Brendans 170 fuel tank install

[Brendanpd28]

Hey all,

     Im starting this topic as a fresh thread for my tank install which i'll be starting soon. It is a 27 gallon aluminium tank built my alloy metal works.  I plan on using the Pascoe method using pvc strips and 5200 to hold it in place (still a little suspicious about that being the only way its secured). I will using the lowrance fluid level sensor to connect my Moeller sending unit into NMEA 2000 and monitor fuel through my Simrad Go5. The only thing I haven't completely decided on is the best method of grounding the tank itself.  I was thinking of running a 14AWG wire from the tank fill to the tank grounding tab, then from the grounding tab to my negative bus.  Will this suffice?  Pics to come soon!!

Thanks

[alandry100]

I am doing the same thing right now - look forward to hearing about the grounding protocol.
A

[Capt. Bob]

The only thing I haven't completely decided on is the best method of grounding the tank itself.  I was thinking of running a 14AWG wire from the tank fill to the tank grounding tab, then from the grounding tab to my negative bus.  Will this suffice?

Yes, this is pretty much the standard application although some (myself included) connect directly to the negative post on the battery. The goal is to eliminate the chance of a spark cause by a difference in electrical potential between the filler neck, the tank and really any other metal part that could create this difference thus resulting in a BOOM . Bonding also helps reduce the galvanic corrosion that can occur in parts like a metallic sea cock so if you have that device on a raw water pickup, you should add it to your bonding loop.

Good luck.

[Brendanpd28]

Thank you Bob. My apologies but I lost you on the raw water pickup part lol. 

[Brendanpd28]

 Just to clarify before I get going on the install. Will PVC trim such as Azek or Veranda as the quarter inch strips suffice or is there another recommended material?  And has anybody else out there used the Pascoe method as the only means of fastening?  I have seen the Pacoe method used quite a bit throughout this forum, but it always seems like additional methods of fastening added as well.  Just want to be sure before I do this install and close up my coffin again. Thank you all!

[mshugg]

I used PVC board from a home store and ripped it to size.  It is a dense foam, so it's not solid, but I think it will be perfect.  After all the original instal used neoprene strips and aluminum bands with a single screw.

I know Pascoe says that the weight of the tank is enough if the 5200 let's go, but I wanted to fully trap the tank.  It's easy to fit chocks or boards that will provide a mechanical connection and still not trap water next to the tank. 

[Brendanpd28]

Very crude drawing but thought it might help other 170 owners visualize the install
And plan ahead. Hopefully I didn't miss anything. Feel free to correct lol.

[mshugg]

Your sketch looks good to me.  If possible, try to loop in your vent fitting so the hose comes down to vent from above and forward.  This will reduce chance of water making its way into your vent line.

[Brendanpd28]

Your sketch looks good to me.  If possible, try to loop in your vent fitting so the hose comes down to vent from above and forward.  This will reduce chance of water making its way into your vent line.

That's a great idea I never would of thought of. Thanks mshugg!

[wingtime]

I did a modified Pascoe method in my XF200.  I bonded starboard strips onto the bottom of my tank.  But I did NOT bond them to the bottom of the tank coffin.  I don't believe adhesive alone is enough to hold a tank in place in rough seas.  I strapped the tank down using aluminum straps that I insulated from the tank with thick clear vinyl.  This is fine since unlike certain rubbers, the vinyl is non reactive with the aluminum.  You can go crazy trying to do the perfect install that will last a life time.  But the reality is do you really need a boat that will last 60 years?  The original tank had lasted over 25 years and it was not leaking when I replaced it.  Heck I sold the boat in a year or two anyways.

[Brendanpd28]

Thanks wingtime. I am going to stick with the Pascoe method and add some modified crush blocks and 5200 them in place to avoid any movement with the tank. And I completely agree with ur mindset about the install.

[Brendanpd28]

Started on the pvc strips today.  Marked and taped off where they were going.


Scuffed up the aluminum with some help with adhesion

Completely covered the strips with 5200 and laid them on.  Ended up using batteries and cinder blocks to weight them down.  Clamps were not helping much. Once it cures I will come back and add a smooth bead on all sides of the strips.

[mshugg]

You're going to trim the pvc strips?  Right?  Pascoe recommends trimming them 1/8" short of the edge.  I think I cut mine closer to 1/4 shy.  You don't want anything that will hold water next to the tank or interfere with drainage.

[Brendanpd28]

Mshugg,

       That picture is just showing the 5200 spread on the strips. They were not secured in place at that time.  They are now in place and are 1/4" short of the edges. 

[Brendanpd28]

Heres as pic of the strips glued in place. It was 60 degrees in my shop the other day when I installed them but tonight its dropping to sub zero temps with the wind chill so I had to bring the tank inside so the 5200 will cure.  Its been 2 days and the 5200 is still wet.  New England!!!!