Minimum thickness of panel for frame and panel door?

[Lord Kitchener]

If I wanted to make some hardwood Shaker style doors, with the panel made of edge joined resawn stock,what would people suggest as a minimum thickness for the panel to get successful edge gluing? I'm thinking maybe 8mm.

 

[Jacob]

Have a look at an old door. You will see that panels on thin doors are nearly always fielded i.e. tapered around the edges so that e.g. a 12mm thick panel can fit into 6mm slots. Usually on the inside so the outer panel is flat. This (12mm etc) also helps the gluing up if you make the panels from more than one piece.

 

[Lord Kitchener]

Have a look at an old door. You will see that panels on thin doors are nearly always fielded i.e. tapered around the edges so that e.g. a 12mm thick panel can fit into 6mm slots. Usually on the inside so the outer panel is flat. This (12mm etc) also helps the gluing up if you make the panels from more than one piece.

Thanks for that. I had considered that solution, but would prefer to keep the panel flat. So at this stage my main concern is the thickness of a flat panel.

 

[Jacob]

8 is a bit thin, depending on size and materials. Say max 250mm wide perhaps? No problem gluing 8 together except bear in mind that you may need to flatten them a bit afterwards with plane or sanding.

 

[woodbloke]

8mm is the thinnest I'd go for, with just a small rebate to locate them into the grooves. This means that you can get away with rails and styles that are 12mm thick, which is fine for a back panel, but too thin for a door...I'd go for between 16 and 18mm here, 18mm means that it's then easy to do a 6mm traditional m/t joint, but anything finer may be a problem unless you can Domino it with say a 5mm dom - Rob

 

[Steve Maskery]

Bear in mind that it will look the same whatever thickness you use (well, unless you want it fielded, but you stated Shaker, so I'm assuming plain, flat). The panel does not add any strength to the door, it merely fill the hole made by the rails and stiles. So 8mm should be plenty. If the panel ends up not quite flat, you have enough thickness to plane down to 6mm, which will comfortably fit a 1/4" groove.
It does, of course, mean that you have to prepare your edge joints carefully and use stock that is not going to do flume impressions as soon as you walk away from the bench.

S

 

[AndyT]

You haven't said how big these doors are!

Are they cupboard doors or room doors? What size are the stiles and rails?

You just need to keep it all in proportion, but the answer could be anywhere between 4mm and 18mm.

And do you want solid wood panels or is veneered ply ok?

 

[Lord Kitchener]

I don't think I've made myself sufficiently clear. The panels are doors for kitchen cupboards, by the way, but that isn't really the issue. The issue is how thin can I make the panels before I run into problems of insufficient gluing surface to resist such forces as may act on the panels, such as shrinkage etc.

Obviously the thicker I make them the greater the gluing surface, but I also have to think in terms of what hardwood stock is available and the thicknesses whereof. If I use american hardwoods 1" stock tends to be 26, maybe 27mm thick. From stock of that thickness I should be able to resaw to get 6mm easily, 8mm maybe, depending on width (resawing inevitably producing some cupping). The easy answer is to go wider and use 1 1/2" stock, but then I might run into colour matching problems with the 1" stock used for the frames etc, and almost certainly the two stocks will come from different trees, maybe even different areas.

 

[Steve Maskery]

You should have no difficulty whatsoever in getting panels from resawn 1" stock.
S

 

[Lord Kitchener]

You should have no difficulty whatsoever in getting panels from resawn 1" stock.
S

I daresay, but that's not exactly what I am asking about.

 

[RobinBHM]

It's likely to be tricky, deeping 1" stock to make 2 flat panels 8mm or so thick. Yes, careful resawing should yield the thickness but deeping almost always results in cupping as most timbers have some tension in them due to the kilning process -partly due to having a slightly lower moisture content at the faces than the centre. If you are able to select some quarter sawn stock then this would minimize any cupping.

If you are using American hardwoods, these generally have a low mc of about 8-10% anyway so shouldn't shrink too much more.

