I recently met a guy that has a '66 Shovel that has obviously been sitting for quite a while. The right tank (the left tank has been replaced) has a milky white sludge in the bottom recesses of the tank. The tank is now dry and he tells me the gunk is hard but if he adds fuel, the stuff goes into suspension and clogs up the tube that connects the two halves underneath.
I've seen gas turn to varnish in carbs when bikes sat unused for a long time but I haven't seen this.
Any ideas as to what this is and the best way to flush it out of the tank?
Thanks in advance for any help.

 

The home remedy is to use MEK or acetone, seal it shake it and drain it. The other way is to take it to a radiator shop and have them boil the tank out.

Almost sounds like someone at some time used some tank sealer on it. With the new gases used, the old sealer came apart. If you take it to a shop, have them pressure test it as well for leaks.

 

I use kerosene or gas as it is readily available and rinse it a few times.That is how I clean the crap out of my old Indian,Shovel,and Flathead..

 

por 15 makes a great product for just that it come in quarts and gallons and you can add water -- e== we dont we heat it 175* up and use it full strength

Marine cleaner its called it works and as of this date it has not hurt any paint NOW if your painter is captain krylon than anything is possable -- jz

 

Thanks for all the suggestions. I'm kind of leaning towards the acetone as I know it will dissolve paint but evaporates pretty quickly. Thanks all.

 

Just an update on the tank sludge issue. We poured some acetone in the tank and let it sit for half hour or so, dumped it out and used a long screwdriver to scrape the sludge out of the bottom. This white gunk had the consistency of old paint at the bottom of a can that hadn't been opened for years. After multiple treatments, we got 95% of it out. He'll just have to keep checking the crossover tube to make sure it isn't getting clogged by whatever is left.
Thanks for all the help.
FL54