Hardware Order

It's time to order the sealed units, seals and hardware. I'm likely to ponder this for a while and check out glazing suppliers. I've got the latest Reddiseals catologue, they supplied the hardware for the small test window, so I'll sit and have a look through that.

The other main decision is the actual seal to the glazing. There are a few types of seal available so got some further research to do.

Whilst I'm at it I'll do some more research in to Linseed oil paints. I was going to go for conventional paints but from what I've read on various forums I'm tempted to go with "Holkham" paints.

If anyone has any experience, please let me know. I'm after the best solution and price doesn't mater.

Cord groove

All the way down each side of both sashes the cord groove is routered.

Although the cord will only go about 200 down the sides the groove goes all the way. This can help stop water being driven on to the brush seals.

To make this a little steadier to cut, as its on the full glued up sashes, I knocked up another large fence. I'm sure it'll come in handy for other jobs.

I also need to widen the groove at the top to allow the pulley to pass. I'll wait until the hardware arrives to figure out the dimensions.

Back to the Job

After a few celebratory beers on Saturday night, it was back to it on Sunday as there's still more to do.

The parting beads, Staff beads and weight separators.

Simple planing thicknessing and routering.

Client Approval

This was the first time Wendy could get a proper idea what they will look like.

RESULT! yeah.

Making the horns

As the rebates are so deep I filled them in by gluing blocks. One for the rebate and one to get the overall depth the same as when the "bead pieces are fitted.

Then I cut the horn shape with my jig saw. This is far from ideal as the longest blades only just manage it. The blade wandered of perpendicular towards the bottom of the cut and it needed a sanding to get the shape right.

However, it worked out well enough.

Now ready for assembly check

With the parts cut and drilled its all ready for an assembly check.

I screwed blocks on cill to make sure the pulley stiles where square before pilot drilling. These will be removed before gluing.

I used 3" No. 8 for the outside and inside lining and 4" N0 10's for the pulley stiles. Pilot drilled for the full screw length, going in to end grain I didn't want anything splitting.

The top rail fitted nicely, just pulling a bit twist in pulley stile back in to shape.

With this fitted I could mark up and cut the top linings.

The top linings are fitted with blocks, crude but effective.

I glued and screwed the blocks on, after marking up on the frame. I used a rule to make sure they where on straight.

So that's it (ish) for the frame. Picture to follow....

Almost Ready for Frame Assembly

With all the pieces cut it's all ready for for an assembly check. But a little more first.

Mark out and drill the screw holes in cill.

Machine out notches in the outside lining, these will stop water pooling where they meet the cill.

Round of any sharp outside edges.

Why? - It is said, and I can believe it, paint doesn't like staying on 90 degree angles. Recommendations are to chamfer corners or round off.

Remember to stop the rounding off:-

1. On the cill where the outside lining will meet.

2. On the outside lining where the outside rail will butt up.

3. While the router's set up do the sash pieces where possible as well - time travel - step now....

I should have rounded off the notched in the outside lining as well.

Setting the Frame Width

The inside width of the frame is determined by the width of of sashes + clearance of 4mm. I marked this on cill and added the thickness off the pulley stile to give me the size of notches I needed to cut.

I cut these by hand. These extend the slope of cill, though the upstand to the width of the inside lining from the back of cill.

From this I could mark up the top frame rail, using the outer edge of the notch.

Cutting the slot to take the tongue of pulley stile using the cross fence, to the inside of the line.

Then (with hindsight) I should have cut the top rail ends to suit fit the outer rebate of the linings and slot the ends to fit the weight seperator. I realised later and ended up with this:-

I've also marked it up for drilling.

Pulley Stile Tops

To make sure the frame will fit the sashes, first check what the two sashes add up to. Rather than just rely on what they should be, why not glue the sashes up and work empirically.

A lot of things to remember from this picture.

1. I planed up two pieces square and flat and bolted them on the router table top. This gives me a flat frame to assemble the sashes on.

2. My cheap " Forged Steel" sash cramps are cheap for a reason, the adjustable back stops don't stay square to bar. Hence twist the rail when clamping. I need to drill, tap and put screws in to stop the movement. Or pack out with flat bladed screw drivers like I did this time.

