Warning: Lots of photos!
Here’s my setup for sand shading one piece at a time. The marquetry has been preliminarily assembled on sticky shelf paper, a sheet of thin acrylic covers most of it, and the sand is hot.
I remove one piece, shade it in a spoon of hot sand, and return it. Then I repeat a thousand times (give or take). I am still developing this way of doing things but it is working very well and I have complete control of how the picture grows as I am shading.
Here’s an example. The curled edges here look flat so I shaded the outer edges a bit and now (second photo) it looks better. I ended up shading almost every piece and all of them seemed to add to the three dimensional effect.
This is the end of day one, about 4 1/2 hours.
A detail at that stage
And day four, around twenty hours total shading time.
One of the advantages of this technique in painting in wood style is that the unavoidable kerf spaces can be managed. In the first photo I’ve moved all the pieces tightly together against one edge. If the marquetry were glued up this way it would look awful.
But the shelf paper has a soft adhesive that allows me to slide the pieces around. Here I have arranged the kerfs to be evenly spaced. These kerfs are 1/100” and can be either disguised with matching mastic or (as will be the case here) emphasized with a black mastic, adding to the shadow effect and creating a “trap line” to isolate the elements of the marquetry.
Once the shading Is to my liking and the spacing has been adjusted I apply a layer of cheap masking tape. I really like the cheap stuff because I can see through it. That helps when you are trying to brush it down to contact the thinner pieces, in my case the ebony. The nail brush does a nice (if not perfect) job of this.
All taped up, the whole thing is turned good side up and the shelf liner is removed carefully. I find that sliding the acrylic along as I peel the shelf liner helps control the pieces that want to lift.
Now I have placed my prepared assembly board (French butcher’s paper) on top of the marquetry. I coated it with hot hide glue and inverted it onto the marquetry. Sorry no time for photos in the process. After turning it back over I once again used the brush to press the thinner pieces down onto the glue…...
And after a light pressing, carefully peeled the tape.
Here all the tape is off and it looks ready to fill and apply to the substrate but there is still the matter of different thicknesses. Even though I am using veneers that are marketed as 1.5 mm and 1/16”, which should be quite even there is a good discrepancy between the thickest (poplar) and the thinnest (ebony).
I set up this enclosure and carefully sanded it to near flush with my Ceros. The enclosure proved a good idea as I blew out about fifteen tiny pieces and found all but one or two which were easy to re-make.
With the sanding and repairs complete I get my first idea of how the shading will look when sanded and finished on the good side. I couldn’t resist a splash of alcohol to see the real colors.
I sort of can’t believe I did this.
Here are a couple of shading videos I made for anyone who has survived all of this lengthy explanation.
Thanks for looking in
-- Paul M ..............If God wanted us to have fiberglass boats he would have given us fibreglass trees. http://thecanadianschooloffrenchmarquetry.com/