Saturday 11 May 2013

It may be boring to you but it is rivetting to me :-) (it's my living)

In my day job I am a bulk handling engineer and we use steel backed, wear resistant rubber to line chutes, hoppers and trucks. Fixing this is not easy and we often need to counterbore up to 120mm into the rubber at 60mm dia.

After much struggle and smoke I came across a 1930's engineering manual which suggested some cutting and clearance angles for machining rubber. I made up a boring bar with a mandrel guide to run in a pre-drilled pilot hole (which would later take the fixing)  and ground up some cutters from HSS steel lathe blanks.

The results speak for themselves, clean hole and shaving, rather than smoke and gunge.





A classic example of not re-inventing the wheel.

Friday 10 May 2013

Built in torsion-box shelves

I wanted to put some shelves in an alcove of a new apartment between metal stud walls. Being new the walls were perfectly square and plumb!!! and tapered almost 10mm, inwards from back to front. This posed the first problem that if I used invisible fixing of some sort they would not slide in from the front.

The solution was to make tapered side cleats, screwed to the wall, leaving a parallel tongue to allow the shelves to slide in. 

First the torsion box shelves themselves. Foolishly I decided to use 6mm oak veneered ply which was a nightmare to keep flat and it would have been much better to use MDF.

I glued the framework which was roughly tongued together onto the first side and clamped it to the bench.








 The cross braces had a sawn tongue each end which located in a groove along the front and back rails to ensure a level.

The full depth front rail was glued to the font of the frame to allow for a radiussed edge later.




 Fitting the other face was much more difficult than I had thought owing to the wild ply and I used every cramp I had and more.




 It were a reet thrutch to get it all together but we made it in the end.






Finally a pair of very strong shelves which had no flex at all.





The front rail overhung the sides which were grooved in preparation for the cleats




The cleats were planed up with a loose tongue screwed and glued in place. The counterbores came perilously close to the edge but I just made it :-)




Test run before installation







A bit of a clean up, radius the front edge and they were ready for fitting





Wednesday 8 May 2013

Alan Peters Oak bench circa 1980 ish


I recently sent an oak bench back to it's maker after a 1/3rd century faithful service. It really was on it's last legs even before my daughter's then boyfriend put his foot through one of the rotten seat rails. Even so 33 years is not bad for untreated oak outdoors.

The original design was by Alan Peters and published in the Woodworker about 1980. You can clearly see the influence of his Japanese adventure, which influenced much of his work, and his Barnsley Arts and Crafts background.





I took measurements and made a sketch before putting it onto the firewood pile so I intend to make a modified version shortly. I'll put the drawing up on here later for anyone who is interested.




This was a far cry from the youthful chippy who was so proud of his first hardwood job, made at the local school evening class with wooden jack planes and hand tools. I chickened out halfway and got my brother in law to put the back slats through the thicknesser at work. It was all in air dried English Oak with drawbored, pegged and wedged M & T's throughout.

I was so into natural things I fastened the slats with oak pegs knocked into the frame. Amazingly they held tight for the full distance.  What finally killed it was rain getting into the exposed tenon ends in the top of the front legs.




We weren't off to a medieval banquet, that was the Laura Ashley "look" of the time, beautiful English ethnic!

Sunday 5 May 2013

Hanging the ship lap door


With the door made and all the hard to find hardware collected, or dug up from boxes where it had lain undisturbed for several years, it was time to say goodbye to our long suffering sheet of shuttering ply.

Friend Doug was on hand and made an excellent job of installing the frame. I was concerned about the weight of the door so we dropped a couple of hammer screws through the cill to eliminate any chance of the door pushing the bottom of the glass wall out when open.








Yes I know it is a big step but the patio will be lifted to match.




Time for a Stella?

At this point I had to depart for a culinary extravaganza  of Barium soufflĂ© at the local hospital so I left Doug to carry on (not that I had actually done a great deal myself so far).

When I got back all was not well. My original 100m roll of seal had run out so I'd bought 10m from Germany via ebay but it compressed to 7mm rather than 2mm so the door would not close.

UKIP supporters may like to be made aware that this would not be possible under Faragism, along with a fair chunk of other vital trade, but don't let any minor inconveniences like that get in the way of the populist lunacy.

Doug was not happy but at least it was Friday. I unhinged the door and the shuttering ply got a reprieve for an extra night.

The warts 'n' all section!

I set about finishing the job the following day and it took all of 10 hours to complete. It is fortunate I am not trying to earn my living at this game!

I had to move the 8mm x 4mm seal groove back 4mm and cut one of the rebates back to suit. I used the Biscuit jointer as a slotter and milled out a 12mm square groove back to the new position.




I milled out some 12mm filler strips from some cherry offcuts and glued them into the groove.




I had a sandwich while the glue went off then trimmed off the excess with the excellent track saw.




Nicely set for a quick clean up with my favourite and much used skew rebate planes





A new grip leaving my other hand to steady the door.




Again the combination of left and right handed planes proved useful.




I put an extra rain drip in the door bottom as a precaution although there will be an external drip rail planted on the outside. All ready for some Sikkens and a re-build




The new oversize seal going in. It really is an excellent product and, being a compression face-seal, way ahead in performance terms compared to the usual UK furry stuff.







I fitted the handles and strikers along with shoot bolts top and bottom so I think it is pretty secure. It was a bit of a lump to balance on a lifting lever but Ro helped and we managed to get it back on it's pins. This time it shut first time and a little adjustment had everything working smoothly. Fortunately the seal also acts as a damper so it doesn't shut with the sort of bang we expected.

I am really pleased with the appearance and functionality but I would make a few less mistakes if I made another - as ever.





It certainly isn't lacking in the hinge department and I could probably have omitted the 4th one in the centre. Then again when you pick it up ......better safe than sorry, but it does clash with the handle.




