Kintsugi Pot Repair

lieuz

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I have quite a few small pots break on me through the years. IKEA was the last straw and pushed me off the fence and into action. I got some dinnerware delivered and a good 20% of the plates that came were broken. I got them replaced, they sent me more than what I ordered, but some still broke. That was when I said, OK, I need to try to repair these pieces, bonsai pots included. My pots that are broken range in value but they all have sentimental value.

I have done some research and I'm a traditionalist and wanted to go the route of lacquer over epoxy. It definitely takes a ton of time, much longer than epoxy; but, I want it to be a natural approach.

321202075_894225655038953_4431296691959798859_n.jpg
Here's the broken piece, you can see the hairline break.

323119350_2568492376615763_7133878537533839133_n.jpg
The two pieces side by side.

323376431_467182348961071_5559648099465386883_n.jpg
Cross section of one piece. The sides were sanded down and the edges were filed down to allow for better infilling for structural support.

323575530_1329271924513945_7966278264498051521_n.jpg
Cross section of the other.

324935071_857345658879067_7134424271321394401_n.jpg
The piece put back together with mugi-urushi (adhesive lacquer).

323530454_873140330593207_3283298404333000561_n.jpg
Bottom view.

321533502_482347587309321_131230107099337922_n.jpg
Note the oozing out of the mugi-urushi. Oozing is good at this stage.

321559440_1544147802718096_3943618324427546603_n.jpg
3 weeks later, the mugi-urushi is removed. I have learned, I should probably mask the area around the break point as the lacquer left a stain.

321925131_877424039980153_1324233670984668341_n.jpg
Side view, note how the oozed out lacquer left unfilled cracks. The next step is to infill those spaces with sabi-urushi.

324839390_928488775181653_3672698746823884015_n.jpg
View of the other side. The the joinery line is quite faint because of the scraping off of the mugi-urushi.

326432560_506323138353708_5846212926680586334_n.jpg
A week later, I applied the joined area with sabi-urushi to infill the small cracks. Note the stain, I will need to test sanding to see if I can remove the stain.

327082132_5868579133180021_2142588560670751721_n.jpg
**TOP PICTURE IS AFTER, BOTTOM PICTURE IS BEFORE** A few days after the sabi-urushi was applied, I cleaned off the infill with sand paper and a utility knife. It seems the sandpaper does remove stains. Note the clean surface afterwards.

327370109_550416433696331_8504907397863357412_n.jpg
**TOP PICTURE IS AFTER, BOTTOM PICTURE IS BEFORE** Note how much darker the fault line is and how the cracked/chipped locations took so much more of the infilled lacquer.

327417454_1233947747544115_1937679821632384752_n.jpg
**TOP PICTURE IS AFTER, BOTTOM PICTURE IS BEFORE** View from the other side, fault line is much darker.

I'm getting closer to the finishing steps. I will perform 1 more application of the infilling of sabi-urushi. Then I'll polish/sand with a piece of binchotan.

For those who are more knowledgeable, is it generally OK for kintsugi bonsai pots to be put back into use if lacquer is the choice of adhesive? I know that for dinnerware, plates are encouraged to not be put in the dish washer or be submerged for prolonged periods of time. Thoughts?
 

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lieuz

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Also, note these small hairline cracks. They only appear on the exterior and does not show up all the way through. I will have to address them. I had thought about just approaching it at the last step where I have to paint a layer of lacquer ontop of the surface; however, I think it is good practice to thin out the sabi-urushi and let that sit hopefully fill what it can fill. I'll go back through with sanding and polishing before I start the finishing step. It's also wise I heard to perform a second application of sabi-urushi on the rest of the project for good measure.

Capture.JPG
 

StPaddy

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I would think the only issue would be freezing temps. Expansion contraction etc. I live in southern California so don’t have to worry about that…I had a cracked pot and used mica powder and epoxy for the repair. Would like to have gone the traditional route but was looking for durability, and I believe even with the jb weld epoxy in sub freezing temps my repair will probably fail.
Nice work!
 

lieuz

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I would agree too, freezing temps would be terrible. What I've learned about lacquer curing is, it's like plaster or cement. It's not a "drying" process but a "curing" process. With lacquer, the more humidity you give it, the harder it becomes. During the curing process, 83% is the best threshold because the inside and the outside will cure together. Too high 100%, the outer layer dries too quickly leaving the inside to be gooey. Below 80% and the lacquer doesn't cure as fast so, what takes 3 weeks can now take twice the time if not longer.

