moulding

[devonwoody]

A friend as asked me to produce a 4" length of beading 15x10mm in volumn. I will post the picture in the gallery of the moulding.
under devonwoody moulding.
I have never created a scratch block any advice on how I could produce this shape would be much appreciated.

[Chris Knight]

Devonwoody,

I don't see a picture yet.

Making and using a scratch stock could hardly be easier here's a link for a "fancy" version
http://www.geocities.com/plybench/scratch.html

I tend to grab a bit of scrap wood about 8 inches by 3 then cut a bit out of one corner about 3 inches long by one high. Bandsaw the skinny bit to create a "split" into which I insert my blade which is held in place with a couple of screws - one either side of the blade. It ends up something like the one in this link http://www.bobdillonwindsorchairs.com/scratch.jpg

To match a moulding:- cut it square, hold the cut end against some suitable blade material (like a bit of an old scraper or bandsaw blade) then mark round the moulding with magic marker and file the profile with some small files. Fasten your new blade in the stock and hey presto, tool finished.
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Chris

[Alf]

DW,

What he said. In addition, there's some more info on them here (great site, btw). Couple of tips; firstly, make sure you go the whole length of the workpiece from the get-go, 'cos otherwise you'll get a step and you won't be able to then, even if you wanted to. But anyway, allow some spare at the ends 'cos they'll get all manky. Secondly, if you can remove as much waste as possible with a block plane or whathaveyou, it'll leave your scratch stock cutter sharper for the crucial final passes. Trust me, as soon as you start to sharpen it you'll end up altering the profile a little bit, no matter how hard you try.

Anyway, here's my take on a simple L-shape scratch:

The result (the wavy edge is actually the architrave next to it, honest):

And some likely, or unlikely, cutter material:


Cheers, Alf

[Chris Knight]

I guess Alf is right about altering the profile when sharpening but if you are careful to file the shape you want very square to the face of the blade and thereafter only hone the faces of the blade it shouldn't be a problem - leastwise, I have never found it so.

Alf, I like your winding sticks
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Chris

[Alf]

[Chris Knight]

Alf,
Gotta be you! After all, apart from removing a wire edge what does one do with planes and chisels - sharpen one of the intersecting planes that make the edge, albeit the bevel in that case.

Wait for my next drive-bys - or perhaps simple unashamed gloats - need to take some piccys first tho'
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Chris

[Alf]

[devonwoody]

I see that the moulding picture has now appeared in the gallery , Do you think a scratch blade can be made that will cut this shape or will it have to be separate blades ?
I have never attempted anything like this before

[Chris Knight]

You should be able to do it in one if you do as Alf says which is to remove as much waste as possible first by chamfering with a plane close to the profile.

If not, cut the blade you just made in half and do it in two. You will then need to round the outermost bead because each blade will be undersized by the width of the saw balde you used to cut them in half.

Alternatively make a couple of new blades.

Using a scratchstock is not a very rapid process but equally it is surprising how quickly you can make it work. Just aim for nice steady strokes and it will go fine. I would expect to be able to make 30 inches or so of the moulding you illustrate in about half an hour (once I have made the tool).
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Chris

[Alf]

DW,

Yep, should be able to do it with one cutter no probs; it's not a very large moulding. Hope you've got some needle files 'cos it might be a bit finicky making the cutter.