We often make lambs tongue moulded doors with moulding cutter which have a 5mm groove, the panel is made about 12mm thick and is fielded on the inside face of the door. The result is a solid panel which is flat on the seen side.

I wouldn't worry too much about the strength of the glue joints, the key is to ensure the panel is able to move in the groove. If its a slack, 1 headless pin centrally in the rails should stop it moving around.

 

[Steve Maskery]

You should have no difficulty whatsoever in getting panels from resawn 1" stock.
S

I daresay, but that's not exactly what I am asking about.

Sorry, just trying to be encouragingly helpful.
S

 

[Lord Kitchener]

You should have no difficulty whatsoever in getting panels from resawn 1" stock.
S

I daresay, but that's not exactly what I am asking about.

Sorry, just trying to be encouragingly helpful.
S

There was no need for you to be sorry, I was just trying to bring attention back to the point of the thread.

 

[speed]

is vaneered mdf out of the question?

 

[srp]

You should have no difficulty whatsoever in getting panels from resawn 1" stock.
S

I daresay, but that's not exactly what I am asking about.

Then I'm not sure what you're asking. It seemed quite simple in your first post, and all the replies so far seem to have covered every facet of making panels in some depth.
In my experience, most panels in solid timber are made up from between one and three pieces, glued edge to edge, and are fielded so they fit the groove in the stiles and rails, and are fitted loose, ie not glued. This then allows the whole panel to shrink and swell within the grooves, and the glue joints in the panel will not be subject to any stress, so will not split. If you glue the (solid wood) panel in the frame it will definitely split. Even Shaker furniture had fielded panels, and like much furniture of the day the panels were fitted so the fielding was at the back, and therefore hidden.
As to thickness, anything down to 6mm is perfectly possible - you can do a very acceptable rubbed joint with pva or aliphatic glue by laying the panels flat on the bench top when you do the rubbing. As soon as the joint 'grabs' lift the panel carefully and stand it more or less vertically on the floor leant against a couple of battens. I've used exactly this technique with 25mm ABW, resawn to give 3 boards, and planed to thickness. Carefull setting of the bandsaw should give you 6mm thick boards. That would allow you to make panels which don't need fielding - and they will then look exactly like veneered mdf or ply, which is probably what you should be using in the first place (why waste money and effort on making a solid wood kitchen unit door when the carcases are made of chipboard and the whole thing will be ripped out and dumped in 20 years time?).

 

[Lord Kitchener]

is vaneered mdf out of the question?

No, it's not out of the question, but the problem is to find veneered MDF which is a reasonable grain match for the solid wood. Take American Ash, for instance, which is very popular in veneered MDF. The stuff you buy (I buy quite a lot of it) is as plain as a plain thing on plain day in plain town, the makers, when selecting veneers, are at pains to avoid anything with any kind of interest in it at all. Buy solid American Ash, and it's not only a different colour (deeper), but the grain is full of interesting patterns, light and dark areas etc.

I've observed the same thing with other species. However, if anyone knows of a maker of veneered MDF who makes something that actually looks like the solid wood, please let me know.

 

[Lord Kitchener]

and they will then look exactly like veneered mdf or ply, which is probably what you should be using in the first place (why waste money and effort on making a solid wood kitchen unit door when the carcases are made of chipboard and the whole thing will be ripped out and dumped in 20 years time?).

I ddin't see this until after I had composed and posted my last reply. I believe that reply will serve as a reply to the point you raise above. My main reason for responding is that I have NEVER made a cabinet out of chipboard.

 

[Steve Maskery]

Veneer never looks like solid wood, at least, not in this context. Veneer is used for uniformity, not interest, in the field of anything except one-off bespoke furniture.
S

 

[Lord Kitchener]

Veneer never looks like solid wood, at least, not in this context. Veneer is used for uniformity, not interest, in the field of anything except one-off bespoke furniture.
S

Exactly
L

 

[speed]

how about resawing your own vaneer? and shoving it in a vac bag? that way you can get the grain you want with the stability of sheet material