So, I think, if I had to use this pot, it'd be for a tropical tree.
 

lieuz

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It's a struggle to keep the right humidity, here is my "muro" (humidity chamber). I just crack open the lid to a certain amount and leave it.

320013076_974441360198415_4792144296357059197_n.jpg
Go Washington Wizards!
 

rockm

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I have quite a few small pots break on me through the years. IKEA was the last straw and pushed me off the fence and into action. I got some dinnerware delivered and a good 20% of the plates that came were broken. I got them replaced, they sent me more than what I ordered, but some still broke. That was when I said, OK, I need to try to repair these pieces, bonsai pots included. My pots that are broken range in value but they all have sentimental value.

I have done some research and I'm a traditionalist and wanted to go the route of lacquer over epoxy. It definitely takes a ton of time, much longer than epoxy; but, I want it to be a natural approach.

View attachment 469887
Here's the broken piece, you can see the hairline break.

View attachment 469888
The two pieces side by side.

View attachment 469889
Cross section of one piece. The sides were sanded down and the edges were filed down to allow for better infilling for structural support.

View attachment 469890
Cross section of the other.

View attachment 469891
The piece put back together with mugi-urushi (adhesive lacquer).

View attachment 469893
Bottom view.

View attachment 469894
Note the oozing out of the mugi-urushi. Oozing is good at this stage.

View attachment 469895
3 weeks later, the mugi-urushi is removed. I have learned, I should probably mask the area around the break point as the lacquer left a stain.

View attachment 469896
Side view, note how the oozed out lacquer left unfilled cracks. The next step is to infill those spaces with sabi-urushi.

View attachment 469897
View of the other side. The the joinery line is quite faint because of the scraping off of the mugi-urushi.

View attachment 469898
A week later, I applied the joined area with sabi-urushi to infill the small cracks. Note the stain, I will need to test sanding to see if I can remove the stain.

View attachment 469899
**TOP PICTURE IS AFTER, BOTTOM PICTURE IS BEFORE** A few days after the sabi-urushi was applied, I cleaned off the infill with sand paper and a utility knife. It seems the sandpaper does remove stains. Note the clean surface afterwards.

View attachment 469900
**TOP PICTURE IS AFTER, BOTTOM PICTURE IS BEFORE** Note how much darker the fault line is and how the cracked/chipped locations took so much more of the infilled lacquer.

View attachment 469902
**TOP PICTURE IS AFTER, BOTTOM PICTURE IS BEFORE** View from the other side, fault line is much darker.

I'm getting closer to the finishing steps. I will perform 1 more application of the infilling of sabi-urushi. Then I'll polish/sand with a piece of binchotan.

For those who are more knowledgeable, is it generally OK for kintsugi bonsai pots to be put back into use if lacquer is the choice of adhesive? I know that for dinnerware, plates are encouraged to not be put in the dish washer or be submerged for prolonged periods of time. Thoughts?
I wouldn't trust ANY pot that has been broken into pieces with ANY worthwhile tree.

If you value the tree in the pot, think of what happens when mixture of tree sap and clay you're using to hold it together gives way under the weight of soil and tree...Particularly if the pot decides to disintegrate while you've moving it...Might work for a while with small mame and shito pots, but anything large and you're exponentially increasing the weight and structural support that mix needs to hold things together. Throw in intense sunlight, constant watering and the corrosive effects of fertilizer and the odds aren't with the pot...
 

rockm

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I would think the only issue would be freezing temps. Expansion contraction etc. I live in southern California so don’t have to worry about that…I had a cracked pot and used mica powder and epoxy for the repair. Would like to have gone the traditional route but was looking for durability, and I believe even with the jb weld epoxy in sub freezing temps my repair will probably fail.
Nice work!
I've used JB weld to put some BIG pots (18-20") back together. They've gone through repeated winters (although not filled with soil or trees). No issues so far. I'm testing them to see if they retain their structural integrity with the repairs over time. Below is a Ron Lang pot I've done this with. That's how the pot arrived via UPS.
 

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lieuz

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I wouldn't trust ANY pot that has been broken into pieces with ANY worthwhile tree.

