Fuel tank tub question

[Miguel]

If I drilled a hole on the aft wall of the fuel tank tub of my 1985 170, would I be able to insert a hose from there to the bilge?  I snapped a picture of the inside of the bilge facing forward and saw that there is some sort of transverse stringer, however, it does not contact the deck.  There is about 1.5" clear space between the top of this part and the bottom of the deck.
I would like to install a couple of hoses to use as cable throughs between the bilge and the inside of the consle and the fuel tank tub looks like the best way to do this. There is about 2.5 inches of free space between the tank and the deck.  Another idea is to use this hoses as water lines for a raw water/livewell  pump that could be installed inside the bilge to send water to the currently unplumbed livewell in front of the console.
Can anybody offer help on this regard?

[seabob4]

Miguel,
As long as the tank is lower than the fore and aft bulkheads (the transverse stringer you mentioned), that would be the best way to do it.  But keep this in mind.  If you are planning on using PVC pipe, a piece of pipe long enough to span the tank compartment may be near impossible to get belowdecks to feed it through the hole(s) you drill.  How good is your access to the forward, or console end of the compartment?  And how would plan on securing your "chase tubes"?

[Miguel]

I´m not sure yet, but apparently the top of the bulkheads is about 1.5" clear of the bottom of the deck.  There is about 2" clear between the top of the tank and the deck. My plan is to use two 1-1/4" PVC pipes.  The console and the tank tub lid have been taken out as the fuel  tank is being replaced.  The pipes can be about 56" long (the length of the tub).  My plan is to drill the holes and feed the pipes from the tub side.  The distance between the back wall of the tub and the little bilge access plate is shorter than 56".  The pipes will be secured to the tub wall with 5200.  I have not figured out how they will be supported on the bilge side because there is very little access.
From the tub side of the pipe I will connect some kind of flexible hose that will come out of the fuel tank lid (the part of the deck under the console) lid using thru-hulls.  This way I will be able to remove the deck if required in the future.  I just have to remember that any wires or hoses that end up in there will require some way to be disconnected for future removal of the deck.
Some questions:
Why do these bulkheads stay clear of the deck?

[seabob4]

Miguel,
Typically, and I say typically, there should have been a bead of bonding putty tying in these bulkheads to the underside of the deck.  These are bonding surfaces.  Why wasn't that done?  Someone most likely didn't feel like doing it that day your boat was decked, or schedule demands required them to do less then the proper job.  Hate to say it, but that sort of thing is common in the boat building business.  Trust me, I've been in the business for 15 years.

A piece of advice.  If you can fit 2" PVC pipe, or even larger, without any fit interference, DO IT!  The bigger the pipe, the better.  It will just make your life easier further down the line when you may want to re-power, add some electronics, re-wire, whatever.  Trust me on that one.

Any other questions, feel free. 8)

[Miguel]

I'll try and measure the space to put in the largest pipe that fits.  Maybe even a hose instead of a pipe so it can be deformed a bit in order to fit the available space.
Thanks for your help!