[Steve Hoffman]

I have a bronze figure, 30" tall, that has a deep abrasion on the throat. I think it was cast into the figure when the wax was damaged. I sculpted the clay model for this piece and this is the first time I've ever created in bronze. I need to deliver this statue in a few weeks and I'm reluctant to go back to the foundry because the work was done by students. Also, the foundry is more than two hours away. Is it possible that I could fix this myself? Or is that too ambitious? I'm hoping that the abrasion can be filed/hammered to minimize it enough without welding. If I did manage to do the work myself, how would that change the color? Could I bring the color back to match the surrounding material?

 

[John Smith_inFL]

welcome to the forum, Steve. You have your sculpting down pat - very impressive.
metal-working is another skill in itself. ANY abrasions in the "fix it" arena will definitely cause you problems. If I had this project, I would use a small hand grinder such as a Dremel tool and several sandpaper grits to get the "defects" to match the rest of the casting. THEN - strip and re-apply the finish (patina) that you are looking for.
Again - metal working is another skillset all together. It might be a good training session for the "students".
"spot repairs" often don't end well with unsatisfactory results. My thought is to do the repairs and re-do the finish so it will be consistent all over and the repair will be invisible.

 

[Steve Hoffman]

welcome to the forum, Steve. You have your sculpting down pat - very impressive.
metal-working is another skill in itself. ANY abrasions in the "fix it" arena will definitely cause you problems. If I had this project, I would use a small hand grinder such as a Dremel tool and several sandpaper grits to get the "defects" to match the rest of the casting. THEN - strip and re-apply the finish (patina) that you are looking for.
Again - metal working is another skillset all together. It might be a good training session for the "students".
"spot repairs" often don't end well with unsatisfactory results. My thought is to do the repairs and re-do the finish so it will be consistent all over and the repair will be invisible.

Thank you for your insight. I'm not sure how the patina was applied. Would this have been some sort of acid solution? I spent two evenings rubbing back the color with abrasive pads. The patina was brown/black. Now it's less so. Seemed like what came off with the pads was a dark wax. Does that sound right? Could this be the only thing responsible for the patina? Or maybe I was removing the (dark) patina plus some wax?

 

[John Smith_inFL]

Steve, depending on what part of the world you are in, different methods and chemicals can be used. Depending on the person or company that performs the finishing task. There are SEVERAL methods that will give a brown/black/green patina in just minutes. Then, a wax can be hand rubbed to provide a bit of protection, if required. (or not).
I use Liver of Sulfur on most cast brass and bronze plaques. If you decide to do the whole process yourself, you could call the Science Company to discuss your project and their recommendations for what chemical you need for the patina you are looking for.
YouTube will give you some insight as to how the patina is achieved. These two plaques are cast bronze copies of plastic resin plaques. Please keep us in the loop with your project. I find scuplting and finishing a very rewarding artform.

 

[iandandavies]

As John says use burr in a dremel type type tool followed by sanding. The patina looks a simple type that can be recreated with liver of sulphur. When you rubbed back you were probably removing wax and underlying patina. A quick way to remove most of the wax to stop it gunking up your sanding pads is t heat it with heat gun or blow torch and wipe of the wax with a cloth. This will also reveal if the colour is a true patina or just in the wax. As you wipe the melted wax if you are left with bare metal then the colour was in the wax, but if the patina is still there then it is on the metal.
From the photos it appears to be on the metal.

 

[John Smith_inFL]

@Steve - do you have a follow-up on this project ??

 

[Steve Hoffman]

@Steve - do you have a follow-up on this project ??

I always have plans for more work but my ADD always wants me to move on to something new. I'm a one-off kind of guy. Rarely do a series of anything. But I do have some clay models of smaller pieces I'd like to cast.

 

[John Smith_inFL]

Thanks Steve.
LOL you describe myself exactly. I have a hundred projects that need attention but always jump on something new and - - - yada yada yada, you get the idea.
Just looking forward to the process you use for the statue defects and re-finish.
Totally at your convenience, of course.

 

[Steve Hoffman]

...
Just looking forward to the process you use for the statue defects and re-finish.
Totally at your convenience, of course.

OK, John. Here's the repair. Patina was spot applied. Not a perfect match but close enough, I think. Now, what kind of finish to use for outdoors? I'm told a hard wax with a polyurathane clear coat over that. Sound right? Does the bronze need to be heated for better waxing? Is there a specific brand of wax you'd recommend? What about the clearcoat product?
.

 

[Steve Hoffman]

PS: I'm told the patina repair was achieved with pot ash. Haven't looked that up so I don't know what it is.

 

[John Smith_inFL]

good job, Steve.
One must understand the chemical characteristics of paint and finishes for outdoor use. From a woodworkers standpoint, there are NO clear finishes that are 100% UV resistant without constant and regular maintenance. Is there a reason you don't want it to weather naturally and take on the patina of "time" ?
I have no idea what wax would be appropriate for bronze or brass that is displayed outside. So, once again i suggest you call "The Science Company" to get advice from the experts.
It's looking great so far.

 

[Steve Hoffman]

...
Is there a reason you don't want it to weather naturally and take on the patina of "time" ?
...

Thanks, John. This is a commission and the client wants a golden tone as much as possible.