I have this Gulf sign that was used at my Grandfather's station from 1937-1947. I've seen a lot of varied opinions on the subject of restoration. I'm not looking to do any kind of restoration other than maybe bringing out the color that is left. My question is more about if the rust needs to be treated or is it ok to just leave it alone. Based on what I've read so far I'm leaning toward just giving it a wipe down with WD-40. Will the effect of WD-40 last or will it need to be reapplied. I plan on hanging this in my garage. TIA.

WD-40 will need to be reapplied occasionally. You might want to just clear coat it. I have a friend that cleared a 6 foot HC Sinclair sign. It was in bad shape but the clear brought it somewhat back to life. It’s hanging on outside of shop but seems to be holding up good in the weather.

...if you want the sign to last, keep it indoors - with some component of humidity control...I've seen painted 'indoor' signs where the paint is peeling off - like a co-ed's tan, a week after Spring Break - because of a lack of air conditioning...moisture - and rust - never sleep...WD-40 will dissipate over time, but can be reapplied as needed...I wouldn't clear a sign of any value other than sentimental, for obvious reasons...

You could also use Howard’s Feed and Wax. It will prevent further rusting and bring out the color. However, like WD-40, it will have to be re-applied from time to time. In fact anything put on an outdoor sign will have to be re-applied from time to time.

Guys have used Howard’s on porcelain signs for years, but it hasn’t been brought up in a while. It’s safe for your porcelain sign too.

Just my two cents,
-Steve

I will add one thing about WD-40, Howard’s F&W, “Sign Juice” or any other product used to enhance a sign. It does make the rust spots a little darker, so if you have a section of light-colored porcelain that has a lot of little hair-line stress cracks (like it was bent, but the porcelain didn’t come off) AND the porcelain is thin, or an area with a lot of deep scratches, it may slightly darken those areas. If the area of porcelain is smooth or just dull this shouldn’t happen. I think you will be pleased with WD or Howard’s.

Here’s an example of scratches darkened on real thin porcelain. It makes the blue look a lot better, but it darkened the yellow a little bit. Overall the sign looks a lot better. (If you zoom in on the yellow and compare each picture, you can see what I’m talking about. However it’s not very noticeable from a distance, I just wanted you to be aware). It darkens it for two reasons... there could be rust/grime in the cracks and/or the porcelain is worn thin where the scratches are and blue is the underlying color.

Make sure you clean your sign and use a clean rag. This will prevent you from dragging dirt and grime into those areas.

All of this was probably way too long and technical of an answer, but just letting those know, who have never done it.

By-the-way, this sign looked like it was used as a door mat in a mud factory when I got it and the porcelain had worn and faded thin.

Thank you for the replies. I plan on hanging this sign in my garage so it will not be outside. The garage is not climate controlled however. Those that use WD-40 or other products, how often do you reapply them?

You will know when it loses it’s look it’s time to reapply.

Great info, Steve!