King Company tenon saw - fixable?

[--Tom--]

Spurred on by some of the recent threads on saws

I have this 14” King Company, Hull saw

Hard to show in a picture but a definite curve in the blade from heel to tip

So to start I went take the handle off but remembered why I hadn’t tried before, the slots in the nuts have been sanded flush.

Can I get the curve out without removing the handle?
Any tips to remove the nuts without trashing them?
Easy enough to make up a split point driver from some gauge plate, but is slotting them in situ feasible.

 

[deema]

Yes, put the blade into a soft jawed vice. With some brass or something soft tap up the hardback off the blade until it is just about to come off, without taking it off; do it initially at the toe, tap the heel and toe of the hard back back down about 3mm. But only tap it at the heel and toe. The induces tension into the blade. If it doesn’t work you need to take the blade fully out and clean it of the rubbish that’s built up causing it not to slip in the hardback evenly.
The Nuts are probably toast. New ones can be bought.

 

[Sgian Dubh]

Can I get the curve out without removing the handle?

I've straightened many a blade that's become bent. The cause has usually been careless or downright obstreperous, destructive and reluctant joinery apprentices on day release at a college where I was doing some short term part-time teaching.

Simply hold the saw by the handle raised slightly with the blade roughly parallel with a workbench and with the front end of the brass back resting on the bench with the concave side down. Then tap the brass back with a hammer to straighten it until the plate is straight. My preferred hammer is one I have handy, which just happens to a 16 oz claw hammer, and this assumes a single curve to the back and the saw plate. If the back and the plate is/are wavy you need to treat each wave separately flipping the saw over as required to tap at each convex part.

I've never found straightening a hand saw to be a particularly fussy or precious task, but it does take a bit of care. For instance, you can over correct, but if you do so you only need to flip the saw over and tap from the other side to take out the overcorrection. Slainte.

 

[IWW]

Split nuts with the slots sanded off is a pretty common problem. Best to leave them alone if they don't need tightening, or you don't really need to remove the handle. If you must get them off, the best way I've found is to grind a smaller-sized nail punch to a chisel point. You can usually get enough 'grip' in what remains of the slot to gently tap the nut in a counter-clockwise direction enough to loosen it - they generally come loose surprisingly easily & with little or no damage. Once you have it off it's easy enough to deepen the slot with a hacksaw, but take it easy, they are usually rather thin, especially when heavily sanded like yours.

As to straightening, see deema's & Richard's answers. Deema is talking about the situation where the spine is straight but the blade is curved (fairly common on old saws) due to uneven grip by the spine, while I think Richard is talking about bent spines (those apprentices must be a rough lot!). I've seen people "fix" a curved blade by hammering a curve in the spine, but that's not a good idea - sighting along a curved spine & trying to cut straight don't sit well together imo....
Cheers,