3. Next time I'll chamfer the end of tenons so they don't push too much of the glue out of mortises.

4. After clamping pressure to close up joints, back off so the stiles aren't bent. Then check they're square.

5. Fox wedges do seem to work. Applying compression but without moving the joint

6. I can assemble and clamp up quick enough to work with PU adhesive.

(Time Travel - Round of the edges I can at before assembly - at the same time as the otside lining, cill and top lining rail, but first know the height, Oh No! chicken and egg time loop. Dr. please help?)

With the sashes glued up I clamped them as they'll be when closed and measured them. Then went back to the paper calculations. I'm glad I checked as I'd not accounted for a rebate on the bottom of the BS Bottom rail (Note: adjust cut list). Apart from that I was only about 1mm out. I'm happy with that.

Adding a 2mm clearance I then knew the height of pulley stile. These then needed cutting with a 5mm tongue added on.

To make sure they both ended up the same height I clamped them together with the bottom ends together. Then the top ends are machined square leaving the tongues.

Cutting the box bottoms

The fitting of the boxes to cill is another departure from traditional designs, where the pulley stiles are set in to the cill and wedged. Thsi is point that is most likely to rot so I'm butt jointing with screws from underneath. Apparently this is common Scandinavian practice and I can see the benefits in theory.

The butting up needs to be accurate, for a good joint and to keep the frame straight.

First to get the angle on the pulley stile. I tried to get the angle from cill. Then cut with the mitre saw. Notice, I said tried.....

I then used the angled ends to set the mitre saw to cut the bottom of the outside lining.

So I thought I could cut it all nice, accurate and neat.

If I had a quality mitre saw this should have worked. The one I've got is OK for floor boards etc. but I've decided not stable enough for this kind job.

Plan B. Another little jig

Using a trimming off the end of the cill this jig works this way round for the outside lining and at 90 degrees against the cross fence to trim the pulley stiles.
I trimmed the inside lining on the table as well, so all the bottoms of the boxes are bang on.

Groove for parting beads

First mark up which edges are going to be the outside edges. With these edges against the fence rout the grooves. As I've not got a 8mm bit I needed two cuts with my 6.35mm.

Pulley stiles and top rail , cut 1 (half top rail minus 4mm). Cut 2. move the fence to make an 8mm slot. Using the fence with the extra bit added that runs on the rebate ensures the grooves will line up.

Bed time

Flatening a new piece

I've just mentioned the top rail of frame. The piece I had planed up perfectly to size, on closer inspection had a twist in it. Rather than try and work round it I picked another piece of rough sawn of the shelf. "It'll not take two minutes to plane up".

This had a twist in it as well, But with 25mm to plane down to 22mm I could use it. Hence another simple jig. I found another length that was flat and skimmed it smooth in the thicknesser. Made a couple of really thin long wedges on the bench saw.

Screwed the new piece on to the flat board, from the back, just at the ends and supported the twisted up sides with the wedges. Then sent the whole lot through the thicknesser.

Result one flat face. Flipped over and faced the other side, hence two flat sides.

Weight Boxes

Each side of the frame is made of three parts, Outside lining, Inside lining and the Pulley stile. These fit together with a tongue on each side of the pulley stile that fit in to a groove in the linings.

I've tried to come up with a method here to make them accurately with the least number of measurements.

Grooves in the outside lining and inside linings. First another fence for the router table so I can use just the one face to make all the cuts. the standard fence doesn't move back far enough to do this.

The inside linings need a groove 5.5mm deep with the side furthest from the face edge being the same as the thickness of the pulley stile.

The outside lining groove has it's closest side being 20mm from the face edge. I've made a 20mm wide stick to use as gauge, its also used in the next step.

The backs of the boxes will have a plywood cover fitting in to a rebate 5.5 x 6mm.

First the Outside lining. Move the fence back so the same face edge can be used, I ended up clamping the fence to a handle on the table, very Heath Robo.

Remember as I'm using the other side of cutter - Feed from Left to Right

Then with the same fence setting use the 20mm stick to pack out the Inside linings from the fence.

On to the Pulley stiles - These need rebating on each edge to make the tongues. The first rebate is easy enough. The tongue wants to be 5mm long.

The rebate on the other edge wants to be referenced from the rebate just cut. Doing it this way means I only need one good edge when I'm planing up - So another fence modification.

I added a piece to the top the fence that run on the inside of rebate. The width between the new fence and the cutter is set to width of the top rail. eg. cill - inside lining - outside lining.

Just had a couple a glasses of wine so apologies if linguist capability levels are dropping......

I was sober when I made them hence results bang on.

Cill- Profile cutting, the best way I could come up with

I spent ages thinking how I could easily and acurately machine the the slope required on the cill. (Thanks for the suggestions folks).

I ended up making a simple surfacing table to use with the router. This has two rails bolted to the router table top to guide the router that sits in a cradle. I used it first flat, to get rid of bit of a twist in the cill then added a batton to one of rails to give me slope.

The cradle is simple enough but took a bit of thinking through to get fence to work.


Next time I'll take a most of the material off with a rough cut first. As I went deeper it got a bit heavy going and took a lot small cuts.

The result was good with only a few slight tramlines, I've improve the router to cradle clamp to hopefully eliminate this next time.

Just for the record the timber is held with a screw at each end clamping it down on to wedges.

Drainage and Ventilation on the Sashes

Nearly forgot, The drainage and ventilation for the space around the sealed units. This goes on the TS Meeting rail and BS Bottom rail.

First drill the holes, a little difficult on the BS Bottom rail as the stroke on my drill press isn't long enough. So I did it in two stages and added a packer for the second stage. Then router the groove in, this should allow any water that gets past the seals to find the hole and drain away.

Credit Dave - clamp a same height as the top of the rebate, use a low fence (to avoid the clamps )on the router table - easy, cheers Dave.

Re-assembled result

Sashes nearly done, on to the frame

I thinks that's all the work done on the sashes for now. There will be more to do after they are glued up.
Do I dip the ends in preserver first? Or maybe even get the parts pressure treated?
Do I use PVA or PU ?

Decisions, decisions!

After gluing the joint end will need trimming, the sides machining for the sash cords, notches cutting for the parting beads, a 5mm rebate on the bottom of the BS.

I need to think about cutting the horns as well. I'll need to fill in the rebate in horn (traditionally the rebate upstand is cut off below the bottom rail, but these rebates are BIG). If I had the cutters I could do them on the router bench, I'll check what I can do with my set, otherwise it will be a job for the jigsaw and a bit sanding.

However now I've got the sashes and they ended up the right size. I can confidently start on the box frame. The starting point here is the Cill, cutting the slope on it, with an upstand is proving interesting... details to follow.

Top Sash side beads

These are easy as the bottoms are a straight cut to face up to the TS Bb/meeting rail.


Clamp up the TS, place the beads on, mark up the side beads and cut.

Ops... just looking at picture, somethings not right. I've cut the rebate in end of the TS Bb/meeting rail at the wrong side. Luckily most of the wrong rebate will be cut away for the parting bead to fit and the rest wont be visable.... phew.

Bottom Sash Side and Top beads

These need measuring to get the height of the bead. Rather then use a tape I assembled the bottom sash and clamped it up.

With a 5mm packer under the bottom of the BS Bb place the side beads on the sash.

Using the top bead as guide, mark where the mitre needs to go. All things being equal the other side should be exactly the same, so the mark can be transferred across.

Cut the mitres off on morticer and router off the excess( as previous step, and all the tooling should still be set up right).

Using the sides, mark up the width of BS Tb

These can then be cut using the the table saw.

The Mating mitre cuts in beads

These mitres are in from the ends and so need a different method.

TS Tb and BS Bb - both ends (These are the ones cut to size with the rebate across the ends)

Mark them out using the mitred ends cut in the previous step.

Then set up the Morticer with the chisel at 45 degrees to the fence. A bit of faffing as the fence needs setting to the right distance as well and it wobbles a bit when clamping.

With the point of the chisel just a smidgen (getting technical) back from the edge of the moulding, make the cut. I found ,when pressures applied the curved end on the chisel pulls the piece in a bit, hence the smidgen.

It makes a good quick clean cut at bang on 45 degrees. There was just a little nib to take of as the chisel wasn't quite wide enough.

