# Homemade Tools > Basic Homemade Tools and Tips >  Jeweling metals, need info

## rendoman

Hi all!

I'm searching info about this technique, I would like to use on the aluminum panel of my next amplifier
I saw some video on youtube about attempts, but there is nothing about a good work.
In local shop there are no tools at all, I saw that there are some rubber rod filled with abrasive, nearly impossibile to find here. 
Someone used steel brush, someone rubber with polishing paste.

For a good job, in your opinion, what's should I need?

That's the effect I desire



https://www.customshopinc.com/produc...shingjeweling/

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Jon (May 17, 2018),

PJs (May 17, 2018),

Seedtick (May 17, 2018)

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## mklotz

The rubber rods filled with abrasive you mention probably refers to Cratex products, examples of which are shown here...

https://www.amazon.com/s/ref=nb_sb_s...=1PG71K5J1ET9R

As an alternative to Cratex, I've had some success using sections of wooden dowel with a patch of leather glued on the end. Smeared with lapping paste and rotated in the drill press, they leave a nice circular swirl. 

An attractive jeweling job requires two things. First the spacing of the circles must be consistent; spacing errors will stand out and look bad. Arrange some method of mechanically stepping the work between swirls. Don't try to space by eye. Second, the pressure with which the tool is applied to the work should be consistent. While this is slightly less of a concern than the spacing, it's still important.

Be sure to experiment on some scrap before working on the amplifier. Undoing a bad jeweling job is very difficult.

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rendoman (May 17, 2018)

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## rendoman

Thanks for your suggestions!

A question for you: which lapping paste is necessary according to you?

I want to try your method, with wooden dowel plus leather patch, I think a 6-8mm diameter should be fine for 250x120mm plate.
Since my milling machine is tiny, I would have thought of building a sort of plate-template with an accurate grid well spaced (according to size of dowel), with a back stop where it's possible to slide manually. It could be a very long work, but it seems a nice idea, I hope  :Roll Eyes (Sarcastic):

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## mklotz

I have a kit containing four grades of lapping compound. It's probably forty years old so I doubt it could still be found.

The grit you use depends on what appearance you wish to achieve; it's really an artistic, not engineering, choice. My suggestion is to get the least expensive automotive valve grinding compound you can find locally there in Italy and try it on a piece of scrap material from the part you wish to jewel. That will give you a sample from which to judge whether you want coarser or finer grit.

Such experimenting will also give you a chance to decide what overlap of jeweling circles you will want. Overlapping by half the diameter of the circle is common but, again, it's up to you to decide what you find attractive.

Good luck and be sure to show us some pictures of the finished product.

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rendoman (May 17, 2018)

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## mklotz

Not that it will be much use to you in Italy, but my aforementioned box of four grades of lapping compound came from:

Gerald Kerr Associates
8999 W. Pleasant Valley Road
Cleveland, Ohio 44130

(I Googled them but couldn't find any current listings; they're probably long gone.)

It contained cannisters of grade 120, 220, 280, 500 (order coarsest to finest) grit. I can remember using the 220 and 280 grit on some jeweling jobs.

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rendoman (May 17, 2018)

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## rendoman

Thanks Marv!

I just tried for my curiosity a fast tool with leather, glued with mastic.
I tried to put some White polishing paste crumbled and amalgamated in oil, I know it's a bad job, but it was just an attempt to see what would happen. I used 3000rpm with light pressure, the signs are visible after cleaning, but I bet I need something more aggressive. The aluminum scrap was only cleaned with 180 grit paper, too rough maybe for the job

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## mklotz

It looks like what we call "white diamond" polishing material here in the USA. A bit too fine for jeweling though, as you've proved, it produces the characteristic swirls. Do try to get some lapping grease in the 100-200 grit range.

At any rate, you seem to have proved the leather-on-dowel tool works reasonably well. Keep up the experimenting; you'll soon be an expert.

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rendoman (May 17, 2018)

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## bruce.desertrat

Grinding and Polishing grits of a variety of sizes are generally available through lapidary and jewelry supply places.

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PJs (May 17, 2018),

rendoman (May 17, 2018)

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## desbromilow

Hi,

in the past I've done this with a piece of dowel (wooden) and common valve paste. The suggestion of using a piece of leather glued on is better than how I did it, since I had to renew the valve paste a few times per row.

