Friday 5 April 2013

Display Cabinet Part 3 - Blue tape is your best friend

I had assembled the carcase of the display cabinet and did a rough fit for the shelves. These simply sit on metal pegs that are in a series of holes with metal liners inside.

Cupping after glue up

Obviously wood being organic it had decided it was going to move after the glue up (doesn't it always?). The centre upright decided it was going to cup near to the rear edge midway up the board. This meant the nicely straight edged shelves had a big gap at the rear on the right hand bay and wouldn't go in on the left hand bay.
Out came the pencil and I traced the form onto the shelves and cut out the now slightly bent shapes. I then glued a thin 1/16" 1.6 mm veneer of oak to the end grain on all of the shelves.
When dry I trimmed with a block plane. Then out came the random orbit sander and the shelves were sanded to 320 grit.

End grain exposed on curved uprights

I also had a problem with the unsightly change of grain direction grain showing on the curved front of one of the uprights. As they were made by glueing 2 boards together and then shaping the curve on the bandsaw/router table it had exposed the end grain but there was a portion where the glue up met where the grain showing was not nice. Unfortunately I don't have any clear photos of this to show just this photo with the veneer attached. I have enhanced the contrast of the picture so you can see the glue line.
You can see where the two boards making up the end
upright are glued up. I was unable to hide this split
when I cut the profile as I had to cut bad
timber from the rear edge (in this shot) away moving
the split line into the path of the curve.

So I found the scrap strips that I had cut off when cutting the boards to width. I then run them through the planer to get them down to 1/16" thickness or less. To do this I used some double side tape on a piece of scrap ply and stuck the cut-offs to it. I produced 6 veneers (1 spare in case I broke one) all the same thickness and about 1-1/4" wide by 48" long.

These I glued to the front edge of each of the components making up the carcase.
I didn't have any clamps that could cope with the slight taper on the top and bottom of the case so I used blue tape as a clamp. I didn't think it would work very well but it did.

Have you met my friend Blue Tape?


Veneered front edges

Pre-finishing

The next job after all the veneering was completed was to fill a few minor gaps that were left by glue voids. I try not to use any filler in my work but I have found a product that was recommended to me by a retired cabinet maker.
It is Artists Paste which is a colourless, acrylic modelling paste used by artists to thicken paints 
I used this artists paste mixed with a little oak sawdust for colour to fill the voids.
It truly is wonderful stuff and I can't recommend it enough.

Then out came the random orbit sander and I sanded this to 320 grit. Next I filled the pores with some pore/grain filler as the material is French Oak. The filler used was transparent Jenkins Jecofil thixotropic grain filler. This is applied with a soft cloth with the grain and any excess wiped off across the grain. It is left to dry for 12 hours or more and then sanded back with 320 grit.
This does take some time to do and you may need to do it more than once but you are rewarded with a beautifully smooth surface ready for finish.

Finishing

The finish on this piece is a colourless, sprayed General Finishes waterbased PolyAcrylic top coat. The first application raises the grain and you have to knock it back using 320 and then another two coats were put onto the carcase knocking back with 400 and then 800 between coats. The top and top surface of the base were given an extra coat.

The entire piece was left a couple of days to harden off before hitting it with 2000 grit to remove dust nibs.


I have the shelves left to finesse fit and finish so that will be in the next post.

Blue Tape

I almost forgot! Blue tape can be used for a multitude of tasks and won't leave a sticky residue on surfaces (if you remove it in time):
  • Mask off an area before painting (its default task)
  • Used in place of clamps
  • Tie up your pants if your belt snaps
  • Cover a wound if you have run out of field dressings
  • Repair cuts or holes in your shop dust extraction collection bags
  • Stick engineering/woodworking drawings/photographs to the wall
  • Use on the base of a power tool (jigsaw) to prevent scratching the surface of what you are cutting
  • Use around a drill shank as a visual depth gauge.
If you know of any other uses leave a message below.


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