Using the end of the router with the bead flat against the fence take the excess moulding off. There's a little bit on flat that needs cleaning with a chisel.

The finished joints mate up well. I should be able cut the mitres on the Stiles and Rails in the same way.

First mitre cuts on the beads

A bit more jigging required to make up for rubbish wobbly guide that came with the saw.

First, a cross cut guide, a piece of ply bolted and screwed on the slider bar. And a 45degree angle cut on the guide I made for the router table.

Cut mitres of the ends of BS Lb and Rb, ST Lb and Rb

Mark across from where the mitre cuts the end of the moulding and cut at 90 degrees. Ending up with it bang on like this:-

Rebates In the Beads for Brush Seals

The beads also take the brush seals so a rebate is needed to take the carriers.

The TS Tb and BS Bb are 2mm deeper than the carrier so the pile of the brushes don't get crushed flat when the sashes are shut.

All the side bead rebates are are as deep as the carrier, I'm aiming for 2mm clearance each side between the sash and frame.

CUT the BS Bb, TS Tb and TS Bb to width using the width stick from earlier.

Then rebate the ends of these.

Note: Don't be a dummy a second time. Cut the rebate on the TS Bb on side opposite the brush groove. (not shown in picture)

You can see here I've made a 90 degree angle block to do these rather than have to set up the cross slide.

Beads - a big difference from traditional construction

Apart from being internally glazed this is where I've made a big leap of faith in the design. Due to the extreme depth of the rebate. The up stand of any glazing bead would require a wide base to pin to and I want to keep the sashes as thin as I can. I also want the internal look as traditional as possible.

The solution I've come up with is to face the entire inner part of the sashes that will, when fitted clamp the glazing in place. These will be screwed on. Along as I get the right thickness glazing tape, I'm hoping it will work out well.



First, a simple quadrant moulding. I took the bearing off my bit so I could the profile I wanted. I made a straight fence for the router table, I was getting fed up with trying to the split fence lined up accurately.

I'll still call these beads even though they aren't.
I'm going to start using some abbreviations now to help speed up the write up.

Top Sash = ST, Bottom Sash =BS

Left stile bead = Lb, Right stile bead = Rb

Bottom rail bead =Bb, Top rail bead =Tb

What follow is procedure I used for accurate cutting of the beads.

Drainage and Ventilation

Leaving aside the meeting rails for a while (this window is for the first floor so security is not so critical). Time to finish of the main sash pieces

The double glazed units will have a 5mm air all round. The bottom rails need venting to allow any moisture in the air gap to get out also any water that gets past the glazing seals needs to be drained away to the outside.


So first drill some holes. I've used 9mm at approx 150 centres. Easy job in the top sash meeting rail but I had to drill in two steps through the bottom sash rail as the stroke on my pillar drill would go the full depth. I also counter sunk the external face to aid painting.

Then with a batten clamped to rails making up for the rebate I routed from the first hole to the last with a round ended bit.

The resulting groove stops any water from the outer face reaching the inner bead. It looks like:-

Another point to the meeting rail design

What about security. A dog leg in the face of the meeting rails would prevent the latch being reached through the gap. So there is a point to the traditional design.

Another re-think is due.

Meeting rail detail 2

So with some more thinking, (with coffee this time), I sketched out some more ideas and came up with even more ideas. The result being:-



A brush to brush seal that will always remain uncompressed. So allowing moisture to pass through without letting draughts in.
The brushes will compress against both sides of the parting bead ending up as like a felt block for the windows to run up and down smoothly.

I might move the brushes down a bit to give a bit more around the upstand of the rebate.

First attempt at the meeting rail detail

A few bits to think think about with this detail.

1. The two rails need to meet and seal .

2. The parting bead has to go between them at the ends.

3. If there is any condensation running down from the top sash, how do I stop water accumulating between the rails.

The permutations seemed endless and i got a bit hung up on traditional designs that have a lip or meet with an angle. I pondered it for a while, probably too long as I had a few cans at the same time. I thought I had the solution so machined the pieces.

I'm sure this would work. The idea behind a brush seal being, if water got to it, it will seep through. Thinking about it the next day I decided, the step is pointless and the sash latches pulling the rails together could over compress the brush seal.

