Topic: In the tank......

[drlarryw]

Through this miraculous website, I now have a beautiful tank for my CB750F.  Internally there is very light surface rust on the bottom surface.  I ask for your wise advice for cleaning it out.  THANKS.

[hopterfixer]

I used muriatic acid to remove the rust in mine.  I coated the outside of the tank HEAVILY with paste wax first, then I carefully poured a gallon of muriatic acid in.  I shook it quite a bit, let it sit, and repeated.  I only left the acid in for an hour or two (that is all the time I had).  I rinsed thouroughly with water after the acid, and then rinsed again with acetone.  It worked out pretty well. 

[cafe75-550]

I know it will sound strange, but do a search on moleasses. There's a thread on here about using a mixture of moleasses and water to remove rust from tanks, and if I hadn't done it myself I wouldn't believe it, but I cleaned the 77 750 SS tank I had with it, and it had more than just light rust. I believe it calls for around a 12:1 mixture of water (I used hot water to initially dissolve the moleasses) to moleasses, then let it sit for a couple of days. The result I ended up with was pretty impressive, I'm running the tank now with no problems and no other treatment (well, I used some acetone in the tank to get rid of the small amount of left over water), and there's no need to line the tank as with the use of some acids...

[cafe75-550]

Found it! link here  http://www.sohc4.us/forums/index.php?topic=7729.0

[drlarryw]

Hmmmm....even with all the testimonials, it's hard to actually pour molasses in my tank!!!  I suppose I can try it without harm first, then use the muriatic acid if not successful.  THANK YOU for the great responses.  I will report on my results.
Larry

[merc2dogs]

I've heard that it works pretty well, never tried it though. It's also been mentioned on a few boat and machining groups I belong to.

    Besides, if it doesn't work you can always pour it out and make cookies.....

Ken

[cafe75-550]

I was pretty skeptical at first myself, but it doesnt cost all that much and you can just dump it, and it rinses out pretty easily with hot water. I had my tank boiled out at a radiator shop because the rust scale was so bad, but didn't have them treat it with acid because I didn't want to line it. So I used the moleasses trick, let it sit for a week, and was absolutely shocked to find nothing but clean metal in my tank at the end of it. I know it sounds strange, but it works! 

[BobbyR]

if it is really surface speckles you may want to use the molasses and just put a filter in line to cathch what is left over

[mkramer1121]

The Works toilet bowl cleaner, dump a whole bottle in, swish it around every ten minutes for an hour, dump it out, wash it out, and you should be all set

[paxtonpony]

Why not rinse the tank out then coat it with kreem?  I read the whole 7 pages on molasses (and other assorted opinions) and never heard anyone say to coat it.

[cafe75-550]

My 2 cents...

I myself have never used "kreem" itself as a product. That being said, I have encountered several tanks that have been lined, on both the automotive and motorcycle side of things. All of my experiences with lined tanks have resulted in plugged filters, carbs, etc when what was used to line the tank began to break down and ended up in the fuel system. Maybe "kreem" is a better product, maybe not. But with a rusty tank, I know exactly what I'm dealing with. The loose scale can be cleaned out, filters will keep the rust out of the carbs, and if the tank leaks it can be boiled and repaired (within reason), easy as that. Not the case with a lined tank. The stuff I have seen resists simply being boiled out at the radiator shop, and the tank can't be welded with that stuff in it. So, I don't use the stuff.

Thats just my opinion, and I've repaired some tanks before (including the one on my bike now), so I'd rather go that route myself, the end product is a metal tank that doesn't leak, isn't rusting and can be repaired again if need be. I'm sure people have used the stuff with success, and like I said, I haven't used the stuff on the market now, just had poor experiences with other lining compounds I have encountered.

Maybe someone with better knowledge of the stuff can follow up...

[BobbyR]

If you read the posts on Kreem, POR and the rest, it is very easy to get it wrong and then you have problems. If you really don't have a problem, don;t look for one. Trust me - they will find you. The Molasses makes sense and you don;t need to be messing with harsh chemicals and risk damaging your paint. A fuel filter will trap any tiny particles  that will come loose in time.

