Delta 'free' mortising chisels/bits...crap! Help!

[loutent]

I bought the Delta benchtop mortiser about a month ago, tried a few 1/4 inchers and was satisfied that all was ok.

Fast forward. Today I had a real project. Four M&T flat paneled doors (roughly 72 x 24). Poplar R&S w/1/4 oak ply panels - paint storage cabinet for the workshop.

Anyhow, I get to mortise #6 on stile #2 and the damn bit snaps. This is crap for sure & I guess I should have known better than to expect more when the bit set is 'free' with the machine.

My question is how do the Delta "professional" chisels/bits compare to this? I would like to get a good set from somewhere, so if someone could recommend another set, I would appreciate it.

Thanks!

Lou

[charlie b]

How much gap did you set between the bit and the chisel? Too much and the bit can move laterally. Tool little and the bit binds against the inside of the chisel. Either one can snap a 1/4" bit.

Did you polish the sides of the chisel and sharpen the bit before using?

Were you getting any burning or did you hear any squealing while making plunge?

Try The Forty Cent Method

Fisch makes pretty good chisel/bit sets.

charlie b

[George]

This is usually operator error, and there are normally warning signs, as Charlie mentioned.

FWIW, I've got hundreds of mortises in on my JET chisels, and they're cheap and easily available.

[loutent]

Hi Charlie. Thanks for the response.

I was very careful about following Delta's instructions on the gap - about 1/8 inch as I recall. I don't think this caused the bit snapping.

No, I didn't do this. I'll try it ob my next set.

No, I didn't have any indication that anything was going wrong. No burning. I was not forcing the bit in any way. I was trying to be careful since this was the first time using the machine 'in production'.

Woodworkers Journal (I think) a month or two back.

Thanks for the info.

Lou

[loutent]

Thanks George, I'll give the Jet chisel/bits a try.

Lou

[Edwin Pawlowski]

I have the same Delta set. I helps to polish the outsides. I used my water stones. I also bought the conical sharpener from Lee Valley. That helped also. Then I used a thin file to sharpen the augers. Just follow the angle and take a half dozen strokes. Do both the bottom cutter and the side cutter.

My guess is that there are still better sets out there, but a little work made big improvements. Ed [e-mail]

[Fly-by-Night CC]

The Delta chisels I bought a couple years ago are from Fisch - got them at the orange Borg. One has to read the country of origin and look for Sweden/Holland/Switzerland or somesuch (wherever Fisch are made).

[George]

Austria. My large carving tools are Fisch, and they make other carvers envious when I show them. Best Forstners out there too, if you can find 'em.

[loutent]

Hi Ed,

I think I figured out what happened. After re-reading some articles on mortising in Wood magazine, I realized that I was taking off too little material with each plunge.

I was using the 1/4 inch set - the most vulnerable to stress when you plunge. The article suggested boring a starter hole at each end, then take "only slightly overlaping" plunges between them. Thinking I would "save" the bit, I was plunging only about half of the chisel width which causes the drill bit to deflect a bit and probably caused the stress which snapped it. I could see the chisel deflect somewhat also. Operator error!

To finish my small project, I dug out my 1/4 bit from my Grizzly set that I used with my drill press - slipped nicely into the delta chisel, but I had to hacksaw off about 4 inches.

Since I will probably use the 1/4 and 5/16 chisels the most, I think that I will upgrade those two sizes.

Thanks for all the help!

Lou

[Edwin Pawlowski]

I read that article. I've done the same thing thinking I'd get an easier cut.

Making the plunge at each end has a side benefit also. You won't overshoot the mark is it is covered with chips when you get to it. Ed

[GerryG]

[loutent]

Thanks for the info Gerry

Those seem to be good suggestions. I'll have to search my FW collection for the article you mentioned.

When you say Delta (Austrian), are those also called Delta "Professional" (by Amazon/Tool Crib)?

Thanks again.

Lou