Jackson]

The plaque was 12 X 12. On an engraving machine with a 0.020" cutter, it took better part of a night to cut. I tried larger cutters but they would not go into the small areas such as inside of a lower case "a" or "e".

I also had the time constraint - limited time for test cuts. I also only had 12 X 24 of the appropriate material. No local supplier, shipping more in would have missed the deadline.

On a metal cutting CNC machine you could do it in much less by using the appropriate roughing out bits.

[Gary Hair]

John,
Just a thought for future use - if it ever presented itself anyway. What about outlining the text and graphics and using a larger cutter to rough it out, then invert the outlining and finish with your .020. That's how I'd do it on my mill, but my programs are designed for roughing out and finish cuts, you would have to get creative with yours.

Gary

[John Jackson]

Well, I really think this was one of those "one and only" projects.

Even as I was cutting it I had ideas on how to improve, but due to time constraints and limited material once it started to cut I was committed!

As I recall I used a 0.040 for roughing and the 0.020 for detail. If I had a do over I would have increased the size of the roughing diameter. I was not sure where the trade off was between rough and fine; go too coarse on the roughing cut and you then need more work on the fine detail cut.

John

[Mike Null]

John

My Graphtec has been very good though it's not getting as much use as I had planned. I bought it because of the optical scanner but haven't had time to work with it.

[John Jackson]

On of the planned uses is to cut sandblast rubber resist. I see you do sand carving - is the CE5000 up to that task?

I can actually get a used Graphtec FC700-130 with ARMS which has twice the down force, twice the speed, true tangential and cuts 54", for a cheaper price than the new CE5000. However, it is a "full sized" machine and I really don't have 30" X 84" inside to dedicate to it.

On a good note, I have not met an unhappy CE5000 owner yet!

Happy Holidays,

John

[Ross Moshinsky]

$600 for a cast bronze plaque seems extremely high. Especially if the dimensions are 12x12. Gemini or Matthews should be about 1/2 that price, if not less.

As for the job you did, it looks great. Can't say it was the best use of resources but it looks very nice. Laser would have done the whole job in an hour probably. I keep thinking about using two pieces of material and a profile cutter but I'm not exactly sure how I would do it. It would be similar to how ADA signs can be done. Just have to get the right adhesive. Probably could have cut the job down to 2-2.5 hours doing it that way.

[John Jackson]

$600 was what the client said it was costing them. I had no part in that transaction, nor do I know how many hands it went through before getting to the final user.

At the time I had one piece of 12 X 24 Gold Rowmark, a 24 hour deadline, and a rotary engraving machine, and a day job. This is a part time evenings/weekend business for me at present.

I took on the job for two rmain easons: 1 - my son told them I could help them out. I did, so now he is +1 in someone's good books. 2 - the person I helped is on the board of directors, has other businesses, and now my business is on their radar map for future engraving jobs. She even sent me a Christmas present.

I had lots of time to think while watching the engraver run on how to improve. but by that time the only piece of material was already being machined.

John

[Mike Null]

I had a larger Graphtec also which I sold. It was a 30" with considerable more down force but I forgot the specs. I was using it mostly for vinyl and for my sandcarving would use vinyl as well. Most of my work is light duty stuff like awards of glass, crystal and marble.

[Martin Boekers]

Great job! It's things like this that get you noticed with companies. If you are looking to get more of this work, I too suggest Gemini. Their
typical turns are less than 10 days. A plaque that size should be less than $200 soooo, that would have been a cool 200% mark up! (not including shipping)
Quite a profit for just doing the layout!