Cinder Block Rack with Warping Wood

[Boca Betta]

Hey all, 

Looking for some help with my cinder block rack: Tanks are resting on 2x8s cut to 69 inches. The frontward top piece is warping. (Pics below, you can see the end is cupping) I am going to replace it (again as this has happened before) but I'm getting so frustrated. This is the second time the wood in this position has warped. All the other boards have held up fine! Suggestions on maybe better distributing the weight on this stand or what type of wood might hold up best? 

PS: The twenty long is getting some rummy nose tetras soon and those 10 gallons used to hold bettas but one died and one was moved to a 5 gallon cube retirement tank because his fins have gotten long and heavy. 

[Wrencher_Scott]

Look for dried wood, sometimes it will be labeled kiln dried.

If that didn't work I think you might have to go with something pre treated. Which is ugly. 😞 

[xXInkedPhoenixX]

I would also suggest warping could happen with the weight of course but also the moisture. I would put some shelf liner down on the wood to protect it from that. Inexpensive investment!

[Boca Betta]

On 6/5/2022 at 12:35 PM, Wrencher_Scott said:

Look for dried wood, sometimes it will be labeled kiln dried.

If that didn't work I think you might have to go with something pre treated. Which is ugly. 😞 

Thank you, looks like the home depot near me has some southern yellow pine kiln dried. If this warps one more time I am just going to go the garage shelf rack route. Just don't want to give up and spend all that money quite yet! Thanks again! 

On 6/5/2022 at 12:42 PM, xXInkedPhoenixX said:

I would also suggest warping could happen with the weight of course but also the moisture. I would put some shelf liner down on the wood to protect it from that. Inexpensive investment!

Yes, definitely a consideration. I stained all the boards and the other 3 seem to be holding up well, but I think your idea is good on top of all that. I'll have to check it out when I go to get my new wood 

[xXInkedPhoenixX]

Yea water has superpowers- it will eventually wear away the best of water repellents- especially when left to it's own devices. 

[Boca Betta]

On 6/5/2022 at 1:40 PM, Pepere said:

As a matter of background information, I used to build boats in wood for customers.  
Wood is an area I know a bit about.

kiln drying of wood is not irreversible. I have bought “kiln dried” woodthat spit at me as I hammered a nail in it.  Ie, exposure toexcess water reabsorbs into the wood.

Also, kiln drying, or drying in any form, does not stop wood movement.  It reveals it.

when wood is cut into boards from a tree, internal stresses in the wood is present.  As it dries, the water in the cells comes out and the wood shrinks.  More across the grain than with it.

treatments to stop this are of limited utility.  Picture Sissiphus pushing the rock uphil.  Usefull for small pieces…

the best you can do is look for cuts that will minimize this function.

 

look at the end grain of the piece that is annoying you. Do you see the very center of the tree is in the center of that board, yet alsow at the lower third of the thickness? As such, as the wood dries your shrinkage is twice amuch across the rings as opposed to through them.  Ie the rings are straightening as they shrink pulling the ends of the boardup.  Ie cupping.

Alternatively, looking at the endgrain of the board not causing you problems, it shows this piece came from further away from the center of the tree.

both of these boards are plainsawn as opposed to quartersawn.  Quartersawn boards would have the growth rings vertical in the board through the narrow part of the board when looking at the endgrain.  Quartersawn boards are the leasr susceptible to cupping.

As a boatbuilder, I would cut strips of wood from a piece similar to the one causing you truble and then reglue them together alternating the growth ring pattern to even out the stresses and avoid that area around the center.

i sort of suspect you would prefer not to be cutting and pasting though.

 

as such I would reccomend buying another piece where the endgrain looks a lot more like the one not causing problems.

Thank you so much for your thorough response. I think I see what you mean about the center of the tree. And you are correct, unfortunately I don't have the tools or knowledge to start cutting and pasting wood. I appreciate your reply and will definitely take this under advisement when I get myself to the hardware store! 

[Wrencher_Scott]

On 6/5/2022 at 10:40 AM, Pepere said:

As a matter of background information, I used to build boats in wood for customers.  
Wood is an area I know a bit about.

kiln drying of wood is not irreversible. I have bought “kiln dried” woodthat spit at me as I hammered a nail in it.  Ie, exposure toexcess water reabsorbs into the wood.

Also, kiln drying, or drying in any form, does not stop wood movement.  It reveals it.

when wood is cut into boards from a tree, internal stresses in the wood is present.  As it dries, the water in the cells comes out and the wood shrinks.  More across the grain than with it.

treatments to stop this are of limited utility.  Picture Sissiphus pushing the rock uphil.  Usefull for small pieces…

the best you can do is look for cuts that will minimize this function.

 

look at the end grain of the piece that is annoying you. Do you see the very center of the tree is in the center of that board, yet alsow at the lower third of the thickness? As such, as the wood dries your shrinkage is twice amuch across the rings as opposed to through them.  Ie the rings are straightening as they shrink pulling the ends of the boardup.  Ie cupping.

Alternatively, looking at the endgrain of the board not causing you problems, it shows this piece came from further away from the center of the tree.

both of these boards are plainsawn as opposed to quartersawn.  Quartersawn boards would have the growth rings vertical in the board through the narrow part of the board when looking at the endgrain.  Quartersawn boards are the leasr susceptible to cupping.

As a boatbuilder, I would cut strips of wood from a piece similar to the one causing you truble and then reglue them together alternating the growth ring pattern to even out the stresses and avoid that area around the center.

i sort of suspect you would prefer not to be cutting and pasting though.

 

as such I would reccomend buying another piece where the endgrain looks a lot more like the one not causing problems.

Soooo.

If you buy kiln dried wood  will it not be stable as long as it doesn't get wet? Say you find a nice straight piece that is dried will it stay that way as long as it stays dry? 

If so then would it be a good idea to seal it to keep it from absorbing moisture? 

 

[lefty o]

On 6/5/2022 at 4:30 PM, Wrencher_Scott said:

Soooo.

If you buy kiln dried wood  will it not be stable as long as it doesn't get wet? Say you find a nice straight piece that is dried will it stay that way as long as it stays dry? 

If so then would it be a good idea to seal it to keep it from absorbing moisture? 

 

even humidity can affect wood. wood will absorb moisture straight from the air.  get good dried wood, and seal it for best results. warning, even that is no guarantee the wood wont move around.

[Boca Betta]

I live in South Florida, so moisture is basically a condition of existence down here haha. I think I'll have to be that person in the hardware store sifting through every board looking for the best possible one. Thanks again everyone for your help and advice! 

[lefty o]

On 6/5/2022 at 5:02 PM, Boca Betta said:

I live in South Florida, so moisture is basically a condition of existence down here haha. I think I'll have to be that person in the hardware store sifting through every board looking for the best possible one. Thanks again everyone for your help and advice! 

thats the only way to buy lumber. each piece costs the same, so you may as well get the best pieces you can.

[Wrencher_Scott]

How about using plywood stacked to whatever thickness you like. Then you could dress up the sides with whatever you like. 

Around here dried wood is pretty stable, it's very dry, the only time there is humidity is when it rains. And that rarely happens. 

 

Edited June 5, 2022 by Wrencher_Scott