Gas tank coatings

[james heider]

I started a thread earlier in regard to galvanising a gas tank Others have talked about the problems with tank coatings peeling off and cloging the fuel lines. Attached are a couple of pictures of a Mercedes gas tank that I removed from a car yesterday that had been sand blasted and recently coated.
One of the pictures shows the coating in the neck of the tank and how it can peel off in a sheet if fluid gets behind it.
The second picture is looking into the tank through the sender opening. You can see the coating on the bottom of the tank. If you look close you will see where the person that did this tank sandblasted the pick up tube putting several holes in it. They obviously didn't notice the holes and went ahead and sealed the tank.
We removed and replaced the tank because the car would only go about 100 miles before running out of gas.
I think I am going to pass on using any coatings after seeing the neck of this tank.

 

[BRENT in 10-uh-C]

I read about 'Fordbarn Folks' who say "I am not going to put any sealer in after they tumble them", ...or clean them with acid, --or whatever. Below is two pictures of a tank that was tumbled and then had a sealer installed.

The other three pics is of a tank that had been cleaned and then no sealer added afterwards.

Explain to me which method is better please?

 

[MikeK]

. . . Explain to me which method is better please?

As soon as I get my flux-capacitor charged I can go back and buy a new tank? Anybody have a '29 price guide handy? I don't wanna pay too much.

A '32 tank is looking better every time I see lousy tank pix! If there was a kit for an A tank gauge that would look "A" but electrically read a '32 type tank I might consider it. Think of all the possibilities for all that vacated tank space. How many points will I loose?

 

[james heider]

I think there is a market for doing the original terne plating again.

 

[Craig Lewis]

I read about 'Fordbarn Folks' who say "I am not going to put any sealer in after they tumble them", ...or clean them with acid, --or whatever. Below is two pictures of a tank that was tumbled and then had a sealer installed.

The other three pics is of a tank that had been cleaned and then no sealer added afterwards.

Explain to me which method is better please?

Brent these are excellent pics and a fantastic way to test a problem we all face.
I think it's important to note that the tumbled tank in picture 1 & 2 was doomed to fail from the start. The rust was simply burnished to an even coating and is plainly visible through the thin white sealer.
Sadly I find this is the extent of preperation one can expect to find in many cases. Far too much is expected of coatings, all it takes is some clever marketing & a couple success stories & overnight the paint or coating becomes "magic"...leaving preperation on the sidelines & the end-all-be-all is eagerly slopped on. It seems that paints & coatings are too often treated like this, the final coat feels soooo good...it brings "closure"
I've found nothing will stick to rust over any appreciable length of time and a gas tank is really the ultimate test... I mean we've got temp changes, moisture, extended periods of gasoline storage & then whatever effects the gas has as it rapidly deteriorates.
...if THAT wasn't enough, now we've got evil ethanol.
It would be interesting to see how a good sealer (POR15???)stands up when applied over steel which is
-chemically cleaned to remove rust from every pore(redistrip/phosphoric)
-tumble abraded with a sharp substance to give "tooth" and remove any residual chemical film.
-immediately heated, to bake out the moisture then coated while still warm.
....Of course if all that works, aren't we still faced with the ethanol threat?
Ultimately, it's really looking like we need to find a way of PLATING the interior of these tanks....

 

[BRENT in 10-uh-C]

Brent these are excellent pics and a fantastic way to test a problem we all face.
I think it's important to note that the tumbled tank in picture 1 & 2 was doomed to fail from the start. The rust was simply burnished to an even coating and is plainly visible through the thin white sealer.
Sadly I find this is the extent of preperation one can expect to find in many cases. Far too much is expected of coatings, all it takes is some clever marketing & a couple success stories & overnight the paint or coating becomes "magic"...leaving preperation on the sidelines & the end-all-be-all is eagerly slopped on. It seems that paints & coatings are too often treated like this, the final coat feels soooo good...it brings "closure"
I've found nothing will stick to rust over any appreciable length of time and a gas tank is really the ultimate test... I mean we've got temp changes, moisture, extended periods of gasoline storage & then whatever effects the gas has as it rapidly deteriorates.
...if THAT wasn't enough, now we've got evil ethanol.
It would be interesting to see how a good sealer (POR15???)stands up when applied over steel which is
-chemically cleaned to remove rust from every pore(redistrip/phosphoric)
-tumble abraded with a sharp substance to give "tooth" and remove any residual chemical film.
-immediately heated, to bake out the moisture then coated while still warm.
....Of course if all that works, aren't we still faced with the ethanol threat?
Ultimately, it's really looking like we need to find a way of PLATING the interior of these tanks....

I think that is the current issue Craig, evidently some folks are now complaining that even the POR15 sealer is now being dissolved by the ethanol fuels.

With regard to the plating, from what I seem to recall, weren't the tanks stamped first, then Terne coated, and then submerged into something (Mercury??) before being welded while being submerged?

 

[Aerocraft]

There have been pictures posted of the welding process which was not done while submerged. I suspect that the terne plate may have been done first. It would be interesting to learn more about the process.

The pictures posted in this thread should put to bed any more speculation about the process of coating the inside of the tank with any "miracle" chemical. Thanks James and Brent for the great pictures! Gar Williams

 

[Keith True]

With my own I am sticking with clean it,whatever way is best for that particular tank,and leave unsealed.I have a few that I did from the late 70's up until the late 90's that I still have around,two are pink inside,but that is the extent of it.Keeping them full and using them makes a difference.I have a tank I did for my 30 pickup in the early 90's,it had hangers drooping down from the top before,now if I reach in the cap and wipe the underside with my finger I will wipe off some powder,but it has not developed any hangers like it had before.I did the inside of a Hough 30 gal loader tank about 8 years ago,we used the Hirsch stuff.It has been fine until the last couple of weeks.It is not dissolving but peeling off in strips.Luckily that tank has a 12X14 bolt on cover so I can open it up to clean again.When I did it before I blasted the inside completely.Both of the tanks Brent pictured show problems,although the unsealed one looks as if somebody let water sit in it.I don't see any good answer,with the old equipment I work on I am telling everybody to keep the tanks full and use the machinery.

 

[Craig Lewis]

I think that is the current issue Craig, evidently some folks are now complaining that even the POR15 sealer is now being dissolved by the ethanol fuels.

With regard to the plating, from what I seem to recall, weren't the tanks stamped first, then Terne coated, and then submerged into something (Mercury??) before being welded while being submerged?

From what I've seen it's impossible to weld against lead. The lead flows against the clean metal, introducing contamination, which would turn the welding process into a splattering mess.
I vote the terne plating was a final step and probably done in the interest of sealing pinhole leaks as much as a preservative coating.
I can see mercury being a wonderfull heat sink while welding, to prevent buckling & warpage of the stamped panels. Not sure how they would do it with keeping the flange above the mercury to weld...and where the heck was WCB while all this mercury was being inhaled?
After 1 week on the job....I suspect the process was as much a mystery to them mercury boys, as it is for us today
Below is the barn fresh tank I recently bought for my coupe. I thought it was a pretty good example of terne plating here at the front, where it was sandwiched up against the firewall and received no paint.
This is uncleaned.....note the absence of rust & also the presence of terne near the rolled weld seam.

 

[Keith True]

There seems to be no rhyme nor reason why some tanks rust up and some survive.I know of some that spent their whole lives under cover,and are full of rust.Some are abused and are nearly perfect inside.I have been out in the junkpiles in the yard,gathering up parts to assemble a 30 pickup cab this winter.I was looking for the best tank to use,and for some reason took the cap off the worst one in the pile.Probably this thread got me to thinking.This tank has been out in the weather since about 1970 that I know of,and for the last 20 or so years I used it as a weight to hold the tarps on the good stuff.This tank has zero paint left on it,the threads are rusted out of the steering column bracket,but it has always had a cap,shutoff,and the guage in it.It looked perfect inside.I stuck the air nozzle in it and got a gray dust out of it.I dumped a gallon of wash thinner in it (laquer thinner)as it will leak out places water won't.No leaks,even the shutoff is holding.I use the late 31 column brackets anyway,so it looks like a user.I have bought tanks in the past,and this one has been dropped,thrown,kicked,even offered it to a rodder for free so he could cut the top off it.He said it was too rusty.It was put up dry,and probably nobody ever opened the cap up and let in any humidity.I have a 96 Harley,and an 03 Yamaha 1600,both are showing signs of rust in the inside tops of the tanks.If I reach in the caps and wipe my finger I can come out with a slight pink stain on my finger.I also have a 63 Honda dream,a 71 Honda 350,and a 71 Honda 100.Every one of those shows no signs of rust whatsoever.In the dream tank you can see the blue discoloration from the welding on the bottom seams.Nothing special has been done about their storage.Sheds,garages,tarps,cellars,shuffled around from place to place.Every few years they get a little gas and a battery to get ridden 10 or 20 miles.

 

[james heider]

Has anyone used the Red Coat sealer for their tank.
Here is a link to their website



http://www.damonq.com/TechSheets/Red-Kote.pdf

 

[gpits68]

i had a tank done by Moyer fuel tank renu in Pa.,has a lifetime warranty.it is some kind of red coating. www.gas-tank.com

 

[MikeK]

Here is a tank (NOT model A) done by one of the many "Renu" dealers. To me, it is terrible work. They did not completely blast the old white coating that failed from the two dip tubes, nor did they coat them! Makes you wonder what horror was left under the ugly goopy stuff covering the bolt in the corner and the tank seam.

The picture is on a Fiero forum.
The guy who owns the tank thinks this is good work! More incentive to fix my flux-capacitor so I can just go back and buy a new "A" tank.
The coating appears to be black "Renu 1999", not the red "Renu 2000".

What they did to the outside:
The coating is the black "Renu 1999", always used on tank exteriors, even if the inside is done red. Looks like my grandma. If you had an "A" tank done,
this would be over the holes cut in the back.
Back holes do not permit access in front of the baffles on 30-31 tanks.

 

[BRENT in 10-uh-C]

i had a tank done by Moyer fuel tank renu in Pa.,has a lifetime warranty.it is some kind of red coating. www.gas-tank.com

Again I wish I had better news or a solution for you but just FYI, I almost became a RENU dealer however there are several things that people should know. A stock Model 'A' gas tank is not lifetime guaranteed unless it is coated on the exterior with their PVC sealer. Since most are not it only carries a two-year guarantee just like a Motorcycle tank.

One other thing, the warranty is only covering the tank from rust & future leaks!! It does not cover the R&R of the tank, nor the repainting of the exterior, ...AND it does not cover any issues resulting from sealer degradation or disolving from gas. Also, this warranty is handled by either doing the repair over, or refunding the money you paid for the initial process (Their choice!). That's it!! ★★

Want more info, go here: www.gastankrenu.com/guarantee.htm


★★(Imagine the frustration when someone has their tank RENU-ed during the restoration followed by Paint & Bodywork and the tedious installation only to find after a few years the tank has issues and they give your money back and say "Sorry". Then who gets to pay for another tank, go through (or pay for) the Bodywork & Painting, and then do the whole installation again?)

.

 

[Keith True]

Almost all the tanks I sent out that went bad were done by Gas tank Renu.There was a radiator shop I used back then that became an outlet for them.Until the new gas came along I had only one problem,it was in a Ford tractor,we sent it back and they took care of it.I have never once blamed them for all the ones that have been going bad with the new gas.Their work and product was fine at the time.How can they guarantee against something not invented at the time it was done?The last couple I have had done were the red,one of those is going bad.The older ones were done in a gray materiel,inside and out.The gray stuff seems to peel off,the red seems to dissolve into the gas,and if you dip your fingers into the gas and rub them together the gas will dry up.Then your fingers are suddenly stuck together from the red residue.If todays coating is good for todays gas,what about tomorrows gas? I sent a couple of tanks to Canada through another radiator shop,I have not heard anything about those.They could still be good,they could have been sold,or they could be sitting melted in somebodys backyard.

 

[Huff]

I have a 49 Mercury and I had a shop do my gas tank in 1991 he cut a square hole in the tank and sand blasted it in side and out and used the Renu product have not had a problem well satisfied.If the tank is not completly clean of rust on the inside nothing will stick.I had another shop clean it and put that Pour liquid in it and all that pealed off in sheats.That was before I had the Renu proudct used.

 

[Keith True]

Brent brings up a good point about the years later thing.I know of a 31 Fordor that the owner has been picking at since 1978.He is very methodical,do one part,make it right,put it away until it is time to install it.Knight engineering did the engine about 1980,he painted the car in pieces and had LB do the interior in the mid 80's,While he had the tank out to repaint he researched the sealing idea.It sounded good at the time.Now it has been a little over 20 years with no gas ever in the tank.Now he is down to the little things,and shortly he will be forced to call the car done.He has seen a lot of sealer failures,and is kind of worried about what is going to happen when he gasses his up for the first time.In his case I told him it wouldn't be a big deal,he had painted the tank while the car was apart and installed it after with no damage.I'm sure he could R&R it again the same way.But,this could be a major operation to the everyday guy.The worst part about this one is that he had a near,if not perfect tank to begin with,and the coating was to be a preventative measure for the future.I just don't see an answer for this problem yet.There is a man near me that worked for a finishing shop,(industrial,no show or pretty chrome)and he talked about some of the tank coatings they used to do for machinery.He said they would never do any old automotive tanks,as they have to be absolutely clean,which is impossible by chemical cleaning.As he put it,try to solder something with your fingerprint on it.It just beads up and rolls right off.They used to do a lot of lead/zinc/copper/cad/ protective plating for new industrial machinery.The new regulations closed them down about 10 years ago and their work all went to Mexico.