Gas tank restoration
 

Any tips from those that have been there to cleaning up an original tank without damaging the original galvanized finish? Here's what I got....

This might help.



http://www.camaros.org/forum/index.p...7175#msg107175

That link doesnt work for me,,,,,,:dunno:

Link worked for me... thanks Darrell! Below is the highlight from that thread for those that are following along....I will likewise give this a try and provide some results.

These backing plates were not in all that bad of condition to start with. It was like the surface had oxidized and turned a dull flat gray in some areas. It was also rough in texture when you ran your finger over it.

Here's what didn't have any effect on them at all: powdered dishwashing soap....vinegar.....milk and baby powder.

Before buying any polish, I decided to try some Brasso that I already had. That worked! I also tried some fine grade bronze wool. That also worked. So I decided to try a combination of both. Applying the Brasso with the bronze wool. I think it worked about as good as anything could. It didn't make them pristine but it made the outside look like the areas inside that had been sealed up and never exposed.

Doing this did not leave any scratch marks unless you pressed really hard. Where I had tried Scotchbrite earlier in a hidden area, that definitely left scratch marks.

After the Brasso, I washed them and tried the suggested buffing with a plastic scrubbing pad. That added more shine to them. I was surprised by that. I didn't think it would do anything. I finished them with a coat paste wax inside and out.

Did a little work on the tank today using the above process.
Photo 1 - "as removed" surface
Photo 2 - cleaned with "purple power" cleaner mix
Photos 3,4,5 - Brasso applied with bronze (fine) wool and wiped clean with a damp cloth.
Long way to go, but it looks doable for saving the original tank finish. I have some evaporust on some of the rusted areas right now, will go back at it tomorrow.

Evaporust did a decent job of removing the rust, am now left with a stain to deal with. The evaporust process revealed a "3" on the rear end/driver side/top of the tank - anyone know what this is for?

That's not a stain....the rust that you removed had eaten away the factory "coating" (tern finish). It's pretty much bare steel in those areas once the rust is removed. Likely, anywhere you have that surface rust you are going to see the same thing if you remove it. It would take some sort of creative "painting" to make those areas look like the better, still coated, adjacent areas.

Eastwood makes a tank tone, is the finish any good?
On the sub gram on f body’s that had a Cat, there’s a galv heat shield, I tried cleaning it up a while ago, didn’t have any luck, once the galv finish is gone it’s gone I think. Tank tone would prob be a silver paint.


https://galvanizeit.org/designing-fo...ip-galvanizing



http://www.mustangsunlimited.com/Mus...ting-13-Oz.axd

Eastwood's tank paint looks like....well.....it looks like paint. Nothing out of a can, etc will give that original look if it matters. Paints just lay down a mono-color/mono-tone finish.

The original tern coating has a sort of hard-to-describe "inconsistent" appearance....variation of the color or look over the surface.

Also...the EWood paint tends to go on very dry and very flat. Typical "dry edge" look from using a spray can to paint a larger flatter piece like a tank.

It looks "OK" from a distance as all you see is a silver looking large part but if you know what an original tank (or new tank) looks like it's not very convincing.

On the Evapo---the stuff is really meant to be used on a part that can be completely submerged. Sure, they suggest laying towels, etc over larger parts like this but the results aren't very good....just not enough "exposure" to a pure Evapo-environment.

Also - I don't know the OP's circumstances exactly BUT......if you are using Evapo in the cooler winter temps...forget it....it won't do much of anything. The temps of the Evapo really need to be up there. It will work MUCH better the warmer it is but using the lay-a-towel-over-the-spot-and-saturate-with-Evapo technique with something like a heat lamp on it may just result in it evaporating off to the point where it's doing even less.

At lower temps the stuff barely works or does nothing at some point.

It is also VERY SLOW to remove heavier rust and really won't "pull" or remove the rust down in heavier pitted areas.

Galvanizing (zinc) turns duller and greyer over time.....that's the sacrificial nature (and purpose) of it to provide protection to the underlying metal. It can be "brightened" a bit BUT BARELY once it's "turned" (ie gone grey) and some of the brightening may just be the optical effect from making the surface glossier with any rubbing/polish, etc. You'll never get it to look like NEW galvanizing again.

The tanks aren't galvanized (which is a zinc type finish)...the flat steel sheets were coated (before rolling into rolls) with a "tern" finish which apparently was a lead/tin coating. Still, similar aging characteristics, etc.

Any tips for preserving a tank? I've got a Spectra Premium coming and was planning on at least a wipe down with Boeshield, but didn't know if anything was better-more durable and long lasting without changing the finish.

IMHO, buy a new tank and be done with it.....

best advice yet......they are EXTREMELY well priced...especially from RockAuto since their tank prices (Spectra Premium) are great and just as importantly, their shipping charges usually beat the heck out of anyone else.

As far as preservation - yes, Boeshield is good but should be reapplied periodically....it's not a "coat and forget forever" type product. The new tanks have an oily film on them out of the box. You could remove that with some wax and grease remover and then Boeshield it.

Can you get something re galvanized?

Here is some interesting info from CRG website.

http://www.camaros.org/forum/index.php?topic=11864.0

Sure.....IF you can find anyone that will mess with it...