I've seen it done with those old school "ink erasers" - the guy used a small section of brass tubing as a die, and cut several pieces from the ink eraser, and then let them feed out of the same brass tube section as pads. They didn't wear too quick, and all he did was push a bit more out as it wore down. I think from memory he had a nut and piece of all thread soldered at the end of the tube for feeding the eraser nubs back out.

Des






> Hi all!
> 
> I'm searching info about this technique, I would like to use on the aluminum panel of my next amplifier
> I saw some video on youtube about attempts, but there is nothing about a good work.
> In local shop there are no tools at all, I saw that there are some rubber rod filled with abrasive, nearly impossibile to find here. 
> Someone used steel brush, someone rubber with polishing paste.
> 
> For a good job, in your opinion, what's should I need?
> 
> ...

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PJs (May 17, 2018),

rendoman (May 17, 2018)

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## blkadder

I have used regular metal polish doing small parts, and they turned out pretty well. I did try using regular pencil erasers, but they did not last very long at all.

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rendoman (May 17, 2018)

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## owen moore

The photo you included in your post appears to be a rifle bolt. Brownells gunsmith supply has a jeweling fixture for similar parts that allows the part to be accurately indexed for rotary and linear spacing. I believe they even sell the Cratex abrasives and grit compounds. You may also want to check Midway USA as well. On your flat panel project you will want to figure out a way to index the part at the desired spacing. A milling machine would be handy.
Years ago, I used a simple pencil with a type writer eraser and a drill press for small parts. Good luck with your project!

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PJs (May 17, 2018),

rendoman (May 17, 2018)

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## drum365

Just a few quick comments... (I have never done this technique, but have researched it some for a future project I have in mind)

AFAIK, a more common name for this technique is "engine turning" - try googling that. There's lots of info out there. It was very popular on aircraft and auto dashboards "back in the day." You might also have more luck using that term in searching YouTube, etc.

mklotz' suggestion of using a piece of leather glued to a dowel is, I believe, the traditional way of doing this.

Good luck, and I hope you post pictures when you're finished!

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rendoman (May 17, 2018)

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## rendoman

Thanks for the advices that you all gave me!
This rubber rods seems "easy" to use, I just sent a mail to Cratex in order to know if shipment is possible. I'm also searching something similar in Europe, till now nothing found, as usual  :Wink:  . Tomorrow I will search better!

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## petertha

I bought this set & use it quite often for metal finishing. Very inexpensive compared to Cratex. I'm wondering if the largest cylindrical shape could just be used directly, meaning chucked in a drill press or mill & impart the swirl. I'll try & see if it works & take a picture for you. If you want lager diameters of course you would have to make a mandrel like you were thinking.
https://www.richontools.com/index.ph...79f0bff49eec1c

This is a cam plate for my model radial engine made from A2 tool steel. After grinding a slight radius on the lobe corners, I used the green wheels (in link) to blend the surfaces. It leaves a semi shiny matt finish. Thereafter I use polish with a felt wheel. Both were done with a Dremel tool.


Also you can get diamond lapping paste very inexpensively from Ebay or Aliexpress. Lapping compound can be aluminum oxide or other abrasives but in your application you don't really have to worry about diamond embedding. They also come in petroleum or water based if that's important. I find the petroleum comes off quit eeasily with alcohol or similar solvent.
https://www.ebay.ca/itm/8pcs-5-Gram-...wAAOSw241Yl89n

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PJs (Jun 30, 2018),

rendoman (May 18, 2018)

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## Jack55

I once did this technique to a Cessna 152 firewall. I screwed it to a table and cut slots in a board that spanned it. The slots were spaced slightly less than half the diameter of the abrasive pad I was using. I then screwed a fence onto the work table to slide the slotted board down as I went. Again, each row spaced down slightly less than half the diameter. The 1/4" shaft of the abrasive pad fit into the slots of the board and I just used a cordless drill and the slots kept the pad in position. Each alternating row I had to move the indexing board down and space it right so all of the circles are staggered. Not a speedy process but it turned out well. I experimented with a compass on paper to get the spacing right. I used one of those screw on abrasive pads for the firewall, about 2" diameter if I remember correctly, but I've also used a scotch bright pad glued onto an elevator bolt with good results.

