Help!

[RusticClay]

I’ve just made a Murphy Drop Down Bar but the wood slats comprising the table have separated (shrunk)!
How can I stop this happening? I realise the wood will contract and expand but how can I combat this problem? I glued the wood together but as you can see by the photos it’s separated quite a bit?

 

[Adam W.]

It's dried out and as you have flat sawn boards it'll cup too.

There's not much you can do about it except have a drink, a shrug and enjoy your bar.

 

[RusticClay]

It's dried out and as you have flat sawn boards it'll cup too.

There's not much you can do about it except have a drink, a shrug and enjoy your bar.

I intend to make one for a friend, what can I do different next time?

 

[Adam W.]

It depends on if you want Chippendale or Wild West.

It's a serious question though, because Chippendale is a long answer and Wild West is short.

What's your original idea for the finish ?

 

[Fitzroy]

What wood did you use? Not the species but the type. Kilndried or construction timber? The glue looks like it’s still wet, was the wood wet or was the glue gap so large the glue was trying to bridge the gap?

Once I’ve glued up a panel (set of boards edge jointed) the panel tends to move as a single piece. If I really retain it strongly then it can split. However yours seems loosely retained, the three hinges are pretty lightweight, so it mainly suggests a poor glue joint.

Lots of assumptions obviously from a single photo! Acclimatise the dry wood to the space, get a tight glue join with not too much glue, lots of clamping and do not remove clamps too early,design a system that can accommodate any movement that does occur.

fitz.

 

[Spectric]

Fitz has made a good point, that glue looks like it is still wet. To edge join panels there is a good thread on here somewhere and once clamped and the glue has set then the joint should not open up like that although the boards may cup. Decent kiln dried wood really helps.

 

[Adam W.]

It looks like the bar is outdoors and the sun bakes it.

 

[RusticClay]

It depends on if you want Chippendale or Wild West.

It's a serious question though, because Chippendale is a long answer and Wild West is short.

What's your original idea for the finish ?

Just a Rustic look

 

[RusticClay]

What wood did you use? Not the species but the type. Kilndried or construction timber? The glue looks like it’s still wet, was the wood wet or was the glue gap so large the glue was trying to bridge the gap?

Once I’ve glued up a panel (set of boards edge jointed) the panel tends to move as a single piece. If I really retain it strongly then it can split. However yours seems loosely retained, the three hinges are pretty lightweight, so it mainly suggests a poor glue joint.

Lots of assumptions obviously from a single photo! Acclimatise the dry wood to the space, get a tight glue join with not too much glue, lots of clamping and do not remove clamps too early,design a system that can accommodate any movement that does occur.

fitz.

I just used Gravel Board and It was glued over a week ago! I don’t think the wood was still wet (I let it climatise for a few days)

 

[Jameshow]

I think you should allow your timber to acclimatise to the final location and glue up on a dry day. That way when you use it- dry days the timber be tight.

But because you have a stretcher across the grain if it gets really wet and expands greatly the stretcher will hold the planks apart still.

Cheers James

 

[Deadeye]

I’ve just made a Murphy Drop Down Bar but the wood slats comprising the table have separated (shrunk)!
How can I stop this happening? I realise the wood will contract and expand but how can I combat this problem? I glued the wood together but as you can see by the photos it’s separated quite a bit?

Setting aside your truly terrible taste in drinks , it looks like you've used treated construction timber and resawn it?

That would make it pretty wet on the outside in particular.

You'd need to dry it thoroughly indoors, then resaw and plane.

 

[Adam W.]

@RusticClay

Is it hanging in the sun ?

 

[RusticClay]

@RusticClay

Is it hanging in the sun ?

No, when the sun is out it’s in the shade

 

[mikej460]

The simplest way to avoid cupping is first to dry out and acclimatise the wood as above then edge join making sure the ring segments on each end alternate i.e. one convex then the next concave. You do have your work cut out trying to edge join gravel board though, silk purse out of a sow's ear and all that. A better, slightly dearer option would be acclimatised T&G flooring or cladding if you can get to a reclaim yard you might be able to pick up some pieces fairly cheaply but make sure it has been stored undercover.

 

[RusticClay]

The simplest way to avoid cupping is first to dry out and acclimatise the wood as above then edge join making sure the ring segments on each end alternate i.e. one convex then the next concave. You do have your work cut out trying to edge join gravel board though, silk purse out of a sow's ear and all that. A better, slightly dearer option would be acclimatised T&G flooring or cladding if you can get to a reclaim yard you might be able to pick up some pieces fairly cheaply but make sure it has been stored undercover.

Would it stay together if I made it from decking timber?

 

[mikej460]

It would be much better than gravel board and doesn't cup badly, but it still shrinks so you do need to dry it out. Have you considered a loose fit and make a feature of the gaps?

 

[RusticClay]

Yes, next time I will leave a 3 or 4mm gap

 

[Kittyhawk]

I has a similar problem on my workbench where I thought the two 6" x 2"s were dry but obviously not dry enough. A real pain when you can't find that 5mm twist bit you know you left on the bench..
My solution was to wait until I was sure the timber was dry and then clamp a plank on the bench as a guide and zoom along the gap with a router and then glue in a fillet. Don't rout all the way through as you need a little lip for the fillet to bottom out on. For RusticClay's project he could perhaps use a contrasting timber and it would look quite smart.

 

[Jacob]

I intend to make one for a friend, what can I do different next time?

Either, don't glue them then the gaps would just be a feature as mikej460 suggests or do a proper table top job and attach the top with buttons to allow for movement.

 

[AES]

I'm definitely NOT into "proper woodworking" so cannot speak from experience, but member @custard definitely IS - he's one of several professional wood workers resident as members here.

I strongly recommend that you read his sticky on edge joining boards. Here's the link (it's at the top of this section):

How To Edge Joint | UKworkshop.co.uk

Good luck & HTH