Citric soak

David · 25th July 2014, 07:03 PM

Quote:

Originally Posted by A. G. Maisey

Even if the gold carving works loose from the cavity, modern adhesives permit undetectable replacement.

Alan, is there a particular modern adhesive you would recommend for such repair?

A. G. Maisey · 25th July 2014, 11:27 PM

The "gold-back-into-hole" job?

My personal favourite adhesive for anything like this is Araldite, its a two part epoxy glue. There is a version that sets within 5 minutes, and another one that sets overnight --- they say an hour, but it only sets in an hour in warm to hot weather.

The surfaces need to be roughened up a little and be very clean and free from any grease, acetone is good for this, and the job needs to be firmly clamped while the stuff sets.

Not clamped to the point where the adhesive gets squeezed out, but just a good firm pressure. With the 5 minute stuff you can just hold it tight with your fingers while it sets.

Once set, but not cured, you trim off the excess with a sharp blade. You can also wash off barely set excess with water, and set excess with acetone, but I have seen jobs come adrift if too much of the fluid is used, or too little care is used, its safer to let it just set up firm, then trim. You can only get as neat as you can see, so bright light and magnification is essential.

In Indonesia they use one of the 'super-glues' for anything like this, but these adhesives dry out after a while, usually a few years, and everything comes loose and you can lose little bits. This is particularly true of the stones in mendak and selut --- if its an old mendak or selut and had stones replaced in Jawa you can bet its been done with Alteco (a super-glue); eventually the glue will give way and you'll lose a stone, and rose cut rock crystal is not all that easy to find outside Jawa --- even in Jawa its not that easy any more. If the stone is a rose cut diamond its even more difficult to get one.

Sorry for the long answer.

Short answer:- Araldite.

Shakethetrees · 26th July 2014, 05:28 AM

Mr. Maisey's advice is excellent!

I have professionally restored blades (and other antique metalwork) for about thirty years. I had the opportunity to participate in a workshop taught by a Western metal smith and his Japanese trained wife whose names I forget just now, both acknowledged masters in their craft. My experience has been with mostly American and European blades, but with some Asian work as well.

I have done a little inlay from scratch as well as restored "around" it and over it depending on the type, or not at all.

Fire gilt decoration on blades is completely fugitive, so the smart thing is to stay away unless the problem endangers the blade to the point where a percentage of sacrificed gilding is a necessary cost in order to preserve the life of the whole.

Likewise with koftghari--too delicate to risk.

I have never run across any gold adhered by an organic adhesive, unless it's on a modern blade, something I usually do not fool with.

A restorer's dream is a blade mounted with undercut secured inlay, I believe the Japanese terms are sen zogan for line inlay, hira zogan for two dimensional inlay. I have rarely seen these last two come loose, but if the inlay is flush with the surface and pure gold (not low karat alloy) it can be carefully tapped into place, spreading the gold into any voids, locking it mechanically and securely. But, I emphasize pure gold only, and very light tapping using the end grain of a hardwood dowel specially shaped for the purpose.

If you have any doubt about your abilities, or any other reservations, leave it alone.

max · 26th July 2014, 08:47 AM

As you can see the rust lay's between the gold pieces

A. G. Maisey · 26th July 2014, 11:19 PM

Yes Max, correct, gold does not rust.

But underneath that gold is iron or steel and that does rust.

What often happens is that over time the rust penetrates to the iron under the gold, and the only thing supporting the gold is rust. The acidic soak also penetrates under the gold and weakens the rust.

My most important lesson came when I saw a highly respected m'ranggi in Solo take a blade out of an acidic soak. When it went into the soak it had been a very beautiful kinatah blade with probably better than 90% of the gold intact; when it came out of the soak it had maybe 20% of the gold still on the blade.

Mechanical clean first, if possible follow-on with an acidic brushing.

Best not to soak.

26th July 2014, 08:47 AM	#4
max Member Join Date: May 2010 Posts: 12	rust and gold As you can see the rust lay's between the gold pieces Attached Images

25th July 2014, 11:27 PM	#2
A. G. Maisey Member Join Date: May 2006 Posts: 7,015	The "gold-back-into-hole" job? My personal favourite adhesive for anything like this is Araldite, its a two part epoxy glue. There is a version that sets within 5 minutes, and another one that sets overnight --- they say an hour, but it only sets in an hour in warm to hot weather. The surfaces need to be roughened up a little and be very clean and free from any grease, acetone is good for this, and the job needs to be firmly clamped while the stuff sets. Not clamped to the point where the adhesive gets squeezed out, but just a good firm pressure. With the 5 minute stuff you can just hold it tight with your fingers while it sets. Once set, but not cured, you trim off the excess with a sharp blade. You can also wash off barely set excess with water, and set excess with acetone, but I have seen jobs come adrift if too much of the fluid is used, or too little care is used, its safer to let it just set up firm, then trim. You can only get as neat as you can see, so bright light and magnification is essential. In Indonesia they use one of the 'super-glues' for anything like this, but these adhesives dry out after a while, usually a few years, and everything comes loose and you can lose little bits. This is particularly true of the stones in mendak and selut --- if its an old mendak or selut and had stones replaced in Jawa you can bet its been done with Alteco (a super-glue); eventually the glue will give way and you'll lose a stone, and rose cut rock crystal is not all that easy to find outside Jawa --- even in Jawa its not that easy any more. If the stone is a rose cut diamond its even more difficult to get one. Sorry for the long answer. Short answer:- Araldite.

26th July 2014, 05:28 AM	#3
Shakethetrees Member Join Date: Apr 2014 Location: Louisiana Posts: 363	Mr. Maisey's advice is excellent! I have professionally restored blades (and other antique metalwork) for about thirty years. I had the opportunity to participate in a workshop taught by a Western metal smith and his Japanese trained wife whose names I forget just now, both acknowledged masters in their craft. My experience has been with mostly American and European blades, but with some Asian work as well. I have done a little inlay from scratch as well as restored "around" it and over it depending on the type, or not at all. Fire gilt decoration on blades is completely fugitive, so the smart thing is to stay away unless the problem endangers the blade to the point where a percentage of sacrificed gilding is a necessary cost in order to preserve the life of the whole. Likewise with koftghari--too delicate to risk. I have never run across any gold adhered by an organic adhesive, unless it's on a modern blade, something I usually do not fool with. A restorer's dream is a blade mounted with undercut secured inlay, I believe the Japanese terms are sen zogan for line inlay, hira zogan for two dimensional inlay. I have rarely seen these last two come loose, but if the inlay is flush with the surface and pure gold (not low karat alloy) it can be carefully tapped into place, spreading the gold into any voids, locking it mechanically and securely. But, I emphasize pure gold only, and very light tapping using the end grain of a hardwood dowel specially shaped for the purpose. If you have any doubt about your abilities, or any other reservations, leave it alone.

26th July 2014, 11:19 PM	#5
A. G. Maisey Member Join Date: May 2006 Posts: 7,015	Yes Max, correct, gold does not rust. But underneath that gold is iron or steel and that does rust. What often happens is that over time the rust penetrates to the iron under the gold, and the only thing supporting the gold is rust. The acidic soak also penetrates under the gold and weakens the rust. My most important lesson came when I saw a highly respected m'ranggi in Solo take a blade out of an acidic soak. When it went into the soak it had been a very beautiful kinatah blade with probably better than 90% of the gold intact; when it came out of the soak it had maybe 20% of the gold still on the blade. Mechanical clean first, if possible follow-on with an acidic brushing. Best not to soak.