Primarily Petroliana Shop Talk Forums Shop Talk Petroliana Forums General Petroliana Discussion Yet another porcelain Cleaning Thread

I just picked up a porcelain sign about 5 ft long. It is white and cobalt blue. Some sections are dirty and some have heavy rust staining that is etched into the finish. I use some BKF powder-worked it into a paste-let it sit for a minute and the stains came right out with some fine steel wool-in a very small area. After I wiped it off I could see it etechd the porcelain(good thing I used a small test area). Would muratic acid be the best method to get these very heavy stains out? I used oven cleaner and compound with no luck. I am just afraid If I use the acid(which is stronger then the BFK) I will damage the sign. Any help would be much appreciate.

Keith

Use it just not for too long. ANY sign that i have ever posted on here has been cleaned with muriatic acid. I have great result every time i use it. IMO nothing works better. Even if the sign is pretty nice before hand with only a little staining i still use it. I just bought 7 more of the Oakland sales-service signs and i will clean them all with muriatic acid i will post a before and after shot.

I'VE ALWAYS HAD BETTER LUCK USING SOFT SCRUB W/BLEACH. IT'S A CREAM TYPE CLEANER THAT I APPLY AND COVER LIBERALLY OVER THE ENTIRE SIGN WHICH IS POSITIONED OUTSIDE SO THAT I CAN LET IT SIT OVERNIGHT AND SCRUB WITH A HOSE NEARBY FOR RINSING.

MURIATIC ACID SHOULD ALSO BE USED OUTDOORS OR WITH GOOD VENTILATION, CLOTHING YOU DON'T CARE ABOUT AND RUBBER GLOVES. USE IT SPARINGLY IN A TEST AREA NOT FOR MORE THAN A COUPLE MINUTES AND ONCE AGAIN HAVE THE HOSE NEARBY OR A BUCKET OF FRESH WATER AND A SPONGE FOR RINSING OFF THE ACID. LEAVE IT ON TOO LONG AND IT WILL DEF DULL THE FINISH.

I took a pic of the worst one. As you can see there are rust stains and even a big thick line of tar. I forgot to take an individual pic of it after i was done but as you can see in the second pic none of them look like that now. I soaked it and scrubbed it with a brush for 5 minutes and it took everything off and still has a nice finish.

Do you use straight muratic acid or do you dilute it? I was told to brush it on and leave it for about a min. Then wash off.

Straight muriatic acid i do not dilute it at all. I apply it with a brush and wash it around for about 5 min depending on the condition. If you leave it on for WAY too long it can eat at the sign but it has never happened to me and i have let signs soak over night.

Muriatic Acid should not be left on overnight & Baking Soda mixed w/ water is a neutralizer w/ a clean water wash.
Toilet Bowl & Oven cleaner are a couple of other options. Use what works Best For YOU.

No it shouldn't but i use it as a last resort with good turnouts. Dick is right do whatever you are most comfortable with. I will take some more pics after i clean another sign tomorrow to give you a better example of what it will look like. If you use it ALWAYS wear gloves and pants because it does burn if it gets on you... Trust me i know.

ALWAYS wear some kind of FULL EYE PROTECTION [not just eye glasses] when using ANY type of ACID/CLEANER.
Leaving a small amount on overnight might not be Bad, BUT never leave a large Puddle on overnight as it will eat at the metal/rust & can eat UNDER the porcelain [done that & had to Throw away some signs that porcelain lifted off of metal].

I tried the muratic acid and did not get good results. I used more BFK on the sign and let it sit for about 30 seconds then used 0000 steel wool. I got a lot of the minor stains off but there are still eteched stains on the sign. I let the acid sit for about 2 minutes. Is there any other option to remove these etched stains without causing damage to the porcelain?

Thanks for the help

What about removing paint from porcelain? I know I have seen several other threads on this, but can't find them with the search feature. Seems like someone suggested something starting with "citri..."??

Thanks! (sorry for the slight highjack!)

Citrus Strip, any paint stripper will work, some faster than others depending on the type of paint. Some swear by Aircraft Stripper but it can be costly. I've used Bix from K-mart w/ great results & it's cheaper than most.
As with any stripper use in a shaded area to slow the Flash-off down from the sun/heat [news paper laid over stripper also slows down the flash-off].