Pulled a chrome super rat tank out of the attic that needed some work. The tank was very rusty inside and some one had painted it red. I first degreased the tank and filled it with Evapo-rust and let it sit for 24 hours. Drained tank, inspected and there was still a lot of rust present and you could hear loose rust particles when shaking the tank back and forth. I did not look forward to spending hours soaking and shaking the tank to get the rust out and this task is complicated further by the small fuel fill opening on the early tanks. I decided to use a 50/50 mix of water and muratic acid. If you are not familiar with working with strong chemicals please do not attempt this. I plugged the petcock holes and put the tank in a large plastic tub. The plastic tub's purpose is to catch any acid solution that may leak out due to pin holes or spilage. Mixed the acid/water and filled the tank. Planned to drain the tank after 1 hour and check progress. This acid solution will damage chrome but considering the condition of the chrome on this tank it makes little difference. Checked the tank a few times and after 45 minutes of soaking a rust pin hole developed and started to leak. Drained and flushed the tank and found all the rust was gone and the loose rust was dissolved. Started stripping the paint and found a few dings. I will post more photos as the work progresses.
Danny Cooke
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dcooke007 - 06/16/09 at 1:14am
Stripped most all of the paint off but still have some remaining in the tunnel area. As you can see the tank is pitted due to corrosion but it is only modestly dented in a few places. Not sure yet what the finish will be at this time but not looking like a good candidate for chrome. Also still have not found any one local that is willing to re-chrome fuel tanks. As mentioned earlier, there is one pin hole to repair and also found a cracked seam weld. Today I will work on the dents. I am using a stud welder and special tool to raise the dents. The stud welder resistance welds a small pin to the tank to allow me to raise the dent. After the dent is raised the stud is twisted off and the metal is worked to finish off the repair. Todays work is the courser sort and will be finished further at a later date.
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dcooke007 - 06/18/09 at 1:23am
Went to work today on sealing a crack in the welded seam on the tank. Doesn't look like the weld was done very throughly in this area from the factory. The crack was at the front of the tank near the steering head area. Also have a small rust hole at the bottom of the tank to repair. Decided to use solder to repair these items. I used a dremel tool to grove out the crack to give the solder some surface area and made a shallow depression at the rust hole for the same purpose. Again this work is of the courser sort and the finer work will begin later.
Also, just so you do not think I am crazy, this tank is not a good candidate for restoration when so many better specimens exsit. I am trying to demonstrate what can be done with a bit of effort, skill and hard work.
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KirkN - 06/18/09 at 6:40am
Hey, Danny,
Great thread and great pictures. I really like following your progress on this.
But, could you use your photo software to reduce the size of 'em before you post 'em? They're so huge, pixel-wise, I can't read the words all on one screen width, so I have to scroll down, scroll to the side, scroll up, read, scroll down, scroll back to the other side, repeat...
Thanks, keep up the good work, and sorry to be nit-picky.
Kirk
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dcooke007 - 06/18/09 at 11:53pm
Kirk, I am sorry you are having trouble viewing the pictures. I adjusted my camera resolution lower, let me know if that helps. If you would like to discuss the process in detail just pm me and I will email you my cell #.
Today it was time to get the metal a little closer to being able to refinish. There is some rust remaining in the pits on the exterior and flash rust on the inside. For the exterior I used a combination of sand blasting and soak in the 50/50 muratic acid/water mix. The sand blasting removed the loose rust and chrome as well as etching the remaining chrome. Soaking in the acid mix removed the last traces of rust in the pits, further cleaned the metal and further etched the chrome for good adhesion of the primer coating. The only thing remaining on the exterior of the tank is clean metal, traces of the copper plate that was under the chrome and a small amount of etched chrome. As long as the copper and chrome is well attached there is no need to try to remove it further.
The inside of the tank has some flash rust from cleaning with the muratic acid mix as well as the exterior. Mixed up some Rustol at 5 to 1 ratio and allowed the interior to soak for about 15 minutes. After soaking poured the Rustol into a plastic tub and soaked the exterior of the tank. The Rustol removed the flash rust and helps prevent the parts from flash rusting afterwards. Rustol is an excellent rust remover but is not strong enough to remove heavy rust in a timely manner.