Some comments I've had

It's been suggested by some experienced woodworkers on forums that:

1. I wedge the tenons. Thinking about this I don't know why I need to do this if the tenons are tight, is it so I can get glue in the joint? Is it so the timber of the tenon can be compressed so if it shrinks it will spring back and keep the joint tight? I have read that only the shoulders and wedges should be glued, is this to allow the tenon to shrink and contract? Any comments please let me know.

2. I should consider haunched tenons (and wedged) instead of dovetails. I don't know how much haunch I need so there is enough timber left on the end of the rails to resist side force from the wedge. I suspect more the than 10mm would be required.

I'll ponder these for a while but will have to make a decision soon.


Still not had the blog unlocked, hopefully today!

Too many posts in a day

Oh no - scary stuff, I posted loads yesterday and the blog has been identified as potential spam.

Please, Mr. Real Person who is reveiwing this, don't delete it, I spent most of yesterday writing it and I'd cry if I lost it.

The finished Mortice and Tenon joints

From the outside.

I'm not wedging these, I currently don't think its necessary as they are good tight fit.

From the inside
Note: Make sure the thicknesser cleans up all the wood. Luckily this bit will be hidden eventually.

Cutting the bevels

Router up to the marks, set the height using a scrap piece or end and one of the tenon ends to check it.

Note: It would be better to slide the piece along a rail in the rebate so the height is taken from the rebate and not the edge of the bevel

Note 2: Don't try and use the router backward to do the other end. It doesn't work!

Trim up to marked line, I found it easier and neater to use a Stanley knife. The chisel, although sharp compressed the grain.

Marking out the mortices

Time for the second measurement. Mark one of the bottom sash stiles to the right finished length.

Mark up the mortice from this length using the tenon of the bottom rail.

Offer up the two stiles and transfer the top mark across to the second stile.

Mark the bottom of the mortice on the second stile using the other tenon of the bottom rail

5/8 bit in the morticing machine and cut to the marks making sure the upstand of the rebate is flat against bit.

Assemble the bottom sash as far as the bevel will allow. Offer up the top sash with the rebates of the top rail of the top sash against the bottom rail of the bottom sash. Then mark up the mortices for the top sash meeting rail.

Cut these mortices and assemble. Mark across using the flat chisel against the bevel of the rails, to see where the bevel on the styles needs cutting back too.

Bottom rail side step

As the tenon on the bottom rail of the bottom sash doesn't want go all the way to bottom of the stile, it needs cutting back.

With the smaller step of tenon set to the sacrificial piece I used the full length of the cutter.

Marking out and cutting the Bottom sash meeting rail female dove tail

With the width gauge fitted to the meeting rail, mark using the stile how deep the female dovetail needs to go. Then mark the angle on the end grain, again using the stile as a template.

Using the mortising machine to take end of the female dove tail through to the other side.

Mark the other side and hand cut the rest. The joint should look like this.

Bottom sash meeting rail male dovetails

The bottom sash meeting rail (left) and the stile right. This shows how the joint will go.

Using a angle gauge mark out the male dovetails.

I hand cut these but I suppose I could use cut most of the angle more accurately with the mortising machine.

Top Sash female dovetail in stiles

Use the male dovetail to mark up for the female on the Top Sash Stiles

Use the morticing machine as much as possible to remove material and transfer the shape on to the other face. Saw and chisel the rest by hand.

Short side of male dovetail - top sash top rail

Mentioned on the list of cuts is the an angle jig for cutting the Top sash Top rail male dove tail.


This is what it looks like:

Ops... I cut this one a bit thin, so I glued a bit back on and re-cut it. I suppose I should also own up to cutting the other end the wrong way round.

Note: pencil in the cut, stop, think, then cut

Cutting tenons - List of cuts

So the next time I can cut them in the right order with a minimum of tooling adjustments: -


1. Long side of the tenons -
Back stop and cutter height to suit first template,
Bottom sash Bottom rail both ends
Top sash Meeting rail both ends
Top sash Top rail both ends


Change back stop, to suit Bottom Sash Meeting Rail template
Bottom sash styles tops only

2. Short side of male dovetail top sash top rail -
Back stop set for rebate in first template, Use angle base (see later) height to suit
Top sash top rail

3. Short side of male tenons -

Set Height using Mortice chisel

Bottom sash Bottom rail both ends
Top sash Meeting rail both ends

Change back stop, to suit Bottom Sash Meeting Rail template rebate
Bottom sash styles tops only (hand cut later to make dovetail male)

I Think !