Friday 3 May 2013

Making euro windows without dedicated tooling (Almost)


I originally saw these windows in Germany but they are widely used throughout Europe, and particularly Scandinavia, where the excellent insulation is essential. Most of Europe likes timber as it is everywhere, although there is a small presence of the dastardly plastic in the cities, along with a lot more powder coated metal with thermal breaks.

Almost all of them are inward opening, tilt and turn, which makes cleaning easy from the inside and use a standard mechanism, usually from Roto. YOu can leave them open in the rain without drowning your  windowsill.






The weather resistance is outstanding with internal drain channels discharging into a special alloy bottom rail which runs the water out to an alloy cill. This deals with the most common cause of rot, the cill, and an additional profile is available to cover the bottom rail of the casement for additional protection. There is a substantial compression seal, much larger than the standard UK wiping seal, which can be augmented by a second seal on the inner rebate for complete draught proofing. There are 3 rebates on the casement, two to provide positive location against the frame and a central one to control the compression on the seal.









In my case I chose triple glazing, owing to the extreme exposure of the site and the large glazed area in our 1960's house. This consisted of 4/12/4/12/4 with K glass on the inside and argon filled. South facing units were additionally bronze tinted to control excess solar gain which proved very effective.

In my case I chose Douglas Fir (also known as Columbian or Oregon Pine) for it's high resin content which resists rot and attractive grain but it is not an easy timber to work with highly defined growth rings which can deflect hand tools and frequent resin pockets and alternating grain. The timber is prone to surface checking and splinters easily which usually turn septic owing to the resin. In some cases the dust and resin can be a skin irritant. It is expensive and often found in the offices of our ever frugal  public servants.

External finish is usually porous Sadolin or Sikkens.

Our house required 37 casements in 1 to 4 pane units, two big tilt and slide patio doors, with glazed panels either side, and two glass walls, one single and one 2 story. If I had realised how much work this was at the outset I would have chosen a different approach but I was keen to make them myself. Although I had a universal machine, with tilting spindle moulder, saw and planer thicknesser I was not intending to become a commercial maker and so did not feel the £4500 investment in purpose spindle tooling was justified. (Maybe not true with hindsight!) Consequently I made them all with standard rebate blocks and slotters.

The design is based on double bridles and stepped shoulders match the rebates. The stock is all 80 x 68 thick with 1 off 8mm and 1 off 10mm tenons per corner, positioned to match the rebates. Felder do a useful book with dimensions of all the layouts including arched tops and double doors, although there is an error in the basic casement size calculation, so proceed with caution. The original versions of this style had external pivot hinges in the bottom corner needing only 18mm rebates for the stays but more recent designs require 20mm rebates and the gear is completely concealed. The good gear was called Roto Royale but this has since been superceded by ST which works but is not so well engineered. On the positive side it is easier to fit. All the gear fits in a standard Eurogroove which for the uninitiated is a 12.3mm square rebate under a 16 x 2 cover strip housing on the surface. It is worth buying a dedicated cutter to make Eurogrooves as they save a lot of time.






There was quite a bit of work just getting the timber to size. Both inner and outer are 80 x 68 in this version.





I used a rod to mark out the dimensions. It is easy to lose your way so I ended up marking each piece of the bridle joints. First the mortices were cut in the top and bottom rails for multi openers while still square.




The bridles are a bit of a brain teaser





Tenons on long sections were cut on the bandsaw







The vertical and short lengths are cut on the spindle using a 250mm adjustable slitter.
I had to use a tennoning hood, rather than the normal moulding fence, owing to the cutter diameter, so used the rip fence to position the rails before clamping to the sliding table for the cut.











The tenon shoulders were cut using a special cap in the recessed head. I had this one made but gather they are now available from Wealdens.





I did try various ways of trimming the scribe with a chamfer knife and the spindle tilted and on the table saw with an extension sacrificial fence but, in the end, it proved quicker to saw them by hand with an angles guide block.




Slotting cut were made with backers to prevent spelching




On the long rails the rebates were run on before the shoulders were cut but this proved to be a mistake as it was more difficult to sight the lines





Rails and stiles waiting for moulding









Glazing beads were moulded on the rail including a useful rebate to ease later removal for repair then parted off on the saw. The kerf width needs to be established so no further cleaning of the bead is needed.










A final clean up needed the Bevel Up smoother owing to the variable grain





Let the glue up begin. The casements were made on a building board to ensure squareness and the frames on the floor with a carful check of the diagonals with extending rods.









There was quite a pile of them














I quickly ran out of building space






The Eurogroove and seal groove are best done when the casement is glued up so that the corners don't need any later cleaning up and they all line up!

Purpose made EG cutter





I made a little special plane to clean the shoulder of the groove on some I had made before I had the above cutter. I just used a blade from a Stanley plough. It worked well and could be set LH or RH but note the mistake on the width of the mouth.






Final job before the hardware is the drainage arrangements. I had put a 10mm square internal gutter along the inside of the bottom of the glazing rebate and drained this with 8mm holes at 150mm pitch having previously had trouble with less. I had a jig to ensure I hit the gutter when drilling up from the middle of the drip.

Effective drainage is vital to give the fragile glazing seals the best chance of survival, especially on triple glazing which has twice the chance of failing as double!









Time for some hardware. Starting with the botttom corner hinge the corners are fitted first and then joined with the connector strips with the multi point rollers.









 

The 4 pane with outer openers awaiting and inner skin of blockwork inside and the drip channels and cills outside.








Taking into account the timber frame, perfect sealing and triple glazing I reckon these are about as energy efficient as it is practical to go in the UK. As a independent mzaker I had to get the BCO to sign them off but he was very happy with the arrangements.