Small jobs for winter evenings
Few years ago I bough this copper can for storing lamp oil onboard. Useful nice thing, looking good in the cabin and making life easier when re-filling oil lamps on Meritaten. However - this one has a flaw: it leaks oil via bottom-side seam. Not much but it gets wet during few days and smells.
Since it was brand new I sent it to Toplicht for repir or replacement. They tried to repair it with epoxy but it still leaked. Replacement was not possible as this is not produced anymore so they simply have no more in stock.
In the end they proposed me a generous re-found if I want to keep it. Basically I got it for less than half-price. Fine - I can fix it myself!
Initially I thought of brazing it with silver but after consulting Toplicht they talked me out of it - it turns out that copper is covered with transparent varnish, to protect it from oxidation. If I apply flame to the bottom it will destroy the protective film. If I could remove the paint from the whole can I would go for it - after all I like copper green patina - but it seems like a daunting job and chances are it will look ugly with partly removed finish.
Instead I decided to seal it now with brown Sika. Non-cured Sika is solvable with oil so I needed to thoroughly clean the lamp and de-grease it. Then I left it for several weeks to allow what remaining oil is there to evaporate. Finally this week I found time to finish the job.
I masked the surrounding areas with paper tape, to make clean cut-out for coming Sika seal.
Then followed Sika, squeezed in and rubbed into the seam, leaving thin layer on surrounding faces for better adhesion. Before it cured I removed the tape to avoid risen edges. Turned out very nice.
To further reinforce this seal - and as a protection to the can when it bumps around on the boat during sailing - I added rubber ring on top of un-cured Sika.
After curing, on the next day, I checked that rubber sits firmly, glued to Sika. I’m yet to check if it became finally oil-tight but in case it still leaks I’ll just reinforce the seam with more Sika.