9 Attachment(s)
Stabilised and Cast Bush Lemon Burls then turned into Spheres
I've made quite few spheres over the years but they seem to be "in" again at the moment. Decided to make a few using some of my Bush Lemon Burls I've collected lately as they dye stabilise well.
First step was to soak them in a chlorine/boron mix for a while, the Boron kills any bugs and protects it while the Chlorine softens the bark and bleaches the timber. Then they were water blasted before putting them into my smoker over to dry. Started at 45C for 2 days, then increased temp by 10C every 2 days, before final drying at 110C until they stop losing weight to ensure they are 0%MC (24/7 for 2 weeks for that oven full)
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Next was to let them cool in vacuum bags before stabilising them in Cactus Juice resin (plain and coloured for dye stabilising). Because of the size it took 4.5 days under full vacuum, before soaking for another 2 weeks, then baking it to set the stabilising resin (at 100C for 4 hours).
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Next I made some simple 100mm/150mm dia molds from PVC tubes and cast the burls with clear or tinted with translucent dyes Megapoxy HX Clear Casting Resin in my pressure pot. The mistake I made was not sealing the dye stabilised surface before casting, so unfortunately some of the dye leached into the resin.
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I then started to turn with TCT tipped tools the sphere blanks between steb-centres to roughly round (using offsets and dia or light shadow techniques - check out Theo's vids on Twitch)
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Then I mounted the rough turned blanks between cup chucks I made from HDPE
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They were then finished turned the spheres and sanded through to 600 grit to form perfect spheres by rotating them in the cup chucks. I got a catch on the clear cast one and a big chunk of resin went flying, so quick design change, now a smaller sphere :rolleyes:
Each sphere was then spray painted with car UV resistant Top Coat Clear acrylic lacquer and left to hard over a few days. As it is impossible to spray coat spheres without overspray, once hardened, each sphere was wet sanded with micromesh then polished with plastic polish all by hand.
I also made stands for the spheres out of Blackwood and Ebonised them with my home brew (vinegar/steel wool/old tea bag) before spraying with the lacquer. Each stand was hollow to receive a LED torch to shine up on the sphere. I made 2 sizes, one for a 30mm dia torch and for 15mm torches, to maintain a base dia for the stand at 50% of the spheres.
Here's some videos of the finished spheres
https://www.youtube.com/watch?v=0d1XWHUUwUQ
The larger 140mm plain burl with yellow tinted resin in sunlight, then on stand lit
https://www.youtube.com/watch?v=hpK4ZRdFO48 https://www.youtube.com/watch?v=lD0rl62C5VM
The 90mm red dye stabilised in red tinted resin in sunlight, then on stand lit
https://www.youtube.com/watch?v=LV2T1OdWkjQ. https://www.youtube.com/watch?v=Dm85oCoWxqc
The 90mm yellow dye stabilised in yellow tinted resin in sunlight, then on stand lit
https://www.youtube.com/watch?v=lEUJ9_q2uWs. https://www.youtube.com/watch?v=NHw26XWiptc
The 90mm green dye stabilised in green tinted resin in sunlight, then on stand lit
https://www.youtube.com/watch?v=h-3jCYsKB90. https://www.youtube.com/watch?v=nS-PIO6824Q
The 75mm stabilised in clear resin in sunlight, then on stand lit
https://www.youtube.com/watch?v=vIuk3tFdEPM. https://www.youtube.com/watch?v=sFIe4_vTaHA