aussie pine and moisture. Prone to cracking?

[antisense]

G'day all,

I'm in the process of designing a fish tank and due to financial constraints it will be made from pine.

For the joinery, I was considering using M&T joints for the central supports. I am just curious if using rigid M&T joints can result in major cracking.

I am assuming that pine would take up a fair bit of moisture and I have concerns about cracking due to the weight involved (around 200kg).

Thanks in advance.

[Just George]

If you seal the timber when built, there shouldn't be much swelling when/if it becomes wet.

[Harry72]

For the main support frame 90/35mm structal pine will hold that weight with ease, use half lap joints and a good moisture proof glue.

[Ianab]

Pine will be fine for a fish tank stand. Use good ole 4x2s for the uprights and make the back / side out of ply for extra strength and bracing. Put some weight on the end of a 4x2 and see if it breaks.. it will take 100s of kgs to actually crush it. If its going to fail it will be due to wracking, folding up like a cardboard box. Plywood sides will prevent that.
Then make some nice trim and doors for the front and you will have a good looking stand that should be able to support a small house.

If you are getting moisture into the base you have bigger problems than just the timber getting wet ;) If you are making a cover / light hood for the top then moisture / condensation may be a problem there. Make sure the cover is well vented and maybe give it all a good coat of poly for some water protection


Cheers

Ian