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PJs (Jun 30, 2018),

rendoman (May 18, 2018)

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## petertha

Here's the green 'rubberized abrasive wheel' results in mild steel spun in a drill press. These are not Cratex, they are offshore brand & I just ran it without dressing the end which is probably why inconsistent rings. Results are so-so. I think the grit is too fine for the look you are after. Somehow I think something like sandpaper on the end of a hard dowel material might be the most controlled way of obtaining whatever degree of micro-scratches in your particular material. If its too faint then coarsen up the paper & visa-versa. I've done this with a Dremel before just free handing over an array of felt pen dots (because the surface was slightly curved). Lapping compound would probably work too, but me thinks rather messy. Good luck & show us what you ultimately decided.

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rendoman (May 19, 2018)

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## Toolmaker51

rendoman, ALL the suggestions made are correct. The tool variations occur in diameter, hardness, and speed of the pad; and on project side in size, contours/ shape and material. Aluminum needs less pressure, grit size, and duration than stainless steel, for example. Valve lapping compound offers a wide range of grit size in convenient packages that likely are sold world wide. 
A panel for your electronics will be a far larger 'spot' than a rifle bolt, based on proportions. I'd tend to sit down with sketch of the panel and start drawing a fish scale pattern to gauge an attractive size. Milling machine isn't critical, they are slow to index and not always desirable RPM. You can use the mills table though; a rail to guide that panel and marks to regulate the spacing. Having the quill stop will make the pattern look it's best.
Leather on a dowel is going to work well, long lasting, and delivering a consistent pattern. You should be able to make equal spares to finish the work.
https://www.google.com/search?q=engi...nt=firefox-b-1

Supposed origin of engine turning was to retain lube in sliding surfaces of firearms, high grade time pieces, and lock works. Not too different than scraped machine tool slides. It was associated with quality, evidence of additional man-hours in products. That degraded somewhat applied as decoration instead of a functional process.

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PJs (Jun 30, 2018),

rendoman (May 19, 2018)

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## rendoman

Thank you all!

I asked MSC Industrial Supply Company for a small quantity of rods , as Cratex said, unluckily they said the minimum order size is $200 USD, with high priced shipping.
For a couple of small rods that you can send in the envelope with normal mail, it's not worth the expense.
I will search soon for lapping compound! Finger crossed

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## petertha

Sometimes you can find inventory or used on Ebay & similar. These look a bit worn, but if you wanted a less expensive way to try vs. new. 
https://www.ebay.ca/itm/Cratex-abras...wAAOSw8Mda6gKy

This is a jeweler supply place in Canada that handles Cratex brand. I'm sure there must be European dealers of similar products.
Cratex Cones

Personally, I think for Cratex you are paying for the quality & consistency of the finer grit wheels. But from what little experimenting I was doing, I think you are going to need coarser grit to make those striations. Without knowing your material or application hard to know, but I'd estimate between 120-220 grit. I'm not sure what that corresponds to in Cratex coarse/fine etc. but the link provided in post #17 looks helpful.

Why don't you make a simple mockup from a wooden dowel or metal rod & glue some common sandpaper or emory paper on the end? You may find its a perfectly good tool, or failig that, at least you will have a better idea of what kind of lapping compound to buy because its not exactly inexpensive either.

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PJs (Jun 30, 2018),

rendoman (May 22, 2018)

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## Toolmaker51

Petertha made a good suggestion about sandpaper. What we call 'wet or dry' also known as silicon carbide [black abrasive on a plastic-like sheet]adhered to a dowel should work nicely. Use water to float away the stuff that will ruin the pattern. If you know a leather worker......his contact cement will work. 
You can catch him with a fast motorcycle, when he isn't busy with electronic projects. Rumor has it, he's nearly always wearing leather.
Lapping compound according to Google.com [US] gets you these results. 
https://www.google.com/search?q=lapp...nt=firefox-b-1

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rendoman (May 22, 2018)

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## Toolguy

I have done a bit of this work in the past. The information here is good. What I didn't see yet is the original surface finish. In my experiments, the engine turning went faster and easier when the original surface is polished to a very smooth finish. This gives a shine and consistency to the swirls and takes a lot less time on each spot because you are not having to overcome a dull or otherwise imperfect finish.

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rendoman (May 30, 2018),

Toolmaker51 (May 30, 2018)

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## rendoman

Thanks for the advice! I will try with polished surface
I'm undecided about which panel I should jewel, maybe the front and the tube top are good size, the big top plate is maybe too wide.

