Advice restoring antique top (of small set of drawers)

[Col]

Hi All,
I want to restore an antique top which has cracked along an old joint line (breaking the veneer on top). The crack is close to 3mm wide.

I have managed to remove the top, but the screws holding the front cracked piece to a frame are rusted solid.

I feel that the gap is too big to fill so looking for some advice on the best way to take this apart so I can reglue the joint.

Also, would appreciate thoughts on how best to finish the joint afterwards to try to match the rest of the top. I'll try to realign the jagged edges of the veneer but i'm sure that there will be small gaps to fill.

Thanks, Colin

 

[YoungSalt]

Hi Colin, have you tried all the tricks for undoing the screws? Sharp tap on the end of the screwdriver? Long screwdriver allowing weight and leverage? Tried tightening the screw then undoing to free them? If those all fail, a screwdriver bit in a brace allows a lot of leverage on the screw. If all that fails, you may have to drill the screws out very carefully - small bit to pilot first of all, then work your way up to slightly undersized. Once you are able to remove and ***** how well the top can be put back together, then perhaps is the time to look at the extent of the visibility of damage and look at the options of how to repair it to the best cosmetic result? Good Luck Ed

 

[Col]

Ed - thanks for the suggestions - I'll try the different tactics on the screws, but i think they're just going to break so will have to fall back to drilling them out ... Colin

Hi Colin, have you tried all the tricks for undoing the screws? Sharp tap on the end of the screwdriver? Long screwdriver allowing weight and leverage? Tried tightening the screw then undoing to free them? If those all fail, a screwdriver bit in a brace allows a lot of leverage on the screw. If all that fails, you may have to drill the screws out very carefully - small bit to pilot first of all, then work your way up to slightly undersized. Once you are able to remove and ***** how well the top can be put back together, then perhaps is the time to look at the extent of the visibility of damage and look at the options of how to repair it to the best cosmetic result? Good Luck Ed

 

[MusicMan]

Before you repair it, can you see why it cracked? It does look like shrinkage, in which case you will need to remount the back piece to take up the shrinkage and preferably allow some more movement. If you do this you may be able to glue the piece together without removing the rusty screws (and then fix the back part down allowing movement - e.g. an oversize hole).

 

[Matt@]

re. the above post, if the rear part of the top is glued to the frame, it will probably be scotch glue, if so get some meths and a syringe with needle and agitate meths between the top and frame in conjunction with a thin metal palette knife to prise the two components apart. Tedious and longwinded but your get there in the end ( an hour or so work)

If drilling the screws out just drill out the CSK head by going gradually from pilot drill size to a drill same diameter of screw head then pull the wooden top away leaving the remains of the screws which you may be able to wiggle (backwards and forwards slightly) free using mole grips - to aid that, drill ultra fine holes down sides of screw shaft and inject with meths to loosen the screw up.

 

[Col]

MusicMan - it is a shrinkage crack and I think I can understand why. The top is constructed of two layers (well three if you count the veneer on the top surface. The upper layer is a laminate of two pieces with the grain running across the unit (it is the small front piece of this that has cracked along the joint (presumably it was easier to make the curved front piece separate from the rest). The lower layer is a frame (with a 3/8inch thick 'veneer' band around it. On the sides of the frame the grain runs along the length of the unit. Given where the screw fixings were between these two layers (probably added as part of earlier repairs?) differential shrinkage between the perpendicular grains caused the crack.
Given the upper layer has a shaped overhang all round the lower layer (except the back edge) I can get away with just reglueing the joint (reducing the overhang at the front edge). Because the back edge of the two layers is flush, the back edge needs to be securely fixed but I will look at oversize holes for the remaining screws so the the upper layer will have some float on the lower frame and not crack again.

Thanks - Colin

Before you repair it, can you see why it cracked? It does look like shrinkage, in which case you will need to remount the back piece to take up the shrinkage and preferably allow some more movement. If you do this you may be able to glue the piece together without removing the rusty screws (and then fix the back part down allowing movement - e.g. an oversize hole).

 

[Col]

Matt - fortunately the movement of the small piece at the front had already broken the glue between this piece of the top and it's frame. The centre screw broke not just leaving the threaded part in the frame, and I was able to get a thin hacksaw blade to cut the screws on each side - so the broken piece has now been removed. Now just need to removed the threads from the frame - nothing to grip so I'll try the fine drill holes around the screw as you suggest ...

Thanks, Colin

re. the above post, if the rear part of the top is glued to the frame, it will probably be scotch glue, if so get some meths and a syringe with needle and agitate meths between the top and frame in conjunction with a thin metal palette knife to prise the two components apart. Tedious and longwinded but your get there in the end ( an hour or so work)

If drilling the screws out just drill out the CSK head by going gradually from pilot drill size to a drill same diameter of screw head then pull the wooden top away leaving the remains of the screws which you may be able to wiggle (backwards and forwards slightly) free using mole grips - to aid that, drill ultra fine holes down sides of screw shaft and inject with meths to loosen the screw up.

 

[MusicMan]

A plug cutter works well. Better would be a tube just over the diameter of the screw head, with saw teeth ground in on end. I think you can buy these but I can't remember the name! anyone? Not hard to make. Then fill the hole with a plug.

Keith

 

[Col]

Keith - good idea - I do have a plug cutter - but have managed to remove them now. Once cut between the frame and the top, the head part of the screw just fell out (not threaded) and the rest is in a non-visible area and with a combination of drilling fine holes around them and a bit of brute force I was either able to remove the screw completely or break if off below the surface so it won't interfere with the reassembly ... Colin

A plug cutter works well. Better would be a tube just over the diameter of the screw head, with saw teeth ground in on end. I think you can buy these but I can't remember the name! anyone? Not hard to make. Then fill the hole with a plug.

Keith

 

[Col]

I've now managed to glue (and dowel) the end of the top back now need some advice on finishing so will move over to the finishing forum. Already looking better.

 

[MusicMan]

well done, looks good. Is it mahogany?

 

[Col]

under the veneer is a actually a hardwood that looks like mahogany - not sure about the veneer - there's a close-up in the finishing forum here: post1128625.html#p1128625

well done, looks good. Is it mahogany?