De-rusting R25/2 Tank

[paddywack]

At ace hardware or a auto paint shop they have plugs to fill the main hole and if using shrink wrap you can plug the two cutouts.

[schrader7032]

Thanks, paddywack! I'm trying to locate an older style gas cap...I saw some on Amazon but not enough dimensions for me to tell. I visited a few auto parts places and basically came up empty...the tank opening is just too big. I'll try a motorcycle shop up the road and see if they have something.

As for the tank outlet, I hope to find what I would call a line cap. Basically it's a cap that would screw onto the threads which are M16x1. I might be able to find something that at the local hardware store.

[paddywack]

[paddywack]

I may have one that was lined by accident by previous owner which you can use if you send back post….let me see

[dardaris2725]

Here's what I have used to de-rust, and then reline a few tanks in recent years. To seal off BMW tanks I found a plumbing seal in the hardware store, and a hose clamp. I may have added a layer of "cling" wrap under. For the fuel tap opening, I brazed an electrical box "knock-out" onto an old fuel tap nut to seal that. I plugged the hole with a cork, the applied the modified nut. To preserve the paint, I coated with "3M Overspray Masking Liquid-Dry", #06847. It washes off with water. https://www.3m.com/3M/en_US/p/d/b40067410/

[weh8127]

Have you tried a local radiator shop? The one near me has re-coated three for me over the years. They have the facility to plug everything and never got anything on the outside. They were even able to plug and pressuerize a used tank and submerge it in their water tank to be sure there no leaks. They left it in there for over an hour to make sure there was no loss of pressure and no bubbles.

[paddywack]

Still looking but so far can’t find it!

[schrader7032]

I hope to find one of those line caps...just need one M16x1...I'm going to Lowes at some point as they have a decent collection of metric nuts/bolts. I'll probably go to the motorcycle shop tomorrow to see what they might have for tank caps. I understand the idea of using cling wrap and a hose clamp, but a motorcycle tank cap that fit securely would be much more secure.

[pmtremblay]

I second the Evaporust suggestion as a first step. I did a very crusty old Honda tank - three days sitting filled with straight Evaporust, shaken gently a few times a day. Evaporust won't harm paint or your skin, and is safe to pour on the ground or in your sink.

[schrader7032]

Patrick -

After that treatment, was the interior ready to be coated/sealed? I wondered about an etching step which prepares the metal for the sealant. But if the Evaporust does that already, then it would be ready to seal. Thanks...