Many years of outdoor storage have resulted in heavy corrosion INSIDE a metal gas tank. Using a smooth edged screwdriver, I was able to scrape off some dark coloured corrosion from inside the tank walls near the filler neck. Doesn't appear cancerous...more like stubborn surface corrosion.
Any ideas on how to get the rest of the tank ready for use ? (older bike for putting around so it doesn't have to be perfect)
-chemicals ?
-sand blasting ?

Thanks for any help

 

Well Kreem makes a kit, I'm sure you've heard of it (if not google it and I'm sure there is lots of info and instructions you can find). I'm currently cleaning an old '73 CB350 tank but I've only had time to derust it. I CAN tell you for cheap go to Home Depot and get some Muriatic Acid. It's NASTY stuff, probably want to dilute it but it works like a CHAMP. My tank was all rusty inside and it cleaned it out to fresh metal. You will need to neutralize it and then coat it when you're done, because flash rust will start immediately. As strong as it is it strangely didn't remove the varnish at the bottom. The Kreem kit did though. It comes in three parts. A cleaner/acid which gets diluted with like 2 1/2 gallons of warm water, a neutralizer for the acid and water, and finally a coating for the tank. It's a good idea to start out with something like nuts and bolts shook inside for the heavy stuff, but again the Muriatic acid worked awesome for me. I had a shop do the Kreem kit for me years back and it seemed to work good. I guess if it's done right it will hold up for awhile. The acids will screw up your paint as well as probably melt the inside of your petcock (AND YOUR EYES AND SKIN!!!) like it did mine (my petcock not my eyes ), so be careful. If money is no object check out http://www.gas-tank.com. Or if you're super cheap/on a budget and not keeping the bike forever I suppose after cleaning the rust out and neutralizing the acid immediately fill it with gas and keep it full. Hope this helps.

 

I've restored a couple old hondas with tank rust and used the Por-15 products - it is amazing stuff, the whole kit is around $35 (comes with cleaner, prep and sealer. I bought mine at cbxman and they had some good info on their site about their experience with photos of old tanks etc. No affiliation but the product worked great. Just read all the instructions all the way through first. The hardest part is getting it absolutely dry before sealing - I ended up using forced air.
bill

here's a link

http://www.cbxman.com/detail.aspx?ID=764

 

Yamaha makes a two bottle kit for about $15 (retail). I just used on a KLR gas tank for a friend. It had minor surface rust from being stored in a metal shed with a half tank of gas in it. The process was simple and the results were great. Unlike "Kreem", there was no coating left on the inside of the tank , it took it back to the origional metal surface.

 

You guys are awesome...

Thanks for the great ideas and options.

This web site/forum/info sharing thing really works !

(FYI after several years in storage since track use in
1999 & 2000, I gave my CB900F carbs a good thourough
cleaning and with a slave tank, she sparked up and runs
like a champ ! The lights & flashers etc. are back on now
and with the exception of the fuel tank, ready to roll.
Sweet sound of a familiar engine after several years !!!!!)

 

Cool!! Now all we need are some pics...

 

This is the first time I attach a photo, so I hope it works...

Upload did not work because photo size is over 97kb.
How do I reduce the size of an image to make this work ?

 

First off, you probably have the kind of normal rust that doesn't require any fix. You certainly don't need to apply a coating to your tank.

That said, guys on the XS650 board swear by using a vinegar and water solution to remove rust.

 

What program do you have the pics in? Depending on the program you can crop and reduce the image size and/or also reduce the quality to make the file smaller. Hope you have photoshop it's easy...

 

Photos of my CB900 & VTR1000;
Just sold the 900 today to my buddy.
After 19 years, it was time....

 

Nice job and good photos! How cool to bring the old girl back and then sell her to a friend. 19 years is a long time. Congrats!

 

Nice bikes! That CB900 is a beauty! Looks really nice-love those colors. My first bike was an '80 CB650 so I have a soft spot for those years CB's.

 

Thanks guys,
The original owner of the 900-another good friend of mine who now lives in Seattle did the paint job. He will be thrilled as I am that I am keeping her "in the family" so to speak.
Best part is that I now have one more pal to ride with !
...and I will still get to ride it now and again on our rides down into New York State & Vermont's silky smooth roads.

 

that is a nice bike. I had a 1981 version I bought new in 81. Kept it till 2000 when I got the superhawk after riding very little else most of those years. I also sold it to a friend who kept it the next 6 years. Still have my 81 cbx - amazing how the feel of those bikes just bring back some many memories. Nostalgia and all, there's no denying how much bikes have improved.

bill