I bought a Skelly porcelain pipeline sign. It has some kind of stuff around two of the grommets...looks like hard crystallized tar. It is stuck to the porcelain. Some has “flaked” off using my fingernail and great pain!!! Does anyone know how to remove this mess or am I stuck with it (no pun intended). I was afraid to use a metal tool thinking I would damage the porcelain.
Thanks,
Steve

I would try a heat gun on low at first and a Chizzler plastic scraper

I've had some luck in the past with muriatic and a plastic scraper. Just make sure to wear gloves and a mask!

Chris

Diesel fuel is what I would start with. Sterling

Just scrape it off with a razor blade, and you will remove the majority of it. Then use any paint remover or some other chemical (like those mentioned above) to remove the brown stain left behind. I know it's not paint, but paint remover works great for me, and removes the stain left behind. I also use Bon Ami porcelain cleaner (similar to Comet powder) and a scrubby sponge and it will clean it nicely and remove the rust stain as well. A razor blade is not going to hurt the porcelain. I do it all the time. Don't worry about it.

Here's one I did about a month ago, with a little more tar.

Buy one of the tools at the bottom (and a bunch of razor blades). One of the best tools I have for porcelain signs.

-Steve

Link to the White Star sign thread from last month:

http://www.oldgas.com/forum/ubbthreads.php?ubb=showflat&Number=711100#Post711100

and here's another, I did today:

http://www.oldgas.com/forum/ubbthreads.php?ubb=showflat&Number=712745#Post712745

Thanks guys for all the advise. Steve...was the stuff on your Mobil crstalized...this stuff is hard as a rock! Also, thanks for the advise on loading pics. It absolutely does work!
Steve

I don't think that is tar....... Looks like someone cut the screws/bolts with a torch, and what you see is the "slag" or melted metal remaining. Some will flake off with a razor blade, but you can see it burned itself into the porcelain.

Yeah, if it’s ‘slag’ from a torch, it’s there to stay.

After reading the past posts I do believe it is “slag”. The porcelain is melted and like small fiords with the slag flowing through them. Thanks for all your help to come to an understanding of what this is....I had never seen it before.
Steve

Guys,
I just finished my sign. I had to make some tough decisions that I am sure not everyone would agree with. I worked with it with a razor blade to remove as much of the slag as I could. I then took a flat head punch and carefully “whacked” the “slag”. Even more came off. I cleaned the whole sign with Zud. Then I took some masking tape and carefully taped around the damaged area (that still had a very darkened finish). Then I covered the rest of the sign and spayed it with high gloss white enamel. I personally like it better than when the”rock slag monster” had it in its jaws. I posted an “after” pic. I would be interested in knowing what some of you would have done.
Steve

Or here is a before and after pic.

If you're happy, I'm happy for you. Looks really nice, good job!

I definitely like your finished product better than how it was.