Re: Stabilizing veined quartz slab?
I would hardly call myself an "expert" on lapidary matters, but would be happy to *noodle* some thoughts on the matter with you - so long as you take them with the grains of salt or ten they deserve as "amature advice."
Fractured materials such as you describe are always problematic at best. As you know, you are faced with trying to hold together thin slices or layers of different tenacity and - probably - even chemistry [quartz & chrysocolla]. I don't know of any man-made material that holds up as well as quartz or similar natural materials. Things like opticon and epoxies are sometimes acceptable "second stringers" but they are not any where near being solid quartz. We make do with them - pure and simple.
Which, I think - is by way of saying what you already know: You are always taking a chance with them. Sometimes it works great, and sometimes we get disasters. - Hope for the former! :~}
That said as a "given", then the next question would seem to me to be how we can optimize any gluing we do. Does drawing our stabilizer into the stock perpendicularly work better than at other angles? I kind of doubt it, but I can't say that I know this for certain. I think, though, that the best coverage you can get - no matter what type of epoxy/etc. you use - is to use low but even heat to SLOWLY draw the binder across all quartz surfaces and get them coated as evenly as possible. [I am applying the cabinet-maker's adage that "Two thin coats beats one heavy one every time." It's time tested and proven.]
Since, as you write, 'The veins isolate small areas of quartz, anywhere from 1/8" to 1" pieces. and I would like to include some of the veins in a cab, but no matter how careful I am, the piece always splits along the vein leaving mostly just a piece of quartz. I suppose I could soak cyanoacrylate or epoxy into the veins before cutting, but I don't know what adhesive would be best, or the best way to soak something in, or even if that would hold up to grinding.'
I don't think it matters beyond doing it slowly to get best possible coverage. Epoxies/resins/cyanocarolates/etc. - even opticon, for that matter... - are all similar, I think, in hardness to plastic resins. By the time you have glued your stock up basically you are dealing with a block of plastic shot through with thin layers/veins of quartz - a composite.
As to color changes over time, I firmly believe that every one of the currently available fillers will yellow with time. One product or another may give some miniscule advantage. But I'm not so sure that any of them have a sufficient one to recommend them over another.
Well... - I don't know if any of that helps, but maybe it does a little - even if only to help you think it out a bit further.
I hope the cab(s) turn out super. Post a shot or two for us somewhere
From Alan - June 03, 2007 at 09:51:35