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#1 TamiB

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Posted 22 April 2011 - 05:26 PM

Looking for words of wisdom. My grinder (Inland wizling, brand new) is chewing up my glass (a variety of glass from a Spectrum rack pack I purchased to experiment with). Being that I am new to all this I am pretty sure it's me and not the grinder. I have tried a lighter touch but that doesn't seem to make much difference. I've adjusted the bit a hair and tried three different types of glass, the damage is happening on the bottom side and the chips coming off seem quite large. The "finished" pieces look like crap, all ragged. Help!!

Also I purchased some agate online thinking I was getting whole pieces but alas! (live and learn) I received all shards. Not a whole one in the lot, but I think I can use some of it. Question is...can I grind down the edges where it is broken? It's quite rough I don't want to wreck my grinder bit.

And one more, cuz good things always come in 3's. I have read to give globs and nuggets a quick grind before foiling and I have read not to. Advice?? Thanks in advance. Tami

#2 Rebecca

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Posted 22 April 2011 - 05:43 PM

Your grinder might not be turning true. Look at the top of the shaft when it is turning and see if it looks "fuzzy" or wobbly. If it does, you might need to send it back to the company.

Yes, you can grind agates.

No, don't grind globs before foiling. Sometimes they need to be washed, but the adhesive on foil sticks better to a smooth surface than to a ground surface.

Rebecca

#3 Stephen Richard

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Posted 23 April 2011 - 03:04 AM

Another thing I have seen suggested is to grind some scrap glass to reduce the" harshness" of the new grinding bit.
It could also be that the bit is a very coarse one, which would add to the chipping problem.

#4 glasstired

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Posted 23 April 2011 - 08:52 AM

Your grinder might not be turning true. Look at the top of the shaft when it is turning and see if it looks "fuzzy" or wobbly. If it does, you might need to send it back to the company.

Yes, you can grind agates.

No, don't grind globs before foiling. Sometimes they need to be washed, but the adhesive on foil sticks better to a smooth surface than to a ground surface.

Rebecca


Rebecca is right, it may be an out of true shaft. Another way to check that is when the bit is totally dry, bring a felt marker in from the side. Just barily touch the rotating bit and pull away. Stop the grinder and check the line the marker left. If it is consistant all the way around the bit. then your shaft is true. If not well pack it up and return it.

On a new bit, I always grind scrap glass or Agate first to take the initial bite off a new bit. Also make sure you do not have a coarse bit.
Mal

#5 TamiB

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Posted 26 April 2011 - 10:06 AM

Thank you.

#6 Larry from BC

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Posted 06 May 2011 - 11:17 PM

Thank you.

It is very unlikely that the problem is due to the shaft not runnung true. The chipping is most probably due to a course bit or not enough coolant or too much pressure against the bit when grinding. I agree with the idea about the marker... that is a neat trick but any bit running out that much would vibrate like crazy and you would know immediately the first time it was used

#7 Rebecca

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Posted 07 May 2011 - 11:21 AM

It is very unlikely that the problem is due to the shaft not runnung true. The chipping is most probably due to a course bit or not enough coolant or too much pressure against the bit when grinding. I agree with the idea about the marker... that is a neat trick but any bit running out that much would vibrate like crazy and you would know immediately the first time it was used



Too little pressure can also cause chipping. But I have had a grinder with the shaft not running true and it wasn't vibrating so that you would know it immediately. The excessive chipping was the only symptom, but we could see it when we ran the grinder and observed it closely. The tip of the shaft looked blurry instead of crisp. The manufacturer took it back and confirmed the problem and sent a new grinder which did not chip. I agree that a new head will cause a lot of chipping, but if it doesn't go away with use, check the shaft.


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#8 glasslass

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Posted 13 May 2011 - 05:52 PM

Looking for words of wisdom. My grinder (Inland wizling, brand new) is chewing up my glass (a variety of glass from a Spectrum rack pack I purchased to experiment with). Being that I am new to all this I am pretty sure it's me and not the grinder. I have tried a lighter touch but that doesn't seem to make much difference. I've adjusted the bit a hair and tried three different types of glass, the damage is happening on the bottom side and the chips coming off seem quite large. The "finished" pieces look like crap, all ragged. Help!!

Also I purchased some agate online thinking I was getting whole pieces but alas! (live and learn) I received all shards. Not a whole one in the lot, but I think I can use some of it. Question is...can I grind down the edges where it is broken? It's quite rough I don't want to wreck my grinder bit.

And one more, cuz good things always come in 3's. I have read to give globs and nuggets a quick grind before foiling and I have read not to. Advice?? Thanks in advance. Tami


If you have ruled out all of the possible problems mentioned in other responses perhaps you may want to try using a GelBit manufactured by Techniglass Co. I find these bits grind very well. According to the packaging label the "polmeric base absorbs shock and reduces chipping". I have been using these bits for about 3 years and will continue to do so. They are very economically priced and do not require a "break in" with scrap glass. Not all stained glass stores sell them. I get mine from an online source in Maryland.

#9 Larry from BC

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Posted 13 May 2011 - 09:11 PM

If you have ruled out all of the possible problems mentioned in other responses perhaps you may want to try using a GelBit manufactured by Techniglass Co. I find these bits grind very well. According to the packaging label the "polmeric base absorbs shock and reduces chipping". I have been using these bits for about 3 years and will continue to do so. They are very economically priced and do not require a "break in" with scrap glass. Not all stained glass stores sell them. I get mine from an online source in Maryland.

That is a great idea. I have read about these bits but not tried one yet. As I often deal with that same source in Maryland I intend ti try a couple. Those having problems should consider this also.

#10 Alan

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Posted 13 May 2011 - 09:30 PM

You stated: "And one more, cuz good things always come in 3's. I have read to give globs and nuggets a quick grind before foiling and I have read not to. Advice?? Thanks in advance. Tami"

I have NEVER given globs or nuggets a grind before foiling - yes, they may need to be cleaned. I usually use just a little plain dish soap liquid, a lot of water and one of those large plastic tubs that the frozen 'whipped' topping comes in - put the lid on and shake it up for a couple of minutes - rinse well and let dry - then foil. Never had a problem. BTW - the same plastic tub works well for burnishing the foil (I just put the foiled globs in the tub, when I get 40 or so globs in the tub - put the lid on and shake it for a minute or so - all the globs are perfectly burnished). YMMV (Your Mileage May Vary), but this works well for me.

#11 Stephen Richard

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Posted 14 May 2011 - 02:20 AM

As Alan say, the globs need to be clean. If you think about the impact/contact adhesive that coats the foil, it is so thin that it cannot fill any roughness. It is designed to go onto smooth surfaces.
In any case, the adhesive is only to keep the foil in place until soldered. It is the solder bead that holds the glass together over the long term, as the adhesive will deteriorate both as a result of the heat of soldering and the effects of time. As it is the solder that is holding the piece together, there should be a bead on both sides. This forms an "H" came to keep all the pieces in place.

#12 glasslass

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Posted 14 May 2011 - 11:18 AM

That is a great idea. I have read about these bits but not tried one yet. As I often deal with that same source in Maryland I intend ti try a couple. Those having problems should consider this also.

For those using these bits for the first time -- do not over tighten the set screw in order to avoid cracking the plastic. Just tighten sufficiently so the bit will not move up or down when you try to move it by hand. I often have two grinders set up using the regular bit and the fine bit for the finish grinding. I started doing this method when I was making stepping stones where any chipping will allow migration of the grout into a chip which causes some distortion of lines.




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