29 May 2010

Transference, part deux...














You may recollect (if you've been paying attention at the back) that it was my intention to make a Robert Ingham transference jig, to ease marking out the pin board from the tails when cutting dovetails.

I had a drive down to Ringwood Precision Engineers on Friday and got hold of a lump of 50x50x6mm ali angle, which cost the princely sum of a fiver. As it was a wet Bank Holiday Saturday (now there's a strange occurrence) I decided to knock one up.

In the original, RI used mdf for the wood part, but as I didn't have anything quite to esoteric, I used an oddment of maple instead. The aluminium was chopped into 50mm pieces and then the ends were made dead square...easier than I thought using files initially and then w/d papers stuck to some 10mm float glass.














The 'T' slot was cut with a 6mm cutter to begin with and then opened out with a suitable keyhole cutter from Axminster. The sliding 'T' bolts were just made from a bit of old gash 6mm studding and a bit of 10mm stuff.

In use, it works surprisingly well and makes what used to be a rather awkward job much easier...

27 May 2010

Genius moment...

After making that drastic error with the veneering, it cleaned up reasonably...not perfect, but sufficiently well for it to be passable. All the surgical inscisions will be on the underside so won't be visible, unless some inquisitive ne're-do-well gets down on his benders for a closer look! The most important thing is that the top came out perfectly...four bookmatched leaves.

Even the biscuits for the drawer unit have been cut...














In the pic above, the four main parts have been biscuited together with a small locating piece of oak in each corner (the groove is for the back panel) to bring everything into line. This has proved quite useful as I needed to shoot in the corners dead flush ready for the 20mm lipping to go on.















One thing that's been a puzzle to my limited mental capacity over the last few days is just how the hell to line up all these heavy bits of wood to mark out the mitres for the Chinoisery style jointing?

Then the penny dropped! In a flash of absolute genius (which I have to say, happens all too rarely) I needed to work backwards (so to speak) as the accuracy of the joint was dependent on how well the biscuits lined up, so I took particular care to ensure that they were 'spot on'. I was then able to mark the extremities of the mitres with a sharp marking knife...shown at the point of the yellow arrow in the pic above...














...so that once the lipping had been applied and flushed level, I was able to turn the micro-marks (yellow arrows again) into proper marking lines (orange arrows) and then pencil in the mitres.

Sometimes, my undisputed talents defy belief... I need to polish the halo a bit more!

22 May 2010

Surgery


Sometimes things go right.

And sometimes they go horribly, unbelievably wrong. These couple of pics show the underside of the top (and therein lies some relief!) which looks, on the face of it, reasonably good.

Except that I didn't dare take a 'before' shot.....

Each of those four leaves were somehow sawn unevenly and so were not parallel, but went down in the AirPress bag as a series of small 'steps' and if looked at from the side would have resembled a saw blade profile. When they were pressed in the vacuum bag I stupidly placed it veneer side down onto the baseboard with the result that there wasn't an even pressure across the lay-up...the thinner bits of the veneers had next to no pressure (even though there was around 2.5 tons on it in total)














Result... huge bubbles under the veneer when it came out the bag. The only way to get round it was with a bit of fairly drastic surgery using a Stanley knife... and it's not easy to cut through veneer 2mm thick. By levering up each side of the cut with a very thin rule I was able to squidge some more glue underneath and then re-press it, this time veneer side up. The second pic shows in a bit more detail three dark post-surgical parallel scars across the board.

When it came out the bag, this was a real mess...so I reckoned the easiest way to clean this side up was to nuke it with the ROS, which took around 20 minutes to finish. Fortunately, because the veneer is so thick, there was no danger of going through it.

Sometimes, 60g paper is the way forward!

19 May 2010

The 'Bump'

No, it's not what you're thinking!

After some protracted effort, I finally managed to finish off my Japanese chisels, recently acquired from Workshop Heaven. It's been a bit of an uphill struggle to sort out the backs...the bevels were fine, but the backs caused a problem. I was told by Matthew that the heat treatment of the steel causes a minute 'bump' to form just behind the edge, shown in the ringed circle. It's easy to see it by holding a rule against the back and then squinting along with a light behind. I tried 100g sandpaper glued to glass and mdf but it was still there and try as I might, I couldn't seem to get rid of it. The 3M papers on float glass were excellent in refining the surface, but the grades I had available were too fine so I thought I'd give it a shot with a couple of coarser papers, 60 and 40micron PSA. I stuck these to some more 10mm glass and within around fifteen minutes, the problems I'd encountered were gone...a dead flat back was produced.














