Wednesday, May 18, 2011
Tiny White Chair
Today, a technical lesson! This little chair is going to be part of a larger project - for that project, I covered it with clay. CraftEdu instructor Kent Perdue makes these wonderful little chair rings of wood (his specialty). For the project, I didn't have to cover it with clay, but I wanted to.
Wood is a tricky material to cover in polymer. It expands and contracts more than polymer and that can present problems after curing. For this reason, the polymer clay you choose must be strong enough not to crack when the wood expands.
Wood is also textured, it isn't stock smooth like glass and textures don't (in my experience) grab the clay like a smooth surface. For this reason, a wood piece should be sanded with fine grit paper - let's make it smoother. Dry sand it well, then brush off the dust - don't wet the piece or else you may have to wait a few days for it to dry out again.
There are so many woods - of so many qualities so if you can, choose a hardwood, with no knots (the sap will seep out - another resist agent - when you heat the piece). The seeping may well also lead to cracking in the wood itself and that may lead to problems with the clay covering it.
Before sheeting a piece with clay, apply a coat of PolyPaste and cure it. The PolyPaste will fill whatever remains of the texture and provide a nice, smooth, polymer surface on which to attach the sheet. When covering a chair like this - it's all angles (except for the round holes) sheet each plane of the chair, don't drape a sheet over. Draped sheets end up with rounder corners and that's not what I wanted!
Because of the issue of expansion, contraction, texture, make that sheet of at least a medium thickness. You may save clay with a thin sheet but it will be more difficult to manage and may even crack after curing. This medium sheet is stronger and offers the capability of sanding and sanding and not exposing the wood beneath it.
I used to cover really big wooden pieces with clay but the level of difficulty of covering larger forms increases with the size so begin with a small piece, then move on to larger items.
Donna Kato is one of the founders of CraftEdu, has her own brand of polymer clay (Kato Polyclay by Van Aken, Int.), is an author and teacher - on the road and online at CraftEdu.com.
Workshops at CraftEdu