Hollow mortice chisels

[Fireburst]

I have over the years collected virtually a full set of imperial mortice chisels. Just missing the elusive 15/16” to fulfil my need for completeness.
The chisels that see the light of day have been 1/4”, 1/2”, 5/8” and 3/4”. That’s covered everything from furniture, doors and windows and the largest chisel for gates. I too use a Sedgwick morticer.

Sorry, you’re correct it does state 1” for softwood. I’d assumed you were timber framing in a hardwood with you wanting M&T joints. You’ve got me curious now, what are you making in 75mm+ that needs M&T in softwood that’s outside???

I will be offering a range of pergolas. The vast majority will be Oak, but I will also offer some in Red Cedar. To be honest, most of this work will utilise a cross-grain chain morticer outdoors, but some work may also be undertaken in the workshop.

 

[Glenhyrst]

It shouldn't be this hard surely with this quality of machine.
One of the key problems I can see from your what you're saying is that first plunge. I find that it is better to be working down in steps and not going for full depth in one go.
Another key point is to look at the fact that a morticer has it's own drill built in which needs to be set sufficiently below the chisel to do it's job.
Sometimes incorrect or over zealous sharpening of the outside can create a wedge effect.
Don't forget the wax candle
Have you got it cleaned, properly adjusted and lubricated in all the necessary places ?
BUT then I've just had a thought, of all the ones I've used have I used a Sedgewick?
Cannot be certain, so I wonder if the gearing in the rack on this particular model is suffering a design fault ?
My present model is a early Multico and it takes no prisoners....
Intriguing, if you were closer I'd have loved to pop in and take a look.
40 years is too long.
Cheers, Andy

Well that stimulated me to have yet another go at it. Sharpened chisel and augur, polished inside of chisel too. And still marked resistance to getting into hardwood with some burning too.
After much thought it occured to me that the burning and resistance may be because the augur was set to protrude too much and producing chips too big to comfortably enter the chisel. And we are talking here of about 1mm protrusion, so not too much although it was a 1/4" chisel.
So I tried reducing the protrusion, in fact, to contact with the chisel, and lo and behold, into the wood it went and with no burning.
50+ years in amateur wood bashing and still learning!
And thanks for the offer to come up and help although still welcome!

Phil

 

[johnnyb]

I had an old william ridgway bm3(record bm75) and this was about twice as hard to pull down. The sedgwick is really easy(in comparison) it also had a movable back fence which moved slightly if it wasn't really tight. The only sedgwick issue is the combined traverse which isn't the best.

 

[Jacob]

No point in having a chisel above say 5/8" unless you have a big machine with the extra motive power to drive it. Easier to do two passes with something smaller, and more control while you are at it. Morticing is not a big time factor for most projects so a bigger machine not necessarily cost effective, but if so, a chain morticer would be the way to go IMHO

 

[Jacob]

....
So I tried reducing the protrusion, in fact, to contact with the chisel, and lo and behold, into the wood it went and with no burning.
....

I set it up tight and then drop the bit by about 1mm or "thickness of a 2p". Too far and you soon find out!

 

[Glenhyrst]

I set it up tight and then drop the bit by about 1mm or "thickness of a 2p". Too far and you soon find out!

I was surprised at how little, if any, a gap worked well. I'm guessing that sharpening/polishing significantly reduced any audible metal to metal contact.
I had never before thought about the size of the chips significantly affecting performance but it now makes sense to me.