Oh Boy...This Smell Ain't Good

[Jason2tpa]

For those interested in learning more about poly fuel tanks:

http://www.seastarsolutions.com/wp-c...ochure-web.pdf

[panasonic]

I think that is pretty much the standard wall thickness for aluminium boats tanks. Folks want cheap and light. A thicker alloy is contrary to what folks want.

What thickness are the wing skins of the aeroplanes that you work on? I came out of general aviation and went to work on air liners. What they called skin we would have called plate.
Wonder what the thickness of an Airbus A380 wing skin is at the wing root? It might not even be aluminium for all I know. More than likely, plastic.

Hard question to answer as it is different everywhere on the wing, fuse, flight controls...

Control surfaces on DHC-8 are 0.020" Rear fuse aft of pressure bulkhead is mostly 0.040"

Wing Planks in near the root can be 0.100" but they taper off as they go out towards the tip.

The pressure fuselage is mostly 0.032" but thicker around openings such as baggage and pax doors, up to 0.060"

Thing to remember that all modern airliner's are build pretty much the same. In the pressure fuse wherever a skin passes over a rib/frame or stringer it has a double layer skin, two pieces bonded together. These tear straps are there to stop any cracks from travelling to far. In between the frames and stringers it is generally just one layer. Wing is build the same, with much heavier frames.

Bigger the airplane the thicker the aluminum to a point. A 747 wont have much thicker fuse skin then our RJ-705. Probably 0.060" But wing skins/frames would be much thicker.

A Cessna 150 is made mostly out of 0.016" maybe some 0.020"

For reference, the top string on a guitar is 0.050" and the bottom string around 0.010"

Big subject.

[TownsendsFJR1300]

Ok Jason, here's how my aluminum tank is securred:

Four tabs on each upper end of the tank. The two (looks like 1/4, 20 screws) going thru a small spacer block, then into the stringer.. There is NO foam anywhere to be seen. And obviously, air can get to everywhere(except the bottom I gather).

Above the tank is the deck, I'm photographing thru the ONE access hole. The camera is literally sitting atop the sender unit..


The screws showing from the top secure the two separate seats..

[Jason2tpa]

Ok Jason, here's how my aluminum tank is securred:

Four tabs on each upper end of the tank. The two (looks like 1/4, 20 screws) going thru a small spacer block, then into the stringer.. There is NO foam anywhere to be seen. And obviously, air can get to everywhere(except the bottom I gather).

Above the tank is the deck, I'm photographing thru the ONE access hole. The camera is literally sitting atop the sender unit..


The screws showing from the top secure the two separate seats..

Nice! I like this method. I guess my only concern is getting into the stringer, which are foam filled. 40 year old hull, so I'm doing what I can to prevent the potential for water intrusion.

Re: Pascoe method
As i mentioned earlier, 5200 coffin bed to the pvc strips is concerning because of how difficult it would be to extract tank (can you say, come along). But in all reality, it is highly unlikely I would be the owner of this boat 20-30 years from now. So some might say, let the next owner deal with it. What do you say?

Greatly appreciate you taking the time to snap the photo.

[Jason2tpa]

Ok Jason, here's how my aluminum tank is securred:

Four tabs on each upper end of the tank. The two (looks like 1/4, 20 screws) going thru a small spacer block, then into the stringer.. There is NO foam anywhere to be seen. And obviously, air can get to everywhere(except the bottom I gather).

Above the tank is the deck, I'm photographing thru the ONE access hole. The camera is literally sitting atop the sender unit..


The screws showing from the top secure the two separate seats..

Nice! I like this method. I guess my only concern is getting into the stringer, which are foam filled. 40 year old hull, so I'm doing what I can to prevent the potential for water intrusion.

Re: Pascoe method
As i mentioned earlier, 5200 coffin bed to the pvc strips is concerning because of how difficult it would be to extract tank (can you say, come along). But in all reality, it is highly unlikely I would be the owner of this boat 20-30 years from now. So some might say, let the next owner deal with it. What do you say?

Greatly appreciate you taking the time to snap the photo.

[DennisG01]

Re: Pascoe method
As i mentioned earlier, 5200 coffin bed to the pvc strips is concerning because of how difficult it would be to extract tank (can you say, come along). But in all reality, it is highly unlikely I would be the owner of this boat 20-30 years from now. So some might say, let the next owner deal with it. What do you say?

Greatly appreciate you taking the time to snap the photo.

Re-read my response above. The PVC strips get 5200'd to the tank, not the boat.

[panasonic]

Ok Jason, here's how my aluminum tank is securred:

Four tabs on each upper end of the tank. The two (looks like 1/4, 20 screws) going thru a small spacer block, then into the stringer.. There is NO foam anywhere to be seen. And obviously, air can get to everywhere(except the bottom I gather).

Above the tank is the deck, I'm photographing thru the ONE access hole. The camera is literally sitting atop the sender unit..


The screws showing from the top secure the two separate seats..

Your boat is even clean under the deck..lol

[Jason2tpa]

Re-read my response above. The PVC strips get 5200'd to the tank, not the boat.

See my recent response ^^^ to scott, about the stringers.

[DennisG01]

See my recent response ^^^ to scott, about the stringers.