If you value the tree in the pot, think of what happens when mixture of tree sap and clay you're using to hold it together gives way under the weight of soil and tree...Particularly if the pot decides to disintegrate while you've moving it...Might work for a while with small mame and shito pots, but anything large and you're exponentially increasing the weight and structural support that mix needs to hold things together. Throw in intense sunlight, constant watering and the corrosive effects of fertilizer and the odds aren't with the pot...
That's good insight. They'll probably stay as display pieces then.
 

penumbra

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I've used JB weld to put some BIG pots (18-20") back together. They've gone through repeated winters (although not filled with soil or trees). No issues so far. I'm testing them to see if they retain their structural integrity with the repairs over time. Below is a Ron Lang pot I've done this with. That's how the pot arrived via UPS.
I have a few large pots that were epoxy repaired. I have experienced no issues despite the fact one was repaired just over 30 years ago.
 

StPaddy

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This is good to know about the durability of jb weld. My pot was merely cracked so I covered the cracks with the epoxy. I plan to retire in about six years to a climate with real seasons so good to know thx.
 

lieuz

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I've used JB weld to put some BIG pots (18-20") back together. They've gone through repeated winters (although not filled with soil or trees). No issues so far. I'm testing them to see if they retain their structural integrity with the repairs over time. Below is a Ron Lang pot I've done this with. That's how the pot arrived via UPS.
How unfortunate... FWIW, this is definitely a learning experience. I have a teacher who is guiding me when I need the help so a lot of this is just learning how to do it so I can apply it to other ceramic ware outside of bonsai.
 

rockm

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Also done this with a big Kouyou that met a sad end during import a few years ago. Pot is 24" across. Made in the 1980's. Repeated application of heavy epoxy went on the inside, scraped off the excess on the outside before hardening, so smoother finish. Never going to be show material, but nice big alternative for one of my larger trees if needed.
 

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lieuz

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A month later, the lacquer in the pot is now cured to the point I can add the gold dusting finish.

Painted the red urushi on the joined site.
328222865_588894673053058_3604369269537358408_n.jpg

Other side of the pot with a more dynamic break.
327291091_506769851541994_1449563298638552389_n.jpg

Applying the gold dust by "pushing" the dust onto the site vs applying it directly.
328781832_607722314432132_7526464354774523288_n.jpg

Finished product.
327524501_716229806637672_7254405975809943035_n.jpg

328021627_633219251904795_9143935046857779671_n.jpg
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What was learned at the last step? The joinery site could have been buffed a bit more. Apparently if you look close enough the gold looks grainy when it can look smoother. Even though the finger can feel a smooth joint, it's still very rough. I will probably have to build multiple layers of sabi-urushi and sand it back and reapply multiple times and then sand with possible a piece of 600+, probably 1000 grit sand paper. This was a good practice run, going to put this piece away back into the muro for another month before taking it out and displaying it.
 

19Mateo83

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I have quite a few small pots break on me through the years. IKEA was the last straw and pushed me off the fence and into action. I got some dinnerware delivered and a good 20% of the plates that came were broken. I got them replaced, they sent me more than what I ordered, but some still broke. That was when I said, OK, I need to try to repair these pieces, bonsai pots included. My pots that are broken range in value but they all have sentimental value.

I have done some research and I'm a traditionalist and wanted to go the route of lacquer over epoxy. It definitely takes a ton of time, much longer than epoxy; but, I want it to be a natural approach.

View attachment 469887
Here's the broken piece, you can see the hairline break.

View attachment 469888
The two pieces side by side.

View attachment 469889
Cross section of one piece. The sides were sanded down and the edges were filed down to allow for better infilling for structural support.

View attachment 469890
Cross section of the other.

View attachment 469891
The piece put back together with mugi-urushi (adhesive lacquer).

View attachment 469893
Bottom view.

View attachment 469894
Note the oozing out of the mugi-urushi. Oozing is good at this stage.

View attachment 469895
3 weeks later, the mugi-urushi is removed. I have learned, I should probably mask the area around the break point as the lacquer left a stain.

View attachment 469896
Side view, note how the oozed out lacquer left unfilled cracks. The next step is to infill those spaces with sabi-urushi.

View attachment 469897
View of the other side. The the joinery line is quite faint because of the scraping off of the mugi-urushi.

View attachment 469898
A week later, I applied the joined area with sabi-urushi to infill the small cracks. Note the stain, I will need to test sanding to see if I can remove the stain.