Cutting stepped tenons - short side

To cut the short side of the tenons

Note 1: The tops of the Bottom Sash Stiles (verticals) need a different setting as this is for the dovetail male to mate with the thinner meeting rail.

Ops...I went wrong here. So cut a new template off the meeting rail to do this to get the setting.

Note 2: The top rail of the top sash uses the first template BUT is an angled to creates the required dovetail (see later post). Ops... I made an added cut processI didn't need.

Step 1. Setting up the back stop as before but using the rebate on the template.

Step 2. Set the height of the cutter using the mortice chisel as the guide (5/8 inch)

Step 3. Refit the Width guide to rail using the same screw holes and cut upto the MDF/fence stop.

How the Long side of the Stepped Tenon should look

A neat cut to the same depth as the upstand of the rebate.

Cutting stepped tenons - step four setting with the jig

Its all ready now to cut the long side of the tenon

Clamp the rail to the cross slide and set the cutter height to just take off the beveled side of the rebate

With a series of cuts, feed the rail towards the fence. DONT GO TOO FAR.

The last cut has to be set with the end of the screwed on jig set against the MDF pressing upto the fence. Once set and clamped, remove the MDF and make the final cut.

The other end needs cutting in the same way.

Cutting stepped tenons - step three , width jig

This is the only step that involves a measurement. Measure and cut, with square ends, a piece that will fit in the rebate, to the exact width of the finished sash.

Screw this into the rebate (screw only need to just grab). Cut off the excess timber but leave a bit (less than the thickness of the MDF) for trimming on final assembly.

Use the same piece for a jig on all the horizontal sash rails, I marked an L & R on the jig and rail as the jig will need refitting on the same screw holes.

Cutting stepped tenons - step three setting the back fence

The back fence needs setting exactly to a tight sliding fit with the template fitting between the cut on the sacrificial piece , the template in the middle and flat piece of against the fence (I've used mdf. Just in case the fence isn't perfectly parallel to the cross slide make sure you take the settings from the same part of the fence.
This distance now set will give the longest side of the tenon accurately. Why I've used the MDF as a removable space will become apparent.

Cutting stepped tenons - step two, setting the table

I have a cross slide on my router table, (something can be knocked up to replicate this if the table only has a back fence). The cross slide needs setting to 90 degrees and a sacrificial piece of wood adding.
Cut the sacrificial piece with the router to get a perfect mark for where the cut will be.

Cutting stepped tenons - step one, template

First make a template for the profile of the sides.

Dead easy

Accurately routered off the bevel as the joint wont include this. Then take a slice of the end, this will be the template to set up the router perfectly to make make the stepped joint.

Cutting the tenons- reasoning behind the method

I've spent some time working out the best way of cutting the tenons accurately, being stepped this makes them a little trickier. I found on the test piece that measuring, marking and setting up on router table introduces inaccuracies The following procedure (if you read this bottom to top) describes and illustrates the method I've worked out.
Remember it relies on accurate profiles to start with.

Cutting The glass Rebates in the sash timbers

I'm going to fitting double glazed units in the windows, these will be 4-16-4 to meet Building control U-Value specifications. This means the units will be 24 thick.

I need a huge rebate compared to traditional sashes, this where the design detail differences start to come in.

I'll be fitting the units using glazing tape either side (2mm) thick, so the rebates I've cut are 28mm wide. I might end up adjusting this if I need some extra compression on the seals.

From research I found that the glass has to be supported on spacers to allow an airgap all round. This ensures the edge seal of the units won't fail prematurely due to moisture attacking them. Its also a good idea to hide the edges behind the up stand of the rebate to shade them from direct sunlight. I've cut the rebates 20mm deep.

I cut the rebates first with the table saw, leaving about 1mm to do with the router to the finished dimensions. I then used a 45 degree bevel bit with a roller to add the bevel. The bevel is to simulate putty hold the glass in, keeping the look of the window as traditional as possible.

