Thread: Dovetail rip saw tooth angle

Dave, I would prefer a slightly different configuration. I am assuming that you want this saw for hard wood?

15 tpi is good, but zero rake is going to be harder work than you need. The addition of 22 tpi at the toe is an attempt to make the saw easier to start. This is a lot of extra work.

Instead, file 15 tpi, but add about 5 degrees of rake throughout. This will make the cut a little less aggressive but should not reduce the speed of cut significantly. If this is still starting hard - which is a matter of experience ... a light grip generally sorts this out - then add more rake to the toe, say 10-14 degrees of rake.

Regards from Perth

Derek

Dave

Progressive teeth are normally reserved for large (26" or 28") rip saws and usually go from 6ppi at the toe to 5ppi at the heel for example. There may be 2" (50mm for the modern woodworker) at 6ppi, 2" at 5½ppi and then the rest of the saw at 5ppi. To start a sawcut with rip teeth you need between four and six teeth contacting the wood with a preference toward six. The trick is to lower the angle of the saw until the teeth are close to flat on the timber. Once the cut has begun a more normal saw action can be adopted.

With any saw above, I was going to say 12ppi, but even 10ppi this is technique is ample. For your dovetail saw it won't be an issue at all. Do as Derek suggests and make the first cuts gentle and file at that 5° angle. 22ppi is very small and hard to imagine that it is really warranted: I think you are young or have good eyes or quite possibly both. Even using a headband magnifier 22ppi would seriously challenge me...Actually, 15ppi I think twice about and then say "No."

Regards
Paul

Thanks for the advice guys.
Well asking around the woodworking shops today, theres no one sharpening saws or re-toothing hand tools in Hobart!! good part time business opportunity if you had the gear! i hate the throw away society...

It's worth filing a ripsaw with zero rake just to find out what it feels like (damhik)..

I'll tell you anyway - years ago, when I first started sharpening my own saws, I managed to do this. I eventually figured out how it happened, I was sharpening 'freehand' like I saw my father do it, and I was pressing the file more on the back of the teeth instead of keeping pressure on both sides of the gullet. Over several sharpenings, the rake slowly diminished until there was none at all. The saw was a real beast to use, "agressive", perhaps but with a horribly rough & unpleasant action.
As others have said, around -5 deg. 15tpi suits a dovetail saw (at least it does for me). Blade length is a personal taste, I find 225mm to suit me to a T, but some like longer blades.

Putting a little more rake on the first 25-30mm of teeth at the toe can help starting if you are a beginner. After very little practice, you'll find it unnecessary, it's a bit of a modern gimmick, imo. But if you need help, I advocate the relaxed rake approach rather than smaller teeth because it's easier to file the same pitch & you can bring the teeth back to 'normal' rake over a few sharpenings when you feel you no longer need the training wheels...

Cheers,