Foam under a SeaStar tank?

imisky · #1 12-25-2010, 06:54 AM

hey Shelley,

It was quite a shock when Paul told me about the tank, so as Paul has mentioned tanks with floating bottoms should only be supported by the trims and should never be put on foam in any situation. The result is usually what happened to your tank

This is usually the case with tanks built with the 4 side panels sitting on top of the bottom glass. These shouldnt sit on foam as any pressure on the bottom will push onto glass that doesnt give much before snapping or in your case cracking.

Tanks thats built with the 4 side panels sitting around the bottom glass has a little bit of a flex if theres any pressure pushing up on it as the silicone holding the bottom panel to the 4 sides will flex as the bottom pannel gets pressure.

Hope that makes sense

Cheers,
Eugene

Borderjumper · #2 12-25-2010, 07:01 AM

Makes perfect sense but now my question is.. Have you ever taken apart a seastar tank? Is it a floating bottom? I can't tell without taking the trim off.

imisky · #3 12-25-2010, 07:13 AM

never taken apart a seastar tank before, but most (80% i would say) of the tanks I've taken apart with trims are infact built with the side panels sitting on the bottom panel. So there is a high chance that the seastars were built the same way.

Borderjumper · #4 12-25-2010, 07:18 AM

Quote:

Originally Posted by imisky

never taken apart a seastar tank before, but most (80% i would say) of the tanks I've taken apart with trims are infact built with the side panels sitting on the bottom panel. So there is a high chance that the seastars were built the same way.

I'm getting confused lol so tanks with trim are floating bottoms and should not be on foam? Or, It sounds to me that if the sides sit ON the bottom glass that the bottom is not floating?

imisky · #5 12-25-2010, 07:36 AM

haha ok, so tanks that have trims are all considered floating bottom.

out of all the tanks ive taken apart (AGA/Oceanic) majority of them were built with the side panels sitting on top of the bottom. That would explain why they needed the trim on the bottom.

In other words, most of the tanks built with 4 panels on top of the bottom are usually built with trims thus making them floating. The reason is because you are not supposed to support the whole bottom of tanks built this way only the perimeters of the base

Aquattro · #6 12-25-2010, 12:52 PM

Interesting, as I'm checking the bottom of my tank, I see it's leaking from somewhere above the foam. Gonna be an interesting Xmas morning for me!!

MitchM · #7 12-25-2010, 02:47 PM

Quote:

Originally Posted by Aquattro

Interesting, as I'm checking the bottom of my tank, I see it's leaking from somewhere above the foam. Gonna be an interesting Xmas morning for me!!

Oh, no!

Mitch

Doug · #8 12-25-2010, 05:40 PM

Shelley, although not much help now, sorry, but I agree with no foam under a framed tank. We had many threads on RC in regards to it. One builder even said it voids there warranty if foam is used under a frame.

Any tank thats custom made, with no frame, where the complete bottom sits on the foam is usually fine.

Borderjumper · #9 12-25-2010, 05:49 PM

Quote:

Originally Posted by Doug

Shelley, although not much help now, sorry, but I agree with no foam under a framed tank. We had many threads on RC in regards to it. One builder even said it voids there warranty if foam is used under a frame.

Any tank thats custom made, with no frame, where the complete bottom sits on the foam is usually fine.

Thanks Doug.. I'm just trying to come to a conclusion as to why this tank failed.. I'm prolly going to have a new one built and I don't want this happening again.

I think there is some confusion as to what foam I used. It's not spongy carpet underlay type foam. I have other tanks sitting on very thin open cell black actual foam.. Spongy foam.. I think that's ok as it can totally compress.
This pink building insulation sheet foam is over 1/2 thick and will not hardly compress even if you stand on it. IMO it's so rigid that once the tank edge settles IN to the foam the whole middle of the tank has an upward force pushing against it.

I won't use it again,, I'm going back to the thin open cell spongy foam, if any foam at all.

Madreefer · #10 12-25-2010, 06:21 PM

Quote:

Originally Posted by Borderjumper

IMO it's so rigid that once the tank edge settles IN to the foam the whole middle of the tank has an upward force pushing against it.

Makes perfect sense to me. I agree. If tanks were designed to have any foam under the tank than why do they not come that way? Or why do they not sell the correct sized precut peices? Good money maker especially for odd shaped tanks? Someone posted about glass bowing out. Maybe there is supposed to a little bit of bowing out underneath.