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Angle Polisher - Process Questions
Posted: Tue Mar 09, 2004 9:36 pm
by cemoore
I've looked at the thread from last year called "Sanding sponges -- and now angle grinders and pads" and while its on topic, doesn't answer my specific question about user of angle polisher/grinder. I have a variable speed Fein tool with the velcro adapter to put the pads on (50,100,200,400,800,1500 grits). My first use of this on the edges of a plate I will slump into a bowl was easier than I thought. However, I didn't get a glossy finish. I realize I must be going too fast through some of the grits but before I do this and go through countless reworks, I'd like some advice. Is there a rule of thumb as to how long to spend at the polishing grits, lets say 200/400 and up? I have a wet belt sander with cork, felt and cerium oxide supplies but wanted to know if that's the way to go after the diamond pad polishing.
Thx
Cathy
Posted: Tue Mar 09, 2004 10:24 pm
by Bert Weiss
Cathy
The idea is to work through the grits from coarse to fine. Each finer grit should take longer to remove the grit above it.
I would use one tool or the other. The tool has a shape of attack that must remain the same through each grit. Basically you are removing the scratches grit by grit. You can go all the way to high polish.
To Fire polish float I take it to 400 and fire polish. BE seems to work OK stopping at 220.
Posted: Tue Mar 09, 2004 11:25 pm
by cemoore
Thanks Bert, I think I did the opposite. I spent much time at 50 grit, then smaller and smaller amounts of time on the way up. I guess I will do again tomorrow, beginning with 100 grit. On this same topic, any advice on how to hold a plate so I can get to all edges without adjusting. Right now I have my plate clamped to the side of a workbench, then I rotate it to get at each 1/3 of the plate, overlapping in some areas. That's the most cumbersome part, stopping to reclamp and rotate the plate. Any better ideas there?
Cathy
Posted: Wed Mar 10, 2004 9:50 am
by Bert Weiss
cahearn wrote:Thanks Bert, I think I did the opposite. I spent much time at 50 grit, then smaller and smaller amounts of time on the way up. I guess I will do again tomorrow, beginning with 100 grit. On this same topic, any advice on how to hold a plate so I can get to all edges without adjusting. Right now I have my plate clamped to the side of a workbench, then I rotate it to get at each 1/3 of the plate, overlapping in some areas. That's the most cumbersome part, stopping to reclamp and rotate the plate. Any better ideas there?
Cathy
Cathy
I'm not the expert here, but I'd work it by hand on the WBS. The trick is to work on the same place for each grit. I'd probably choose an unsupported spot of the belt to get a slight rounding of shape. Once you begin there, you need to do each grit in the same spot, being careful to hold the glass at the same angle.
Posted: Wed Mar 10, 2004 10:28 am
by charlie
i built a small table for my wbs so that i could just put it on the table and turn the edge against the wbs. this gives me the same angle against the belt all the time, and i don't get tired holding a heavy platter for a long time. the tabletop is on hinges, so that i can make a constant bevel if desired.
if you're doing this by hand, try doing it such that the grinding marks are at differing angles for each grade. you can then see when the previous grit scratches are gone much more easily.
Posted: Wed Mar 10, 2004 11:24 am
by hoknok
To Fire polish float I take it to 400 and fire polish. BE seems to work OK stopping at 220.
Bert, this seems to be a low temp? Did you mean 1400? I have never fire polished that low so I am currious if this works. Great if it does!
MIke
ps, like the easy bake oven photo. Do you use it as a tanning bed as well!!!
Posted: Wed Mar 10, 2004 11:26 am
by charlie
200 and 400 grit, not degrees.
Posted: Wed Mar 10, 2004 11:28 am
by Jackie Beckman
hoknok wrote:To Fire polish float I take it to 400 and fire polish. BE seems to work OK stopping at 220.
Bert, this seems to be a low temp? Did you mean 1400? I have never fire polished that low so I am currious if this works. Great if it does!
MIke
ps, like the easy bake oven photo. Do you use it as a tanning bed as well!!!
