Fuel tank removal

[outboardsurplus]

On my 1982 170 I took the tank out and there is a good bit of water and mud dober nest,I don't see a drain hole any where.How can I clean the hole out with no drain hole

[mshugg]

It’s probably best to drill one or more drain holes. 

At one time the sales pitch was that the tank coffin was sealed to keep any leaking fuel out of the bilge.  I think everyone agrees that it was a failed experiment.  Once salt water made it in to the coffin, as it inevitably did, the tank was soaking in sea water. 

[outboardsurplus]

Thanks for the info,that is king of what to do myself.I guess the best is to drill vertical and not down so as to not drill a hole in the bottom

[Capt. Bob]

I'm not sure it was a failed experiment but rather to meet a Coast Guard spec for a below deck fuel tank install. 
In any case, many of us have indeed drilled holes in the coffin.

The coffin nests above the hull itself so you would need both a long bit and a heavy hand to puncture the hull.

Still the key here is not to drain the coffin so much but to insure it doesn't get water in it to begin with. Sealing both the cover and the access plate(s) is very important. Yes, your tank (assuming it's aluminum) will get some condensation forming at certain times but that is usually a small amount that evaporates with time. It's the constant immersion in water trapped in the coffin that greatly reduces tank life. Pop in a couple three drain holes and seal up the top and your tank will last a long time.

Good luck.

[boatnamesue]

Elevate tank in coffin per modified pascoe method, don't use foam, drill a few holes in aft end of coffin to allow water to drain into bilge.  Crevice corrosion occurs when stagnant water is contacting tank ... Foam holds water.  Depending on your location, condensation will occur in coffin.  Hence the tank elevation and drain holes. 

[wingtime]

The modified Pascoe is how I installed the tank in my 200XF coffin.  The was a thread on my install on here. Not sure if Photbucket allows the pics to be displayed anymore.