De-rusting R25/2 Tank

[schrader7032]

I finally reach the point where I have to pay the piper! I didn't take the opportunity to seal my tank when I first got the bike. I remember attempting to get the petcock off and it was having none of it, so I kicked the can down the road. The bike died on my with enough fuel so it appears the rusting has reared its head. I've taken several weeks, applications of Kroil, a hair dryer, and some love taps and the petcock is off. It appears that the internal screen for filtering the gas has long since disappeared...probably cut out by the previous owner. I don't see where I can buy a new screen by itself...the Salis site seems to suggest that I have to buy the whole petcock which might be the way to go.

Anyway, I'm beginning to think about cleaning the tank and going to through the de-rusting process. Starting to do my research - Snowbum, my own saved comments over the years. I had always thought that I'd just put plugs in the inlet and outlet as I slosh liquids around. But I just looked at gas tank opening and realize that because of the design, I can't stick a rubber plug in there. The paint on the tank is very nice...the bike was painted just before I got it. I want to do everything I can to protect it, especially when I get to the nasty chemical stage.

Any suggestions on how to seal the gas cap to prevent those cleaning/sealing liquids from escaping?

[weh8127]

Kury, Bing agency sells the screens. http://bingcarburetor.com/petcocks.html

[vechorik1373]

You will never seal the gas cap, and whatever you put in the tank will get on the paint.
If you use your existing cap, and you tank coat the inside, it will plug the vented cap and ruin it, so plan on buying a new gas cap.
Here is a trick I figured out many years ago.
Get a tub of wheel bearing grease, and heavily smear it all over the outside of the tank. That way, when you spill tank coat, or solvent, or whatever on the tank, (and you will) it will lay on top of the grease, and never touch the paint.

After your done, and the tank is bone dry, wipe off the grease and give the tank a soap and water bath, on the outside, to get all of the grease off the paint.

[tboooe]

I recently had to remove rust from a Ducati I am restoring that sat for over 13 years with gas in it. I soaked the tank in EvapoRust for 8 hours and it did wonders! It doesnt affect paint either. I ended up re-orienting the gas tank in various positions every 8 hours. Highly recommended. Living in Socal I decided to not coat the tank since I never have had any issues with rust in any of my motorcycles. However, many people recommend using a DIY sealing kit like Por15 or using a professional service like GTL.

[schrader7032]

Bill - the petcock is not a Karcoma, but is an Everbest. I'd like to keep it if possible.

Vech - thanks. Sounds messy and will create issues when handling with all the cleaning steps, but likely something that needs to be done.

[schrader7032]

tboooe - I've experimented with a small amount of Evaporust so may consider that. I also saw something about Rustzilla...probably similar to Evaporust.

On some of the car overhaul/restoration shows, one of them had a severely rust frame but rather than strip the entire chassis from the frame, they applied some kind of coating with encapsulates the rust and keeps it from getting any worse. Not sure on that.

I think I need to knock as much of the rusting layer back...it's not serious flaking...to get as close as I can to bare metal. Then etch and apply the sealant. I've used Caswell before and was pleased with what it did.

[schrader7032]

Still thinking how to seal the open gas cap. Don't want to sacrifice a cap. Was thinking about shrink wrap over the opening with a hose clamp to secute it.

Maybe should consider a sacrificial gas cap. Is there a generic type of cap, maybe something that would work from an older car? I measured the opening of the tank and it's about 2.3 inches in diameter...that seems bigger than most older car filler necks. Something like this...not much in the way of dimensions I could find.

[Andrew]

Hi, regarding the tank to protect it from the chemicals ,I used very successfully 'cling film" it self sticks to itself and clear it can go all over including the the filler opening. Not sure if its called the same thing there in the States but in the UK it's what we use. Andrew

[schrader7032]

Andrew -

I was thinking about shrink wrap which is what I would call it here. If I could find a generic gas cap like the one above that would seal, I could back things up with copious amounts of the shrink wrap all over everything.

[tboooe]

Kurt, if you use EvapoRust you wont need to worry about the paint. Instead of using the gas cap, I just moved the tank around (flat, left side, right side, standing on its nose) to make sure the EvapoRust soaked the entire tank. Its as easy as soak, drain, rinse. I didnt have to do any work afterwards.