Triangle joint expansion split fix?

[Ramiro F]

Dear All,

While living in the UK, I made this jewellery box for A-Level DT (see photos). It stayed there for a couple of months to be graded, and was transported back marked fragile, wrapped in bubble wrap etc.

Upon arrival, there were no signs of cracking or splitting on the lid. About a month into the Spanish summer, the split seen in the photos was observed (approx 1mm in width).

I suggested applying PVC again, making some wooden sockets and using a vice to see if the crack could be closed under pressure (this would be trialled under low pressure beforehand, to check if the crack was actually able to be closed), or flipping the box and placing it into a bed of rice. Dad suggested just using caulk or placing a small bowl of hot water under the lid, to see if the wood could be coaxed to shift back into place with the steam.

The lid is made out of Black American Walnut, and has a triple coat of all-purpose waterproof wax. It was joined with PVC and an adjustable band clamp with steel tape, applied overnight. The skirting is made out of Canadian Maple. The drawers and other moving parts of the box haven't become stuck or tighter.

I'd very much appreciate any suggestions you may have to fix this (apologies for the bad image quality).

Ramiro

 

[dzj]

I suspect, the lid conformed to a lower atmospheric moisture content and shrunk.
This in turn resulted in the miters opening up in the middle of the lid.
It is a common occurrence when wide elements are joined in such a way.
In your case, the only long term solution would be to make a new lid with ABW veneer.
Not a quick fix, though.

 

[custard]

While living in the UK, I made this jewellery box for A-Level DT .

There's some excellent craftsmanship on that box Ramiro, I hope you passed with a very high grade because you certainly deserve to!

=D>

Regarding your box lid. Unfortunately solid timber mitred in this way often shows this problem, it's very common for example to see exactly these same gaps opening up on the mitred corners of picture frames, and the thicker the frame the worse the problem.

The thing to do now is precisely nothing! Just leave it for another year, seeing if it moves any more during a full 12 months in its new home. If it closes up and then re-opens that's one thing. But if it stays relatively stable that's something else entirely different.

If it continues to move with the seasons there's really very little you can do except replace the lid with a veneered version.

If it stays stable then you could take it apart, plane it flat, and try again. If you can't reduce the size of the lid by planing then you could insert a thin fillet piece in the shape of a cross, possibly in a contrasting timber, to add to the dimensions.

Unfortunately I think this is most likely to be a re-occuring problem, but you never know, you might get lucky and be able to effect a reasonable repair. The real lesson though is that big mitres in solid timber are always going to be high risk.