Gas tank cleaning

[hartmandm]

People seem to generally follow two approaches to cleaning the gas tanks - chemicals or contact cleaning (sand blasting or tumbling using gravel or washers/nuts/bolts/etc.).

I've been cleaning my pair of tanks for a bit now. I was surprised to find a 2" x 3" x 4" metal box welded to the interior of each tank. The box is positioned near the outlet pipe opening (about 1 inch away), above the drain hole, and is on one half of the tank. See photo showing one side of the box. The box has only 2 small openings. One opening is near the outlet pipe and a second opening is on the opposite side. (It also appears to have an air vent or two on top.) My guess is the purpose of the box is to reduce the rate at which fuel will flow out of and into the tank.

I don't see how sandblasting or tumbling gravel will clean the interior of that box. Even with the Gas Tank Renu process of drilling a bunch of holes in the tank to sandblast (then welding up the holes afterwards), the inside of that box won't be clean. Even if you cut the tank in two, you'd still need to remove that box to blast its inside.

My conclusion is a chemical process is the only way to get everything clean inside the tank without cutting up the tank. Liquid paint stripper and hydrochloric acid (muriatic acid) have been working well so far for cleaning. I expect vinegar sitting for many days would work instead of the hydrochloric acid.

I have hopefully one last pass using the liquid paint stripper, then I'll be ready for phosphoric acid etching and then the coating.

BTW - the old rubber hose joints, a couple of clamps, and a PVC pipe cap make a nice seal for the tank holes during cleaning. See photos. You do need a vent when using the paint stripper or acid, otherwise the chemical reactions will build high pressure in the tank. I always leave one hole open.

Mike

 

[George Coleman]

In the past I have a chemical stripper service near me and they just dip the tanks, fast and easy and they are real clean when I line them. Carolina Chem Strip. Burlington NC

 

[Alpine 1789]

BTW - the old rubber hose joints, a couple of clamps, and a PVC pipe cap make a nice seal for the tank holes during cleaning. See photos. You do need a vent when using the paint stripper or acid, otherwise the chemical reactions will build high pressure in the tank. I always leave one hole open.

Mike

Clever idea. For another option, I used rubber expansion plugs designed for plumbing. As I recall, most - if not all - of the sizes I needed were available at Home Depot.

 

[65beam]

tank

I have to agree with George on having the tanks dipped. We use American Metal Cleaning in Cincinnati. They dip the tanks and will also coat the inside of the tank. I recently picked up the tank for the new Harrington and have less than 100.00 total. I know of a couple people that spent a lot of years doing restorations of sunbeams and they did not recoat the inside of the tanks.

 

[Warren]

.05 cents

If I had a nickel for every time this question was asked, in my small motorcycle group. Little bike riders may make us look like big spenders. Google motorcycle battery charger gas tank cleaning. I have done 10 to 20 tanks over the years for pennies and never use that expensive brain numbing epoxy crap. If you are the kind of guy who likes to pay to have things done that'd be the only excuse to not try it. If I could I'd drop a whole car into a electrolytic solution in a swimming pool.

 

[hartmandm]

If I had a nickel for every time this question was asked, in my small motorcycle group. Little bike riders may make us look like big spenders. Google motorcycle battery charger gas tank cleaning. I have done 10 to 20 tanks over the years for pennies and never use that expensive brain numbing epoxy crap. If you are the kind of guy who likes to pay to have things done that'd be the only excuse to not try it. If I could I'd drop a whole car into a electrolytic solution in a swimming pool.

How does electrolysis do in regards to removing the old paint?

Thanks,
Mike

 

[Alpine 1789]

How does electrolysis do in regards to removing the old paint?

Thanks,
Mike

I did the electrolytic route with my tanks. I rigged a large plastic bin with electrodes and soaked them in the tank for close to a week each. Most of the paint came away, but I still had to use paint remover to get them completely clean on the outside. As for the insides, they were clean but not completely. I used paint remover and then muriatic acid to get them all the way before using the Hirsch product to coat them. That was probably about 10 years ago and all is still well.

