Sunday 17 April 2011

The Art of Pinning

Coteaz temporarily held together 

Grey Knights HQ model - Inquisitor Coteaz will make a great subject for pinning. He only has 2 fixing points for drilling and glue, and they're both quite small.

If you're new to working with metal, you have probably never had to worry about bits falling off after you've painted them. Believe me, it's a real pain, and can get pretty messy - often ruining hours of hard work previously spent painting.

Normal plastic glues work by melting the surfaces of the joining parts, and when it's dry, they're stuck together. Metal doesn't behave in quite the same way. Super glues are mostly useless and even 2-part epoxies aren't always successful. This is because the mating surfaces are smooth, non-porous, and provide no gripping point for the adhesives.

This is where you'll want to employ the technique known as pinning.

Get a box of paperclips, a pin-vise and a set of micro drills. I'm using a 0.75mm bit to dill these holes.

Pin vise, paperclip and hole drilled
A fresh drill bit will bore through white metal with ease. A more well-used bit will take some effort. Blunt bits don't cut well.

With this model, I've drilled a hole into the wrist section - about 2mm deep.

Test fit the paperclip before using glue
After dry fitting the paperclip to check depth, I dabbed a drop of Zap medium CA Glue to the exposed hole (I know - it's superglue, but this way it works) and inserted the paperclip.

Leave the whole clip - it's easier to handle than a 4mm length - cut it later.
While this dries, drill a hole in the arm section of the body piece. On a small model like this, it's easy enough to judge where to drill.

On a more complex fit, before you glue a pin into the first hole, paint over the hole with a relatively thick paint. Fit the part and the paint transfers over to its matching point. Drill and continue.

Once you've drilled the matching hole, and the glue holding the pin has dried, cut off about 2mm length and test fit with the target. If it's a good fit, glue and refit. Allow to dry. Fill any gaps with putty/greenstuff and spray with primer.

Coteaz primed with cyber eagle, daemon hammer and custom base
That's it for this one.

NB: On larger pieces, you may find a double-pin will stop a piece from rotating while it dries. This is simply a case of drilling 2 holes on each side. Transfer paint as above to figure out placement of matching holes.

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