Gummed-up Fuel Tank Outlet

[avhation]

The outlet pipe from my fuel tank is completely blocked with gunge. A probe seems to reach the floor of the tank but 50 psi will not blow through the pipe. The tank is only 10 years or so old and I assume that there is not a pick up filter. The gunge looks like a black mass about 1cc right in the corner of the tank around the pipe. Fresh petrol added for the past 3 months has not shifted it. Can anyone recommend a powerful solvent (e.g. cellulose thinners or Nitromors stripper) that I can tip into the corner of the tank to dissolve the gunge and enable me to flush it out with petrol? I want to avoid the expense of using the POR-15 process if possible.

Thanks in anticipation of results from this brilliant site.

Avhation
'67 S3 FHC Medici blue

[nebogipfel]

Sounds like someone may have used an internal sealing compound on your tank?

I'd try cellulose thinner (gun-wash because it's cheap) but if it is sealant you'll either have to do it again or buy a new tank

[gjz30075]

I agree with John. I think someone tried to seal the tank or, if you had bought it new, perhaps some solder or weld or paint got down in that corner. I'd try a flush with a can of bolts and nuts as agitators. Swish around some cleaning fluid of some sort along with the nuts and bolts to see if you can dislodge it.

Greg Z

[rickf]

If you haave the tank out, I'd take it to a radiator repair shop and see what they can do with it. Once they've boiled it out they can usually solder up any leaks. i haven't had a tank done in a while, but it didn't used to cost too much.

[brassringfarm]

As a young Chemical Engineer I loved Xylene or Toluene as a solvent for such things. It's the main ingredient in Carb Cleaner I believe. You can buy a quart at Home Depot or home centers. Paint thinner for urethane paint is also a potent mixture. Of course all of these are now labeled as hazardous/carcinogenic - so don't drink them or smoke near them. In the old days I washed my hands with them all the time. Nowadays, I might wear latex gloves if I had some. Just do it outside. I doubt that alcohol based thinners would touch it.
Paul Zimmerman
65 S2

[avhation]

Thanks for the advice guys. Cellulose thinners (toluene and xylene) dribbled down the outlet pipe and left for several days has enable me to poke through at last.