Glazing tools - using magnets

[Min]

Glazing tools and tips brought up in this thread, starting a new thread as this should probably be in the Studio Operations section.

This is how I use magnets when glazing, no tong marks, drips or finger marks on the glaze. It’s been a game changer for me with the pots I dip. Flat bottoms on pots work the best but you can do rounded bottoms, it’s just a bit less stable while dipping. 

- liner glaze the inside like usual

- rare earth magnet(s) wrapped in a scrap of plastic with twist tie inside the pot. twist tie is used as a handle. keep the twist tie below the rim of the pot

- another rare earth magnet(s) with a flat head bolt for a handle on outside of pot

- fishing magnet used for larger pots, they come with a handle so don't need a flat head bolt for a handle

-number of magnets needed determined by pot weight (and base thickness). I try to use just enough to be adequate to pull the pot from the glaze but not more or else they can be fiddly to remove. for tiny pots I use 1/2 pieces of broken magnets.

- hold the pot by the bolt and push the pot into glaze then lift it out. (rotate the pot slightly to have any excess glaze roll around the rim) 

- when the pot is dry enough to touch at base area turn it over and remove magnet(s) from either side. 20 seconds or so for most glazes. I hold the pot on the outside bottom of the pot when flipping over 

- you can slide the pot onto the edge of a counter while removing the outside magnet if you don’t want to wait for the glaze to dry enough to hold onto the pot, or stuff your hand inside the pot to move it to a ware board.

- when I first started glazing like this I got a couple blood blisters, don't pinch your fingers, those magnets are strong!!!! I use the ones from Lee Valley tools. (to separate them use an edge of a counter and push them apart)

Anyhow, that’s it, simple and it works. I tried to think of a way to market the magnet glazing but life got in the way.

Edited December 17, 2022 by Min
added the link

[GEP]

I’ve been using neodymium magnets as glazing tools too, thanks to @Min suggesting this to me several years ago. Can confirm that this is a game changer! I have my inside magnet wrapped in fabric held on by a rubber band. The fabric helps cushion the magnet so it doesn’t disturb the liner glaze, and the rubber band “stem” is like a handle. My outside magnet has a big eye bolt as a handle. 

I’ve learned to keep them stored on two different shelves, otherwise they will seek each other out and stick together, and it takes a lot of strength to pry them apart! 

[Babs]

Keep them away from yur controller, dont think they like magnets.

So they elease from the glazed ware ok?

[GEP]

1 hour ago, Babs said:

So they elease from the glazed ware ok?

As long as the liner glaze is fully dry. I hold onto the rubber band “stem” of the inside magnet while I pry off the outside magnet. The outside magnet doesn’t touch a glazed surface, just the waxed underside of the pot. Once the magnetic field is broken, the inside magnet simply falls away. 

[Juxtaposie Jen]

My husband uses some really strong magnets that he can turn on and off with the handle.  I am goi g to need to “borrow” one   

I have a thing for magnets in general and kinda mad that I didn’t think of this before.  
 

Genius I say!!

[Hulk]

Quieter than the vacuum cleaner method!
Looks good.

Edited December 18, 2022 by Hulk
on account o' because

[PeterH]

7 hours ago, Juxtaposie Jen said:

My husband uses some really strong magnets that he can turn on and off with the handle.

I haven't heard of this before, do you have a trade-name for them?

This explains a/the mechanism, and may be a starting point for some DIY-er . 
How to Build an ON/OFF Switch for a Permanent Magnet
https://interestingengineering.com/video/build-on-off-switch-for-permanent-magnet

The ones I saw on the net looked expensive, and possibly overpowered for the application.

Edited December 18, 2022 by PeterH

[Min]

11 hours ago, Babs said:

So they elease from the glazed ware ok?

Yes, like Mea said once you remove the magnet on the outside the inside one falls away. If the inside glaze is soft then just drop a scrap of newsprint into the pot first and set the magnet on that.

