Power file for saw sharpening

[spanner48]

I restore classic English saws [hand and backsaws], from the 19th and 18th centuries. I'm looking for a power tool to re-file teeth and gullets into damaged saws.

A big part of restoring is sharpening. Particularly where the saw has either been badly sharpened in the past, or has been damaged or has broken teeth. Then you have to "joint" the toothline: run a flat file or a grinder straight across the tipes of the teeth, until all have been 'point-flattened'. Then cut the gullets anew - individually - to even out the faults.

It's a lot of work. Hand work. A full 28" ripsaw with say 3 teeth per inch might involve filing away a total of 6 to 8 square inches of saw blade, between all the teeth. By hand, that's several hours of wrist- and arm-numbing work.

So I'm looking for a hand-held reciprocating power tool that will hold a triangular saw file. And I haven't found one so far.

Any ideas, UK Workshoppers?

 

[--Tom--]

A die filer would move the file for you reducing the repetitive strain. Another thing to look at would be using a fly press and suitable die to recut the teeth.
I’d avoid a power file belt sander as they aren’t really precise enough to work well

 

[Ttrees]

Likely wrong here, but I've got a saw or two which the plate has gone hard and brittle,
which will dull a file pretty quick compared, much like the hardened teeth on a throwaway saw,
and complicates sharpening by a lot compared... or indeed establishing teeth in the first place.

I'd go looking for sawplate for that one.
Interesting idea regarding the power file.

Tom

 

[graham88]

https://dynashop.co.uk/product-cate.../dynabrade-reciprocating-filers-sanders-saws/
Is this the sort of thing you're after? Grab a cuppa and sit down before scrolling down to the prices. I searched the term "reciprocating filer"

 

[Jester129]

Ye Gods! See what you mean re prices.

 

[Fergie 307]

I think Desoutter used to do a similar tool, at a similar sort of price probably. But you might find a second hand one. I have one of their right angle die grinders, I think it was about £70 on e bay brilliant tool. Or could you contrive a way of mounting your file in a jig or sabre saw to get the reciprocating action, some of the cordless ones are quite small.

 

[johnwalls26]

Could a saw file be adapted for use in a scroll saw?

 

[niall Y]

Try googling reciprocating file there are a few much cheaper ones listed.

 

[spanner48]

https://dynashop.co.uk/product-cate.../dynabrade-reciprocating-filers-sanders-saws/
Is this the sort of thing you're after? Grab a cuppa and sit down before scrolling down to the prices. I searched the term "reciprocating filer"

Yes; that's what I want. But: 1: It's phenomenally expensive. 2: Idon't have air.

 

[spanner48]

Could a saw file be adapted for use in a scroll saw?

Well, at the moment I'm leaning towards trying to attach a piece of saw file to the blade stub of a sabre saw. The small ones are quite 'handy'; and you don't need to use force when sharpening or jointing.

But: how to bond two pieces of heat-treated steel – where welding would destroy the temper? Soldering? Brazeing? Epoxy?

You would think that SOMEONE in the die-sinking industry would have a need for a small power file . . . . .

 

[Dalboy]

Two examples which may be useful


power file

battery filer

 

[ChaiLatte]

But: how to bond two pieces of heat-treated steel – where welding would destroy the temper? . . . .

Why do both pieces need to be heat treated?

All you need to do is retain the cutting ability of the file teeth.

Poke the file into a large potato so that only thpart you are soldering gets hot.

What is the minimum stroke speed of the device you wish to use? How does that compare with your arm in terms of control of the cutting action and frictional heat entering the item being filed?

The 58 up-and-downs of this per minute would seem a lot more useful, if only you could eliminate (disconnect) the 2000 round-and-rounds.

https://www.rutlands.com/products/oscillating-bobbin-sander

 

[--Tom--]

Here’s a die filer

https://www.ebay.co.uk/itm/276103401722?
You want something that’s slow with long strokes as saw plate is pretty thin.


Recutting the teeth will save a load of filing though, and is how saw makers do it

 

[ChaiLatte]

Here’s a die filer

The problem with a die filer is finding the files for it.

Proper die filer files have the teeth cut so you pull on the tang.

It may be possible to modify a standard file, but you'd lose a good bit of length.

 

[--Tom--]

Here’s more on punching the teeth

https://eccentrictoolworks.com/2010...soup-part-i-background-to-punching-saw-teeth/
https://eccentrictoolworks.com/2010...-press-in-my-soup-part-ii-punching-saw-teeth/

 

[Alli]

https://www.amazon.co.uk/Needle-Electric-Diamond-Reciprocating-Sharpening/dp/B0BX39JS9M?th=1
Any good?

 

[canuck]

What you need is a Foley Retoother. It uses a punch and die to cut new teeth in the saw plate. They may be hard to find in the UK, but are fairly common over here in North America. I have a couple of them in my shed.

 

[deema]

I’ve been looking for years for a Foley here in the UK, not found one yet!

 

[canuck]

Could a saw file be adapted for use in a scroll saw?

Here's a page that describes a scroll saw conversion for power filing: Die Filer - HomemadeTools.net

The older Rockwell 40-440 scroll saw was also made to accept needle files:

 

[Fergie 307]

Well, at the moment I'm leaning towards trying to attach a piece of saw file to the blade stub of a sabre saw. The small ones are quite 'handy'; and you don't need to use force when sharpening or jointing.

But: how to bond two pieces of heat-treated steel – where welding would destroy the temper? Soldering? Brazeing? Epoxy?

You would think that SOMEONE in the die-sinking industry would have a need for a small power file . . . . .

If you MIG or TIG weld it I doubt enough heat will travel to damage the temper of the file.