He didn't mean that was the temp, but the grit which he he went up to. In other words, with float, he says he polishes the glass up to a grit of 400 before firepolishing. So, (I'm guessing here) he probably starts with 80 or 120 grit, then moves to 220, then 400 - then firepolishes the glass in the kiln.
Posted: Wed Mar 10, 2004 12:20 pm
by Bert Weiss
When teaching, I talk about the concept of "Thinking in Glass" Charlie and Jackie are well versed in this language.
Posted: Wed Mar 10, 2004 1:02 pm
by cemoore
Unfortunately I have to get this piece polished without benefit of fire as its already been textured on the top surface (I'm grinding the bottom to a soft bevel on the edge of the plate). I plan on preserving texture during the slump. I won't go crazy though on the final polish as its going to pick up some slight texture from the mold anyway.
Thanks to all for your input.
Cathy
Posted: Wed Mar 10, 2004 1:08 pm
by janine
cahearn wrote: On this same topic, any advice on how to hold a plate so I can get to all edges without adjusting. Right now I have my plate clamped to the side of a workbench, then I rotate it to get at each 1/3 of the plate, overlapping in some areas. That's the most cumbersome part, stopping to reclamp and rotate the plate. Any better ideas there?
Cathy
I'm no expert but try laying the glass on a sheet of rubber. I have used this method with a similar tool to yours and it works fantastic, the glass sticks like crazy to the rubber. For edges I clamp the sander in a vice.
Janine
Posted: Wed Mar 10, 2004 1:47 pm
by janine
janine wrote:cahearn wrote: On this same topic, any advice on how to hold a plate so I can get to all edges without adjusting. Right now I have my plate clamped to the side of a workbench, then I rotate it to get at each 1/3 of the plate, overlapping in some areas. That's the most cumbersome part, stopping to reclamp and rotate the plate. Any better ideas there?
Cathy
I'm no expert but try laying the glass on a sheet of rubber. I have used this method with a similar tool to yours and it works fantastic, the glass sticks like crazy to the rubber. For edges I clamp the sander in a vice.
Janine
After rereading this thread, I see that you are bevelling the edge
I shouldn't have butted in. Guess it's obvious I'm no expert. I have however, used the rubber mat method on my potters wheel for edges, using various sizes of rubber mats and bats (need a slow wheel), and wonder if you could bevel it this way too????
janine
Posted: Wed Mar 10, 2004 2:13 pm
by cemoore
I didn't think of using the rubber alone. I had rubber under the plate when I clamped it to keep the glass from breaking against my table. I use the stuff that's meant for under rugs I believe, I buy it at Walmart in their crafts dept by the yard, very cheap that way. I use it to hold my glass in place when I'm cutting.
Thx
Cathy
Posted: Wed Mar 10, 2004 2:31 pm
by janine
Cathy:
I am using solid black industrial rubber, that comes in big rolls. It's about 1/4 thick. I don't know if the under carpet stuff would hold it. Sometimes I slightly moisten the glass and then I almost have to pry the glass off.
My boyfriend has an industrial fibreglass and metal fab shop so I have access to all manner of weird tools and polishing equipment.
He saw me struggling with clamping the glass to the table one day and gave me the rubber to try alone. It worked a treat. It was my idea to try it on my wheel, my only original idea to date, but it also works great. I have not had one piece fly off .......yet.
Janine
Posted: Wed Mar 10, 2004 3:05 pm
by Lauri Levanto
As I opened this can of worms...
I do it the other way. I clamp down the drill - yes I use it on a hand drill for speed control. For edges the pad is vertical,
for bottoms horizontal. a DIU lapwheel.
I keep the piece in hands and move it against the pad.
For sculptural forms, I use it like a car polishing
pad.
-lauri
Posted: Wed Mar 10, 2004 3:37 pm
by janine
lauri wrote:As I opened this can of worms...
-lauri
Yes but at least they're tasty worms, don't you think
???
Janine