I did. But that has nothing to do with the coffin "bed". I'm not sure what you're getting at. From what you wrote, it appeared you were concerned about gluing the tank to the bed/hull.

[panasonic]

Jason, from looking at the pictures you posted it LOOKS like the floor board above you tank is pretty much parallel to the top of your tank. Once you decide how to secure the tank in place. I like the way Scott's tank is held down. You could take some Precision Board and cut pieces to fit down all around the tank to keep it from shifting side to side, fore and aft. Maybe even bond some pieces to the bottom of the access panel that would just touch the top of tank when the panel is down in place.

Precision board is a water proof high density foam board.It is not effected by solvents either. Meant to replace wood in sign making and is used in boat construction as well. I used it to replace rotten transom and stringers in my boat.

[Jason2tpa]

I did. But that has nothing to do with the coffin "bed". I'm not sure what you're getting at. From what you wrote, it appeared you were concerned about gluing the tank to the bed/hull.

You're correct, that is a concern. Your suggestion talked about securing tank by using a "few lengths of 1-1/2" PVC angle "iron" secured to the stringers". Scott's suggestion is similar, in that you're using the stringers as an anchor. My concerns about using the stringers as an anchor is detailed in my reply to Scott.

That's what I was trying to get at, sorry for confusion.

[Jason2tpa]

Jason, from looking at the pictures you posted it LOOKS like the floor board above you tank is pretty much parallel to the top of your tank. Once you decide how to secure the tank in place. I like the way Scott's tank is held down. You could take some Precision Board and cut pieces to fit down all around the tank to keep it from shifting side to side, fore and aft. Maybe even bond some pieces to the bottom of the access panel that would just touch the top of tank when the panel is down in place.

Precision board is a water proof high density foam board.It is not effected by solvents either. Meant to replace wood in sign making and is used in boat construction as well. I used it to replace rotten transom and stringers in my boat.

I too like scott's method. I have my concerns about using the stringers as an anchor, only because my hull is 40 years old. I'm a member on a classic aquasport forum. I started a new thread voicing this concern. I'm hoping to hear from a few members who i know have a lot of experience with classic AQs. If they think screwing into adjacent stringers is no problem then scott's method is what i'll do.

I got 8 quotes on a custom made AL tank from 8 different sources. The highest was $515, majority in the $430-$480 range. Low quote is $355, which is the one I'm going with. Not because it's the cheapest, though this works out nice. Fabricator named Tony, Sunrise Marine Tanks in Venice, FL. He had been recommended by 3 different sources. Good price and good referrals, no need to shop around anymore.

[Jason2tpa]

Jason, from looking at the pictures you posted it LOOKS like the floor board above you tank is pretty much parallel to the top of your tank. Once you decide how to secure the tank in place. I like the way Scott's tank is held down. You could take some Precision Board and cut pieces to fit down all around the tank to keep it from shifting side to side, fore and aft. Maybe even bond some pieces to the bottom of the access panel that would just touch the top of tank when the panel is down in place.

Precision board is a water proof high density foam board.It is not effected by solvents either. Meant to replace wood in sign making and is used in boat construction as well. I used it to replace rotten transom and stringers in my boat.

I too like scott's method. I have my concerns about using the stringers as an anchor, only because my hull is 40 years old. I'm a member on a classic aquasport forum. I started a new thread voicing this concern. I'm hoping to hear from a few members who i know have a lot of experience with classic AQs. If they think screwing into adjacent stringers is no problem then scott's method is what i'll do.

I got 8 quotes on a custom made AL tank from 8 different sources. The highest was $515, majority in the $430-$480 range. Low quote is $355, which is the one I'm going with. Not because it's the cheapest, though this works out nice. Fabricator named Tony, Sunrise Marine Tanks in Venice, FL. He had been recommended by 3 different sources. Good price and good referrals, no need to shop around anymore.

[TownsendsFJR1300]

I would think think the stringers have to have wood in the middle...

How would you make a stringer of foam, then Fiberglas over it, just doesn't make sense..

In any event, IMO, have the tank built your yours, (print out my pic for the welder) and as shown it'll fit slightly loosly in the hull.

Now custom cut some of that material (posted above) to take up the little bit of extra space between the tank and stringer (each side). Epoxy that piece to the stringers and bolt the tank to those.

A for the bottom, dunno what's at the bottom.

BTW, thought my tank was a 60 gallon. Per the original sales brochure, it's 50 gallons..

Re my tank, that's the first time I've seen how it's mounted. As noted earlier, I did wipe off a wet , saw dust like material years ago. That black color on the top of the tank was my acrylic paint I applied years ago(looking thru a mirror-working backwards-PIA) to stop the couple of white spots. Thought I might find some "dust" under there today that needed a wipe down, nope. That hasn't been opened up in at least 4 years... I kinda dreaded having what your going thru right now but I guess that's highly un-likely (thanks Jason, really)

[panasonic]

it's a hard foam and it's meant to be glassed over, resin does not melt it.

I just meant he could use pieces of this material as spacers AFTER he gets the tank secured in. To make sure it doses not shift around.

I made stringers from it and glassed them in, very stiff and strong and will never rot like wood.