Retinning & restoration

Guest post: Restoring a pot at home, part 2

VFC

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And now, on to the thrilling conclusion!

Guest post: Restoring a pot at home, part 2

A note from VFC: This is the second in a two-part guest post written and photographed by reader Roger W. Part 1 showed the pan as Roger found it and how he cleaned it inside and out to prepare it for retinning.


Episode 9: Tinning

I am now almost ready to attempt tinning, so a final wipe of the inside with hydrochloric acid toilet cleaner to remove any new tarnish and help clean any pits that mechanical cleaning did not touch, it will only take 2 or 3 minutes. I then rinse thoroughly and dry. Some people immerse the whole pan in an acid solution, drain cleaner being the home method. I tend not to put strong acids on the outside because although it removes tarnish very effectively it erodes the surface leaving it matte and needing a lot of polishing and so destroys patination. Patina is desirable outside but not inside hence the local treatment.

The hazy darker strip on the upper part of the interior is what I believe to be nickel, now made clearly visible by the acid. I’m way out of my depth with the chemistry here, but a root around the ‘net informs me that that when brass electronic components are electroplated with tin, an interface layer of nickel is used because tin doesn’t take well to the zinc in brass. Also hydrochloric acid is used to prepare the nickel so I think all should be well here. I am feeling lucky.

Guest post: Restoring a pot at home, part 2

I lay out my tinning kit: gas blowlamp, glass fibre insulation, sal ammoniac (ammonium chloride, NH4Cl), the remainder of a tin ingot, and a piece of denim from some old jeans. I also have a bucket of water.

Guest post: Restoring a pot at home, part 2

The sal ammoniac is a traditional flux, if you have ever seen tinners working in places like Turkey and noticed plumes of white fumes, that is this stuff. There are more modern and probably better options used by tinners in western countries but I bought this when I knew no better and it works well, there is enough in this bag to last more than a lifetime. The principal drawback is the residue which must be cleaned away afterwards.

I have improvised a grid to support the weight of the pan, and the broken aluminium pan is there as a chock to stop it rolling when it is on its side. With a smaller lighter pan I would prop up the blowlamp and hold the pan above the flame by its handle but I don’t have the strength to support this one-handed for an extended period. It is common to apply a masking agent to prevent dribbles and splashes of tin adhering to the outside but I have been careful and not had a problem so miss this step.

Guest post: Restoring a pot at home, part 2

I hope that you will not be too disappointed by the lack of action shots but the actual tinning is a job where a third hand would be useful! Once it’s hot and flowing nicely I certainly don’t want to stop to take photos. A picture may replace a thousand words but by necessity a block of text must stand in lieu of a picture.

I begin by preheating on my kitchen stove, this is going to absorb a lot of heat and the mains gas is much cheaper. Heating the handle where it attaches is also essential to stop it acting as a heat sink and cooling that area.

Now that it’s hot I carry it outside using the denim rag wrapped round the handle and playing the blowlamp flame around the base of the saucepan to keep it hot. Once it’s settled on the grid and I am holding the lamp underneath I take a pinch of flux and sprinkle it in the pan, a few seconds and white fumes begin to rise. I take my wad of glass fibre and vigorously rub the flux around the entire interior. Once the fumes thin out and I can see what I’m doing I touch the tin on the copper and it melts almost immediately like chocolate and I rub it till I have a pool of molten tin.

What follows is kind of midway between spreading melted chocolate inside an Easter egg mold and greasing a baking sheet.

What follows is kind of midway between spreading melted chocolate inside an Easter egg mold and greasing a baking sheet. I tilt the pan and wipe with the insulation material till the bottom is covered topping up the heat all the while. Next I tilt the pan towards me so the tin pools below the handle and while there is plenty I wipe it over the rivets working it into the creases around them and up to the rim. I am right handed and find the quarter of the pan to the left of the handle rather awkward so I tackle that next wiping the tin that way before working round the pan from the other side of the handle.

Ideally the whole pan would be evenly heated and the tin wiped around quickly. We have all seen those demo videos of expert hands working in ideal conditions to achieve a seamless coverage in seconds. It is not like that, I am inching round little by little trying to keep the area I’m on hot enough but not overheated to oxidize the copper or burn the flux. To any bit that will not wet I add a tiny bit of flux and rub till the tin takes. When I get right round I melt the join together and wipe surplus tin out of the pan saving it for the next one. This must have taken 15 to 20 minutes. Even professional tinners have to tackle really huge pans in sections so this is fine but makes it harder to achieve a perfectly smooth finish.

The picture shows the pan cooling, after a few minutes I pour in some water.

Guest post: Restoring a pot at home, part 2

All that remains to do now is the clean up and polish. There is a limit to how many pictures of a saucepan being washed that you will want to look at so I didn’t take any more of those. I use a well worn scouring sponge and some cream cleaner intended for plastic bathtubs to remove flux residues and then buff the tin with kitchen paper towel. The wood fibre content is just abrasive enough to polish without scratching. I polish the outside first with autosol and then brasso.