 

[65beam]

gas tank

There are some owners that prefer to pay to do it right the first time instead of having to pay to have it done right the second time around. these photos are the tank for the RHD Harrington we're working on. The tank went to the dipper and was cleaned. It then went to Tiger Auto and had some pin holes repaired and dents removed. Doug painted it with epoxy paint and then took it back to the dipper to have it coated on the inside. The second picture shows the filler neck with the red coating that they use. The wife's blue car received the same treatment 20 plus years ago when Doug restored it. No problems yet.

 

[Warren]

Paint

The electrolysis method was not mentioned to push off paint but it will if given enough time. It is doing it right no matter what anyone else says spend what you want 3 dollars or 100 dollars or more. Most of us look for a fix that'll out last us. I'd do it on my Tiger or on all of my cars. It is done right and I have had rusty tanks on vintage bikes that came so clean they never got rusty again and it cost 3 bucks. I know Doug does good work and even let's guys pay to hang around the shop, remember that labor per hour sign ___ per hr. ___ if you watch ____ if you help

 

[DanR]

George reminded me.....

I too have my tanks dipped.... Door, hood, trunk lid, hinges, window tracks etc.etc. et alllll by Carolina-Chem-Strip

Very good work! removes everything from the metal, looks like new and clean and coated with a substance to elimentate rusting until you can do you thing

They have a shop in Wagner, OK in addition to NC & SC.

DanR

p.S. Even dip a car

 

[hartmandm]

I think I may have outsmarted myself on the fuel tank cleaning process.

As I think I indicated in another thread, I purchased the POR-15 Fuel Tank Repair kit. It is a 3 step process. Step 1 in the kit is using the Cleaner / Degreaser product (formerly known as Marine Clean) to remove varnish and gunk. The Cleaner / Degreaser product is water based and is indicated for use on painted materials. So I assumed it would be great on normal fuel tanks that are not painted inside, but of little or no value in removing the paint that is flaking off the Alpine fuel tank interiors. I assumed I needed to use other products to remove the paint first. I used nasty stuff like muriatic acid and liquid paint stripper. I managed to get a small chemical burn through sloppiness. I also used electrolysis. After all of those efforts, I still had some residual paint on the "roof" of one of the tanks.

I decided to try the Cleaner / Degreaser product to see what it might clean up. What did I have to lose at this point. I mixed it 50/50 with hot water, poured it into the tank, and sealed all holes in the tank. I rotated the tank for a little over 20 minutes, the minimum recommended time. I then drained the liquid in the tank into a 1 gallon plastic container. (Note there was no pressure build up in the tank while all the holes were sealed.) A bunch of large paint flakes were in the liquid. I thought that was great and probably the result of vigorous shaking of the tank. After drying the tank, I used an inspection mirror and there was still some residual paint on the tank "roof". I closed up the plastic gallon container and left it in the garage. I put some vinegar into the tank to let it work on the "roof" for a few days.

Tonight it has been about 5 days since I drained the Cleaner / Degreaser liquid into the plastic gallon container. The container has been sitting in my garage unmolested since then and the days have been fairly hot. High 80s and low 90s outside. Even hotter in my garage. I looked at the plastic gallon container tonight and all of the paint flakes are completely dissolved. The liquid is now just a dark color. I poured the liquid to another container to double check the paint flakes are gone. They are indeed gone.

So my theory is that the Cleaner / Degreaser will dissolve the paint if given enough time, and warm temperatures likely help. I am thinking I could have started with the Cleaner / Degreaser in the tank, sealed up all holes in the tank, and let the cleaner do its work for 5 to 7 days, rotating/shaking the tank a few times a day to ensure the cleaner is attacking all surfaces. I could have avoided those nasty chemicals.

Mike

P.S. - Not looking to restart the DIY vs Pro debate. I'm good with either approach. Just passing along an observation.

 

[Alpine 1789]

When I cleaned my tanks prior to sealing, threw a handful of sheet metal screws in with the cleaner (paint remover in my case) to help break up the old paint. As I recall, I still had to do a second cleaning with muriatic acid and the screws to get them completely clean. And, that was after using the electrolytic method, as well, so I guess the acid was really the third cleaning.