Any galvanizer will be a huge outfit...industrial concern doing BIG stuff. First reaction will be "we don't do one-offs, small stuff, etc.

Next reaction, as mentioned in the linked-to Camaro site thread will be - we won't touch the part because it's thinner metal....too much risk of distortion, etc. I got this reaction from a galvanizing outfit down in S. TX many years ago when checking into it.

Can't blame them....they specialize in volume/thru-put and it's probably all done on a competitive bid basis. Folks like us are not worth their time and I can't blame them for not wanting to mess with us "retail" folks.

I did look into it in the Chicago area as well with a customer up there a few years back when I was doing resto work on his '72 442 convert. We found a galvanizer up there (think rust belt...plenty of need for protective coatings on metal) and they did re-galvanize his gas tank straps. I think they just figured, WTH, get this guy out of our hair and dip the darn things...no skin off our noses. We ended up throwing them away....the finish was way too thick/globby, etc (hot dipped galvanizing)..went with new galvanized straps from Inline Tube on the car.

The "thing" is the metal you see on these cars that was galvanized was done so IN SHEET FORM before the part was actually stamped. Probably done at the steel mill, again on a massive controlled-condition basis where they had the knowledge and equipment to put a nice SMOOTH galvanized finish on the sheet steel.

That is A LOT different from trying to have someone do it "locally", etc.

I do remember many threads, pics on the big Chevelle site years ago where people were having their Chevelle frames galvanized. Don't remember where it was being done at the time...seems like one guy had his done in Houston but probably others had it done at different places in the US.

Tank tone or new tank I’d say. I have the same dilemma. My 78 was painted back in 82. The guy sprayed undercoat on the tank to cover overspray. I want to drop the tank and strip all that crap off. Maybe it’s nice under. But I doubt it.

Burd that tank might be well protected and nice underneath. Some place, probably on crg someone did that and it was very nice

Whatever you do, don't spend any money on the Tank Tone stuff from Eastwood - it looks exactly what it is; paint.

Thanks for all the feedback gang. As with everything on this car I would like to retain the original "born with" parts if possible vs doing a "computer restoration" with a bunch of repro parts - even if it means a less than perfect appearance. The rust condition in my photos is on the trunk side of the tank so it would not be seen after install. We'll see how I do on this tank - I can always buy a repop if it turns out like dog$hit.

While we’re on this topic, what are the 2 straps to be pained or what? (GM)

Now you got me going on this, I’m going to clean a spot with something to see what it looks like. I remember seeing blue steel,company names on the tanks, i don’t want to remove that. Do all tanks have this mark?

Tank straps are painted black, not sure if 30 or 60% gloss. Photo of my strap below, original black paint evident where the strap was tight to the tank.
As far as the steel manufacturer's mark on the tank. Those are stencils that were applied to the strip after it was cold rolled to the final gauge at the mill. I do not know if there was a required or standard spacing of that stencil when it was applied, but there would have definitely been a space between stencils. If the spacing was close enough, you could potentially have it appear on every tank made from the steel coil shipped to the tank manufacturer, but you can be fairly sure it would not "land" in the same place on every tank.
Our business slits millions of tons of steel every year for all the domestic steel mills and apply stencils to some of that metal. These days the stencil requirements are everything from continuous through the entire coil to just marking different areas of the coil. The requirements are generally driven by traceability for quality purposes.

I saw an OG rubber hose still on my tank looking at it. It’s full of cracks too, spring job. Also I wan to replace all the hoses again and put the rite color pinch clamps back on.

FYI I ended up doing a little paint in my gas tank of my old 67. If this is something that interests you can shoot me over a text and I can give some tips on how I did mine. But honestly I’d just polish the bare metal areas and roll with it.

Depends on the GM division and/or the plant.....Oldsmobiles are galvanized steel straps with no paint. Looking at the Fisher Body video showing a Monte Carlo it looks like those were black as mentioned by someone else. Could have also changed depending on model year I guess. I've dealt with a massive number of Oldsmobiles and they're always galvanized/no paint so there is some variation. Same thing on the Buicks I've dealt with and seen (at least '70-72)...galvanized w/no paint.

I've also had plenty of clean original tanks with no evidence of the large ink/paint stamp.....must have been fairly widely disbursed on those rolls of steel back then.

Might as well talk is there insulators under the straps? I see them on eBay, but not sure all the Gm straps got them?

Again, on Olds and Buick I have never seen any insulators b/n the straps and tank on originals I've dealt with. Maybe some divisions used something but I can't tell you 100%. There's no need for anything....there isn't any movement once the tank straps are snugged up tightly.

There is a bit of "revisionist history/marketing" done by some of the repro parts places to sell stuff that was never used.....they are in the business of "selling" after all.

I guess drop the tank and see if their there. I saw them on eBay so that figures. Lol
Like the wheel well rubber skirt PCs, my car doesn’t have yet they sell them.

I'm inclined on the insulator-strap issue to fit something plastic-rubber-non metal that is hidden, possibly in the bead to keep the metal strap from contacting the metal tank directly. Seems like even if it doesn't move much, it would still eventually wear the galvanization off to start rust spot.