Best filler for wood cracks in Live Edge piece

[JonoA]

Hello,

First post here, hoping to get some help if possible.

I've managed to get my hands on a great piece of lumber (Sycamore) and was looking to turn it into a coffee table of some sort. Cost me £10 off Gumtree!

The size is about 90cm x 120cm and is about 5cm thick.

The issue I have is that I'm wondering how best to go about filling the cracks in the wood. There are a few that span the whole depth of the wood and at the largest point are about 12mm wide. Some of the smaller ones are just a couple mm deep.

I'm wondering if an epoxy or wood filler would be best? Also, there are that many to choose from would people be able to point me in the right direction as which brand or even type to choose as I'm still learning my trade, as it were.

Also, what's people's thoughts on keeping/removing the bark? I've read that they can be dust magnets and really hard to maintain with chipping quite common. But, I do like how it looks on there.

Thanks in advance!

Jono

 

[Random Orbital Bob]

Hi Jonoa and welcome to the forum

I rather fear your coffee table project may be a little doomed before it's even begun! That is unless you're happy to continue filling new cracks that will be opening for about the next 3 years on the piece.

The problem is that what you've bought is a slice off the end of the tree ie it's an end grain disc. Wood when processed in this manner will dry very rapidly but differentially from the pith outward. Those stresses will cause huge cracking, typically in a radial pattern starting at the pith or outside running toward the pith.

What you could do I guess is make a solution where the legs aren't fixed and you could quite literally refill the opening cracks once every 6 months or so until it stabilises (at which point you could fix the legs). The rule of thumb on air drying timber is 1 year per inch of thickness plus a year!!!

It's going to be a bit of a bellyache I'm afraid. Normal practice when milling wood when its going to be used in a project is to cut slices (boards) along the grain of the tree rather than across it as you have there.

Don't mean to be a pessimist on your first post but this is a very common mistake for folk getting into the art first time....I'd stick another stump under it to support and watch what it does over a year or so. See how you feel after some time.

I must say I had a wry smile at the idea that paying a tenner for that was a bargain Lets position that as a training course eh

 

[SkinnyB]

I think the cracks give it character and as stated above it will continue to dry and possible split some more. I would be inclined to make the coffee table and keep the cracks as part of the design and then maybe in a couple of years once it has stabilised you could decide to fill them then if you wanted to.

Edit:

Or try your hand at butterfly/bowties.

 

[Sheffield Tony]

If you do use it, a design where the top is not a structural component would be a good idea. So legs and rails for the structure, and the top fixed on in such a way as to allow it to move - buttons, slotted screw holes or such. The 1 year per 1" is normally the rule, but when cut crossgrain like this it should dry much faster. I'd make sure it has done most of it's moving and drying in a similar environment to where you'll put your coffee table before you spend effort planing filling or sanding.

It will still keep moving to an extent with the seasons. Butterfly keys might just make it crack somewhere else !

 

[JonoA]

First off, thanks for all the feedback, much appreciated. It does appear that my bargain certainly is not.... too good to be true maybe.

But, for a tenner I may as well go ahead and work on it as I still think it will be good practice. Plus, if it all goes wrong then nothing lost really and can chalk it down to a bit of experience.

I think what I'm going to do is leave it for at least a few months to dry out. The person I had got it from said it's been sat in their garage for about a year, so I'm hoping that has helped somewhat. We have a big dresser in our dining room that it can go behind actually, so means if will be in the house and the same temp as where it will sit.

So, with regard to not using the top as a structural component.... My original idea had been to simply put it on some hairpin legs. Alternatively, I could me a friend to weld some legs for me, potentially just a rectangular bar frame, so I'm assuming the latter is what you are suggesting then just having one fixing hole for it, is that right or have I missed it?

Back to original point of the filler... If I decide to leave it as is, will those existing cracks develop or will it be a case of new cracks forming? When looking at filler for them, what would be best to use?

As I said, thanks so much for all the help so far, just shows how much I've got to learn.

 

[Sheffield Tony]

So, with regard to not using the top as a structural component.... My original idea had been to simply put it on some hairpin legs. Alternatively, I could me a friend to weld some legs for me, potentially just a rectangular bar frame, so I'm assuming the latter is what you are suggesting then just having one fixing hole for it, is that right or have I missed it?

I was thinking of wooden legs and rails, but the principle is the same, you want to let the top move a bit. So not necessarily just one screw, but to a metal frame I might use say 4 screws through oversized clearance holes in the frame, with a repair washer, so the top has a little scope to move around, rather than cracking.