Another point about why I use a twist tie with the inside magnet is so I can reach the magnet without touching the inside of the pot. Bend it shorter for short forms. For wide open forms like bowls just using the magnet bundle is enough. 

Use enough magnets to get a strong bond between the inside and outside magnet(s), needs to be strong enough to hold together while removing the pot from the glaze bucket (with the suction from glaze) but not so strong that they are difficult to remove.

Rare earth magnets are strong but they are fragile. I've tested ones from different suppliers, I have found there is a difference in the strength of them. They can break but are still useable. I have read that if you have a pacemaker then it's best not to use them. 

 

[Juxtaposie Jen]

@PeterH  his is similar to one he has  

Magswitch

I almost wonder if it might be too strong 

 

[Callie Beller Diesel]

@Min@GEP do either of you have recommendations on how much weight the magnet needs to be able to hold? The ratings on the lee valley website assume you’re just attaching it to a metal surface, but when there’s a second magnet involved, I assume there’s a difference. 

[Bill Kielb]

15 minutes ago, Callie Beller Diesel said:

The ratings on the lee valley website assume you’re just attaching it to a metal surface, but when there’s a second magnet involved, I assume there’s a difference. 

Just a note, the separation thickness definitely has a major impact on holding power. A friend - very accomplished potter - has been rehabbing both arms after major surgery and needed to resort to trial and error for her throwing thickness. As part of rehab she has been making small pots / bud vases over time to rehab …… lots of them thus far, so speed and ease in glazing led her to the magnets. Separation between the magnets has a giant effect that likely requires testing to figure out.

[Min]

35 minutes ago, Callie Beller Diesel said:

@Min@GEP do either of you have recommendations on how much weight the magnet needs to be able to hold? The ratings on the lee valley website assume you’re just attaching it to a metal surface, but when there’s a second magnet involved, I assume there’s a difference. 

Like Bill says it depends on how thick the floor of the pot is. Mug in my image above was thrown from 1 lb 2 oz + weight of handle, no trimming, base is about the same thickness as the walls which you can see at the top. I use these 3/4" ones, average mug uses 3 magnets. Doesn't matter how they are split up, 1 inside and 2 outside or vice versa. So, just ball park math Lee Valley says 3/4" ones will lift a 22 lb block so with a fairly standard thickness of pot base 66 lbs of lifting power for a bisqued mug weighing approx 1 lb. 

If you need more than 4 of the round ones I would suggest using a rare earth fishing magnet instead, less chance of chipping them. Fishing magnet on the outside, single round magnet on the inside.

Edited December 18, 2022 by Min

[Min]

2 hours ago, Juxtaposie Jen said:

I almost wonder if it might be too strong 

Could be but would be a good experiment to try! Let us know how it works if you try it.

BTW it seems your link isn't working.

[Callie Beller Diesel]

@Min I was looking at these ones from the Canadian Lee Valley site, because they have the hook attached. I was fighting with glaze tongs and some serving dishes in a glaze bath about a month ago, thinking there had to be a better way. 

[Min]

2 hours ago, Callie Beller Diesel said:

@Min I was looking at these ones from the Canadian Lee Valley site, because they have the hook attached. I was fighting with glaze tongs and some serving dishes in a glaze bath about a month ago, thinking there had to be a better way. 

That doesn't look much stronger than the flat ones I mostly use. How deep are your serving dishes? What shape / how heavy are they? If it's a bowl shape and not too shallow I'ld use a stronger fishing magnet outside then you only need a thinner magnet inside so you don't land up glazing it along with the pot. I have one I scrounged from my husband, which I have since lost in the move, river in South America has a few with good reviews, could return it if not strong enough.

Edited December 19, 2022 by Min
added a link

[Callie Beller Diesel]

The shallow serving bowls I was thinking of start their lives as 5 and 8 lbs of clay respectively, but I can’t say as I’ve ever weighed the bisque piece. Between drying and trimming, I’d estimate loosing about 1/3-1/2 the weight. They’re the pasta bowl kind that are kinda trendy right now. I sold out of them, so I don’t have one to measure exactly, but the largest size is probably somewhere between 12 and 14” wide, and about 3” deep.

