New Ridgid Tablesaw

[dpb]

Robatoy wrote: ...

The diamond cleaves, not along a "fissure" but along the underlying crystal facets or planes.

Granite is not a ductile material even as compared to cast iron. It has excellent compressive strength, thermal stability, doesn't rust, etc., ... _BUT_ it doesn't have any significant bending resistance and is far more likely to fracture under a moderate impact than cast iron.

The two materials are so differing in their properties it's unlikely you can even find equivalent measured values for them -- there's no essentially no such thing as "ultimate strength" or "yield strength" for stone as well as a measured Young's modulus.

I've no real idea how well these new tops will hold up in normal use but the disadvantages still seem to have much going against as the pluses have going for them to me. Time will tell, I suppose. If they're really a great thing, they'll take over; otherwise it'll just be a relatively short-lived fad. (The latter would be my guess at the moment)

--

[LEGEND65]

And then Lee Valley will come out with their new line of granite hand planes ;)

UHMW hand planes?

-Kevin

[Morris Dovey]

Stainless steel, please!

[Lew Hodgett]

Only if it is 316L.

Forget the cheap stuff the use for pots and pans (304 AKA: 18-8)

Lew

[Swingman]

"Robatoy" wrote

Used two part epoxy to glue the wood "backsplash" on this 'kitchen desk' last year:

month later someone apparently hit it with enough of a 'shear' force to knock it loose and chip the granite, leaving 1/4" deep pits where the glue had been applied. The granite chips were still neatly bonded to the wood and the wood was not damaged, so it certainly appears that the epoxy indeed weakened the granite?

Decided I didn't want to repeat the process, so I drilled 1/4" holes through the granite and ply substrate under each foot, applied some construction adhesive, and ran a wood screw into the wooden feet from underneath. I figured a mechanical fastener would hopefully preclude a future service call, and there have been no reported problems since (now that that was said out loud, just watch the phone ring tomorrow!).

The question: what would *you* have used as an adhesive in the first place if forced into a similar situation?

[MikeWhy]

I doubt the epoxy penetrated the stone surface by 1/4" and compromised the material. What likely happened is the material directly under the adhesive spots failed in direct shear, as concrete would in similar circumstance. I would expect to find 45 degree cones under the spots of adhesive.

Depends on edge distance. The expected failure mode is still direct shear, this time from the bored hole to the edge. The backsplash likely will now fail first.

It isn't a matter of which adhesive. The epoxy held. The failure was in the substrate, the granite. Approach the problem as though the desktop were high strength concrete. How many anchors, how deep, how far from the edge, would you use if it were concrete?

[Lew Hodgett]

Like you, my first impulse would have been epoxy; however, on 2nd thought, the epoxy cured and provided a connection which transmitted the impact to the granite, resulting in failure.

A good adhesive such as Sikaflex 291 or 3M 5200 would provide a good bond while absorbing enough of the impact energy to avoid granite failure.

IMHO, mechanical fasteners should be avoided.

If you do use them, make sure holes in granite have clearance to provide float.

BTW, the epoxy didn't attack the granite, it was simply stronger in an impact application.

HTH

Lew

[-MIKE-]

Chrome plated granite, thank you.

[-MIKE-]

What, you couldn't find any more wood to trim out between crown-n-crown? :-p

Nice work.

[HeyBub]

I think I would have glued a small trim piece to the granite and the divider to the trim piece. That is, install a "weaker link" than the granite itself.

[Larry Jaques]

Yeah, I know this is an ancient thread, but...

On Sat, 14 Mar 2009 21:32:33 GMT, the infamous Nova scrawled the following:

Ditto, whenever possible, Yack. But I want them to pay for parts and shipping.

Many large item mfgrs allow you to return them to the dealer you bought them from and their trucks will pick them up. Check with yours before buying. Also, disassembly and returning the broken part with pics should be allowed.