Thread: Granite references: importing or not

Originally Posted by ian

Greg,
go easy on me if I'm barking up a tree, but how does spot lapping granite differ from spot sanding wood?
being granite and therefore relatively soft, I would think you could spot lap with AlOxide, carbide or diamond paste

In fact I am up against my ignorance boundary. I know jack about lapping (apart from the foolishness of trying to "lap" a plane sole on glass years ago). I suppose that diamond paste and some kind of tool would allow you to knock down the high spots. The idea of spotting with another 100kg+ granite for dozens of cycles makes me tired. (And I have a crane)

lapping it would be easy....

But how are you going to know where to lap and how much to lap and when to stop lapping?

I know it is bloody frustrating to see plates in the US for $50 and they are $700 here...

Here's a lengthy thread on why you cannot affordably lap your own plates:

Lapping A Granite Surface Plate - The Home Shop Machinist & Machinist's Workshop Magazine's BBS

As RC says, the spectre of cheap granite in the US haunts all of us. As does everything else. I just bought a couple of machine lights for $60 each. The same lights here are almost $900 (nine hundred) each. That's gotta be a record disparity.

Getting back to the plates, I am going to see if I can get one on an ENCO free shipping deal sent up to a car importer for forwarding to me.

Greg

Originally Posted by Greg Q

As RC says, the spectre of cheap granite in the US haunts all of us. As does everything else. I just bought a couple of machine lights for $60 each. The same lights here are almost $900 (nine hundred) each. That's gotta be a record disparity.

thats it.... we all need to all immigrate to the USA

"prices"...it also happens with clothing..in my case icebreaker thermals...going to be getting real cold in the shed for the next few months ..... here in adelaide it cost me 130 for a pair during a sale...can get the same stuff out of NZ for NZ$130.00 thats AU$96.00
if you order NZ200 or more you get free freight...and you $20NZ bonus voucher for every 100 you spend....who's gunna be a warm toastie in their shed this forthcoming winter when machining stuff....ME!!!!
(pm me if you want the web site)

Bought a few odds and ends via Alibaba and haven't had a problem - yet, touch wood! Last quote was CIF to port, but that's where you get the rough end of the pineapple, as others note. If there's processed wood in the shipment it's normally OK...at least from the first world, raw timber will be another matter.

Know sfa of much anything to do with lapping, had four cast iron surfaces done some years back though, for a few hundred bucks. This mob was helpful with suggestions and I imagine lapping a large surface by hand would have me at least, suicidal......Kemet International - Precision Lapping and Polishing with Diamond Superabrasives

Be aware with shipping charges you have several organisations to go through.. All separate..

You have the boat that delivers it..

Then you have the state transport department who pilot the boat to get it alongside the port.

Then you have the port authority who runs the port, they look after the tying up of the boat and charge the boat owner for the length of time it stays tied up.. more fees

You then have AQIS to inspect the freight. Another charge

You then have the stevedoring company who unloads the boat.. more fees

You would be forgiven to thinking that docking a boat and getting freight off is a simple procedure like unloading a car or a plane but it most certainly isn't..

It opened my eyes when I saw it all in action..

Originally Posted by eskimo

thats it.... we all need to all immigrate to the USA

"prices"...it also happens with clothing..in my case icebreaker thermals...going to be getting real cold in the shed for the next few months ..... here in adelaide it cost me 130 for a pair during a sale...can get the same stuff out of NZ for NZ$130.00 thats AU$96.00
if you order NZ200 or more you get free freight...and you $20NZ bonus voucher for every 100 you spend....who's gunna be a warm toastie in their shed this forthcoming winter when machining stuff....ME!!!!
(pm me if you want the web site)

My wife works for one of the major retailers (who were in on the push to cripple online shopping a couple of months ago). She'd like to buy one of her products, but even with the 20% staff discount it is still twice the (shipped) online price. The irony that she is part of the reason for high local prices does not escape her.

If I thought there was a market I'd import a container load of these things and sell 'em at some reasonable mark-up.

Greg I thought it was actually possible to scrape granite too? I'm not about to try it on mine, but given that it scratches it should be able to be scraped if my logic isn't too flawed I think the reason that they're not scraped is firstly because they are typically very heavy, and lifting one on/off a master plate would be a nightmare, even for a smallish plate like mine. But mainly the question would be why be would you? The granite is very stable, so the only reason it should be anything other than as flat as the day it was lapped is due to wear. None of us here are ever going to wear out a granite surface plate I'd suggest. For professional shops that do in fact wear their plates I understand they send them back to be relapped flat again.

As far as lapping 3. Good luck with that! Yes the principle is sound but I'd expect you'd give up in frustration a long time before it was flat enough for serious work.

The irony about the access to cheap tooling in the US is that most of it comes out of China. There's therefore no good systemic reason for the massive disparity in pricing between here and there. Too many fingers in the pot, all trying to take too much from too little is typically the reason for it.

Pete

Originally Posted by Pete F

Greg I thought it was actually possible to scrape granite too? I'm not about to try it on mine, but given that it scratches it should be able to be scraped if my logic isn't too flawed I think the reason that they're not scraped is firstly because they are typically very heavy, and lifting one on/off a master plate would be a nightmare, even for a smallish plate like mine. But mainly the question would be why be would you? The granite is very stable, so the only reason it should be anything other than as flat as the day it was lapped is due to wear. None of us here are ever going to wear out a granite surface plate I'd suggest. For professional shops that do in fact wear their plates I understand they send them back to be relapped flat again.

As far as lapping 3. Good luck with that! Yes the principle is sound but I'd expect you'd give up in frustration a long time before it was flat enough for serious work.

The irony about the access to cheap tooling in the US is that most of it comes out of China. There's therefore no good systemic reason for the massive disparity in pricing between here and there. Too many fingers in the pot, all trying to take too much from too little is typically the reason for it.

Pete

Yeah, you've got it Pete...too few buyers having to support too many people in the supply chain.

WRT to scraping a granite flat: You are right that it would take three (in which case you have already paid more than one good one). Or it would take a good master, in which case why scrape the other one?

Earlier this evening I was trying to evaluate a milling machine component on my granite flat and ran out of room for indicator stands etc. One more damned thing to feel inadequate about.