Driftwood Refuses to sink

[sairving]

At the beginning of July, I started soaking a piece of driftwood. A month and a half later, it still won't sink. The driftwood is hollow in the middle. Could that be the issue? 

I really like this driftwood and want to use but at this point, I may have to buy something else. My anubias has been floating for a month and a half.

[Guppysnail]

Your hollowed out portion is most likely the reason. Large pieces sink because of their weight long before they are saturated internally. With the absence of weight from the missing portion you need to wait until it soaks through. 
 

I drill holes in places you can’t see on stubborn floating pieces. I then use plant weight spools strung through the holes to add the weight to overcome buoyancy. 
 

[TOtrees]

I have a different perspective from guppysnail above. Politely, kindly and respectfully 🙂 

Having a middle area that is hollow should speed up not slow down the saturation process. Water in the hollow area will neither hasten nor slow saturation, since it's exactly the same density as the rest of the tank. If anything, the piece being hollow should allow it to saturate faster, since water is soaking in not just from the outside but also from the inside. I think you just have a very buoyant piece, and it'll take time. 

For myself, I'd try to get the piece into a deeper container, like the bottom of a garbage pail. If the pail is full, and the piece is right at the bottom, it will be under greater pressure that if it is floating at or near the surface. Water will penetrate the wood a bit faster under that higher pressure. You can use big rocks to hold it down if needed. 

[lefty o]

id find a thin chunk of slate slightly bigger than the base of the wood. drill a hole in the slate, and screw it to the wood. it wont float any more.

[Biotope Biologist]

Yeah I was going to say attach a weight for now. Some woods have different absorbency rates. And this piece once it does absorb the water will be heavy!

 

I have a small piece similar to this. It took 6 months to sink. And now it weighs like 20lbs. It’s about 8” tall. So it’s basically a watermelon at this point

Edited August 15, 2023 by Biotope Biologist

[Guppysnail]

On 8/15/2023 at 10:17 AM, TOtrees said:

Having a middle area that is hollow should speed up not slow down the saturation process. Water in the hollow area will neither hasten nor slow saturation, since it's exactly the same density as the rest of the tank.

I would listen to this. My physics knowledge is total guesswork 😝🤣

[Lennie]

I like it easy. I just scape with my driftwood and put a rock on top, in a position where it won't fall down and potentially hurt the fish. All I have to do in the following days is remove the rock, and the scape is there

 

I check every now and then to see if it is soaked. I never presoak my wood pieces and enjoy the ugly rock on top my wood for some time 😝🤪 First, I boil mine if I can tho

[Galabar]

Fill the empty middle with rocks and pebbles, held in place by aquarium safe silicone.

[nabokovfan87]

On 8/15/2023 at 5:14 AM, sairving said:

At the beginning of July, I started soaking a piece of driftwood. A month and a half later, it still won't sink. The driftwood is hollow in the middle. Could that be the issue? 

If the air can't escape the middle, drill some 1/4" holes in the base.  A lot of times when you buy driftwood this step is done before it arrives to us as a preventative measure to floating.  As long as the void in the wood isn't stuck holding air, drilling holes should let it sink.  Shove it in a bucket with a weight on top and give it ~2 weeks.  If you don't see any progress by then.... stick it permanently to a weight or just cut it in half.  You'll end up with two caves at that point.

[Shadow]

On 8/15/2023 at 10:22 AM, Lennie said:

I like it easy. I just scape with my driftwood and put a rock on top, in a position where it won't fall down and potentially hurt the fish. All I have to do in the following days is remove the rock, and the scape is there

 

I check every now and then to see if it is soaked. I never presoak my wood pieces and enjoy the ugly rock on top my wood for some time 😝🤪 First, I boil mine if I can tho

Yea I am with Lennie on this...if after me boiling(I do this OCD with all my hardscape lol) and letting it soak for a couple hours, it don't sink. I am attaching a rock to that mug. Ole MD Fish Tanks YT rubbin off on me there! 🤣

[Odd Duck]

 I had pieces that were soaked for a few months, then held down with rocks zip tied to the pieces for several months more totaling just over a YEAR.  I cut the zip ties to remove the rocks to use for another project and the wood floated up!  🤦🏻‍♀️  So now I drill holes in flat slate pieces, pre-drill smaller holes in the wood and use stainless steel screws to hold them together.  No more floating wood.  We used a concrete drill for the slate.  It worked very well and was easy to do.  I keep that one stashed with my fish stuff.  Regular drill for the wood.  The hole in the slate is for the threaded part of the screw to pass through but not the head and we use stainless steel washers, too, to spread the pressure.  The hole in the wood is only the diameter of the screw’s inner shaft diameter so the threads will still have bite but the driftwood won’t split.  Forgive me if I’ve over-explained, I tend to do that since some people may not be very mechanically inclined.

I showed the basics in my 14 G cube build.  You can follow the link in my signature below.

Edit to add that the other pieces that floated and the rather long story about “the episode” are in my 100 G nanofish tank link.

Edited August 16, 2023 by Odd Duck

[tolstoy21]

On 8/15/2023 at 10:28 AM, lefty o said:

id find a thin chunk of slate slightly bigger than the base of the wood. drill a hole in the slate, and screw it to the wood. it wont float any more.

I did this trick with a large stump like piece of driftwood. Works well for wood that would otherwise take a millennium to sink. Slate is pretty easy to drill through, just make sure to use a masonry bit and not a wood bit. Bury the slate base in your substrate and the wood should stay put.

Dense hard woods like mopani or malaysian sink pretty fast.  In my estimation a piece of wood the size you show in the picture will normally take many many months to become waterlogged enough to sink.

I doubt a hollow middle will affect its 'sink-ability', except that it probably exposes more wood surface to the water which should allow it to become waterlogged faster.

Either way, slate is your friend. You should be able to pick up a piece inexpensively at landscaping store, or possibly at a place like Home Depot. 

This is my piece of wood that I had to attach to slate. It sinks fine now, without the slate, but that's because it's been underwater a couple years. But, I'd say it took a good half year before it sunk on its own.

 

Edited August 16, 2023 by tolstoy21