I sawed out the rest of the parts for the small rosebud motif I’m doing as my practice exercise, and I’m ready to face my assembly demons. More or less.
The main assembly problem I had was with the hot hide glue (HHG) “going off” way too early. I may have had to HHG a touch too thick. Patrick did a really great tutorial on “animal protein glues” in the class, and he said pretty clearly that the water carries the heat in the glue. It was also fairly cool in the shop.
So I decided to use some training wheels. I’d seen Paul (Shipwright) on LumberJocks use clear shelf paper as an intermediate step in assembling his projects. He’s been doing some really amazing work, so I picked up a roll at the hardware store. I rented a house when I was in college that had the kitchen counters “refinished” with shelf paper. I tried to remove it because it was hideous, but it had bonded on some sub-atomic level and it was going to require toxic chemicals and haz-mat suites to get it off.
So, I wasn’t sure how this would work. Turn out, it works like a charm. This clear shelf paper has a low-tac adhesive, it’s less sticky than blue tape. I can position pieces on it, remove them, and put them back.
(the parts in this picture are scraps from the first rose experiment)
Eventually this will need to be glued down to an assembly board covered in the French ribbed Kraft paper using HHG. Remember, the flip side has newsprint laminated to it. It’s the newsprint side that will be bedded in the HHG. So, to be able to trial assemble the project seeing the veneer colors I have things backwards. I’ll need to cover the front with blue tape when I’m ready to glue to the assembly board, then remove the shelf paper.
Once it’s glued down to the assembly board I can fill the seams with mastic. Then it gets cut free and flipped over to glue down to the actual substrate. Good grief, it’s no surprise I got confused last time. I’m confused now.
So, here is the game plan, starting from the point where all the parts are sawn out:
- Shelf paper stuck to the newsprint-covered face side of the background veneer. Fit all of the parts in place to ensure they are all accounted for.
- Remove parts one at a time to sand scorch them to add shadows, put each part back
- Cover the assembled picture with blue tape on what will be the glue face (e.g. the side without newsprint)
- Remove the clear shelf paper, apply a coat of HHG to the kraft paper that is stretched on the assembly board and lay the newsprint side into the glue. Clamp and let cure
- After the glue up is cured, mix the mastic and force into any gaps in the marquetry with a putty knife.
- After the mastic has dried, cut the veneer picture free from the board by cutting the Kraft paper around the edge. Glue the picture to the final substrate on the project with the paper side up.
- Once this final glue up is dry, wet the Kraft paper with a sponge and scrape the paper off.
It seems like a lot of steps, but in class it was simple and went pretty quickly. I just need to practice a bit.
The main reason I want to do these extra steps with the shelf paper and tape are to buy myself some extra time to go the assembly. But the other reason is so I can do the sand shading, and see how it affects the picture as I go.
So, sand shading. Should be pretty simple, as long as I don’t turn any of the pieces into tiny thin charcoal briquettes. I decided I’d best do a practice run at this.
I have a small cast iron pan that I don’t use to cook — it came as a set of 3 from Kmart last year. I use the large one and the small one in the kitchen, but the middle has just become a marquetry tool. I filled it with “reptile sand”, which is just very fine sand. I put it on my $19 hot plate that I use for heating glue (and warming pieces of glass for foiling when doing stained glass).
I cranked up the heat to the max, and tried scorching some scraps of veneer. I started with the pieces from the “waster” veneer on the front and back of the packet. In this example I have two pieces that together are a leaf in the pattern.
I stuck them in the pan of hot sand, and waited…
I checked at 5 seconds, nothing. 20 seconds…nada. Around 40 seconds there was a little color. I had to put them all the way to the bottom of the pan and wait another minute to get a reasonable amount of shading.
It seemed like the shading was waaaay too slow, even given that this was using thicker scraps. I watched a YouTube video, and they were getting shading in a matter of a couple of seconds. In fact, on some parts they scooped up a teaspoon of sand and poured if over the tip of a small part and got shading.
Long story short, I need a hotter hot plate. One thread I read on the ASFM site said that a 1,500 watt plate was what they used at the school. We didn’t cover sand shading in the class, so I’m taking it on faith. I ordered a $29 hot plate that is rated at 1,500 watts. When it arrives I’ll repeat my experiment and hopefully will have better results. What I have works, it’s just too slow, it ends up baking the whole piece to get a little color.
Even using the .020″ thick (“thin”) veneer, it took about a minute on the bottom of the pan to get color. Here is the same experiment with scraps, before: