Sheet Goods question

[Shady]

OK folks: I'm doing a number of cabinets (wardrobes, bookcases and study filing cabinets) over the next few weeks.

The intent, for various reasons, is a mix of blockboard, MDF and ply raw materials, with poplar edge banding (all will be painted a silk white finish). Not high end stuff, but good solid furniture to take teenage boys' kit.

The question is, what's the best way of getting a good finish on ply? Before I put a fairly substantial order (for me) in for all the sheets, I need some advice. I would like to use the cheaper, Far Eastern ply for things like the Wardrobe drawers and doors. At 1/2", MDF will buckle under the weights involved. But a) will cheap FE ply be just too horrible for a smart looking finish? and b) Would that be solved by using more expensive (Gaboon?) ply? or c) should I plan on designing with a 9mm MDF face where appropriate to give a smoother surface?

NB - I'll be spraying with a SATA RP gun, before construction, if that affects any answers.

Grateful for all thoughts/comments.

 

[Chris Knight]

Shady,

Filling the grain/defects of whatever you use is an obvious first step. If filling large areas, stay away from oil based fillers, they dry too fast and would make a lot of work. I would suggest you consider plaster of Paris for FE ply, it is cheap and easy.

You may have to fill voids or those places where Dutchmen have been applied but fallen out - I usually use polyester body filler (ie for cars) for this.

With the right filler and sanding etc you can make anything look like anything basically. It is just a question of the time you want to spend on it. FE ply would work fine for your application in finishing terms I think. I will just say once more that I think construction ply (fir shuttering stuff) is good value and robust if you are planning to fill/paint.

 

[Shady]

Chris - thanks for that: happy on using PoP - I just wondered if there was some 'magic' trick or secret that I wasn't aware of: any particular paint you'd recommend for spraying on?

 

[Chris Knight]

Shady,

You can apply the PoP as a premixed paste or by using a wet(tish) rag and picking up dry powder from a tub as you apply it to the wood. It does dry quite fast although it is easier to deal with than oil based stuff when it is dry.

I am no paint expert so can't really advise there I am afraid - beyond stating the obvious that a good primer is essential for the best finish.

 

[engineer one]

shady, i often wonder why we do not follow the american model, and
use car primers and paints, they are designed for better coverage,
for spraying, and working on areas which have had filler in them.

also you can polish them out better.

in principle ply will i think take paint better than mdf, particularly at the
edges. even car primer get soaked into mdf, unless you spray it almost dry, so that as it hits the surface it is almost dry but does not orange peel.

i find that the car primers, even p38, but some of the more modern ones
shrink less than wood specific ones, and they are easier to rub down, and feather to make a flat surface.

i think if you are going to spray it is worth looking at a whole range
of car type water based paints to give surface coverage, strength and quality.

my 2p :lol:

paul :wink:

 

[Scrit]

I often wonder why we do not follow the American model and use car primers and paints. They are designed for better coverage, for spraying, and working on areas which have had filler in them.

Some of us already do :wink: Blockboard and plywood still present edges which never seem to fill right so are probably best lipped with hardwood before finishing - that's one area where MDF has definite advantages. MDF edges can be filled with anything from automotive body filler (like P38) to drywall jointing compound or even well-thinned French polish. I find the best way to get a good smooth surface for painting is to use a high-build automotive primer, which is a pretty quick way of hiding minor surface blemishes. Nice thing is that there is someone, like Autopaints, selling car paints in almost every major town.

Oh yes, and the other reason I'm not a great fan of blockboard is that with time the laminae invariably seem to telegraph through to the surface which with a painted finish looks awful.

Scrit

 

[engineer one]

shady you might look at the latest issue of FWW about built ins
has some good advice about finishing including some stuff about
mdf.

might help

paul :wink: