Let's get this place rockin or atleast awake

[ldb2000]

Hi All
This question is directed more to George (Texasdurango) but all are REQUIRED to chime in with ideas(hee hee ) .
I'm working on a PMC clip with Heavy Music wire as reinforcment and am wondering about Work hardening of the PMC to make it a little less brittle .
Has anyone had any luck with tumbling the clip for long periods of time to work harden the PMC as per the posts in the PMC guilds fourms .
Lets get some ideas going here about clips and the likes .
Also anyone casting any other kinds of low melting point metals for any other reasons that might be used for making clips and stuff .

 

[BRobbins629]

I've been making some clips recently out of silver sheet or even half round wire. To me, the most important factor to maintain shape is the thickness of the metal. So far, anything 0.060" and thicker seems to work fine. You can also harden the clips by hammering with a rawhide mallet. A few good whacks is all you need and will do as much or more than tumbling.

 

[Texatdurango]

I never had any problems with the PMC clips being too brittle, actually the opposite was my problem. The clips would bend too easily. I even put a couple in a tumbler with stainless steel shot up to 24 hours and never noticed any difference.

I thought about using support wire to stiffen the clip and give it strength but wasn't having any lick since I was after slim clips not the big heavy clips others are using.

 

[ldb2000]

Could it be that I'm not firing the PMC right I've made several and they all broke when I put (I have to admit too much) force trying to lift the clip away from the pen body , as if trying to clip it on a thick notebook (about 1/8") .
I'm firing the PMC with one of the ceramic beehive kilns w/gel alcohol till the cup burns out (about 10 to 12 mins) .
Any ideas?

 

[BRobbins629]

Originally posted by ldb2000

Could it be that I'm not firing the PMC right

Could be a defect even before you fire it. If you are using a mold to shape the clip, then you should remove the piece from the mold while it is still pliable and treat is very carefully. PMC is very brittle when it is dry and before it is fired. This is when most of the defects initiate. If a crack is started at this point, it is very difficult if not impossible to fix or patch. I've even tried soldering them with silver solder and that doesn't work.

 

[ldb2000]

Thanks for the idea Bruce , that might be the problem , I will have to watch the next one I do .
As for fixing and patching PMC yes the stuff is a bear to work with . I was trying to silver solder to it and was having very little luck as the solder seems to flow well and stick but peels off way to easy

 

[Texatdurango]

I've had good luck with patching tiny cracks and imperfections with the PMC syringe paste both before and after firing and re-firing. I just use a torch and get it the PMC to bright orange for about 5 minutes then dump it in some water.

 

[ldb2000]

George how about attaching the finial mount to the clip .
I tried silver solder but the brass ring just peeled off the clip (solder stuck to the brass ring assy but not the clip)\ also tried a PMC slurry/paste (the slurry/paste was about the consistancy of toothpaste) with similar results is the PMC paste any different the a homemade PMC slurry/paste

 

[Texatdurango]

Originally posted by ldb2000

George how about attaching the finial mount to the clip .
I tried silver solder but the brass ring just peeled off the clip (solder stuck to the brass ring assy but not the clip)\ also tried a PMC slurry/paste (the slurry/paste was about the consistancy of toothpaste) with similar results is the PMC paste any different the a homemade PMC slurry/paste

I was told by my PMC instructor that any PMC pieces "glued" together with PMC paste was bonded into one piece when fired. I couldn't answer the question about the home brew since I never tried any.

I joined a PMC discussion group on Yahoo that gave me a lot of valuable information...http://groups.yahoo.com/group/MetalClay/