Can you fix a tank leak ?

[RayRay]

I have a M94 Wombat and was just about to send the tank to be re-chromed and discovered it is leaking around where the petcock goes.........
GGGGGrrrrrrrrr.
Any suggestions?

[Gary G]

There are the tank lining systems for small pin holes. The chromer may be able to repair if he does metal refurbishing and repair.

[Bullfrog]

If the petcock boss is leaking where it attaches to the tank . . . I would lean toward welding it up. But I am one who steers clear of the tank liner systems if at all possible.

Since you are heading toward rechroming anyway, there is no concern about welding discoloring the chrome.

Ed

[RayRay]

Thanks Guys!
I too kind of tend to stay away from sealers but I do appreciate the suggestion. Ed do you think like Mig welded or brazed?
Ray.

[Camman]

Caswell makes good epoxy based liner products. Preparing the inside of the tank is critical when using a liner. There are many methods and products for prep. I had a tank rechromed that had a small pin hole in the tunnel. Caswell sealed the leak. If the tank is rusty inside, it could develop additional leaks down the road. Then you pretty much have to use a liner after re-chroming. Liners have gotten a bad rap. The Kreem products have a poor reputation. Most likely poor surface prep is the real problem. Then there is the longevity of liners debate?? Motorcycle restoration is so complicated...but it fun and rewarding.

[Scribbler]

My Wombat tank developed quite a bit of rust inside and I sealed it about 20 years ago. It still looks great inside today. I used a clear sealer from Bill Hirsch, an automotive restoration supplier. I believe it was a moisture-cure urethane. As mentioned, the key is cleaning the tank first and derusting so that it is pristine bare metal. KBS Coatings sells a similar product.

The downside of sealers is once they are applied, its doubtful you could ever completely remove them.

[bobwhitman]

OK, on that note - I just had a tank which was Kreemed, develop a crack. If I have it welded, can I effectively remove the Kreem liner, in order to re-seal it, and if so, how? Outside of the tank is very nice, and thee is no visible evidence of significant rust-through...
Bob

[Zyx]

Doubtful that the liner can be effectively removed. Welding will probably cause the liner to ignite, and for that matter, burning may be the only way to get a urethane liner out.

Liners are a last resort for an obsolete tank that has thin walls and pinhole leaks due to rust. If lining is the only way to return it to service, line it. If the metal is essentially sound but is cracked to perforated, welding or brazing is superior every time. Whether to MIG, TIG, or braze depends on judgment and access to equipment. Brazing is fine, easier to do for most folks, and far less likely to burn out the metal if it is thin, but in any case, the metal has to be clean of rust in order to weld or braze, so the outside at least will probably need to be abraded. Cheap sand blisters work fine for small jobs like this, just messy because they blow glass or soda or whatever you use all over the place. If you don't have a blaster booth, do it outside away from things you like.

Also, not mentioned yet, if you weld or braze, thoroughly wash out the tank with water and detergent. Otherwise something bad can happen.

I am curious to know if the leak around the petcock is simply a leaky seal, or if the metal is breached. Petcocks do leak sometimes. It isn't necessarily a defective tank. Could it. E just a gasket or o-ring?

[Dale]

Bob, I have read where Acetone will remove Kreem. I have not tried it and don't care to as I can only imagine how messy that would be. I do believe that it can be done, but one would want all the right set up to attempt it.
Dale

[Pep]

Ok, so that brings up one of my dilemmas:
I have a beautiful tank that some %^^## lined via a radiator shop. They did a poor job of it, about half the tank is bare, the other half is red (not sure what radiator shops use for coating).
Whatever they use, it seems gas-soluble, as the fuel gets dyed red and stains the lines.
I've tried a few harsh chemicals and abrasives to get the stuff broke up and out, but no real luck so far.
The red sludge is not carb-friendly, so at this point I'm willing to risk exposing some pinholes and repairing them like I have others - otherwise the tank is useless to me.
Any ideas out there?
-Laurie

[Zyx]

If soluble in gasoline, it may be more so with something stronger like methylene chloride or carb cleaner (the dip tank type, not the spray can type), or toluene. Methylene chloride is the main ingredient in most paint strippers. Carb dunk is usually found in 5 gallon buckets.

[RayRay]

Well at least it seems to be a good discussion point!
My tank is leaking right around the petcock boss just as Ed described. And yes there is still a little rust in it I need to treat it again!!!
other than that and a very low budget the bike is coming along quite nicely. SLOW BUT NICE. I think I am going to try the welding route....Just wish I could do it myself.....(not a welder at all!!!!)

[bobwhitman]

My on-line research suggested either the use of MEK (Methyl ethyl ketone) or acetone. MEK is very dangerous and will melt brain cells whether or not it melts Kreem. A good discussion is: http://www.hondatwins.net/forums/34-tip ... -15-a.html. Lack of agreement on whether either works flawlessly.
POR15 does seem to be the pick, if liner must be used, tho some advocate Caswell products. Few like Kreem.
Bob

[RayRay]

[RHall1972]

Ok, so that brings up one of my dilemmas:
I have a beautiful tank that some %^^## lined via a radiator shop. They did a poor job of it, about half the tank is bare, the other half is red (not sure what radiator shops use for coating).
Whatever they use, it seems gas-soluble, as the fuel gets dyed red and stains the lines.
I've tried a few harsh chemicals and abrasives to get the stuff broke up and out, but no real luck so far.
The red sludge is not carb-friendly, so at this point I'm willing to risk exposing some pinholes and repairing them like I have others - otherwise the tank is useless to me.
Any ideas out there?
-Laurie

Hi Laurie,

It sounds like someone tried to line your tank with Red Kote (see links below, pretty good info there). The spec sheet indicates it can be removed with MEK or acetone, but I’m guessing you’ve probably already tried that. Everything I’ve read about Red Kote indicates that the red dye leaching into the gas is harmless, but if it’s coming loose as sludge that’s obviously a whole different matter. I know the product has an excellent reputation -- sounds like someone just did a lousy job on your tank. It might be worth calling the company and asking for tech support (800-362-9850). Good luck! --Russell

http://damonq.com/red-kote.html
http://damonq.com/TechSheets/Red-Kote.pdf

[Zyx]

MEK, while certainly not harmless, is also not "dangerous" to use. It is available at most hardware stores outside of California. I have used it for years, on occasion without gloves, which I don't recommend as it will absorb through the skin to some extent. It is a fair solvent. Just use it with caution, and if the fumes from solvents is a concern to you, use it outside. Those brain cells I have lost over the years are more attributed to bourbon and old age than to MEK.

[Zyx]

RayRay, from the photo, it appears very likely that the boss is leaking at the weld, which is probably why the chrome is delaminating. Rust is creeping in under the chrome and lifting it. Welding should be simple, but I would remove the chrome in the weld zone. Brazing will work for something like this. I would not use a liner just to fix this kind of leak. TIG, MIG, or braze in that order.

[RayRay]

Yes that is exactly where it is leaking. I will check with one of my neighbors that has been welding things for me and see how he feels about welding it up. And I have heard and read all the good the bad and the ugly of liner systems and think for me I would try to get by with out.