Thread: Help with mitre-key saw

This one gives you a whisker over 1mm kerf but depends on how much you want to pay.
Very smart jig by the way.

I am not an expert or so, but if I understand correct then your jig is keeping the saw blade vertical and on track.

My first thought was to do your first cut and then move the jig by just 1 mm and do a second cut. Although I guess the saw will then wonder off into the first cut, but maybe worth a try.

You could get an old panel saw. Mine have blades around one mm thick and with the set do cut more than a mm kerf. For your purpose you can butcher one, shorten the blade and cut new teeth with a higher tpi ( e.g. similar to a tenon saw) and choose a set which will give you a kerf thickness you want. Your jig will keep it on track I suppose.

Just some thoughts......

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Not that I’m a fan of the big green shed,
Or even Irwin tools,
For the price this may get what you want.

Irwin 185mm Dovetail Pull Saw | Bunnings Warehouse

It’s “claiming a thin kerf cut”


Cheers Matt

Even 0.75mm keys have plenty of strength in the direction it counts - along the grain. That's the direction mitres will pull apart. For thin keys, I use a gentleman's saw, like this, only a cheapie.

Originally Posted by AlexS

Even 0.75mm keys have plenty of strength in the direction it counts - along the grain. That's the direction mitres will pull apart. For thin keys, I use a gentleman's saw, like this, only a cheapie.

I do have a dovetail saw of sorts to use with a magnetic guide but it only has a kerf of about 0.4mm or less. What is the kerf on your your cheapie??

Originally Posted by Simplicity

....
Irwin 185mm Dovetail Pull Saw | Bunnings Warehouse

It’s “claiming a thin kerf cut”


Cheers Matt

Probably too thin I'm guessing - sounds like a Japanese saw which might only be 0.2 or 0.3mm

Originally Posted by Treecycle

This one gives you a whisker over 1mm kerf but depends on how much you want to pay.
Very smart jig by the way.

Can't see myself spending that much on something I use so rarely but it would be nice

Not only are they strong enough but they also look right - if you go to 1.5mm they will make the box look clunky. The boxes in the photo look great as they are.

Originally Posted by labr@

Not only are they strong enough but they also look right - if you go to 1.5mm they will make the box look clunky. The boxes in the photo look great as they are.

Might go with the consensus then and stick with the 0.75mm - maybe I'll try dropping them in in pairs to add to the aesthetic and satisfy my inner-engineers reservations!

TIT

I think Cklett was close to the mark.

I would find an old panel saw (24" or less), which should be around .032" thick. Then set the teeth heavily until the kerf comes to 1mm (.040"). Because you are using a guide box you don't need a back saw, although you could do the same with a back saw and a heavy set. You can't use the throwaway hardpoint saws because the teeth will break off if you try to set them or they won't bend at all.

As hand saws get longer they tend to have thicker plates. The only problem I see is that your kerf may be a little coarse with a heavily set, narrow plate saw. A 28" hand saw will have a plate about .039" thick, but a little unweildy for your purpose. If you found such a saw, you could always cut the length down. (angle grinder with a thin cutting disc.)

Regards
Paul

i have a weird idea so i'll see if i can draw it in paint.

so build/modify your jig so it has 2 slots:

slot #1 is what you have now a guide the thickness of your saw blade (lets say its 1mm)
slot #2 is say double your saw blade kerf (2mm)

do your first cut in slot #1
then slide the cut back to slot #2 and insert a shim (the blue color) that is 1mm thick down into it and press that hard up against the jig edge
now do your 2nd cut with the shim in place to essentially double your mitre key thickness with out it wandering into the first cut.

jig.jpg

Vern, you could try a back / tenon saw. That should give you a bit more kerf width.