Yixing Repair - Gap Filling

[ShuShu]

JB Weld or Epoxy does a very good job with putting together pieces of broken teapots, but is there a homemade solution to fill gaps or replace missing pieces? something like a clay that can dry and not need firing?

[pedant]

do you have a pic of something you're considering repairing?

if jb-weld is acceptable, it can often be used to fill gaps.

one or more of the following techniques may be helpful:

• using a form (masking tape? construction paper?)
• thickening by waiting about 30 minutes before using
• using an aggregate (sand?)
• building up in layers/coats
• sanding to remove excess material or smooth a surface

[ShuShu]

Thanks!
I don’t have a pic here with me, unfortunately. Basically a small piece of the edge of the spout is missing - I would say about 5 mm.
Since it is the spout, I’m somewhat worried about about jbw (should I?).
I have just seen so many pots repaired with clay and wondered if that is even an option.

do you have a pic of something you're considering repairing?

if jb-weld is acceptable, it can often be used to fill gaps.

one or more of the following techniques may be helpful:

• using a form (masking tape? construction paper?)
• thickening by waiting about 30 minutes before using
• using an aggregate (sand?)
• building up in layers/coats
• sanding to remove excess material or smooth a surface

[Baisao]

A common way to fill caps among luthiers is to use a mixture of baking soda and cyanoacrylate adhesive (aka superglue). The result looks similar to ivory, is nontoxic, tough, and able to be sanded.

[pedant]

Since it is the spout, I’m somewhat worried about about jbw (should I?).

what are your concerns?

A common way to fill caps among luthiers is to use a mixture of baking soda and cyanoacrylate adhesive (aka superglue). The result looks similar to ivory, is nontoxic, tough, and able to be sanded.

that's good when you need something clear or colorless. i've done that to fill glaze blisters on a cup's exterior. also to fill small voids in quartzite countertops (imo these guys make the best stuff, and they also sell an aerosol accelerator which works even faster than dusting with baking soda). i don't for certain know the chemistry, but bicarbonate probably accelerates the curing process and may enhance mechanical properties (seems to cure harder?). its properties are still generally inferior to epoxy's though (e.g. with peeling), so for demanding applications, clear epoxy is often better.

another consideration for gap filling is shrinkage. it doesn't matter for normal gluing, but it does for gaps because you have a relatively large volume of glue between two surfaces it needs to adhere to. volume shrinkage for cyanoacrylates (there are various kinds) can be 10% or more. many epoxies have 0 shrinkage.

i don't think there's a perfect solution for teapot repairs. i haven't found a product that i'm 100% comfortable with for direct contact with tea. there's also not a good one-size-fits-all approach. if available, look up the specifications of the products you're considering to help you decide.

for jbweld: http://www.aeroelectric.com/Mfgr_Data/J ... asheet.pdf
for an ethyl cyanoacrylate product: https://www.alliedelec.com/m/d/c4f69eb2 ... bc41fa.pdf

[.m.]

I've been pondering on the same problem. One thing that I've been thinking of, but never tried, so cannot say if it could work, is to use lead-free solder (tin/silver) to fill the hole or recreate the missing piece. It would probably not hold in place by itself, so some kind of epoxy glue would need to be used.

[Elise]

If I may suggest, you should have a look here. It needs a little practice to be done in a nice way but I know a guy who started repairing teaware for himself and other people started to send him their broken parts and he does a good job now. You can see an example here:
http://www.forumdesamateursdethe.fr/vie ... 40#p169548

[pedant]

I've been pondering on the same problem. One thing that I've been thinking of, but never tried, so cannot say if it could work, is to use lead-free solder (tin/silver) to fill the hole or recreate the missing piece. It would probably not hold in place by itself, so some kind of epoxy glue would need to be used.

that might look nice. you can also use a piece of gold if you have any of that lying around

[pedant]

If I may suggest, you should have a look here. It needs a little practice to be done in a nice way but I know a guy who started repairing teaware for himself and other people started to send him their broken parts and he does a good job now. You can see an example here:
http://www.forumdesamateursdethe.fr/vie ... 40#p169548

nice. i was wondering about that stuff but never bought any because i couldn't find what exactly it was made of.
i emailed them asking for the MSDS. if they reply, i will share the info.

[theredbaron]

The Japanese art of Kintsugi, done with Urushi (Japanese laquer) and gold or silver dust. In Kintsugi missing pieces of clay can be replaced with different contrasting pieces. In Kinstugi one does not hide a damage, but incorporates the damage and creates beauty out of it.

[Elise]

If I may suggest, you should have a look here. It needs a little practice to be done in a nice way but I know a guy who started repairing teaware for himself and other people started to send him their broken parts and he does a good job now. You can see an example here:
http://www.forumdesamateursdethe.fr/vie ... 40#p169548

nice. i was wondering about that stuff but never bought any because i couldn't find what exactly it was made of.
i emailed them asking for the MSDS. if they reply, i will share the info.

It is made of epoxy resin with golden colored powder (not real gold I think). Epoxy is a 2 component resin which is very stable when the reaction has finished.

[Bok]

It is made of epoxy resin with golden colored powder (not real gold I think). Epoxy is a 2 component resin which is very stable when the reaction has finished.

But as far as I am aware, not really food-safe.

[Elise]

After the reaction initiated by the combination of the two components, epoxy resin is supposed to be non toxic and food safe. I wouldn’t put it in the microwave or dishwasher by precaution, but you don’t do it with your teaware, right?
Anyway, epoxy will be less toxic than traditional Japanese kintsugi which remains slightly volatile even after complete drying.

[ShuShu]

Epoxy is just very hard to work with when you have to recreate missing pieces. This is why I was actually thinking of real clay. Does such a thing exist? a clay that doesn't need to be fired?

[Elise]

With the epoxy set comes a piece of paste that you can model in the shape you want and then cover with epoxy when it’s dry.

But I also saw yixing pots with chips that were sent back to yixing for repair and came back nearl as new. The missing piece had been made of a composite resin (also used in dentistry) which is a photo polymer (getting hard with uv-like light).

« Clay » that don’t need firing is not clay, there are some cement or plaster you could put color in. But, IMO, it won’t resist with water as a resin like material and it will be difficult to reach the exact color of the pot.