Advice please re cupped box side

**homey** · 24th June 2020, 06:22 PM

One of my Men’s Shed friends has “volunteered me” to so some light unpaid restoration to an old writing slope. Most of it is simple - new key for the lock, new hinges, a few veneer repairs, cut a new mother of pearl escutcheon etc.

The box, veneer over cedar, is probably mid-1800’s. It was never a class act to start with and it’s had a hard life but there is sentimental attachment for the owner.

One thing concerns me. The left side of the box (veneer over cedar) has cupped outwards at the front. I suspect this may be because only the outside of the box was veneered, but anyway...

029D29E3-6A9C-4F37-A753-9F73C280D2E9.jpeg

722ED907-F4CA-45BB-BEC0-F9FA55F6E852.jpeg

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The offending corners can be brought together by clamping, but it does require quite some pressure. I’m concerned that glue alone will not be strong enough to hold this.

Does anyone have any suggestions how this might be fixed? I can’t put mitre keys/slipfeathers in from the outside as the box is veneered.

Some things I’ve considered:

1. Cutting a channel on the inside of the box side and front and gluing a plywood L-shaped key inside the channel- effectively a mitre key from the inside.

2. Is it possible to reduce the cupping by, say, heating the inside of the wall?

3. Making a triangular bracing piece to glue into the corner.

Option 3 is my least preferred option as it would be an obvious repair.

Inside of the box can be finished with period-design Lokta paper or similar so surgery to the walls is not a problem.

Any advice would be very gratefully received!

Thanks,

Brian

**Fumbler** · 25th June 2020, 06:07 AM

Brian, I would put slip feathers all around, make it a new feature to the old piece. short of you undoing the entire thing and doing an internal spline. or your No.2 suggestion with a few tacks from a pin nailer.

**homey** · 25th June 2020, 10:46 AM

Thanks, Richard.

Good suggestion, but I’m a bit soft about visible changes to old things. If a visible repair/change is essential I’ll pass it back to the owner for someone else to handle.

Regards,

Brian

**botesmj1** · 25th June 2020, 11:10 AM

Hi Brian.

Seems like heating it is a thing as per the below.

YouTube

Alternatively how about some poxy glue and a strong clamp? Surely that should hold? To get some face grain in there I assume you can drill in from the top on the mitre, once clamped and glue a dowel into the hole.

**homey** · 25th June 2020, 11:35 PM

Hi Jacques,

Thanks for that. Great suggestion with the dowel.

I’ll try heating the convex (inside) surface with a heat gun first just to see if that has any effect. If that doesn’t work I’m tempted to see if veneering the inside surface brings the piece back into shape, i.e. countering the pressure from the veneer on the other surface. I can’t iron the concave side as it’s french polished

Epoxy looks the go, thickened a little to fill any gaps.

My original thought was to cut a 20mm long, 6mm wide, 3mm deep channel inside the front and side surface to put in an L-shaped internal spline:

C7FCEBC0-BD29-45A8-B345-920679B4DEDE.jpg

These are made from 5-ply hardwood:

4DD2B849-0E7A-448F-A44F-3332FF62CB45.jpeg

It gets rebated in to each piece so it sits flush with the inner suface and will not show once the box is lined:

3666F769-C9CA-4816-B0C0-E885AACD2DF1.jpeg

However - now you’ve got me thinking about the dowel....

Thanks, guys. I think I’ve got enough now to tinker with this for a while. Will report back.

Regards,

Brian

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