[drlarryw]

OK, I'm going to try the MOLASSES, next weekend, right after TGiving.  Unless there's some unseen risk, I can't see it doing any harm, won't hurt the paint, and I like the idea of making cookies with the leftovers.  I will let you all know how it goes.  THANKS FOR ALL YOUR SUGGESTIONS AND COMMENTS.

[mkramer1121]

im not eating those cookies......

[USN20]

If you do decide to coat the inside of your tank take a look at a product called Red-Kote. My tank was done with this product 5 years ago by the PO and is holding up quite well. A thin coat will do the job unlike other sealers (Kreem) which go on too thick and create problems later on. The final word is: If you don't need a sealer - don't use one.

http://www.4secondsflat.com/Fuel_Tank_Sealer.html

[gtyler5]

You can also put an assortment of nuts and bolts with other random metal pieces with some acetone or m.e.k. seal it up and shake the heck out of it for about 1/2 an hour or more. Remove all the pieces, and rinse it out with more acetone or m.e.k., let it dry and it will be pretty clean and it will be prepped for Red Coat. Red Coat is great stuff. I would not want to put water in my gas tank with or without sugar.

[wardmoto]

Bill Hirsch Automotive....google and read, good stuff.

[Peter]

This post has convinced me to get some molasses.  I bought a gallon.  I read on the other thread that some dilluted the mix with water.  what was the ratio?  Should I go back and get more to fill the whole tank?

[lrutt]

I mixed it about 4 to 1, water to Molases. Worked great. I started the other thread and did 3 tanks. All 3 have held up well.

[Peter]

I'll mix it up tonight, thanks

[csendker]

I've used The Works on some really cruddy tanks, and molasses on some lightly cruddy tanks.  Both worked well for their intended uses.  However, some random thoughts:
1. Pull the petcock off first, don't use it as a stopper because it will get eaten alive; I know this for a fact. 
2. Dry it out immediately after you're done with the cleaning.  You can use a hairdryer, but keep the petcock hole open to prevent burning out the hairdryer, and do this outside just in case there's any volatiles leftover. 
3. Have some diesel fuel handy for when you're done, and slosh some around inside to lightly coat it to prevent flash rust.  Particularly when you use The Works, less so with the molasses.  Immediately filling with gas will work too, but you'll be amazed as to how fast the flash rust will form. 
4. If you have a solid tank to start with, you probably don't need to coat the inside with anything.  If you have pinholes, you're likely to be screwed anyway. 

[mrbreeze]

I don't see anyone posting here about POR-15. I have read many praises here on POR-15 and also many boos on Kreem. The tank that came with my bike (in 2000) has bad rust in it.I would like to try and restore it being that it is dent free. The stock paint is faded and has the usual scratches so I am not too worried about the paint.It did not leak but I would still like to line it if I can sucessfully get the rust out.I bought a gallon of muratic acid awhile back but haven't tried it yet.Now I'm hearing about this toilet bowl stuff and molasses. Whatever I use, I will make sure it don't leak before I go any further with lining it.I am currently running an ebay purchased tank that is clean but has dents. (if it ain't one thing,its another!!!!). One more question.....what works good to cork up the fill & petcock holes when cleaning with chemicals? How about those rubber expansion plugs you can get for freeze plugs? Look forward to any tried & true testimonials.

[csendker]

One more question.....what works good to cork up the fill & petcock holes when cleaning with chemicals?

For The Works, I used the petcock.  Now I can use it (petcock) again for anything except an operable bike...

For the molassas, I used some SaranWrap and a rubber band. 

The expandable rubber thingys would likely work, but only on the pipe-thread style petcocks.  The 2-bolt style (earlier models) are a different beast.

[mrbreeze]

I thought about using a spare petcock Csendker. Mine is threaded on. I heard it would eat the petcock alive but I do have a spare. Further down on my never ending parts list is a Pingle fuel tap so eventually, I will have 2 spares.

[csendker]

Mine would still work as long as I don't care about not having any reserve capacity.  I suppose I could still use it in an emergency...