fuel tank - time to clean the inside. Was thinking of plating the inside to seal it instead of using a tank sealer. Thoughts?

[Mike "Hubbie" Stearns]

I’ve been working on restoring an old tractor. It’s been lots of cleaning and rust removal. I just finished cleaning the outside of the fuel tank and it’s time to clean the inside. Once that’s is done, I was thinking of plating the inside to seal it instead of using a tank sealer. Any thoughts on this idea would be appreciated. Mike

[7th Son]

I don't understand why you would want to deviate from a tried and true, proven method of sealing and preserving a tank by possibly ruining it during the plating process or later finding out that whatever fuel you put inside it reacted with the plating and may have even damaged more of the fuel delivery system or even the engine. I can also envision future disagreements between you and your plating shop as to what might have gone wrong and who's fault it might be.

For my money, and peace of mind, I'd go with a proven tank sealer and not experiment. I have used DIY products and also farmed out the job locally and have always been satisfied over the years.

 

Good luck, whatever your choice is.

 

 

 

[playswithbrass]

Mike if you talk with the plating people they will tell you that it takes very special equipment to plate the inside of an object that mostly only manufactures have. I tried to get the inside of a pair of cowl lights done and was told this.

[ArticiferTom]

OEM was mostly tin metal, soldier together . Tinned metal is available as specialty today . I had to clean mine of old sealant from po . Had cut open cleaned  ,window welded shut and been using Marine Sta-bil . This product designed to vapor anti rusting . Last six years still looks great.

[46 woodie]

I can see where Mike would be looking for something better than the latest gas tank sealer. Back in the '70s, I coated a Model A gas tank with the "latest and greatest" gas tank sealer. Along came the new gasoline and it caused nothing but problems for many of us. Who knows how long it will be before the government comes out with a new gasoline directive that will attack the new "latest and greatest" tank sealer? I wish I had an answer for you Mike.

[Dave Henderson]

I'm shy about using tank sealer dope too and wouldn't use it, or try interior plating.  I'd start by rinsing/soaking the tank out with lacquer thinner if there are any gummy deposits, then put in enough metal prep so that by turning the tank periodically in all positions the prep is able to reach and soak the entire surface of the interior,  including it's top.  Metal prep eats rust but won't hurt the metal. Then rinse again with thinner and put a filter on the line.  Keeping the tank topped up with gas would help prevent interior rusting.  If it sits for long periods use Sta-bil.

[TAKerry]

I had a motorcycle tank that had some sort of sealer from the PO. I didnt notice until it was almost too late but the stuff came apart and I ended up with chunks of a rubbery material in the tank. Had to take it off and sent it to a guy to clean it completely out. I have been gunshy of anything gas tank sealer related since then.

[jdome]

I have made early gas tanks using 20ga galvanized plated sheet steel. This is what the HVAC industry uses but 20 is a thicker gage than they typically use. It is mostly zinc and soldered easily. I like to use 1/8 in electrical rosin core solder to start the tinning process followed by solid core. Rosin clean up isn't as critical as acid flux. Make sure that cut edges that expose steel are outside the tank or  solder those edges if inside.  I've also had to make new water tanks for the radiator system . Those were originally galvanized but I made those out of copper. Tank sealants won't withstand boiling coolant. 

 

 

 

 

Edited May 8 by jdome (see edit history)

[ABear]

On 5/6/2024 at 7:13 PM, Mike "Hubbie" Stearns said:

Once that’s is done, I was thinking of plating the inside to seal it instead of using a tank sealer.

Plating only works if things are 100% spotless, the metal must be dirt. grime, grease, oil, rust free and the base metal is 100% compatible with what the plating coats will stick to.

 

Have my doubts it will be successful unless you cut open the tank, power wash, sand blast and then power was again then weld in a patch..

 

Simply pressure washing from tank openings will not be sufficient to clean the inside of the tank.

 

I tried pressure washing a small generator tank to clean out someones attempt to use tank sealer that they tried without using a liquid metal prep (rust converter) first. Couldn't get the wand in to the tank far enough to remove much. Ended up rigging up a way to spin the tank slowly and added rocks, screws, bolts and nuts with some water and let the run for several days.. That helped but still had rust and leftover sealer inside.. Spent too much time on that generator, put it up for sale with a note to the buyer that I cleaned the tank but there is still some rust.. Couldn't justify spending $50 on metal prep and tank sealer on a $100 generator.

