Glazed over holes

[Soupchef]

I have a question, I have a stepdaughter that is starting her own ceramic studio. She's making Christmas trees. How do I prevent glaze from going in the holes? If they are glazed over how do I clear them period of tried using diamond tips dremmel, I've tried using grinding bits. But the ceramic keeps chipping or the bit wears out after one use. What speed do i set the bit to?

[Soupchef]

Pardon the newbie question,  I'm a 56 yo trying to make a stepdaughter happy.

[neilestrick]

You have to clean out the holes after glazing, but even then some glazes will run and fill the holes. So you have to make the hole big enough that it won't fill in if the glaze runs. When I make colanders, I use a 1/4" hole, and immediately after dipping the glazes, I blow on the holes to remove excess glaze. I don't clean them out beyond that. With 1/4" holes they won't seal up completely with a little glaze in them. If you're trying to get very small holes, that can be very difficult, because it won't take much for them to seal up. Can you tell us more about what the holes are for? Just for a hanger? If you do a larger hole, you could use ribbon or nice twine for the hanger.

[liambesaw]

You can get the hole wet before you glaze, or remove the glaze from the hole before it's fired.

[Soupchef]

Will this prevent the glaze from sticking in that location? She's been having me use a rat tailed file after burning our dremel bits galore. I just want to understand the reasoning. (It's only because I am an engineer 

[Soupchef]

She is creating a business of selling ceramic Christmas trees. Please have 1/8 holes in them for the standard medium and small like it's. When they glaze them the supposedly they use a dry brush that's round to clear out the holes, but I'm getting 3 to 5 holes in each tree that are almost always glazed over. I'm using currently a diamond tip drummle and I'm finding that I can't get a bite to start the whole and I'm sliding off the hole making  cutting into the sides. 

[Mark C.]

First lets start at fixing the issue before its an issue-once the tree is glaze find the right size drill bit to hand ream the glaze out of the hole before its fired-do not worry about a bare spot inside the hole-get all the glaze out.I often used a needle tool to work the outside glaze near the hole down. Just insert a needle tool and spin that around in a larger arc to remove some glaze thickness near the hole edge. I made pincushions for 4 decades that had small holes so I have lots of experience in this field. The small hole dilemma .

Use the largest bit that fits through the hole with your finger ream the hole of all glaze. This will cure 99% of all clogged holes.

The diamond Dremel bit is the best but it takes tons of time and patience .These is no shortcuts. That why I want to you to do the reaming of all glaze before firing.Its the only way to make this work easy.

Often fixing glazed over holes is just not worth it. Toss them and make new trees and do the cleanup on the front end of job so you do not have to drill them out which is prone to breakage and heartbreak as well as time suck.

 

One last note-its easier to add a small wood handle to that drill bit for hand use if you are doing a lot of this glaze hole reaming. I made one as I cleaned many hundreds of holes over the decades.

[Min]

1 hour ago, Soupchef said:

I'm using currently a diamond tip drummle and I'm finding that I can't get a bite to start the whole and I'm sliding off the hole making  cutting into the sides. 

If you have to drill them out then start with the smallest size diamond bit you have to make a pilot hole then swap bits to the finished size. Also keeping a slow stream of water on the area you are drilling out helps the bits last longer. 

I made buttons for a while, used a round toothpick dipped in water then pushed through the buttonholes to clear the glaze out. Like others have said far easier to prevent the problem rather than fixing it.

[Chilly]

Everything that @Mark C. said.  Doubled.

[JohnnyK]

What about the possibility of using wax resist in the holes before glazing? Photos would be nice for those of us not familiar with the problems...

[Chilly]

@JohnnyK  I'm guessing it's for something like this.  The holes have to be big enough to get the little bulbs in.  (They're not actually bulbs, you put a light fitting with an ordinary bulb at the bottom, but the light shines out of these little "bulbs.")

[Fred Sweet]

You might also consider getting a Kemper Cleanup Brush (CUB) or use a  pipe cleaner with both plastic and fiber bristles, or even Q-tips to clean the holes after glazing and before firing. If you taper the glaze back a bit in the outer surface a little it should help keep most of the glaze from flowing into the holes.

Regards,

Fred

[Babs]

Block holes with toothpicks or whatever prior to glazing

Any bare areas touch with paint or perm. texts after firing