Food safe adhesive - stainless to porcelian
January 17, 2010 10:57 PM   Subscribe

What sort of adhesive do I need to stick stainless steel to a ceramic surface, which will withstand repeated immersions in boiling water, and will be food-safe?

I have a pair of egg coddlers which have a stainless rim-with-a-thread, which mates to a stainless lid. The rims have detached from the ceramic main part of the coddlers, and I would like to reattach them.

Pic here.
posted by pompomtom to Food & Drink (11 answers total) 1 user marked this as a favorite
 
You're not going to find one. That's the point of stainless steel.
posted by Chocolate Pickle at 11:25 PM on January 17, 2010


I checked this website, but it doesn't say whether you can put it in boiling water so YMMV.
posted by TooFewShoes at 11:25 PM on January 17, 2010


I'd go with silicone sealant, since it's waterproof, copes with temperatures well above boiling point, chemically almost inert, and should be flexible enough to cope with the differential expansion of ceramic vs. steel. Get one that's rated for underwater use.
posted by flabdablet at 11:42 PM on January 17, 2010


What about a ring-shaped rubber seal, of the kind used in coffee percolators?
posted by embrangled at 11:43 PM on January 17, 2010


Food safe RTV (IE: Silicone) adhesive. Check restaurant supply houses for a local source.
posted by Mitheral at 12:01 AM on January 18, 2010 [1 favorite]


3m.com also has a lot of options, and their contact form has been very helpful in the past answering questions for me like "which adhesive is best to stick x to y while still meeting z, 3 and 4 requirements?". My questions were more for industrial use, but I have a feeling they'd be willing to answer this type of thing too.

Also there are several of different types of RTV (room-temperature vulcanizing) adhesives, so be sure to check that it's food-safe.
posted by This Guy at 6:19 AM on January 18, 2010


Looking at your picture and thinking about your description, it sounds to me as if the threaded rim will no longer tighten down securely on the ceramic cup because of wear or chipping on the cup where the threads of the stainless rim engage (which I guess to be a couple of tabs since no threads are visible on the part of the ceramic shown), wear or bending of the rims, or some combination of those.

Instead of glue of any kind, I would try building up the rim of the cup underneath the stainless steel with either several layers of aluminum foil wound on as if it were tape, or some stainless steel wool, or, if you are lucky enough to be able to find some, stainless steel foil. The aluminum foil might tend to corrode a bit, and could make for a very tight seal.
posted by jamjam at 11:28 AM on January 18, 2010


Yeah, I think food-grade silicone would do it. You shouldn't be immersing the whole coddler, though -Royal Worcester recommends that coddlers only have water halfway up the sides.
posted by oneirodynia at 12:54 PM on January 18, 2010


Response by poster: it sounds to me as if the threaded rim will no longer tighten down securely on the ceramic cup because of wear or chipping on the cup where the threads of the stainless rim engage (which I guess to be a couple of tabs since no threads are visible on the part of the ceramic shown)

Sorry if I've given the wrong impression. There's no thread at all on the porcelain part. The rim was secured by some sort of adhesive which has worn off through repeated use. The surfaces to be stuck together are each quite smooth.
posted by pompomtom at 1:23 PM on January 18, 2010


You didn't give the wrong impression, I guessed wrong. I told myself that if it had been glued I'd probably see some residue on the porcelain, and I couldn't detect any.

Thanks to Mitheral for finding a link to food-safe silicone; I've been using aquarium sealer which I could find only in small tubes.
posted by jamjam at 4:32 PM on January 18, 2010


(Chocolate Pickle is completely wrong, please don't be discouraged.)
You may be able to fix this with no adhesive at all:
1) Wrap the porcelain with a thin plastic strip, aluminum foil, or better yet stainless foil until you cannot get the ring on.
2) Heat the stainless ring in the oven (to 200C) so it expands a little and can be dropped onto the cup, allow to cool.

This will hold because in future you will be heating the porcelain and stainless at the same time, and despite the low expansion of porcelain with heat, you'll only be heating it to 100C and the ring shouldn't expand enough to fall off. It's labor-intensive, may fail, and you run the risk of burning yourself, but it's a solution that doesn't risk any chemicals in your eggs.
posted by wzcx at 6:12 PM on January 18, 2010


« Older Where to live in the San Rafael, CA without going...   |   How do you write a construction contract in a... Newer »
This thread is closed to new comments.