Bump in goblet after flaring

[HiAltitude]

I have been struggling with goblets for a while now, but I seem to be stuck.

My goblet feet are much improved, following RAM's class. And the blown stems work fine and are lots of fun, thanks to Sizelove's and Goldschmidt's DVDs. But my cups come out, well, hippy. They seem okay right up until I'm flaring the lip, and then there is still a weird bump in the sides, below the lip. Am I'm not flaring far enough down into the bubble? Or, in trying to keep the opening small, am I opening the bubble too far up the point?

Should I try marvering the bump in or flaring the lip further out? I've tried both and messed up the cups in the process, but if I just knew which was right, I would keep practicing until I succeed. :bangHead: I worry that if I keep doing what I'm doing, I'll keep getting what I've got.

Here is what I've got (the two cups without bumps, I cut off the lip and reflared. Ugh.):

[petto]

the bump is there because the flare is not big/wide enough. the flare needs to go out as wide as the "hip" then there will not be a "hip".

[HiAltitude]

Thanks, I will try flaring further.

[HiAltitude]

Just to be clear, you mean wide as in further down to the widest part of the bubble? (As opposed to wide, as in a larger radius perpendicular to the axis of the cup.) Yeah, that makes sense.

I looked closer at the cups, and I only heated about an inch past the lip. Doh! Of course, cold glass won't move. So I re-re-...-re-watched the DVDs, and I see that the heat gradient is supposed to go WAYYYY further than what I'm doing.

Thanks again! That was very helpful. Sometimes it's hard to see things that are right in front of me. :blinky:

[davidwillisglass]

I would say you're trying to tool too much of the cup. If you completely shape the cup while you're blowing it, and open it right where you want the lip to be, then you don't have to tool the shape of the cup to match the lip, because it matches already. Firecutting your opening is helpful because you open the cup basically at full size and most of the tooling is eliminated (for most shapes) which eliminates the straight line defined by the flaring tool, as well as the gathering (thickening) of the glass that most likely accompanies tooling or "marvering in".

Parramore is great at teaching cups.

[davidwillisglass]

where do you live?

[HiAltitude]

I'm near Santa Fe.

What you say about flame-cutting at full size agrees with my experience: that if I flub flaring the bubble and then I cut off the icky part and re-flare, the results are okay. But, well, I've never seen anyone say that's the RIGHT way to do it. Everybody says to make a dime to nickel size opening. Plus, what to do about the lip-wrap? It looks ungainly if the bubble opening is too large. I guess I want to learn to do things "right".

But I agree with you that I am likely shaping the initial bubble poorly. Most of my feet flare correctly, so I must be doing something wrong when I try to change things for different bowl shapes.

[davidwillisglass]

part of my philosophy is that there is no "right" and "wrong" but there is good and bad. Whatever your method, if you get good results then that's great.

I really have a lot to say about all of this as I've studied on it quite a bit, if you email me your phone number, or i'll email you mine, we can chat about cups. davidwillisglass@hotmail

[Robert Mickelsen]

Remember what I said during the class about heat gradient making the shape.

If that "bump" forms while you are flaring, you are allowing the lip to get too cool. The lip must always remain hottest.

If that bump is there to begin with, then David is right and you should do as much shaping before flaring as possible. You remember I said during the class that you wanted to flare as little as was possible to obtain your shape. Do your shaping before the flare.

Also... practice with clear. Save the colored stuff for when you get the hang of it better.


- RAM

[HiAltitude]

Ah, well... cheap china color == cheap thrills. And every morning is Christmas morning, when there's something fun in the kiln.

I know that you said it in class and, again, last weekend -- "the heat gradient makes the shape." I am beginning to appreciate just how true that is. I really do replay these sayings in my head as I work. I think it helps.

At any rate, my small cups usually flare okay and without the bumps (those cups are the round shape you covered in class). But I started trying to make bigger bowls and other shapes, so it is likely something weird that I'm doing to the bubble. I will try to do more shaping using the heat, before opening the bubble. I think I'm keeping the lip itself hot once the bubble is open, but sometimes I do get carried away with making sure it's round and flat, so I'll try to pay more attention there too.

Anyway, Robert, that organic-looking sleeved stem that you made at the demo was amazing! I hope it fetched a great price. Hope to see you again next Spring, if your schedule permits. I will continue practicing diligently until then.

Thanks for the insights, one and all!

Peggy

[HiAltitude]

Just FYI, I assembled one of the goblets and, while far from perfect, the bump isn't so objectionable as I had feared. But I will still work on making better shapes.

(The top of the cup looks funny in this picture, but not in real life. I've noticed this before, when using the photo-cube. I think I may need additional lighting. Also FYI, the assembled goblet is 9" tall)

Cheers!

[Robert Mickelsen]

Well you remember the *other* thing I told you... always say you did it on purpose! ;)

Try using a gradient background inside the cube. Back your lights off for more diffusion, and go for longer shutter times. Then run levels on it in photoshop to step up the contrast a bit. That should help.

- RAM

[HiAltitude]

Thanks for the photo tips, too!

[Reflection]

I would say you're trying to tool too much of the cup. If you completely shape the cup while you're blowing it, and open it right where you want the lip to be, then you don't have to tool the shape of the cup to match the lip, because it matches already. Firecutting your opening is helpful because you open the cup basically at full size and most of the tooling is eliminated (for most shapes) which eliminates the straight line defined by the flaring tool, as well as the gathering (thickening) of the glass that most likely accompanies tooling or "marvering in".

Parramore is great at teaching cups.

I haven't had much experience with these yet, but the few times I'd tried I kept running into the same problem HiAltitude's having. This seems to make sense though. Going to try another this weekend and see where I get with it.

[BORO]

Great zombie thread , amazing info. rep +

I wish more people would bump the old threads with the gold nuggets.