Acrylics, oils and polyurethanes

[jhl.verona]

I'm thinking of building a few zen gardens, much like a serving tray, around 375mm x 275mm (say 14 3/4" by 10 3/4"), something like this:

Nothing too spectacular, and I'll be using some 'plain jane' wood, pretty light in colour, with hardly any figure - Kotò.

What I'd really like to do is experiment with some colours and finish. I'm thinking of using acrylic paints, heavily diluted with water, dark first, sand then lighter colours. Something on the lines of those superb guitar backs.

Since there won't be any figure, I won't get the 'classic' rippling of fiddle back woods. So I am toying with the idea of mixing in a little oil to get a smear effect. I'll see how that goes on some test pieces first, of course.

I'll be wiping the colours and finish - I've seen that this gives good results without brush marks.

The question is this: water finish for water based colours, oil based for oils. If I let it all dry for a week or so, I assume the water will have completely evapourated, or been absorbed by the wood, so I can use the 'oil based for oils' rule?

Or are there other techniques for achieving a ripple (or similar) effect on unfigured woods?

TIA

John

[jhl.verona]

So I decided to try a few experiments, not entirely sure of the results though...

The tools of the trade; acrylic paints, Ronseal water based varnish, and some pieces of Kotò, the samples are 10cm by 30cm.

I didn't have any precise measuring instruments, so the acrylic is by length 2, 4 or 8cm squeezed from the tube, and the water is 1/4 plastic cup - about 50 ml I think, though I also dropped down to 1/4 of that measure to thicken the wash, say 15 ml.

Everything was wiped on, and the excess wiped off using simple paper napkins, except for the green samples where a 15mm artist's brush was used.

Here the plain sample; Ronseal on the left, bare wood on the right.

The Ronseal barely changes the colour of the wood.

First the blacks. This was pretty much a total let down. The best of the bunch is 8cm 15 ml then Ronseal.

8cm 50ml then Ronseal on left, 2cm 50 ml right.

8cm 15 ml then Ronseal on left, bare wood right

8cm mixed into 50ml of Ronseal (toning) on left, bare wood right

Cadmium red. Needs toning down with some black or violet to be attractive. Reasonable colour/wood grain though.

8cm 15ml then Ronseal on left, bare wood right.

Green toned with black. Again reasonable colour/wood grain.

About 8 cm black and 16 cm green, brushed on wetting the brush in water then Ronseal on left, bare wood on right.

(the coat was so thick that the grain vanished, so I wiped off the excees with a napkin)

Same mix but in about 20 ml of water, the Ronseal on the left, bare wood on right

The excess was removed using the brush wetted in water.

I prefer the brushed look, as this seems a little less professional and a little more artisan.

Any comments or hints greatly appreciated, as I'm pretty much in the dark here...

John

[jhl.verona]

Little bit more experimenting today.

First the blues.

20 cm Blue 8 black mixed in 10 ml of water and 40 ml of Ronseal (toning). Brushed.

To that mix, I added an additional 20 ml of water. First brushed:

Then wiped with a paper napkin:

A retry at the red.

12cm red, 4 black, 4 violet in 15 ml of water. Brushed then tipping, removing excess in the cup.

Same mix but added 10ml of water and wiped.

Same mix as previous, but added 40 ml of Ronseal. Wiped on. Too much thinner - the water.

Out of photo space, so see next comment...

[jhl.verona]

20cm red, 8 black, 4 violet in 15 ml of water. Brushed and tipped, drying brush on napkin.

Same mix, but wiped with napkin.

The results to this point seem to be better with a toning mix, some Ronseal added. Unfortunately it is pretty thick which makes wiping difficult, even with a 20% dilution.

The next step is to scuff sand all the pieces.

To cut a long story short, all the pieces which were coated with Ronseal (either during colouring or after) scuff sanded reasonably well. The two red test pieces which I only coloured with acrylics faired very badly, the acrylic doesn't seem to penetrate the wood:

So I think I go with a toning colour, and brush it on, though I'll need a bigger and better brush for good results. Once scuff sanded the brush marks should flatten enough that the following Ronseal coats (2 or 3) should add a fairly flat gloss finish.

We'll see how the zen garden trays go...

John

[Bobby Slack]

Ciao John,

You live in the best country for finishing. When I sold high end picture frame finishing lines (Makor from Bolognna) I was told that the best finishing systems come from Bella Italia.

Bobby

[jhl.verona]

¡Hola Bobby,

That's some serious machinery that Makor makes. Maybe in a future life... Did you mean Biella (Turin province) perhaps?

John

[Bobby Slack]

John I can't believe you know about Makor, great machines. I sold those for the picture frame business. There is another brand Delle Vedove which was not considered as good. For flat panel there was one .... I have to think about it.

Makor tried to get into flat finishing and never really nailed it, They are the best for moldings though. It was amazing to see finishing lines performing perfect at 150 feet per minute.

[Bobby Slack]

Now I remember the Italian line for flat finishing ... Cefla