 

I have however used Por15 tank sealer along with Por15 metal prep on a new tank I made for my oldest car, I reused a small portable air tank that I modified with a large opening on the top to put gas in.. When done welding, I used the metal prep to etch bare metal and convert any rust to a paintable surface and then added the sealer and sloshed that around. So far, I have had no issues with the sealer getting soft or flaking off, and the tank has been in used since 2012.. I have checked it a lot since I have a large filler opening and I allowed the sealer to coat the short pipe on the opening..

 

Proper prep is key to making the sealer work and not to mention not all tank sealers are not as good..

 

Follow the directions to the letter.

[mechanician]

I have owned two cars with sealed tanks.  Both done by previous owners.  Both needed to be replaced.  Fortunately neither was difficult to replace.  If the shape is simple just replace it and be done with it.  If the shape is complex, clean out the fuel residue first, then clean with evaporust or something similar.  If it is a collectible tractor drain the fuel after use and store it dry, you will get more condensation on warm humid days if it is full of fuel, if it is a working tractor parts must be available enough to replace it.  I have doubts that you will get it clean enough to plate, but I suspect that you wouldn't be doing that yourself so if someone has developed a process I would be curious (but quite skeptical).

[60FlatTop]

If I needed to repair a fuel tank I would cut out the top for full access to the insides. I would gently glass bead all the internal surfaces in the lower sections or joints. Then cut out and replace anything weak. We have a local radiator shop that will do that. I might try it myself when the pending opportunity arises.

 

Once I worked on a mid-1950s Bentley tank that had many dividers and chambers that never could have been done effectively without opening it. That is when I decided to continue with the more difficult method.

 

I would not use any internal coating and rely on leading all the seams. Once installed I like to keep my tanks full. It is my summer routine to top off the old cars on Sunday afternoon every week. I have thought of adding oil to create a thin film as the level falls but keeping them full is best.

[ABear]

1 hour ago, 60FlatTop said:

I would not use any internal coating and rely on leading all the seams.

Leading is good way to seal seams, not so much for an entire tank which most likely has internal rust spots issues.

 

Any internal rust spots left untreated will eventually turn into swiss cheese holes even if you keep the tank 100% full.. Any moisture in the fuel will eventually drop to the bottom of the tank and will continue to make a meal out of the tank.

 

If one insists on not treating or removing the surface rust inside the tank, you will eventually be greeted by a sprinkler system instead of a tank.

 

Treating the rust by chemical conversion, sand blasting or removal is the only way I know of stopping rust, ignoring it just makes it worse to deal with as you kick the can down the road.

 

Leading requires 100% rust free new surface to work with as does tinning, galvanizing, ect. Leading, galvanizing, plating will not work with chemical rust converters as the chemical rust conversion process turns the rust into a black paintable surface that lead, tin, galvanizing or plating will not stick to.

 

OP could look into having it hot dipped galvanization done provided they can find a place that does it on small scale jobs, but I suspect unless that inside is 100% rust free it won't work..

[Ben Bruce aka First Born]

Mike, if you get the tank clean enough to seal,  it will likely last more years than you have left WITHOUT  sealing.

 

  Ben

[60FlatTop]

The seams I am writing about are the seams from cutting out the top of the tank and any seams where weak or perforated metal is replaced.

 

I sold a lot of gas tank sealer at swap meets. It was hard to convince someone to buy 2 quarts for coverage. About the only way was to make them think a friend needed a tank sealed as well. Tell them they could do theirs first and then pour it into their friend's. That worked quite often.

 

Buying a reproduction anything doesn't sit well with me. The conversion from Inch/pounds to Metric doesn't give me a lot of confidence from my experience.

 

Well, that's it for me, back out to the garage and file fit the ears on my brake pads so they will go into the sliders. What was that about manufacturing measurements.

[ABear]

4 hours ago, 60FlatTop said:

The seams I am writing about are the seams from cutting out the top of the tank and any seams where weak or perforated metal is replaced.

Got it!

 

Although, I wouldn't recommend solely depending on soldering or leading in the case of holding the patches in place. Made a lot of money resoldering circuit boards over the yrs, solder can get little tiny cracks which are often called "cold solder joints", have nothing to do with the temp the solder was used at.. The cracks come from temperature swings which causes enough expansion/contraction to create the cracks over time, the solder gives out before other metals as it is very soft compared to the parent metal it is attached to. Soldering a seam requires a very good mechanical means of holding the patch or seam together (like the ends being crimped over) and the solder is applied after the mechanical fastener as a means of providing a liquid tight seam.

 

If you really enjoy frustration, try resoldering the seams of a brass float.. The brass doesn't fail, but the solder that holds it together and keeps it liquid tight does, creating little tiny pin holes in the solder that will drive you mad..

 

For something like fuel tanks where you really do not want leaks, welding/brazing would be a lot more robust than solder.. With a well cleaned tank void of any residual fumes I would be thinking of MIG or TIG welding shut, then apply solder/lead..

[Larry Schramm]

I took the tank for my 1915 truck and had it hot zinc dipped - galvanized a number of years ago.  Still looks good inside and out.  That is the only way that I would coat a tank.

Edited May 12 by Larry Schramm (see edit history)

[mechanician]

2 hours ago, Larry Schramm said:

I took the tank for my 1915 truck and had it hot zinc dipped - galvanized a number of years ago.  Still looks good inside and out.  That is the only way that I would coat a tank.

Did it take some convincing to get them to dip a tank?  I would imagine they needed to position it just so to get it to fill and again to drain and prevent undesirable build up.

[Larry Schramm]

9 hours ago, mechanician said:

Did it take some convincing to get them to dip a tank?  I would imagine they needed to position it just so to get it to fill and again to drain and prevent undesirable build up.

 

No, they just looked at it and said OK.  Inside and outside are now galvanized.

 

PS: it was bone dry, no gas fumes.

 

Edited May 12 by Larry Schramm (see edit history)

[jdome]

"Hot" dipped. How hot? What does it do to soldered seams?

[ABear]

1 hour ago, jdome said:

"Hot" dipped. How hot? What does it do to soldered seams?

Most likely melt the solder..

 

Key ingredient to galvanizing process is Zinc, zinc melts at approx 787F according to HERE which is within most solder mixes melting range.

 

Hot dip galvanizing process is outlined HERE

 

I suspect that it may be possible that the dipping process might even provide a liquid tight seal as the same process has been used to make galvanized liquid tight containers like buckets, pails, tanks which used crimp seams..

 

One would have to ask that question at a place that does hot dip galvanization for clarification..

 

Of coarse, one can also solder seams after the galvanization process..

 

Galvanization does make painting a bit tricky, one must properly prepare the galvanized surface with and etch-ant to allow the paint to get a good bite. Zinc Chromate  primer was often employed but is pretty dangerous to use, less hazardous is acid etching using most rust converting solutions like Ospho..

[Mike "Hubbie" Stearns]

Thanks to all. I’m still unsure what I’m going to do at this point. I’m definitely not going to use a sealer. I’m leaning towards just cleaning it. I can still get a new one if needed. Mike

[Ben Bruce aka First Born]

Once clean, keep it full.   Ethanol does indeed ATTRACT moisture. Methanol absorbs water.   Add methanol to the tank.   

  A clean tank is not going to rust up in a few years, I bet.

 

  Ben 

[Mark Shaw]

On 5/6/2024 at 4:35 PM, E-116-YH said:

These tanks were originally tin plated. I called and spoke with someone at a plating company in Portland, Oregon several years back and they said that I should not solder the fittings and end caps until after they plated the tanks since the tin would not stick to the solder.

Many years ago, I had my speedster tank tin plated in Portland OR.  They insisted on sending it out to be hot tank cleaned before they submerged it in their molten tin bath.  The nice older gentleman spilled a 3' strip of tin on the floor and gave it to me for any spots that needed soldering.  It is still in the car.  

[31Buick96S]

On 5/6/2024 at 7:13 PM, Mike "Hubbie" Stearns said:

I’ve been working on restoring an old tractor. It’s been lots of cleaning and rust removal. I just finished cleaning the outside of the fuel tank and it’s time to clean the inside. Once that’s is done, I was thinking of plating the inside to seal it instead of using a tank sealer. Any thoughts on this idea would be appreciated. Mike

Hi Mike,

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