Sheet goods advice

[Shady]

I'm re-doing some cabinets/buit ins, with the help of my trusty new sawguide: what do people think is the best cost/finish option for plywood?

I'm looking at 3/4" and 1/2" sheets, that'll be lipped with solid wood where appropriate, and painted. I've used cheapo ply before, but found the surface required a significant amount of work to get an 'acceptable' look, even when painting.

(NB - no to MDF, despite the surface, because of weight issues)

So, what would you use for kitchen cabinets, study desks, and built in bookcases? TIA.

 

[wrightclan]

Birch ply is probably the best sheet material I know of for painting, apart from MDF. That said; my opinion is that finishing of any kind, on any material requires a significant amount of work to achieve a good finish. Just some slightly less than others.

Brad

 

[Colin C]

HI Shady
If you have good surplier near you, you can try to get thet light weight mdf as it is much lighter than the bits you have got before

 

[Nick W]

If you can find any these days then I'd go for blockboard. It is light, stiffer than most (all?) other sheet materials, cheap, and relatively easy on your tools, takes screws well, glues well, doesn't produce the nasty dust that some (let's not name names here, but you know what I'm talkiing about) do, doesn't creep under load ....

 

[jasonB]

A good quality birch ply will only be 1 or 2 kilos lighter than a sheet off MDF

eg 8x4 of standard Caber MDF = 44.21kg
8x4 of Latvian birch ply = 43.05kg


So the weight issue does not really come into it. I would go with MDF as you don't need to lip, no risk of break out on the underside of a cut and it takes a paint finish is better. Other option is overlay plywood if you can find it - MDF type surface on a ply core.

The light and ultralight MDF does ont finish well on cut edges.

Jason

 

[RogerS]

Jason

'no need to lip'...how do you get a smooth finish on the cuts so that you don't need to lip? I'm thinking as smooth as the basic surface?

Cheers

Roger

 

[jasonB]

Coat of dulux quick drying primer undercoat, rub down with 180g silicon carbide then the same over the whole board buy then the edge is as smooth as the surface so just carry on painting as normal. This is the advantage of working with decent MDF over fluffy shed bought MDF. Go for Caber or Medite and preferably MR(Moisture resistant).

If you lip it there is more likelyhood of the timber/MDF joint showing through the paint as the timber lipping moves at a different rate to the MDF.

Jason

 

[Shady]

Interesting Jason - what about 'sag resistance'? My other problem with MDF has always been a perception, rightly or wrongly, that it will bow more easily than an equivalent thickness of ply/blockboard - and nothing looks more ugly to me than obviously bowed/warped shelves etc...

 

[Nick W]

Shady,

You are right about the sagging problem, and MDF will continue to creep under load. Now of course you will be advised to apply deep lippings to any shelves to overcome this problem, which is fine if you want large shelf profiles :roll: , but why should you have to go to these lengths, and spoil your shelves' looks.

Join BIG (Blockboard Is Great) - you know it makes sense.

 

[Shady]

Nick - all other things being equal, I'd agree: but the stuff is all but impossible to source nowadays: do you know anyone who sells it at reasonable prices??

 

[jasonB]

Far eastern blockboard is not too hard to come buy but the surface is not as good as the old birch faced boards. I think Silverman do a premium blockboard but I have not tried it.

Jason

 

[Nick W]

... do you know anyone who sells it at reasonable prices??

'Fraid I don't, I was kind of hoping someone else would come up with a source .

I have one 8 x 4 of Oak veneered blockboard in my stash - goodness only knows how I'm going to replace/add to that.

 

[johnelliott]

Jason is right, go with the MR MDF. No need to lip. Design so the shelves aren't too long and there will be no problem.

Even birch plywood can be a problem to finish. We know, we get through several sheets a week. Main problem is variation in the angle of grain to the surface, which causes areas to 'go fluffy' as my painter puts it.

John

 

[engineer one]

sure it's heavy, but so is wood surprisingly enough.

i think for most cases, the unsupported width of a shelf is around
600 mm /24 inches i think, but a front lip always adds to the
look.

paul :wink:

 

[Shady]

Thanks for the suggestions folks: I'll let you know how it all goes in due course.

 

[LyNx]

You could always add a supporting lipping to the back edge, this way it's not in your face. Or even rebate in a piece of Alu angle into the back bottom corner to add strength to a thin shelf.

We add the angle to 25mm shelves that are around 1000mm long and after a month these are full of box files in lawyers offices and only a very slight bit of sag.

 

[RogerS]

into the back bottom corner to add strength to a thin shelf.

Andy

Can you explain a bit more as I don't quite follow back bottom corner. I can understand fitting the angle all the way along the back of the shelf.

How thin a shelf did you do this on and what sort of angle dimensions?

It's a neat idea

Roger

 

[LyNx]

Sorry mate, i was thinking from a section view. Your right, alone the back/bottom edge. The shelves were 25mm chipboard with a 20x20mm angle. As long as the shelves are around 300-350mm wide which will suit most books/files etc then it's not too much of a problem with the front edge sagging.

We did have a case that the associates in this lawyers office complained about the shelves sagging. The shelves was loaded up with the large box files, end to end and stacked 3 high. They even took the shelves above off so they could stack more onto this single shelf. It was lucky it didn't rip the whole workwall off the wall. :shock:

 

[George_N]

To go back to the original post, why not MFC for the kitchen cabinets? Apart from edge-banding it's pre-finished and easier to keep clean and more durable than paint.

 

[engineer one]

george you are right, but the question also asked for other
areas, like built ins.

at the end of the day, are the items going to be painted, or
white, or stained?

so mfc for white goods, but 18mm thick i think.
for painted ordinary mdf, not least because it is
relatively easy to paint, and wont shrink too much.

for two reasons, one because on my own i cannot lift it,
and also to cut down bending i stick to no more than 24 inch/600
mm wide, and max 600 back to front, but generally for bookshelves,
only 300mm back to front.

the unit i am building at the moment is oak veneered mdf
and will have a face frame in oak. each top unit is no more than 24 wide
overall outside, and in this case 42 inches high. sorry to keep switching
but still can't get my head round the relationship of metric.

so none painted, go for veneered boards, and lipping. i think in this
case i will face frame, but in the past have used the iron on for
units which look better stark and flat.

the other thing is the way in which you fix the items to the wall.
with mdf i tend to go for belt and braces, including support ledges
under each unit. then i will put a pelmet around the skirt to hide the mess.

paul :wink: