Inexpensive fill for log cracks?

[Steve Mathews]

The 24" diameter log that I'm using for an anvil stand has a couple of large and deep cracks. The wood has already started to rot near the center. I would like to prolong its use for a while and thought of filling the cracks with something. Epoxy would certainly do the job but I would like to use something less expensive. The material would have to be fairly thin to flow into the cracks. Any suggestions?

[Jamie Buxton]

A big log like that is probably drying and shrinking. As it shrinks cracks will open up. That is, even if you perfectly fill today’s cracks, there will inevitably be more cracks next year, and probably some of the filled cracks will open too.
To keep the log together, often folks use mechanical means - essentially giant hose clamps - and tighten them up as the log shrinks over the years.

[Zachary Hoyt]

One way to reduce the probability of cracks in a new log is to drill a hole through the middle of the log, maybe 1 or 2 inches in diameter. That way when the wood shrinks it has a little bit of room in the middle and is less (although still fairly) likely to crack. The bigger the hole is in proportion to the log and the more accurately it follows the heart of the tree the more beneficial it will be. Once you've got cracks I would not try to fill them for the reasons above.
Zach

[Bill Space]

How about covering the top with a disk of plywood? 3/4” thick, or more laminated together if you want thicker?

[Ted Calver]

Minwax wood hardener would probably handle the center rot. It's very thin and soaks into end grain. Also, the big box stores used to sell a Watco butcher block finish that really soaks into end grain (I use it on cutting boards) and might be worth a try. I guess there's always Bondo for the big cracks, and if you thin epoxy with denatured alcohol it will flow into the finer cracks.

[Bob Falk]

I have heard it said that if you fill the crack with a filler that hardens, it will act as a wedge and worsen the problem as the wood expands with increased moisture in the wetter seasons.

[Jeff Bartley]

Steve,
Is it outside? If it's actively rotting you could try Abatron's Rot Consolidate, it's fairly thin and will soak into the fiber that's rotting but not good fiber. Just don't put too so much in that it fills a void.

[Scott T Smith]

I have a 300 lb anvil and am on my third log in 20 years. This one is 10 years old with no major cracks!

What I did was to soak it in used automatic transmission fluid before setting and mounting the anvil. For a couple of weeks I kept it upside down and treated it every time I walked by it. Then I turned it over and did the same thing until it wouldn’t retain any more fluid.

i think that the fluid ultimately displaced the water but made the wood soft enough to shrink without cracking.

[David Zaret]

one quick note about thinning epoxy with solvents --- you can do it, solvents will reduce the viscosity, but they also drastically change the characteristics of the cured product. the physical characteristics, the curing times, the color, and even the porosity of the cured epoxy will change (yes, solvents in epoxy can lead to a porous cured product). if you can do so, a better way to reduce the viscosity of epoxy is with heat - ideally, heat the substrate, not the epoxy itself, and the mixed epoxy will soak in deeper to the warm wood without impacting the pot life of the epoxy mix.



Minwax wood hardener would probably handle the center rot. It's very thin and soaks into end grain. Also, the big box stores used to sell a Watco butcher block finish that really soaks into end grain (I use it on cutting boards) and might be worth a try. I guess there's always Bondo for the big cracks, and if you thin epoxy with denatured alcohol it will flow into the finer cracks.

[Jim Becker]

Agree, David. Another option is to use a resin product that's designed to be thin and penetrating. Z-Poxy, for example.

[Michael A. Tyree]

I'd do the above used ATF solution. Log concentration yards trim logs and the guys working there take them home for firewood. I've got a few and made bowl blanks. Point is it's not like a tough thing to replace, so use it as is or find another one? I use used crankcase oil or ATF on my white oak floored utility trailer when I catch a dry spell and think about it.
Using a steel log dog to keep the crack closed is not worth the trouble unless your into esthetics under yer anvil?