That's the amplifier for electrostatic headphone i'm trying to build, if someone was interested in seeing more pictures

https://www.facebook.com/stefano.ran...4376382&type=3

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## rendoman

Hi all!
I just finished to polish the front panel. This aluminum is very difficult to polish, it's easy to leave marks on the surface.
It should be shiny enough, I hope, for the jeweling process. 
I will cut round disc of sand paper, different grit, in order to see what's the best grade. I have to prepare a test alu panel (same metal)

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Jon (Jun 22, 2018),

PJs (Jun 30, 2018)

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## rendoman

Little update
I just tried with another test plate, same aluminum polished and sand paper disk attached to wooden rod. 

Setting is :

-3000 rpm,
- 180 and 220 grit disc 5mm diameter

Not working configuration, the sand paper in really no time is full of alu dust and stops cutting. Even the control is not good compared to leather pad, the plate tried to move, making work difficult.

I'm having trouble finding coarse paste, I can find only very fine type, not enough. Currently I don't want to spend lot of money in shipping and different pastes in order to try different attempts. To be honest, I don't know if continue or not, this type of aluminum is not like ergal or stainless steel, I have sensation that a normal mirror finish could be better

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## petertha

Something you might want to try if the classic swirl is not a prerequisite. I had some dead easy results on aluminum using a random orbital sander & coarse grit sandpaper (100 grit I think). Photography of metal never seems to look like real life but to describe - its kind of a sugary looking textured pattern like coarse sand blast but not deep & not quite as matt. It easily hides scratches & blemishes. This shows before & after of off-the-mill stock & another scrap part was machined but with scratches. Harder to describe than actually do, but here are some samples.

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Jon (Jun 29, 2018),

olderdan (Jun 29, 2018),

PJs (Jun 30, 2018),

rendoman (Jun 29, 2018),

Seedtick (Jun 29, 2018),

sossol (Jun 29, 2018)

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## olderdan

Peter that is quite an attractive decorative finish, could be useful for panels etc, I like the hint of a flower in the middle.

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PJs (Jun 30, 2018)

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## Toolmaker51

Rendoman; 3000 RPM is kind of fast for jeweling soft material. While abrasive is needed, a lot of common products can be tried. Kitchen and bath cleansers come to mind, ours are Comet, Bon Ami, Barkeepers Friend...maybe cement mix, grout, toothpaste, emery dust deserve a shot too. 
Set a positive stop on the quill and count [experiment]1 2 3 for consistent timing and degree of spot desired. A spot of X diameter should overlap preceding spot about 1/3 proportionally. The next row originates 1/2 a diameter above and over. Something like stacking tubes or racking palla da biliardo.

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olderdan (Jun 30, 2018),

PJs (Jun 30, 2018),

rendoman (Jun 29, 2018)

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## petertha

> .. I like the hint of a flower in the middle.



HaHa. That's actually kind of a fluky photographic highlight aberration of the random orbital motion. The surface looks quite equally textured at eye level

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## rendoman

I will try with reduced speed and leather pad so!

I just found oxide aluminum, 220 gr in a local shop, it seems a good choice maybe mixed with toothpaste or oil.

Thanks for the advices!

https://www.hobbyland.eu/ita/shop/os...-1-kg/p-12953/

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PJs (Jun 30, 2018),

Toolmaker51 (Jun 29, 2018)

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## olderdan

Agree with your comments Toolmaker 51, if a fairly coarse finish is the target I have used fine sand mixed with a little oil to a paste with good results on the end of a plain wooden dowel, at least it is cheap to try.

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PJs (Jun 30, 2018),

rendoman (Jun 30, 2018)

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## Moby Duck

Toolmaker 51 - I like your alternative suggestions but isn't one of the trade marks of Bon Ami, "Hasn't scratched yet".

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rendoman (Jul 1, 2018),

Toolmaker51 (Jul 1, 2018)

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## Toolmaker51

> Toolmaker 51 - I like your alternative suggestions but isn't one of the trade marks of Bon Ami, "Hasn't scratched yet".



Absolutely, but it sure can polish softer metals. Now, on it's own that may give Rendo a texture for his panel, maybe a good slurry for a more aggressive grit instead.

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rendoman (Jul 1, 2018)

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## rendoman

Hi hope I will find a good compund tomorrow, the frame of my new electrostatic headphone amplifier is Painted, I'm ready to weld circuit
As you can see there is huge difference between top tubes and the front plate, that's why I will try to jewel…
Finger crossed!

