Thread: Newbie - Preparing plywood for lacquer?

When you say lacquer, do you just mean a clear coat?

And you want it 'smooth to touch'?

The sanding between coats will be as important as the initial sand.

I'm just a DIY guy, but I reckon if I was trying to achieve the finish I think you want, I'd be doing about 4 coats of clear with a light sand between each.

It wouldn't be hard to do yourself if you're trying to save money.

Don't quite follow your method of dealing with the ply edges. Often plywood has small voids between abutting internal veneers which shows in the edge of the sheet. Would veneering after fabrication be an option?

Wot rusty said above. Yet to see a ply edge without voids, unless it is marine ply

I'm nearing the end of building a spare kitchen at home. The whole thing is plywood - doors, shelving, 3000mm long island bench top and 3000mm wall bench top. All edges are exposed. Very few voids. Hardly any, in fact. I'm guessing I would have close to 40 meters of lineal edge exposed (the benches are 2 x 18mm sheets glued together) and there might have been half a dozen small voids. Maybe I got lucky. Filling them was easy, too. I like the look of exposed ply edges.

Originally Posted by Tenson

Hi guys,

A little background:

I run a small business in the UK that makes top quality loudspeakers. So far I have had them made by local cabinet makers using solid timber for the side panels (other faces are covered with leatherette).

Given the downturn in purchase of luxury goods I'm looking at having the cabinets made with birch plywood sides that can be accurately CNC cut and then stored until I get an order. I would then assemble the cabinets and prepare the plywood sides myself and send them to a local paint shop for a lacquer finish. This is rather than having batches of cabinets made fully at one time.

The question:

So, what is the best way to prepare the plywood for lacquer? The main face of the panel will be Beech or Walnut veneer, and I would like to leave the (chamfered) ply edges visible, but perfectly smooth like the main face. I think the ply construction is a nice design feature, as long as it is perfectly finished and smooth to touch.

I guess you will tell me 'sand a lot!' but if so, what are the details that work well? Belt sand, orbit sand, how many levels?

Thanks so much!

Well Tenson, I think you're asking for trouble.

I assume you will use one of your local cabinet makers to attach the veneers to the Birch Ply, or will the ply be delivered to you with the face veneer already applied?
Because the Beech or Walnut veneers will typically be less than 0.5mm thick -- sanding through to the substrate is highly probable, so I advise against it.
Given you want smooth to the touch, I'd be looking to give the veneer surface a very light sand and then fill the grain with a colourless grain filler -- multiple coats of dewaxed blonde shellac is probably the easiest to apply if you don't have a dedicated spray booth. This can be sanded back so that the timber pores are filled and the surface is smooth. Alternatively, a comercial finisher could fill the pores with a solvent based grain sealer.

smoothing the cut edge (where the plyes are on display) will depend on the equipment you have to cut and finish the edges. the veneer along the cut lkine will be very brittle and subject to breaking off leaving unsightly "jaggers" along the edge

I'd store the panels cut to size and semi-finished and strapped (or weighted) flat to minimise problems with moisture absorption.

if the aim is to reduce the cost of your speaker enclosures, have you considered the option of asking your local cabinet maker to use veneer panel rather than solid wood? Similar cost savings without the hassel (for you) of storing and finishing veneered ply.

We're probably talking to ourselves because the bloke who asked the question has not been back.

If I was doing it, I would get the ply with the veneer already attached. And I would get it cut to the sizes I wanted - Mr Plywood in Sydney have done this for me.

Then I would finish it myself.

For the ply benchtops I've just done (with the 36mm edges) I used the 'Claw Finishing Regime'. It was a sand first, then four coats of Floorseal with sanding between coats and the last coat cut back with wet and dry and the linseed/turps mix. Gee, they came up well.

I've now got a Festool Rotex and it makes that sort of stuff incredibly easy and quick.