I know some of you do not like to use tank coatings but in this case it is appropriate. I use a product called US Standard Fuel Tank Coating sold on the POR-15 web sight. It is a good product and has never failed me.
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R Duttry - 06/19/09 at 12:08am
Hey Danny! You are correct! I forgot about the POR15 CO. There's a lot of guys I know in the automotive industry that use POR15 products for vintage restorations, They won't use anything else. Good Call!
Roger
P.S. Are you prepping this for chrome or paint? I ask, because this is a process I know little about!
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Bullfrog - 06/19/09 at 12:20am
Photo size can be tricky issue. For really good detail on screen it's nice to have about 1280 pixels wide (Bill's most recent photos are that size) . . . but that usually still requires scrolling sideways to look at the whole photo -- and more pixels than that are pretty much just taking up memory and slowing down loading speed. Photo widths around 600 pixels are still pretty darn good and usually don't require scrolling to look at 'em (and they load fast).
Throw in the problem of scrolling to the right to see the right side of the photo(s) . . . and then not being able to see the left half of the text immediately above or below the photo . . . and it can get to be kind of time consuming.
Bill, this is a nice progress report on techniques for saving a pretty well "gone" tank.
Ed
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dcooke007 - 06/19/09 at 12:51am
Hey Roger and Ed, I have decided this tank is not a good candidate for chroming, to many pits on the exterior. Shame really as this tank appears to be correct for the early Super Rat. Small capacity, small fill opening and dual petcock holes. I have not decided what to do with the paint scheme yet. Maybe camouflage so you can sneak up on the competition? Smiley Will have to give some more thought to it.
Thanks Ed for the input on the photos. I have a wide screen monitor and suppose that is the reason this had not occurred to me. You guys know fathers day is coming, maybe a new monitor for the holidays. You might need to drop some hints to the family.
I will have to put this project on hold for about a week, other priorities are calling.
Early happy fathers day to all.
Danny Cooke
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warhatchet - 06/19/09 at 9:03pm
Nice job Danny! Good step by step info and it is turning a lot better that I thought. POR 15 is good stuff. I used it on my 57 Chevy pickup that I street rodded. Richard
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gpar - 06/28/09 at 6:58pm
Danny it looks like the interior acid wash was a good idea. On my current chrome gas tank resto I used Evapo Rust to treat the interior rust after the botched plating job. I thought it removed all of the interior rust, but I still ended up getting fairly large amount of rust in the fuel filter.
Contrary to popular belief, the plating process did not remove any of the interior rust. In fact there was more rust inside the tank when I got it back from the plater, than there was before the plating process.
I almost wonder if it would be feasible to remove the tunnel, bead blast the interior clean, and then weld the tank back together.
I'll call you about another tank I picked up that needs your dent removal service!
Gary
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dcooke007 - 06/28/09 at 11:03pm
Gary, the acid treatment method worked very well on the interior of the tank. It totally dissolved the loose rust and cleaned the interior as well. The concern I have for the average person is not knowing how to work with muratic acid. Straight from the container it is not something you want to be careless with, once diluted with water it is a lot less hazardous, but still should be used with care. If you try this method you pour the water into the acid not the acid into the water and do not use it near any other steel parts. The fumes from the acid will cause any parts they come in contact with to rust, good ventilation and eye protection is also required.
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joebat - 07/02/09 at 7:44pm
Also, the muratic acid burns chrome...turns it black in seconds! ...OOPS! How do I know that?
It wasn't my tank though.
Joe
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Bullfrog - 07/02/09 at 9:23pm
Danny:
Every chemistry class and every technical process I've encountered calls for adding acid to diluent(water in this case) rather than your recommendation to add the diluent(water) to the acid. Why are you recommending that procedure?
My long term understanding has been that if you add water to acid, there is a tiny amount of water at the start and copious quantities of the active ingredient (acid) which can react with the water (especially if there are ANY contaminants in the water) and the result could be a steam explosion. Not good.
On the other hand, if you add the acid to the water - the first tiny amount of acid is surrounded by copious amounts of good ol' cool and calm water. The small amount of active ingredient (acid) can't work up the reaction energy to cause problems even if there is some contamination in the water.
Ed
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hodakaronwa - 07/02/09 at 9:49pm
I have used US Standard Fuel Tank coating in the past with less than satisfactory results. I coated a tank and it had all winter to cure in the shop. Come spring thinking that it was a sure thing I installed on my bike. A couple days later the coating gelified and plugegd everything up. The new fuel we are having to use does not work with US AMERICAN STANDARD FUEL TANK COATING. SORRY!
The absolute best solution is to purchase a new Plastic tank for riding and for show keep looking.
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dcooke007 - 07/02/09 at 10:41pm
Ed, you are correct about the acid mix procedure. Should add the acid to the water, I guess it had been a long day when I first posted that info.
As for the US Standard Fuel Tank Coating, I stand by the info I posted and find it to be an excellent product. And no I do not have any association with the company. To test the products durability I tried to remove it with every chemical I could find and nothing was very effective. I did try electrolysis and it finally came off in large sheets.
I have noticed when I drain the excess coating from the tank and back into a small container, the excess coating will skin over on the top and leave the product at the bottom of the container un-cured. If excess US Standard Fuel Tank Coating is left in the tank it can pool at the bottom of the tank and just cure on the surface leaving liquid material below the surface cured layer. This type of circumstance would surely lead to failure of the coating. Proper metal prep and technique is a must for good results.
Danny Cooke
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R Duttry - 07/03/09 at 1:29am
Hey Guys, When using Muratic Acid, Don't get it on anything made of aluminum. It will eat that stuff right up. We use the acid to get melted pistons off the cylinder walls of the alcohol 270 motors only because they are Nikasil Coated! Muratic Acid won't hurt Nikasil, But be careful not to get it on the outside of the jug. Provided you haven't taken any chunks out of the coating in the cylinder, they usually clean up pretty good that you can run it again.
Roger
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dcooke007 - 07/03/09 at 10:29am
Roger, I had heard about using muratic acid to remove the aluminum material that transfers to the cylinder walls also, though I have never tried it. What ratio are you suggesting, would think that straight from the container would be too strong?
I find muratic acid to be a very useful product when used with care and at appropriate dilutions with water. Kind of concerned about using it full strength, though I have experimented with it that way. Used at proper mix ratios with water it is a good tool, used to strong or carelessly it can destroy the part you are working on or cause personal injury.
I have a boat trailer that the lights were wired up with plain butt connectors before I purchased it. The lights were less than reliable due to the poor electrical butt connections that had corroded when exposed to water. I had decided to cut out the butt connectors, solder the connections and seal the connections with shrink wrap tubing that has the adhesive sealant built in. When I stripped back the copper wire I found a black coating on the copper wire and it would not accept solder even after cleaning the wire, as would usually be done when soldering. I experimented with the muratic acid to clean the wire and found a ratio of acid to water that cleaned the black corrosion from the copper wire and allowed an excellent solder joint. Tested the muratic acid straight and when the wire was inserted into the acid fumes were emitted and after only a few seconds the copper was clean but badly etched and brittle. Began mixing the acid with water in increasing amounts of water to acid and ended up with a mix of about 10 parts water to 1 part muratic acid. This mix worked perfectly to clean the wire and provide an excellent solderable connection. Only had to strip the wire end, dip in the acid solution for about 10 seconds and the wire was clean and undamaged. I did rinse the wire in clean water before soldering. Since then I have had no problems with my trailer lights.
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R Duttry - 07/05/09 at 2:51pm
Hi Danny, Sorry, I'm just getting home from Baltimore MD. My son got married this weekend on a pirate ship in inner-harbor! It Was Awesome! The muratic acid I use full strength for cleaning cylinders with a min. 600 grit paper and heavy rubber groves. It's also nice to have a fan blowing across the work & yourself! You also know, You Do Not! want to breath the fumes from that stuff. I also keep a bucket or tub of water close by to rinse things off once they are clean. I've never tried it on heavily oxidized copper, But thanks for the tip! I've gotta remember that one.
Roger
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dcooke007 - 08/06/09 at 5:27pm
No further updates at this time, the remaining work would consist of filling the pits, prime and paint. I will try to get back to this as soon as possible.
Still looking for 2nd gear for a super combat. Will consider trades or purchase out right.
Danny Cooke
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END OF THREAD