How do I take out the bow in a cabinet front?

[Martin King 2Participant @martinking2]

Hi all,

We have a very nice small oak watchmakers tool cabinet with a couple of issues to sort out.

It has a front flap that is hinged at the bottom with a small lock at the top.

I am making some small bun feet to raise it up a bit as the flap fouls the base when opened.

The main problem is that the flap has a vertical bow in it and does not shut flat against the case, also giving a problem with locking.

I am wondering how I might go about removing this bow without damaging the flap? Maybe steam and addition of pressure? We have several book presses that can apply pressure but is this the best way?

Any advice will be most welcome.

Cheers, Martin

[Dave HalfordParticipant @davehalford22513]

Is the inside still varnished?

Has it been kept in a damp place?

In other words the inside may be drier than the outside so it bends. If not weight and heat will take out a bow. You will have to take it a bit past flat so go in slow steps. If the grain has a curve in it there may have always been a bit of a bow.

[JasonBModerator @jasonb]

What Dave says the outside may have been more subject to any recent change in temp/humidity so first thing I would do is leave it open for a few weeks to see if it flattens back down by itself.

If that fails pack out the top slightly and apply weight or clamp pressure to the middle to take it to a concave and leave for a while then when pressure is removed it may spring back to flat

[bernard towersParticipant @bernardtowers37738]

I agree with Jason and Dave with the add on of removing the tongue, straightening then fitting a new tongue which has been cut on the curve to assist in keeping it straight.

[Graham MeekParticipant @grahammeek88282]

From what I can see from the photograph the front is made up of individual board?

If this is the case then the tongue is there to stop these boards parting. If I am right then the tongue is the item causing the problem. Removing it and replacing it with some new material should cure the problem.

Regards

Gray,

[JasonBModerator @jasonb]

I’d tend to call it a spline rather than a toungue and it is unlikely to be of sufficient cross section to be holding the front boards flat or causing the bow. It would need a substantial “breadboard” edge to have enough stiffness to resist the cupping of the front

[DalboyParticipant @dalboy]

Not being able to see all the end grain properly which would give a better understanding of the construction, for example if each board is orientated in such a way that the end grain is running in the same direction on every board then cupping is going to happen. Each board should have the end grain alternating to counteract the problem, but to sort that out would mean taking the panel apart and starting again.

Looking at one board it seams as if that one at least should not cause a problem as it looks to be quarter sawn.

[Martin King 2Participant @martinking2]

Hi all,

thanks for the feedback.

the front appears to be 3 pieces all quarter sawn; inside looks like it only has one thin coat of finish, much more matte than the front.

the tongue (spline) is very thin indeed, whole part is under 1/2” thick.

i may take it off and apply VERY gentle reverse pressure for some time to see if it helps?

cheers, Martin

[SillyOldDufferModerator @sillyoldduffer]

I get to watch Repair Shop with mum, and they tackled a similar problem by adding wood to straighten the bow, making the item rather thicker than before.  Reason: too difficult to straighten with steam or pressure because the result is unstable – the bow is likely to reappear.

New wood applied as shown below in Blue.

 

As usual with Repair Shop, the important details of how the new wood was fitted and shaped were skipped over!   I guess the curve was measured, and one side of a thickish slab was chiselled out and smoothed to match.   Then glued to the bowed original, so the outer side could be planed and sanded down to kiss the bow.

Another problem with programmes like Repair Shop is they have no problem sourcing materials and parts.   When they need a plank of antique oak, or a prism to fit a pair of WW1 Czech binoculars, it miraculously appears.  No doubt a big budget, a team of researchers, and having access to industrial suppliers helps.

Watched consistently, Repair Shop is interesting.   Later editions are more likely to reveal ‘tricks of the trade’ than earlier ones.   The repair work varies from excellent to bodge.  But the workers are certainly effective, restoring wreckage I wouldn’t attempt.  God knows how much it costs!  For fun, there’s a kind of running joke in that Jay Blades dresses up in a posh work-jerkin, but never does any.   Although he’s a professional furniture restorer, on this programme he’s a TV Presenter who never breaks a sweat!  Get’s teased for this occasionally by the real grafters, and it’s amusing to count how often a poke gets broadcast.

Dave

 

 

 

 

[Dave HalfordParticipant @davehalford22513]

You could try covering the inside face with a dampened cloth and leave 1/2 a day and see if it straightens. If it raises the grain the finish may be porous. Sand lightly to remove raised grain and varnish with 2 coats of a water based product.

It it doesn’t stay put it won’t make anything worse.

[SillyOldDuffer]

On SillyOldDuffer Said:

As usual with Repair Shop, the important details of how the new wood was fitted and shaped were skipped over!   I guess the curve was measured, and one side of a thickish slab was chiselled out and smoothed to match.   Then glued to the bowed original, so the outer side could be planed and sanded down to kiss the bow.

 

Another problem with programmes like Repair Shop is they have no problem sourcing materials and parts.   When they need a plank of antique oak, or a prism to fit a pair of WW1 Czech binoculars, it miraculously appears.  No doubt a big budget, a team of researchers, and having access to industrial suppliers helps.

Watched consistently, Repair Shop is interesting.

 

 

 

Repair Shop wouldn’t be interesting if they showed in detail how all the bits were repaired! It’s done by careful removal of stock using appropriate tools, and repeated test fitting. That’s not easily filmable and is boring as hell to watch, especially if you know how to do it. Anyone who doesn’t know how to do it will only watch it once. Consider how often you re-watch basic training videos for new beginners….

 

The explanation for RS’s apparent lack of problems(you’re not shown how long this takes) sourcing stuff is simple: professional expertise. Again, nobody is going to watch 37 emails and hours of phone calls and ebay searching to track down one part.

[Gary WoodingParticipant @garywooding25363]

The guy in this YouTube video is a genuine expert in woodwork and forging in his job of renovating old horse-drawn wagons. He shows a novel way of removing a warp in an old piece of timber, starting at about13:00. The first 13mins are also interesting, but not really relevant to your needs.https://www.youtube.com/watch?v=bTD2oG4mLhM

[Author]

Posts