What's interesting though is that these chisels are really quite crudely made, showing the legacy of hand forging and grinding. If you look at the bevel on the 30mm Orie Nomi, you'll see that it's not been ground square by the maker as the bright shiny bit is where I prepared it on the 3M papers with the Kell III guide, which is guaranteed to produce a square edge. (The black triangle is just a marker pen so I could see progress)

Purists though, may well be gagging into your morning coffee if you have a look at the section of steel behind the blades...that's been ground away as well! This has been done for two reasons, firstly to give clearance when mounting in the Kell III and secondly to maintain a dead flat surface as the blade is moved back and forth over the float glass. If it hadn't been ground, then as the heel of the chisel meets the edge of the glass it'll lift the blade (or chip the edge) further exacerbating an already existing bump...

...definitely not required!

15 May 2010

Compression














Some progress was made yesterday evening on the Media Unit...that was after I'd spent most of the day finishing off the last of the Japanese chisels from Matthew at Workshop Heaven. Some more work is still needed on them, but that can be done in 'slow time' as there's no desperate urgency for them to be finished. It would be great if they were done and dusted, but I need to get hold of a few more sheets of coarser 3M papers to prep the backs.














You can see from the first pic that the veneers have gone into the shute to plane each adjacent bookmatched pair. This really is the only way to give yourself a fighting chance of a decent join...planing them freehand in the vice is a bit of a non-starter! The 'lay-up' was then produced (in the second pic) and shows one complete and the other yet to be made. If you look carefully at the one with the roll of veneer tape on it, you can see that as the tape has dried out, it's pulled the veneer into that curved shape...a good sign that the joints are mating.














Finally, once both were done, they were glued with TBIII, popped into the AirPress vacuum bag for a bit of concentrated suction and left for around three hours. Although the pump itself is a great piece of kit, the welds on the bag, especially at the open end are utter rubbish...hence the blocks and crampage to get it air tight. In case you're wondering, I always cover the sharp corners with thick pieces of paper from magazines just to relieve the stress.

Discussing stress, Gareth, my No1 son is home for the weekend and yesterday morning succeeded in munching his way through a whole, unopened bag of dried apricots.

I'll wager you a £1 to a pinch of something unpleasant that his insides this morning are under considerably less stress than the contents of my vacuum bag...

12 May 2010

Kingdom


The hard work has started and the pic shows current progress on the Media Unit. What you can see are the two ends (one piece ply and t'other mdf...well, gota use whats available!) where each piece has been lipped with some 12mm oak which will eventually be on the floor.

What I'm doing here, having planed a face side and edge is to attempt to make each piece exactly 450x400mm and absolutely dead square in all directions.

You'll note of course, that since I sold on the Kity 419, this mind numbingly, wearisome task has to be done the hard way, with hand planes that need very frequent honing owing to the abrasive nature of the material.

Good news is these are the short bits, the bad is that I've got to do the same thing on the top and bottom that are about three times as big.

Whilst I was slogging on with the planing this evening, I thought about the Great Bard who penned the immortal words...

"A horse! A horse! My kingdom for a horse!"

Right now, I'd gladly give my kingdom for an Altendorf....

09 May 2010

Confection

In case you're wondering why it's gone a bit quiet on the Blog, over the course of the last week I've changed work locations with all the ensuing chaos that it brings. However, things are starting to settle down now. I have to say that I far prefer my old office as I really don't think that the open plan environment works for me...but hey, it's only for a few months!

Shown in the pic is a full size mock up of one of the joints for the Alan Peters style Media Unit that I've started to make now in earnest. I was initially quite concerned as to just how I was going to make this Chinese looking confection, but in the end, it was relatively straight forward, but did require some seriously accurate marking out to get the mitres to meet.

The construction is as shown...the core is two layer of 18mm ply with 2mm oak veneer over the top. A 20mm oak lipping was then applied and the joint cut.

If you want to know exactly how...you'll need to stay tuned!

02 May 2010

Comfy curvature...


Having made all the necessary 'fixes' to the offending mortise and tenons, this little stool has been finally finished.

Notwithstanding the errors made in the final glue-up, it's turned out quite well. The timber (air dried English Oak) has been left mostly straight from the LV BU smoother, with a quick touch from a card scraper here and there, finishing off with a light pass with some 15og paper. Aris's were not sanded either...I used the LN block to take off the sharp corners on straight bits. The curved shape of each foot was bearing cut with the router and then the chamfers were left straight from the LV 'shaves. Again, no sanding.
The applied finish is two coats of matt Osmo Poly-X oil with a good application of Alna teak wax (sadly no longer available) over the top.














The other thing I would have liked to have done is to book match all the timber...you can see there's an inconsistency in the boards for the top, but as I was using up the oddments from an otherwise split and knotty board, it was necessary to 'mix and match' as best I could. The only bit which is a true bookmatch is the thinner centre rail.

All told though, not a bad effort.