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I bought some new Hammerlok shelving a fortnight ago, and well, its fantastic!

the problem is the shelves are MDF (supported on all 4 sides tho, so minimal warping i should hope) and well, water and MDF a soggy mess make!

can i stain the MDF with standard woodstain or do i need paint?

If i need paint, would an interior do? If i laquer-coated it afterwards?

Anything else i should be aware of?
Callatya attached this image:
[img]http://www.fishprofiles.net/attachments/407729.jpg"]

For animals, the entire universe has been neatly divided into things to (a) mate with, (b) eat, (c) run away from, and (d) rocks. - Terry Pratchett

Hi,
I'm sorry to say, but that "wood" will not support
the tanks. It is actually made of compressed saw
dust and glue. It is not water proof, and if
subjected to constant moisture, it will warp and
crumble.

If you want to keep the metal frame work (it does look
nice) then replace the "wood" that came with it with
at least 3/4 inch thick marine plywood, or "outdoor"
plywood.
This wood is especially treated layers of wood
(hence the name ply (layers) wood) pressed, and
glued together with a glue that is water resistant.
This wood is used to make boats, and home made,
very large aquariums.
Once you have replaced the shelves, do paint them,
particularly the edges to help keep moisture out of
the layering.

Frank



[span class="edited"][Edited by FRANK 2004-08-02 10:08][/span]

-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--

Right now, i cannot afford to replace them.

I have paint and gloss, and i thought i could get some time out of them if they were sealed up.

I know MDF is stoooopid to have near water, but right now, its all i have to work with, so i'm trying to get as much time out of them as possible.

Weightwise, i'm pretty certain they can hold that setup and then some. My Dad has the same thickness shelving holding up all our camping gear (weighs a heap!) and after about 7 years, it is visibly bowed, but its holding well. (its only supported at the short sides)


I am planning on getting hardwood or marine ply shelving, but not right now.

How do i make the best of what i have?

For animals, the entire universe has been neatly divided into things to (a) mate with, (b) eat, (c) run away from, and (d) rocks. - Terry Pratchett

Hi Cal,

Well you realize that it won't work long term.
How long will depend upon how well you seal the
"wood" and how much weight you put on the shelves.

As you, yourself, said - "the camping gear weighs a
heap" and the shelf is bowed. If your tank shelves
bow, and depending upon the size of the tank, the
tanks will spring leaks at the seams, and could
even crack causing a real disaster. Remember those
tanks weigh at least 10 pounds a gallon.
+ the hob filter and heaters, etc.

No one wants to tear a tank apart that is fully
cycled and has everything working great. That is
what you are saying, and admitting, that you are
going to have to do at some point in the relatively
near future.

It would be best to do the "Pretty please, Dad" thing
grovel if necessary, and put some substantial wood
in place of that "wood" that came with them.

Frank


[span class="edited"][Edited by FRANK 2004-08-03 12:35][/span]

-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--

Hi Callatya,

I think that if it is furnature MDF it is already "sealed" with a plastic layer (usually they cover naked MDF for furnature with a layer to make it look like real wood), this is maybe not really waterproof, but it is at least pretty water resistant. This layer also adds a load of strength to the MDF, making it almost unbreakable. As long as your tanks don't spring a leak it should be perfectly fine to keep it as support, especially if the support is on all sides.

Regards,
Martin

Catallya, try coating the mdf in either clear polyurethane (like a nice wattyl clear varnish) or a sanding sealer.

the real problem with mdf is it doesn't have the best structural strength, plywood is better, but you still need to seal it (even marine ply needs to be sealed) in the same way as MDF.

If you wanna stick with your mdf, whether it's strong enough depends on how much wieght you plan to put on it.

If it's a lot, buy some 2 x 1 1/2" pine battens and screw them on to the underside of the mdf, at spacings of about 300mm. this will stiffen the MDF enough so that it wont sag.

Or if you can make a grille sort of thing using the steel shelving to support the mdf that'll work too.


If you wanna know more, feel free to contact me.

Callatya

That MDF will support you tanks easly. The biggest problem whith that stuff is it is extremly not water proof. Regardless what you finish it with it must be sealed extremly well all over especially the ends.

Keith

Near enough is not good enough, therefore good enough is not near enough, and only your best will do.
I VOTE DO YOU if not WHY NOT?
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Frank
Unless they make it different in USA it is not made from (Saw Dust) as such the timber is reduced to a very fine particals and glued to together.

Structually it has a lot of strength if it is supported correctly, but if it is not supported correctly like any thing else it will not do the job.

Callatya shelves have a good support all around not just the ends.

My quals for making these statements 10 years in the trade and 26years teaching the wood trade. Plus several indrustral and design quals.

Keith

Near enough is not good enough, therefore good enough is not near enough, and only your best will do.
I VOTE DO YOU if not WHY NOT?
VOTE NOW VOTE NOW

Hi Keithgh,
We have similiar shelving here in the states
available from any number of sources such
as Home Depot, Lowes, Sam's and Costco Clubs.

All are mdf shelving and all are supported along
the full width, and sides, with about a 1/2 inch
of steel. After years of holding weight, they
all bow into the middle and if the supported
weight is at one end or the other that is the
point where the bow occurs.

As Cal stated in her own post, the camping gear
weighs alot, and has become bowed over the years.

Placing an aquarium on that material without any
preparation will bow it alot faster than with,
but it will still bow, and stress the tank resulting
in leaks or outright cracks.

I agree it looks nice, but still maintain that it
is not a long term solution, and one that will
eventually cause problems. When I set a tank, I
expect it to still be on its frame in 10 years.
I'd hate to have to tear down a fully cycled tank
in its prime because the frame I had it on warped
and caused leaks.

Essentially, I don't believe it is a good, viable,
long term, solution.

Frank


-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--