Mounting steel gas tank?

[bossee]

Hi,<br /><br />What is the best and durable way to fasten a stainless steel gas tank under deck?<br /><br />Today the tank is mounted in foam. Last year the tank came loose and now the boat has been in for warranty repair to fasten the tank again (the boat is from 2003 so rather new).<br />Problem is they have not used any other method then previous from factory foamed in tank. So it is nothing better then before. Since I do not want to have the tank come loose again I have decided to take the tank out and then mount it in a better way then in foam.<br /><br />Can You give some advice what method(s) is recommended? Any links to info with pictures of tank installations on internet?<br /><br />The boat is a DC/Bowrider type boat (max speed is about 40 knots). 115 hp outboard.<br /><br />Picture of my tank and how it looks like. The airgap is about 3 inch.<br /><br />

 

[prockvoan]

Re: Mounting steel gas tank?

You could have some tabs welded on the top and front and back sides that would let you screw it to the top and sides of the stringers.

 

[bossee]

Re: Mounting steel gas tank?

Hi,<br />Would that not be to rigid mounting?<br /><br />I was thinking of some mounting solution that is flexing somewhat. The tank will expand/shrink some depending on gas level, temperature etc. The hull itself will move/flex a little also. So in my opinion the tank should be mounted an a flexing way.

 

[amidaeus]

Re: Mounting steel gas tank?

I'm not sure about newer boats but my 1980 was foamed in.

 

[bossee]

Re: Mounting steel gas tank?

Hi,<br />My boat is almost new - 2003. The gas tank was foamed in from the factory. The tank came loose last season (and I made a temporary repair). In the winter the dealer had it for warranty repair to fix the gas tank. The problem is that the same method is used again - foam. And I do not want to come in same situation as last summer. So I have decided to mount the tank in a better way. I can imagine the foam method is very cheap for the boat builders. But there must be better ways. You get many advantages also if You do not use foam since You can inspect the tank better and see any leaks early.<br />And I want to be able to easy take the tank out of my boat if it leaks and repair it imedeately. To dig it out of the foam first will take some time and then foam it back after a repair does not attract me at all.

 

[Boomyal]

Re: Mounting steel gas tank?

It's hard to imagine the foam not hanging on to the tank. I thought I was going to have to destroy my stringers to get my tank out. Foam makes quite an adhesive.<br /><br />I doubt your stainless tank will ever need repair. My 30 year old aluminum tanks had a few pits in it but it was sitting in a pool of water.<br /><br />If your drawing is correct, I would get four angle brackets and four very dense rubber pads. Glue the pad near the four corners of the tanks, set the angle brackets on the pads and screw or bolt the brackets thru the stringers.<br /><br />I would allow the brackets to drop down a little at the stringer so that when you apply the bottom screw/bolt it would draw the bracket down tight on the pads.

 

[cc lancer]

Re: Mounting steel gas tank?

This the way Iam doing mine which is a 100 gallon tank. to explain I will use your numbers.<br /><br />Starting at the front corner, 1-1/2 wood strips down the sided to the floor, every 12". Tops will be notched so I can run a cross brace to the strips on the other side which will hold the tank in place. Epoxy to glue the strips to the sides then one layer of glass and poly to water proof it.<br /><br /> I am using the same technique on the bottom leaving a 2" gap for water to run to the bilge.<br />For added safety to stop any water from standing on the bottom strips, I will glue Formica strips to the strips.<br /><br />This may be over kill for your situation, but it will give you an idea.<br />My boat will be used strictly in salt water, and I have to weld pin holes in it now because of foam and salt water.<br />One other thing, if you make modifications to the boat can it void your hull warranty?

 

[cc lancer]

Re: Mounting steel gas tank?

Yes Boomyal:<br />I broke down and bought a gallon of epoxy "wonder glue" to do this project.<br /><br />Ah....but the sweet smell of polyester resin in the morning.

 

[bossee]

Re: Mounting steel gas tank?

Hull warranty is only 2 year in my case. Warranty will end in beginning of June 2005. It does not matter my modification since I will make sure the tank will be fastened in best possible way. I really want to detect any leaks before I go out to sea. When I open the hatch over the tank today I see foam and only top of tank. If it start to drip gas I want to see that as soon as possible. I just do not trust the foam thing since the tank came loose and the foaming was made by the boat factory - and they should know how to do it properly (but not in my case obviosly).<br />When I have modified the mounting of the gas tank I will take full resonibility of that modification of course. Hard to belive it can be worse than today mounting solution in foam.

 

[bossee]

Re: Mounting steel gas tank?

Boomyal, <br />If You have been out in rough sea in planing speed or so the hull can get rather hard punches. That was why my foamed in tank came loose. It will be like glue to a certain point then it will break loose (it is not that flexible, at least not the foam that has been used in my boat from the factory).