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jools02
16-12-2009, 04:06 PM
Hi there, I wonder if anyone can help. I've made about 100 PMC fingerprint charms for Christmas orders and haven't been doing it for very long. My pieces turn out beautifully, however, most of them have light scratches all over them even after vigorous polishing. Whatever I try I just can't get of them! It seems to be happening at the dry clay stage when I sand them down. I use sanding pads around the edges and over the surfaces (bar the fingerprint and engraving) - I think this is what's causing it because I can see the scratches on the surface after I've sanded. Its definitely not my burnisher. The only other thing it could possibly be is either the soft brass brush which I use on the piece after firing, or its happening in the polishing process (I use the graded polishing papers) but I can't see it somehow.

What should I be using to sand the dry PMC? Has anyone else experienced this.

mizgeorge
16-12-2009, 04:29 PM
I don't work with art clay very often, but my standard answer to ALL polishing problems is micromesh, and I think it would be the same for this one!

The Dragon
16-12-2009, 04:50 PM
I agree with George, a final finish with a very fine micromesh to even the surface out then a gentle wipe with a miost baby wipe or similar.

Nic may have a few other suggestions but you need to be looking at getting the best possible finish to your piece before you fire it.

Hope this helps

:snow:

jools02
16-12-2009, 06:50 PM
Sounds great! Where can I find it? I've googled it but what grade do I need to use?

Petal
17-12-2009, 07:15 AM
Hi Jools,
I got mine from Ebay but the name of the co is called theturnersworkshop as Cookies don't stock it.

9 X PAD VARIETY PACK (2 > Micro Mesh Products > Abrasives (http://www.theturnersworkshop.co.uk/store/view_product.php?pid=13&cat_id=14&prod_id=35)

Good luck.

jools02
17-12-2009, 07:25 AM
Thanks Jules I'll order some of those! Forgive me for being a complete novice but which grades are supposed to be used on the dry clay? And can these also be used to polish once its been fired?

Sorry for all the questions!

MuranoSilver
17-12-2009, 07:55 AM
I use those impregnated rubber burrs from cooksons on my flexshaft.
(Dremels are fine with them too) Use brown then the green (avoiding the print)
Mirror finish by using wenol and a soft cloth
nic x

jools02
17-12-2009, 09:23 AM
Thanks Nic, I've had a look at them but would have no idea about how to use them. My husband has got a 'drill type thing' which has an extra bit which you hold like a pen - is this the kind of thing you use them with? Forgive me for sounding dumb! Also, Nic do you mean you use these on the fired clay or the dry clay?

MuranoSilver
17-12-2009, 10:30 AM
As long as it's got a chuck that will fit a 2-3mm bit in then you'll be fine.
I use them on fired silver.

Nic x

jools02
17-12-2009, 02:42 PM
Ok thanks Nic, I'll check. If you don't mind me asking, what do you use to smooth the surfaces and edges when the clay has dried (before it gets fired)? Because the sanding pads I'm using are leaving loads of scratches.

Di Sandland
17-12-2009, 04:06 PM
Ok thanks Nic, I'll check. If you don't mind me asking, what do you use to smooth the surfaces and edges when the clay has dried (before it gets fired)? Because the sanding pads I'm using are leaving loads of scratches.

Another job for micromesh

MuranoSilver
17-12-2009, 05:16 PM
On dried clay I use the sponge back sanding pads from silverclay.co.uk
They're better when the clay clogs them up a bit no scratches :)
The sponge back makes for lovely slightly softened edges.

A gentle smooth over with a baby wipe finishes the pre-firing prep.
Nic xx

jools02
17-12-2009, 07:42 PM
On dried clay I use the sponge back sanding pads from silverclay.co.uk
They're better when the clay clogs them up a bit no scratches :)


Yes these are the ones I use and they are pretty clogged up but still leave scratches. I've not tried the baby wipe tip though, will this get rid of the scratches then?

MuranoSilver
17-12-2009, 11:02 PM
I don't really get scratches, by the time I'm at the finest grade it's pretty smooth. You have to be very gentle :)
A baby wipe will smooth any little marks and also seems to help get a better final shine (post firing).

Must admit though I try and make sure the clays worked enough in it's moist state and that it's smooth before drying.
On f.print pendants I often only sand the edges and the top gets the lightest of touches (if at all) before baby wiping.

nicx

wifey1612
05-09-2012, 10:36 AM
As long as it's got a chuck that will fit a 2-3mm bit in then you'll be fine.
I use them on fired silver.

Nic x

Hi, Ive been reading and reading about removing scratches from PMC and have followed everything above from start to finish as advised above etc, yet i STILL have scratches on my finished piece. I have tried finishing with both the 3M papers and the Spectrum papers on 2 different pieces to see if its one or the other, but scratches are still there. Ive bought the silicone polishing tips, and used them in all grades, and they seem to mark my silver. Whatever I do i simply cant win!! Maybe Ive got my dremel on too fast? I've used every kind of tip from fat to thin, and worked through the grades.
Can anyone please please help? Its had me in tears again today!!

ps. tumbling is doing a wonderful job, but I is no good for fingerprints :((

medusa
07-09-2012, 06:01 PM
if I'm using PMC (and I do only use it for the fingerprint rolls I make) I do an initial clean using 3M radial wheels, use a superlight touch, don't press! Then I just use a basic polishing rouge on a polishing mop. PMC is so soft that unless it's a deep scratch from the dray stage, it just polishes out. I've also found that I can burnish scratches down enough to polish them out either with abrasive wheels or a mop.

wifey1612
07-09-2012, 09:15 PM
Thanks.. I'll give that a try