View attachment 469899
**TOP PICTURE IS AFTER, BOTTOM PICTURE IS BEFORE** A few days after the sabi-urushi was applied, I cleaned off the infill with sand paper and a utility knife. It seems the sandpaper does remove stains. Note the clean surface afterwards.

View attachment 469900
**TOP PICTURE IS AFTER, BOTTOM PICTURE IS BEFORE** Note how much darker the fault line is and how the cracked/chipped locations took so much more of the infilled lacquer.

View attachment 469902
**TOP PICTURE IS AFTER, BOTTOM PICTURE IS BEFORE** View from the other side, fault line is much darker.

I'm getting closer to the finishing steps. I will perform 1 more application of the infilling of sabi-urushi. Then I'll polish/sand with a piece of binchotan.

For those who are more knowledgeable, is it generally OK for kintsugi bonsai pots to be put back into use if lacquer is the choice of adhesive? I know that for dinnerware, plates are encouraged to not be put in the dish washer or be submerged for prolonged periods of time. Thoughts?
Fantastic job! The processes involved in kintsugi and pottery restoration in general are fascinating. I saw a documentary on the NHK network a few years back about a master of pottery restoration I think you may get a kick out of. It may also help you in your kintsugi journey.

NHK the unknown masters of restoration
 

Chop_n_Change

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Cheers to you for going through the traditional process! I have repaired a few Chinese glazed pots with the shortcut method of 2 part epoxy and some Gold enamel paint (model paint). I contemplated going through the process you did, but went with the quicker route given the non-sentimental nature of the pots I had.

my pots are going on 2 years with a schefflera and a Jade and still going strong. In a greenhouse or outside during the summer months and he enamel looks the same as the day I put it on. Still use 2 hands when carrying tho. 😙
 

lieuz

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Fantastic job! The processes involved in kintsugi and pottery restoration in general are fascinating. I saw a documentary on the NHK network a few years back about a master of pottery restoration I think you may get a kick out of. It may also help you in your kintsugi journey.

NHK the unknown masters of restoration
Thank you for this. I built a mutual relationship with a more advanced Kintsugi hobbier who studies under a Japanese Kintsugi artist in NYC. I'm thankful to have her because she is so available and all my questions gets answered and certain nuances get explained.
 

lieuz

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Since this is a test subject, I wanted to take it all the way. I subjected my repairs to weight tests as a durability analysis. Large glazed plates that are 10" wide with a majority thickness of 1/8" inch and thickest of 1/2" at the base, using some anchors, fastened to the top of the repaired pieces placed on the edge of a table, I slowly added weights dangling over the edge and found failure starts to appear at 25 lbs. Total failure happens at 30 lbs with the piece completely coming apart. Shohin pot non-glaze was roughly the same. These repairs were made at the same time and are subjected to the longest possible curing length of time of 4 months. I'm going to place a tree in the shohin pot that was repaired to see what will happen given the full growing season and into winter. I figured why not try it out?
 

lieuz

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This was completely out of curiosity, I wanted to test the strength of the adhesive. The right ingredients for the kintsugi adhesive are flour (all-purpose), water, and urushi (lacquer). The right ingredients for kintsugi filler are water, tonoko (clay and silicate powder mix), and urushi. Because I wanted to see what would happen if I flipped the ingredients. It's exactly as I would have thought, changing the recipe for the adhesive resulted in a fragile bond. I've come to realize, that flour is kneaded with the water for a bit until it comes to the consistency of gum, and then the urushi is added. The final consistency is like toothpaste right before application. The flour is almost needed for its gluten structure when being kneaded as an adhesive. This seems to make the bond tighter and; therefore, holds stronger.

On the flip side, using flour instead of the tonoko for the filling material made for a very soft filling material. Once settled into the nook and cranny, it also took twice as long to cure and once the surface appeared to look cured, there are still bits at the core that is very soft still. This makes for inconstant curing. As mentioned above, since humidity controls curing so the right percentage needs to be at a constant 83%. Any more and the exterior will cure much faster than the interior, any lower and the material won't cure as quickly. One can imagine the frustration if the humidity isn't monitored. I once heard mortar is like that, the filler material between bricks, if the ratio is off, it can take years if not decades for it to "cure."

Shouldn't question the process ever again. It was good to know.
 
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