Lessons

Making a new dashboard has taught me some wood butchery lessons.

I sanded down the original, right-hand dash panel using the bench sander I bought last year.

Then I stabilised the plywood with a couple of layers of worktop lacquer, which is hard as nails and impervious to almost everything except bleach.

Next I filled any small imperfections (a couple of areas were indented) with car bodyfiller. Now the first lesson was that car body filler isn't really a suitable base for wood glue and I should perhaps have used wood filler. That's not to say it didn't work when I applied glue and the veneer, but it wasn't ideal. I couldn't, however, sand it perfectly flat as it would have taken too much of the ply off and leave a step when mounted next to the centre panel on the dashboard backplate.

Using a craft knife, I cut out a suitable piece of veneer. Now veneer is very brittle and you can see in the photo below where a couple of bits chipped off during the process.

Not a problem, I thought, as I could fill these tiny areas in with small specs of veneer after the main layer was stuck on.

After applying the glue I added the veneer and then used another piece of ply as a press, clamping the whole lot down for half a day.

The problem arose once I tried to take off the plywood press - some glue had squeezed out and stuck the press to the dashboard panel, requiring some force to release it and chipping off even more pieces of veneer in the process. The lesson learned was to use a silicone mat (left over from my resin lamp making phase) between the two pieces of wood to ensure they didn't stick together.

I decided to remove the veneer I had applied using the bench sander to take it off in thin layers. The interim result produced a beautifully smooth veneer, so I'll use the bench sander to refine the veneer on the final panel before applying high-build, clear polyurethane.  

Having some time on my hands, I had another go at making a totally new right-hand panel and learned another lesson.

I carved out the indent for the steering column using my jig-saw and thought; "Damn! I should have used a drill hole saw at the top and the jig-saw for the sides - a jig-saw is too imprecise. I should also use hole borers for the instrument holes, rather than a jig-saw." I corrected the error by clamping a spare piece of ply under the indent (to give the centre of the drill bit something to bite into).

I pulled out my hole borers, but didn't have one the right size for the required instrument holes. So I went on to e-Bay and ordered a set for every conceivable size. Only a tenner. I also spotted a variable hole borer which allows you to bore out any sized hole you want. It only costs a fiver.

I'm going to have to start from scratch, but I'm going to wait for the centre section I bought on e-Bay to be delivered, plus I need some more burr walnut veneer.

So, the lessons learned were:

1. Use wood filler for small imperfections, not car bodyfiller. Wood filler grabs the wood and polyurethane paint better.
2. If the imperfections are too deep to fill effectively, use a new piece of ply. Pressing the veneer with another piece of ply won't facilitate the veneer adhering to the dents.
3. Don't use a jig-saw to cut out holes - a drill hole borer produces a far more precise cut.
4. Use a silicone mat between the veneer and the wood that's clamped over the top to press it down to aid release.
5. Don't pre-cut the holes in the veneer - cut them out with a craft knife after the veneer has been firmly glued to the substrate. Doing it beforehand risks splintering and cracking the veneer.

I did carry on with the original right-hand panel, just as a test piece, but again I managed to chip a piece of veneer off on the far right corner, which I glued back on before gently sanding on the bench sander and applying one coat of  polyurethane varnish. For a first attempt it's not too bad, but not to the standard I want.

Once I've built up a good depth of polyurethane coats and it's thoroughly dry, I'll sand it back to a flush, satin finish (to avoid glare) and see what it looks like. It's been useful for learning from.

The panel on the right is the one I'm actually going to use, as there are too many low sections on the original and they're damned difficult to fill properly, being on thin edges with little sideways support. 

The new section of plywood has the advantage of being totally flat and I'll bore the holes to the correct size when I receive the tools I ordered. Reboring them to the correct size will be a doddle if I back the panel with some ply and clamp the two pieces of ply together.

Here's the panel with at least half a dozen coats.

It has a good lustre and depth, but needs a good week to dry out thoroughly before sanding. Even then, I may have to add a couple more coats to ensure an even, flat surface.