I suggested not just fixing legs into the top on the assumption that the cracking might weaken it too much to be a structural component. I think only time will tell how mich more cracking you'll get. If you do as you suggested and bring it indoors, you'll find out before expending much effort on it, and at least you will have well dried firewood if it all goes horribly wrong

 

[disco_monkey79]

I've used some waney edged sycamore for shelves. I left the bark on, as I like that look, and have noticed that bits have dropped off over time, without being touched/knocked etc.

Not trying to influence you either way with yur project, just wanted to let you know that sycamore bark is not very hard-wearing.

Good luck, and kep us posted with it!

 

[Droogs]

In answer to your original question, I would suggest using one of the epoxy based fillers. Depending on the effect you want you can add colourants from coffee granuals to metal powders or leave it clear. But best wait until you think the movement has finished

 

[rafezetter]

For the metal frame you might consider a simple X shape with legs at each tip rather than a more conventional square, it would be just as stable but allow you to just fix it in the centre for now (no wood movement at that point) so it doesn't fall off, once it's dried a year or two, you could add fixing points along each support section of the X but allow the holes in the frame to be elongated - small slots if you will, to allow the wood to move with the season changes. I'd recommend just 1 extra fixing per horizontal bar or you'll restrain the wood too much.

For the cracks I'd personally use clear epoxy + a colorant of some type as Droogs said, lots of ideas on google for you to consider. Metal powders look especially effective and can be polished to a high metallic shine.

 

[rhrwilliams]

I made a kitchen worktop and table out of large slabs of elm.

I was worried it would warp, move about, cracks open up etc etc.

I used Epoxy Resin and its fine. Not moved at all. You need to make some shuttering out of 2" x 1" to keep the resin in cracks.

Here is a pic of finished stuff. http://bridge-hall.blogspot.co.uk/2016/06/kitchen.html

 

[Random Orbital Bob]

Folks would do well to read all the posts???

Your table is a board, running with the grain, it's completely different from the OP's Sycamore and will be infinitely more stable. Just because it has waney edges on each of the sides doesn't mean it's the same thing. The OP's is an end grain disc cut off the end of the tree, tree surgeon chopping firewood style. Woodyards milling wood for commercial use bandsaw the tree longitudinally down it's length creating boards. If those boards are the entire width of the trunk then they will of course have a waney edge on 2 sides. The OP's has bark in an entire circle round the disc....because its cut off the end grain. This is inherently unstable because of the differential drying rates between the pith an the edge. The water loss occurs at different rates and those stresses cause the cracking...major....massive....irreversible cracking. It will have split far beyond the pictures of your Elm Kitchen table I'm afraid. It's important people understand the difference between the grain orientations of wood as it has a critical influence on how the material is worked if it's to be a success.

It is a beautiful bit of Elm though isn't it.

 

[rhrwilliams]

Well I stand corrected / slapped wristed then.

I have a circular piece of oak in my workshop that is similar to to the OP's which is about 15 years old, although it is cracked in a similar fashion it has not opened up or got worse. Im keeping it as I planning do a similar project. I cannot see its going to move much more than it has already.

That said though.... point taken . If the OP's wood is green its going to be a long while before its dry enough to do anything with and will crack until it is fully dried out.

 

[Random Orbital Bob]

No probs......if your oak has been in the dry for that long it will have stabilised and will therefore be usable as long is ends up in an environment where the relative humidity is similar to where it's been stored. But given it's age, it's almost certainly done the majority of it's wandering

 

[JonoA]

Sorry about the late response and thanks to all that have contributed, some important lessons have been learnt.

In terms of moisture, It's ranging from about 5-9% in places, but has been outside drying over the last week or so whilst the weather has been dry and already seen it drop from about 10-15% in places. Seems an awful lot in a short space of time, so hopefully on the right path.

I'm still going to go ahead and work with it, just for practice more than anything and see what happens with it.

The idea RE the frame rafezetter and Sheffield Tony are both good ideas and this is what I'll likely going to be doing with it when the time comes.

Also, disco_monkey79 point taken RE the bark and I'm just going to remove it from the start, even though it does look pretty cool.

Random Orbital Bob, thanks for giving me the heads up on what I've actually bought. As a novice it's easy to just call wood, wood, if you get me, but I now realise that many different properties make up a good piece of timber. Next time I will be a bit more selective about what I get and a bit of history in terms of when it was cut etc. I've a lot to learn!

I'll post some pics when I get it cleaned up and filled. Also needs levelling out somewhat as well. Just need to find the right exoxy for it now...

I'll also post follow up pics of when it falls apart in a big heap in about a years time

As I said, thanks again for all the help, massively appreciated and highlighting what a great resource this place is!