The ones I’m making are just a single dip with wax resist decoration, so touching up a void where the inside magnet is wouldn’t be onerous. I just don’t want to kill my wrists trying to fish a giant platter out of the glaze basin because the points slipped. 

[Min]

I have dipped wide shallow bowls with magnets, they start out as 5 lbs then get trimmed down. I wax the liner glaze with the shallower ones. I haven't glazed over an entire bowl inside and outside with magnets. Have you seen the way Hsin-Chuen glazes inside large bowls with a plastic bag of glaze then pours the outside? Would this work better for a single glaze like you are doing? 

https://youtu.be/8U_5aVopa1k

 

[Callie Beller Diesel]

Interesting approach, but I usually do the entire piece in one go. I just need something to grip it with properly. I’ll get some magnets and report back when I’ve started to restock in the new year.

[kswan]

Happy new year to all!

Are you all using the same glaze inside and out when doing the magnet method? My liner glaze is different, and I've always hated when I dip something upside down and then it burps on pulling out of the glaze bucket. The burp slops glaze onto my liner glaze and I have to carefully get it off without also removing the liner. I tried practicing methods to reduce that effect, but I gave up. I know you can wax the lip, but I don't want to deal with that. Now I put my hand (or both if needed) inside the piece and lower into the bucket. It took practice to not let glaze flow inside, but it's better results for me since I can see what's happening. If there's a bare spot where the two glazes didn't overlap, I just dot glaze on with a brush, but most of the time it's fully glazed.

I could see the magnet method being really helpful for a wide flared bowl where I can't get good friction on the insides to hold it while dipping. In those cases, I hold it by the top of the rim to dip and then brush glaze near the rim afterward. That's not such a great method, though, I'd say. It doesn't look smooth, and it's time consuming. 

My current goal is to find a permanent dipping container for my main glaze. I would love to have a rectangular container wide and deep enough for platters to go in dipped straight down. Not too big, maybe 6-8 gallons, sturdy and with a lid. I should probably do a separate post on that. I'm sure people know about resources I haven't heard of! I want to save strain on my body not to lift my whole bucket and pour it into a pan for glazing plates and platters.

[Min]

22 hours ago, kswan said:

Are you all using the same glaze inside and out when doing the magnet method?

Not usually. If I don't want the outside glaze overlapping the inside liner glaze then I wax. If it's the same inside and out and an overlap is okay then just tilting the pot very slightly at the very last moment when lifting it out of the glaze prevents the burping. 

 

 

[Hulk]

There's a nice write up on page fourteen of this month's (March 2023) Ceramics Monthly magazine.

If ever I transition away from tape for a clean line at the foot, magnets it will be!
I've tried waxing, wasn't getting the sharp line, where there's full thickness up to the edge that tape can give, and there's the grip problem.
The magnets would solve the grip problem!

My grip isn't reliable enough on a narrow footring.
I want to be able to give the ware just the right amount of shake at the right time, in the right direction(s), so grip is important.
Also, keeping the ware flat throughout the dip is important - to avoid the burps - having a good grip helps a lot.
Min's magnet on a wand/handle should make keeping the ware flat much easier, as deviation from flat is amplified by the length of the wand.

[Bill Kielb]

5 hours ago, Hulk said:

If ever I transition away from tape for a clean line at the foot, magnets it will be!

Although not easier, real quality pin stripe tape is my go to for a super high quality edge. 1/8” gets me any radius / shape I want as well. Costly and time consuming, but old habits are ……… proven for when I want it perfect.

[Min]

7 hours ago, Hulk said:

There's a nice write up on page fourteen of this month's (March 2023) Ceramics Monthly magazine.

Thank you Tom!