If you are going to get wear it will also wear the laminate, it's not that tough and once the laminate is worn you have to take your window apart to replace it. Any bit of delamination and capillary action will draw water in but it can't dry out so it will rot. I wouldn't use any sort of plastic seal, it will just add friction and make the window harder to use.
You've convinced me. I'll ditch that idea. I probably will still use that seal because I intend to use the cad drawings i have downloaded s basis for the design. Their jamb section is a couple of mm narrower behind the cord groove than the other side and that seal is let in to the slightly narrower section. Seems like quite a good design because the bearing area of the jamb is reduced to half width reducing friction and the seal should control rattling and aid draught proofing. Thanks. Eventually I'll post some photos
You were right about the hardwood cill though and I would strongly recommend Douglas Fir for the sashes.
Y.i would like to use Douglas fir and I'm going to look in to it, but the problem I might have is I would have to either convert rough sawn planks myself to the sizes I need with the kit I've got or pay more to have all the sections pre machined. I could convert rough sawn planks, but it increases the work by quite a lot. My merchant uses their own redwood to make their ranges of windows and I can obviously get PAR sections in near enough the right sizes. I've been looking at timber types for ages but as there seen to be several sash window makers using redwood I've decided it's probably an OK option and the practical choice if not the best. the merchant carries good stocks and I will be able to hand choose my timber with care. I'll be using preservative and then high quality paint and taking care to seal joints.
You can buy ready prepared redwood timber from most decent timber yards in the sizes for sash boxes, give or take some trimming. I use redwood for the cills. The main problem is water. How it can get in and be managed. Most folk will flood an area with sealants. It keeps water out but also holds it in and leads to rot. Water can arrive through the brickwork and stone cills. If there is contact with the sash box and sill then they will go on to stay wet inside the wall. So the thing to do is provide ventilation through the box to allow water to dry out. Put the sill onto some brick dpm. Most problems with sashes and traditional wood fittings are caused by overpainting, underpainting and damp management. I rework many old sashes in a year and find all sorts of surface treatments, aluminium paint, beaten zinc and lead, floods of damn silicon; all useless if the box is wet inside. Worst offenders are aerials through the sill or nearby brickwork.
Thanks DW. Good tips. Been talking to arnold laver today at the renovation show in Harrogate. They say they will sell me Accoya in the quants I need. Think I'm going to use it for the sashes and pulley linings at least. It then runs out at about £120/window which isn't too bad - which when you take off the cost of alternatives is acceptable to my budget!, I'll have to suck up the extra work converting the rough sawn planks. then Hardwood cill, and treated redwood for the remainder. Was quite interesting to see lots of joinery companies with sash windows on the stands, and all with slightly different draught proofing arrangements. Don't like those spring balances! The laminate idea is dumped!
Well the work has started. I'm confident I can do this (SWMBO still has some doubts), but 8 sash windows is a big project for me. 0.7m3 of Accoya now arrived (ouch!), along with various beadings, weatherstrips, seals etc. I decided to buy one of screwfixes cheap planer thicknessers to help convert the timber,including the 200 x 85mm x 3.6m plank of utile I need to convert to 68x165 cills. I've modified the thicknesser with an extended lower deck, improved fence, and tie wrapped the stupid interlock so I don't have to use the crappy chip extractor hood. Had to reset the blade height as well. It spits shavings everywhere but my garden vac (handy tool in a workshop for bulk shavings) and workshop vac make quick work of that. Have to say though, it coped with that big chunk of Utile admirably, and is going to be a great help. My sliding mitre and table saws both handled the thick section no problem. Finished cill #1 and turned out fine. I have 3D CADed the window sections, so hopefully the next stages will go smoothly. Unless anyone objects I'll post occasional updates on what I hope is an interesting project for others.
If I had a hard deadline, I'd agree, but I thankfully I don't. This restoration can take as long as it takes. I will post some pictures.......
Apart from the practical side of getting the Windows made, I guess this more for enjoyment / learning / achievement as well. Hope it is a success
Well, it took me 2 weekends to make the first frame, working fairly slowly and having to make a couple of jigs along the way. Not too bad considering I was working from sawn. Next ones will go a bit quicker. - still got the sashes to make. Couldn't have done it without the cheapo screwfix thicknesser - works well after the bed is extended. Accoya machines beautifully, but it is fairly brittle. PU glue is not as nice to work with as PVA, but apparently PVA is no good for accoya. Not used it for assembly before. Learning how little to put on to stop it foaming out everywhere!
No, you can't use Cascamite for Accoya - This is the tech info:- "Since Accoya® is drier than normal woods and absorbs water in a different manner, this can affect the suitability and curing time of some adhesives. Suitable glues for Accoya® wood are PU, Epoxy and PRF glues. The results of gluing with PVAc can vary and gluing with MUF is strongly discouraged." Cascamite is either UF or MUF, not quite sure which but is definitely a urea formaldehyde
It looks very nice but I have a couple of questions, what are the second set of grooves that are at the inside of the box for and why are there grooves in the top?
I have seen boxes with a parting bead across the top, but do not know about the groove where the staff bead will go.
I think your pulley rebates are too tight to the top of the frame. But good looking work. Why have you got that route between the pulley stile and cheek?