And in case you were wondering the sashes will be internally glazed.

There's a flat at the top of the bevel that will take a bead of silicon as an extra seal.

Final sizing, sawing and planing

I took my time over this, I'm sure experienced woodworkers and joiners would have no problem but I'm learning as I go along.


Some of the Sash pieces had bowed, fortunately I'd left enough on to correct this. After setting the saw up really accurately ( as mentioned before it didn't come out of the box accurate) I set to work sawing to within about 3mm of the finished sizes. The bowed ones I screwed at the ends on the convex side to a straight piece that then slid along fence.


Then it was down to planing. I need these really accurate so I could get all the joints bang on without having to make little adjustments to suit.

With the thicknesser I recon the average tolerance is about +/- 0.2mm

Seasoning the Timber

I left the timber at the rough cut stage for a couple of month to allow a little extra seasoning. In my opinion its kiln dried it should be good to work straight from the yard. But, I was warned that it can still have a way to go, it seems its an cost cutting practice from the suppliers and merchants.
I didn't want to get all the pieces planed, straight and square only to find them warping badly.

Timber for the first window

I bought a load of timber from Arnold Lavers for this window, spiral stairs and some shelves. I'll work an accurate price at some time.

This is all the timber required for one box sliding sash window (overall dimensions 1300 x 1900). Its all U/S grade a mix of Swedish/Finish and Russian redwood. I dont know exactly what U/S means I think it's Un-Sorted. But I was advised it was the best grade available.

The shifty looking character next to it is me, to give an idea of scale. The stack to the right is for the Box frame, to the left is for the two sashes.

I've rough sawn these to planeable dimensions. Working ecconomical cutting is quite on art to reduce wasteage. I've not fully mastered this art yet and ended up with quite a bit of off cuts. This wasn't helped by some shakes in the timber and knots I wanted to avoid.

Next time I'll select the timber myself down at the wood yard, I'll also have another look at timber sizes to reduce wastage.

Tooling Up - New Toys

With a potential massive cost saving I had no problems getting authorisation from Wendy (the Missus) to purchase some new toys for the workshop.

Bench saw

From Screwfix, "Wood Star" not an expensive one as a result I've had to do some tweaking to get it running smooth and true. I've bought a decent blade for it and it's working well enough although a bit fiddly to set to accurately.

Planer Thicknesser

From Screwfix. It's another Wood Star product but with a much better build quality than the Bench Saw. The side fence for planing however isn't very accurate so I now clamp a hardwood block to the table. The in-feed part of the table doesn't sit true and I have to tap it in to the correct alignment. After some practicing I can now dimension wood accurately and square.

Router table and Router

This was the most expensive purchase (from Screwfix again Record Power) and works well. However I'm surprised the back fence isn't easier to adjust accurately. The Router extension that came with it also seems to be out of balance at high speeds. To go with the table I splashed out on a Trend half inch Router, which so far seems to be excellent.

To fnissh tooling up I bought a morticing machine on offer at the time from screwfix.

I knocked up a dust extractor to go with these and now have all the tools I need. These tools have already been put to good use making the spiral stairs for the loft conversion.

Refining the design of Timber Sliding Sash windows

With the first designs sketched out I've built a mock up to test my thoughts, work out joint design and check clearances.

This all seems to work well. I've made a few refinements and tweaks but it looks like a goer. So I'm ready to start on the first full sized one.

A Quick Introduction

Our house is an 1890 semi. The current windows are single glazed softwood casements fitted in the early Eighty's I think. They, due to neglect are slowly rotting away and some are in desperate need of replacement. We definately don't want plastic and want to replace the windows with Box sliding sashes.

The options are therefore limited. I've had quotes for supply of timber box sliding sashes that come out at around £1000 each. This is way over our budget. We could get cheaper but when looking for longevity, research suggests that I'd be making a bad choice.

Next step was to find out what it take to would take to make them. The advice and construction details available on the web all seem to relate to single glazed windows. The timber sections are available for these but nothing for double glazed windows.

So I've spent some time over the last year researching timber window design to modern specifications, asking questions on forums and then applying what I've learnt to my own designs.

I'll go in to more detail as a go along.