Matting cushion under stainless fuel tank?

[xpertski]

Hi all!

After your wisdom please!

Looking to fit a stainless fuel tank in the console to replace current plastic tank, but hear that the main risk with stainless tanks are the joins. To help with this and potentially reduce noise when bouncing on waves I thought it might be a good idea to place some cushioning between the stucco gelcoat floor and the tank. I hear that there is a need to prevent water from sitting in contact with the tank so thought of matting that had grooves in to let the water escape.

Looking at the below from force 4 chandlery, any thoughts?

Thanks!

[gtflash]

Hdpe strips would work. Chemically inert. And strong. I have the one on the right in anchor locker. It can compresss quite a bit if you have a big tank

[pagick]

I use neoprene rubber. It close to a wetsuit but just rubber no fabric, but still closed cell. You might first think too soft but over a whole gas tank it has almost no give except for pressure points like corners and edges. 1/4" to 1/2" thick. Some come with adhesive back but contact cement works great. Stick it to the bottom of the tank. Put it around the edges and strips in the middle. Cover 1/3 to 1/2 the tanks bottom?
Google "LDW219 Amazon"

[xpertski]

Thanks both, is there a risk those products may trap moisture under the tank?

[pagick]

I suppose it would, so using strips east/west or north/south under the tank would be let it breath. Then again you can store water in a stainless tank for far longer than you would own your boat so water under it should not be a deal breaker, IMO. Unless some smarter guy or gal knows something I don't.
I have a sheet of this 1/4" in my sib where the tank (plastic 12 gal), the battery box, a plastic crate with anchor, prop, tools etc... on it. it protects the aluminum floor and stops the rattle and scratching from sand.
Isn't HDPE a hard plastic? Like a cutting board? Or is there a softer version

[Phil M]

Originally Posted by pagick

Then again you can store water in a stainless tank for far longer than you would own your boat so water under it should not be a deal breaker, IMO. Unless some smarter guy or gal knows something I don't.

Not so straight forward I'm afraid. A tank full of water would indeed last a long time however there is a phenomenon called crevice corrosion which will eat at stainless much faster. Essentially, where you have damp salty things pressed against stainless steel where there is limited opportunity to dry or for air to circulate, corrosion can be very much accelerated. I'm no corrosion expert so can't comment on how long the tank would last but personally I'd avoid something that will hold water like expanded neoprene.

Phil

[pagick]

I wonder if that process would be less if you left the white protective sheet that comes on stainless sheets is left on the bottom. If it doesn’t come with it perhaps vinyl car wrap is even better.
My last boat a 23 year old fiberglass open bow ChrisCraft had it’s tank (aluminum) under the floor with some kind of foam sheet as a pad under it. If the boat stayed in the water it would be damp/wet all the time. I would bet stainless would hold up better than aluminum.
But I have only life experience and observations to pull from and actual knowledge about this problem should be taken over my opinion.

[xpertski]

Hi all, yes I have decided to go stainless because if it’s higher corrosion resistance. The challenge is to have a matting underneath that does leave the tank in permanent contact / longer term contact with a salty / moist / wet floor, this would probably only be an issue when moored for durations for any water than manages to get into the floor part of the console. I had thought something fairly rigid with gaps between tread or strips to let eater pass and drop between (ie not trapped) would be the way to go, so firm anough to hold a shape that allows water to move out from under the tank while the weight of the tank is on it - further it would need to be softer than the stucco gelcoat floor to protect the tank joints from fracturing (apparently the greater risk with SS tanks than Ali).

My initial thoughts were the products on my original post but a kind gentleman on this forum who has helped with the transom repair I needed a short while ago suggested spaghetti matting picture example below