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Toolmaker51 (Jul 9, 2018)

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## rendoman

Finally found an emery paste, it's silicon carbide in water solution. It seems not good to spread on the plate, should I dry the carbide and mix with grease or oil maybe?
I'm trying to create a leather pad with wooden dowel and glue. I tried leather contact cement, it seems not enough, I'm trying Vinavil with the tool pressed in the vice. I will try in a couple of days

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## Toolguy

Here, I use Clover brand lapping compound. It's silicon carbide in oil. I just use the end of a soft wood dowel that has been trued by spinning the end on med. grit sandpaper laying on a flat piece of steel. Then just use the end of the dowel rod on the lapping compound slurry. I usually run around 250 to 500 RPM range. This needs to be a somewhat gentle process. No high speed spindle or heavy down force.

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rendoman (Jul 13, 2018),

Toolmaker51 (Jul 13, 2018)

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## Toolmaker51

Yes Rendoman, water is certain to evaporate while you are trying to jewel the plate. Any reasonably clean oil will give better results. Mix up a paste about the consistency of toothpaste. Too thick the swirls will be hard to see appear. To thin, and whoever does the laundry; well you know the rest!

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rendoman (Jul 14, 2018)

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## rendoman

It seems a good pattern, I tried a mix of carbide, oil and grease, light pressure, 900 rpm, 3 seconds. It should be enough, or maybe should I raise the second?

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PJs (Jul 20, 2018),

Seedtick (Jul 17, 2018)

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## mklotz

The circles in the test piece look good.

In the patterns I've seen, the circles are overlapped by about the radius of the circle. (The tool is moved about a half diameter before making the next circle.) You might want to make some samples on your test piece to decide how much overlap you think looks best.

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rendoman (Jul 16, 2018)

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## Toolmaker51

I agree; the swirls appear 'right'. The suggestion I'll make for the pattern; continue with the grid sheet for spacing, and clamp a rail [straight edge] of some kind to guide the plate. It will make following the increments SO much easier.

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PJs (Jul 20, 2018),

rendoman (Jul 17, 2018)

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## Frank S

I haven't done a lot of jeweling but I did learn early on that the diameter of the swirls need to be of some direct proportion to the size of the item being jeweled. 1 inch diameter swirls look as out of place on a 69 Chevy C 10 firewall as do those on a 31 ford at 2 inches. 1" on the Ford looked great as did the 2" on the Chevy. Probably why a 12" swirl pattern looks better on a ceiling than a 6 inch does

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PJs (Jul 20, 2018),

rendoman (Jul 17, 2018)

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## rendoman

Hi all!
I tried engine turning - jeweling, that's the front panel of my Esl headphone project. Not a perfect job, but good as first real attempt, not with small test plate. 
Unluckily leather pad glued to wooden rod disappeared, the wood did a nice job. Due to little experience in jeweling with the lack of a good tool, the circles are not all equal, plus I made some errors, it's hard to see the pattern under the emery paste without cleaning. Another difficult point is the square and large shape, it's easier to see errors, above all with more than 1K circles.
I will trim and polish the edges, as scheduled.

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PJs (Jul 20, 2018),

Toolmaker51 (Jul 17, 2018)

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## Frank S

Rendoman I have a philosophy about slight imperfections which may occur when doing projects like this. First off your panel looks great to me from the pictures. Secondly any slight imperfections are proof that the panel was not purchased ready made. To me this makes it worth a lot more.

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PJs (Jul 20, 2018),

rendoman (Jul 17, 2018)

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## rendoman

Thank you very much Frank!

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## cdakers

Looks great! Slight imperfections don't detract from the appearance at all, and only amplify the handmade, one of a kind nature of your work. You have inspired me to try this myself. Looking forward to seeing what I can do to improve the appearance of some of my handmade bits and pieces. I have plenty of firearm and motorcycle parts that could be improved in this manner.

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## rendoman

Thank you cdakers!
I'm thinking a good way to make the "right" tool, able to mark the metal every shot the same circle. In this little panel I made more or less 1150 dots, 3 seconds with light pressure, with a good layer of abrasive, maybe the wooden rod was too hard.
I'm thinking about making another big plate (250x300mm soft alu) with wine cork, for sure softer than wooden dowel. This panel will be the top casing, useful to stand the headset when not used.
About firearms… I have only one rifle with jewels, it's the 700 model in 416 rem, it would really nice to prepare bolts and parts

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## PJs

Mighty Fine Job on the panel Stefano!! A lot of work and learning really paid off. Perfection is one of those things sought after but never really attained, just approached...yours is at 98% in my book! Well done!

PJ

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rendoman (Jul 20, 2018)

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## rendoman

Thnak you PJ!

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PJs (Jul 22, 2018)

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