Some mention should be made of safely. I know many will be concerned and deterred from having a go. I wear leather boots to protect my feet from uncomfortable splashes and wear spectacles so my eyes are covered but that is about it. I am in awe of anyone who can do this while wearing thick gloves. The kind of temperature used is only comparable to to those used by cooks all the time. The pan radiates enough heat that you know if you’re getting too close. The small amount of molten tin is less dangerous than a pan of hot oil and does not stick or burn the skin like hot caramel. Flux fumes are unpleasant and likely less toxic than cigarette smoke but fairly easy to avoid when outside though a proper respirator would be wise if using it everyday. The acid which is not essential is certainly the greatest hazard.


Episode 10: Results!

So how did it go? I am pleased with the results, not a flawless finish but coverage is good with no copper showing, including the difficult bit round the rivets. The surface feels smooth and the only small lump in the tin is at the edge just below the rivets. There are a multitude of imperfections and varied textures in the underlying surface so these catch the light and appear as dark patches which disappear when viewed from a different angle. Once the tin has lost its shine and darkened as it inevitably will then the inside will look more uniform in appearance. I will have no qualms about cooking in this pan now should I ever have to feed 30 people!

Guest post: Restoring a pot at home, part 2

The cast iron handle has responded well to cleaning and polishing with Autosol, it is as fine a casting as I’ve seen. Silky smooth to the touch and no grinding or file marks anywhere, it has a surface that makes me think of a shotgun barrel.

Guest post: Restoring a pot at home, part 2

The sides of the pan are hammered, it is irregular enough that it could only have been done by hand and I don’t think a hydraulic or pneumatic hammer was employed because it is very subtle. In fact wear and repeated polishing means it is now little more than ripples on the copper.

Guest post: Restoring a pot at home, part 2

The base has no central dot so it was either machine cut or more likely a template was used rather than compasses. Now that I look from a distance and check by measuring there is a slight flare to the sides, about a centimeter wider at the top. This means my earlier supposition that the sides had been cut from a pre-made tube is incorrect. Can copper be welded so perfectly that the join is completely invisible on both sides? I can think of no other way to make this as an open ended cylinder. The lower edges taper to mate with the base with hardly any thickening of the walls at the join. This joint is brazed and clearly visible, it wanders a little making me think the edges were worked by hand. When it comes to construction this pan has not yielded all of its secrets.

Guest post: Restoring a pot at home, part 2

I think this is a French pan in a size suitable for a commercial kitchen, probably made as a “casserole russe ” and cut down to almost “saucier” proportions though the thickness of the copper is more suited to wet cooking. Probably started with a thinly-plated nickel lining which wore through and was eventually renewed with tin. Certainly one and probably two of the rivets have been replaced with some skill and care. The scratches, minor dings, wear, alteration and repair are visible testament to its utility and long service.

There are no maker marks but of course they may have been trimmed off.

Guest post: Restoring a pot at home, part 2

I think this is a transitional piece. There is evidence of skilled craftsmanship but I’m also suspecting bean counter involvement here. That brazed joint without cramping has held up well but it doesn’t look like a good idea, more like a manufacturer desperately trying to compete in a market where other products can be bought more cheaply. How happy was the old-school Coppersmith with this product I wonder.

I’m sticking with my 1900-1910 estimate date-wise as I think the use of nickel and probable welding support this. It will be interesting to read any suggestions others have on how this saucepan was made.


Epilogue

Perhaps the most difficult part of any restoration/conservation is deciding where to stop. Not bad-looking, I think. I’m going to let it tarnish a little then polish again. I find that the appearance of copper pans no matter how old or in what condition on arrival tends to become homogeneous over time as a result of the care they get in my kitchen. New surfaces acquire a haze of tiny scratches and battered pans gradually become smoother with handling and cleaning, and deep tarnish kind of sweats out.

 

I can’t give a definitive reason why it was tarnished in such a strange way. Anyone who owns both solid and plated silver will know how differently the two tarnish. Does the combination of copper, brass, nickel, tin and cast iron cause such an effect? The two other theories I have is that direct heat to the base has altered the copper at a molecular level while the indirectly heated sides were not affected. This would seem improbable as I’ve not seen it on any other pan.

A more likely explanation is contamination of the copper, silver being a possibility because the ores sometimes exist together and it used to be difficult to remove copper from silver. The metals alloy. Henry VIII had silver coins so heavily adulterated with copper that they went green and he became known as old copper nose.

I hope that you have enjoyed this and maybe even inspired to have a go.


VFC says: Roger, thank you so much for this wonderful story! I am impressed by your gumption at retinning the pan yourself — thank you for describing it step by step, and also for emphasizing the safety considerations and how you handled them. Readers, do you have any questions for Roger about this process, or any ideas about the provenance of this unusual pot?

 

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3 Comments

  1. Thank you, Roger, for having the courage and generosity to show us in detail your method of restoration. The result is all the more convincing, since the original condition of the pot was a bit of a mystery.

  2. Bravo, Roger! Retinning is not a trivial task and you’ve thoughtfully brought a beautiful old pan completely back to life! I concur that pickling the entire pan in an acid bath is much too aggressive for antique copper. Further, your hand treatment produces much nicer results. I can’t wait to read what you decide to cook in it first!

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