Veneering question

[peter-harrison]

Has anyone tried veneering a shape that's curved in two planes? I am looking at a job which has an element that's basically a huge oak picture frame, 3.1m x2.1m The complication is , 1st that it's a very large section- 290mm x 50mm, with a 400mm radius cove moulding, 2nd that they want the corners radiused too, and 3rd that they want all the grain parallel to the floor.
I like a challenge, but this is crazy to do in solid especially as the design is very crisp and exact, not at all rustic, and the expansion or shrinkage of solid timber 2.1m wide is quite large!
I can work out how to mould and veneer the straight sections (tilting spindle and bag press) and I can make the corner pieces with a mixture of machine and hand work from MDF, but what then? Is it even possible??

 

[HOJ]

Anything is possible! as I used to say "the impossible I can do at once, but miracles take me a little longer"

PDF attachment just gives me a blank page.

 

[worn thumbs]

I can't see the attachment either.In essence you can veneer a developable shape,which is a shape that has basically been derived from conic sections.For a compound curved shape,for instance an enlarged rugby ball,you can only do it using strips as the periphery at the ends will be a different dimension to the distance around the more bulbous parts.This means cutting each segment to fit the gaps.Takes time but can be done.

 

[HOJ]

it's a very large section- 290mm x 50mm, with a 400mm radius cove moulding

Just checking?

 

[peter-harrison]

Just checking?

Yep

 

[peter-harrison]

Just added a GIF which should give an idea

 

[niall Y]

Looks like a job for -Vinyl Wrap - Or is that just a little too "naff"?

 

[StevieB2]

Do it in two pieces, 45 degree angle from the corner down. So the top piece and the side piece are separate. Even if you were able to do this in a single piece by 'forcing' the veneer into shape through a vacuum or cauls, because of the curve your grain is not going to run true

 

[peter-harrison]

Yes, that's what I was thinking.
I think the problem is Sketchup Syndrome- the easy drawing of cool looking stuff that's very hard to make!
I have said I can't do it in its present form. I know I could make something OK, but I'm not sure I could make it look sharp and crisp.

 

[peter-harrison]

Looks like a job for -Vinyl Wrap - Or is that just a little too "naff"?

If only!

 

[Cozzer]

To save money (which I didn't have!) I veneered my MG Midget's dashboard - including a marquetried octagon - many years ago. (Crikey...nearly 40 years!)
It seemed such a good idea at the start, working off paper templates in order to get grain directions correct for those pieces that had to be cut, as bending/shaping walnut veneer wasn't easy in the confines of the car.




I went quite mad....

 

[niall Y]

I've been trying to wrack my brain to try and remember where I saw a a complete description of how to veneer a Bombe Chest. It could have been in Charles Hayward's "Practical Veneering" This might well offer a few pointers as to how the job could be tackled.

From what I remember it seemed to be more a tailoring technique, where excess material is cut away, so as to follow the contours , with lots of pointy triangular fingers of veneer coming together to to overcome the ups and downs of the surface.

Failing this approach, could there be a case for combining solid wood. with board and veneer? As long as you are able to match the grain you could loose the joins. And the solid wood might be easier to form into some of the trickier shapes.

 

[peter-harrison]

I've been trying to wrack my brain to try and remember where I saw a a complete description of how to veneer a Bombe Chest. It could have been in Charles Hayward's "Practical Veneering" This might well offer a few pointers as to how the job could be tackled.

From what I remember it seemed to be more a tailoring technique, where excess material is cut away, so as to follow the contours , with lots of pointy triangular fingers of veneer coming together to to overcome the ups and downs of the surface.

Failing this approach, could there be a case for combining solid wood. with board and veneer? As long as you are able to match the grain you could loose the joins. And the solid wood might be easier to form into some of the trickier shapes.

I’ve been thinking along the same lines. Going to wait and see if the client sticks to his guns or if he suggests some changes.

 

[Vintage Frames]

I'm a picture frame maker and have had several years' experience of making veneered frames.
Can I ask what is the wood species you wish to veneer and is the base profile oak? And when you say to have the wood grain run parallel to the floor, do you mean running parallel on the side pieces as well?
Finally, the two long lengths are just over 3.1m. Where will you get a vac. bag to fit those into?

 

[peter-harrison]

I'm a picture frame maker and have had several years' experience of making veneered frames.
Can I ask what is the wood species you wish to veneer and is the base profile oak? And when you say to have the wood grain run parallel to the floor, do you mean running parallel on the side pieces as well?
Finally, the two long lengths are just over 3.1m. Where will you get a vac. bag to fit those into?

Hi, it's white oak as it has to match some veneered MDF. The way they have drawn it, all the grain runs parallel to the floor, so top and bottom are long grain and the uprights are cross grain. I was thinking of making the ground from MDF.
I can get a very long bag from Bagpress- they will cut it to order.

 

[Vintage Frames]

Well, in that case, if we think of the frame in landscape format, then make the corner blocks separately first. Join the blocks to the longs at either end. Veneer those sections with the oak.
Then veneer the shorts with the oak laid cross grain. Because the veneer will be cross grain, you will be able to disguise the joins both on the lengths and where the shorts are joined to the top and bottom corner blocks.

You will have a challenge preventing the veneer creasing at the corners. Maybe some sort of feathering cuts there might help.

 

[worn thumbs]

It comes as a surprise to some woodworkers that you can use the same sort of vacuum bag that is quite normal in composite work and they don't cost much since they are disposable.I have used damp proof membrane myself with great success.All you need is the pump and a tube,plus some release film and breather cloth,I have used discarded towels and cling film at times when there was no time to do the shopping.I wouldn't rush into bagging the piece in question without doing a small sample piece of the awkward area to begin with.It will take some careful tailoring to work with those compound curves and a boldly figured piece of veneer might look wrong with a few darts cut into it.

 

[peter-harrison]

It comes as a surprise to some woodworkers that you can use the same sort of vacuum bag that is quite normal in composite work and they don't cost much since they are disposable.I have used damp proof membrane myself with great success.All you need is the pump and a tube,plus some release film and breather cloth,I have used discarded towels and cling film at times when there was no time to do the shopping.I wouldn't rush into bagging the piece in question without doing a small sample piece of the awkward area to begin with.It will take some careful tailoring to work with those compound curves and a boldly figured piece of veneer might look wrong with a few darts cut into it.

(And vintage Frames) yes- that’s my dilemma. I know I could veneer it but can I make it look effortless?
There’s a lot of other stuff going into this project- glass, stone, leather and fabric, lots of steel and gadgets. The nightmare would be if it all came together at a cost of several 10s of thousands, and those bloody corners look like they were made in a shed!

 

[Inspector]

I would be tempted to make the horizontals of solid wood and carve the end corners into them with the intention of not using a mitre joint in the corner. Then the verticals with their crossgrain veneer would be relatively easy. The crossgrain verticals being butt joined to the horizontal pieces with biscuits, Dominos or simple half laps. If the veneer was sawn from the same oak the colour and figure could be matched better. On a frame that wide quarter sawn would look the best I think. Back of the veneered verticals will need to be veneered too. A smaller frame I would make entirely of solid but because of the size of this one there would be too much crossgrain movement.

Pete

 

[profchris]

I think that however you cut the veneer for those corners, you'll have visible lines where the pieces meet because the grain lines can't all run horizontal and meet up at the join(s). Your grain will be angled somewhere.

Is an option to paint the corners and paint on grain lines, matching the veneer? That might even be easier. Instrument repairers use this to hide patches quite successfully, though colour matching takes some trial and error (especially as everything changes under finish).