Summary for brass cemetery plaques Discussion
Brass cemetery plaques are tarnishing under a clear two-pack urethane, and Rob asks whether anything can be applied to the exposed brass lettering without harming the brown polyurethane backing or the topcoat adhesion. Jake Koch of G. J. Nikolas & Co. says the clear two-part urethane should be the best protection against oxidation, but suggests checking how long the brass sits exposed after sanding and whether ferric chloride is fully cleaned off before coating. His practical advice is to sand, then wash the lettering with acetone or a cleaning thinner immediately before applying the top coat. The thread also includes later questions from Beth H. about cleaning weathered memorial plaques for photocopying, with a preference to avoid abrasives, and from Garry Cole about polishing an inherited plaque and removing tarnish. Those later questions ask about phosphoric acid dips or brass dip products, but no detailed recipe is given in the excerpt.
HI,
OUR COMPANY MANUFACTURES BRASS CEMETERY PLAQUES. THE BRASS IS ETCHED IN ferric chloride
⇦ on
eBay or
Amazon [affil link] , THEN A TWO PAC BROWN POLYURETHANE COATING PUT ON. THEN WHEN DRY THE SURFACE IS SANDPAPERED TO SHOW BRASS letterING ON A BROWN BACKGROUND. A CLEAR TWO PAC POLYURETHANE IS THEN APPLIED TO THE SURFACE. THE PROBLEM BEING IS THAT THE BRASS THAT IS SHOWING THROUGH THE CLEAR TARNISHES UNDER THE CLEAR COAT.
IS THERE SOMETHING THAT CAN BE APPLIED TO THE SURFACE OF THE BRASS letterING THAT WILL NOT EFFECT THE POLYURETHANE BACKING OR THE ADHESION OF THE TOP CLEAR COAT AND PREVENT THE TARNISHING.
ROB M [last name deleted for privacy by Editor]
PHOTO ENGRAVERS – ADELAIDE, AUSTRALIA
Hello Rob,
How long is the bronze exposed after sanding and before coating? Do you clean the ferric chloride
⇦ on
eBay or
Amazon [affil link] off of the piece before the coating is applied? I’d think the clear two-part urethane would be the best way to stop oxidation. I’d try sanding and then wash the exposed lettering with acetone
⇦ on
eBay
or
or a cleaning thinner just prior to the top coat.
Good luck,
Jake Koch
G. J. Nikolas &Co.,Inc.
Bellwood, Illinois
I am a local history librarian who has inherited the brass plaques from a memorial wall (now demolished). The plaques themselves have been out in the weather (of course) for some time. I would like to clean them for photocopying so that the photocopied information is readily accessible to Local and Family History researchers. The gentleman who will clean the plaques prefers not to use abrasives as it apparently takes off the clean edging of the lettering. It has been suggested that I use a phosphoric acid dip or “Bright Brass Dip”. Can you suggest a ‘recipe’ to make this or where I can get it…?
Many thanks,
Beth H [last name deleted for privacy by Editor]
– Queensland, AUSTRALIA
Q. Hi,
I have my grandparents’ original plaque after we had to get it altered after putting my auntie’s ashes with them. My dad used to clean it but he has passed away as well. I want to give it a polish and get the tarnish off. Can someone please recommend what I can use to get it back to or close to the original state as I now have it in the garden.
I eventually want to get it mounted on something so it lifts it off the ground
Garry Cole
– Warner QLD Australia
January 30, 2012