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Forum topic by sarahss posted 02-10-2013 12:51 AM 885 views 0 times favorited 16 replies Add to Favorites Watch
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sarahss

254 posts in 1398 days


02-10-2013 12:51 AM

I’m having issues with my mortiser—or maybe it’s just the chisel. I’m using a brand new 3/4 inch hollow chisel mortise bit (Jet brand) and it’s not cutting. The auger seems to be fine—it’s cutting like butter, but the hollow chisel won’t penetrate the wood. I also tried a grizzly brand bit of the same size—also brand new. I put some beeswax on the auger like the mortiser book recommends—it a Grizzly G0448 machine with a 1.5 hp motor. The motor is fine, and is not binding or anything and I believe that I have the bit set up properly with the auger about 1/16 to 3/16 below the points of the chisel as the book says to do. I’m getting a round hole, but the chisel just isn’t doing anything. I believe that they are not truly sharp out of the box, but my hubby thinks I’m crazy to believe that. Our smaller bits—1/4 inch up to 3/8 are all sharp right out of the box—but they are of a cheap set and not the same brand. We have a set of cones for sharpening, but they are too small for this large bit. we are trying to cut 1/2” hickory. The chisels feel really sharp to me—the points demand blood sacrifice, but I’m not totally sure about the arched portion of it, and that’s where we’re having problems. It’s just giving us a round hole with pointy little corners. Does anyone know how to be sure the chisel is sharp enough?


16 replies so far

View SamuraiSaw's profile

SamuraiSaw

489 posts in 713 days


#1 posted 02-10-2013 01:04 AM

My experience with a bit that large is it takes a lot more pressure to work it into the wood.

Pull harder!

-- Artisan Woodworks of Texas.... www.awwtx.com

View AandCstyle's profile

AandCstyle

1477 posts in 1005 days


#2 posted 02-10-2013 01:10 AM

Sarah, I just went through similar frustration with a Jet hollow mortiser. Even though the points are sharp, you can try polishing the out side surfaces of the chisel up to at least 600G but 1000G would be better. Basically, you want it so smooth that you can see your reflection. Then try waxing it and see if it works. Think about it, a 3/8” chisel has 1.5” outside dimensions and a 3/4” bit has 3” outside dimensions; twice as much. Also, you may need to drill out the mortise with a 3/4” Forstner bit on the drill press, then use the mortiser to clean up the corners.

In my situation, I used a Forstner bit on the drill press to the full depth, then used the mortiser to make a series of shallow cuts, then increased the depth slowly and repeatedly until I reached the final depth with frequent waxing of the chisel.

Good luck and let us know how you make out.

-- Art

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sarahss

254 posts in 1398 days


#3 posted 02-10-2013 01:19 AM

@Samurai—we’re compressing the fibers of the hickory—not sure i’m strong enough to pull much harder :-)

@ Art—gonna try a softer wood first just to see what happens—may also try predrilling. wish I had a sharpening cone large enough for this monster bit. trying to use it to make a jig for a project, and really want to make the 3/4×3/4 cuts in one pass to be as accurate as possible. right now, sure can’t see a reflection in that chisel—gonna take alot of polishing to get there. think i’m gonna call Jet on monday too—if it’s supposed to be sharp out of the box, then this one failed QC and should be replaced—just bought it today.

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sarahss

254 posts in 1398 days


#4 posted 02-10-2013 02:06 AM

cuts poplar—just doesn’t like hickory. guess we’ll use poplar for the jig. just had some scrap hickory that we were trying to use….oh well. at least problem resolved.

View arcwds's profile

arcwds

5 posts in 666 days


#5 posted 02-24-2013 08:38 PM

I’m with Art on the predrilling- I’ve had issues with a 3/4” bit on a Powermatic mortiser. The best solution I found was to use a forstner bit to partially clear out the mortise (say, use a 1/2” or 5/8” forstner bit) to make an opening. (I keep a set of “beater” bits that I even use with a hand drill to make things go quicker). That void allowed my mortiser to plunge into the wood with greater ease, and gave me a cleaner cut.

P.S. is your Exaktor fence still for sale?...I’d write you directly, but I’m new to this site, and the rules state that I must make 5 postings first? seems odd…

-- www.arcwds.com

View sarahss's profile

sarahss

254 posts in 1398 days


#6 posted 02-24-2013 11:24 PM

I’ve ordered the sharpening cones from Lee Valley and am waiting for them to come in. I tried pre drilling, but the chisel wouldn’t stay true to the line and the cut was pretty nasty looking. I’m using through mortises with exposed tenons, so it really needs to look good. Gonna give that a try.

Yes, the exactor is still for sale, but cost prohibitive to ship. I’m about 1 hour outside Memphis, TN if you’re down this way and wanted to pick it up.

View runswithscissors's profile

runswithscissors

1235 posts in 773 days


#7 posted 02-24-2013 11:30 PM

I realize the original post was 2 weeks ago, but I’ve been pondering this in the meantime. I’m wondering if it might work to set the point of the drill quite a bit further below the chisel than you normally would. Say 1/2” or so. Then the chisel might be able to carve away the corners because the waste would have somewhere to go.

Just a thought, and maybe somebody else will have a similar issue. If I run into a situation like that, I’ll give it a try. Of course the only hickory we see in my neck of the woods is in axe handles and pallets. (The latter is not the best quality).

-- I admit to being an adrenaline junky; fortunately, I'm very easily frightened

View SouthpawCA's profile

SouthpawCA

256 posts in 1981 days


#8 posted 02-24-2013 11:55 PM

By now you should have your sharpening cones, however, the cones are not enough. As the name implies, these are chisels and you have to sharpen them just as you would your plane irons or chisels. I had the Grizzly chisels and fresh out of the box they wouldn’t cut anything. I spent a lot of time on the 4 outside faces flattening and polishing. I went thru the grits starting with 150 grit sandpaper glued to a flat surface and ended with my 4000 grit stone. You have to be careful to take equal amounts from each side .. Don’t rush it.

Once you have a mirror finish on each side then take the cones and GENTLY sharpen the insides. Then you might have to go back and remove any burr from the outside. My chisels now will easily cut thru quarter sawn white oak. The wood whisperer has a video on sharpening … I believe the name of the video is something like Mortiser I Hardly New Her .. It a good video for anyone new to mortising with a mortiser.

-- Don

View arcwds's profile

arcwds

5 posts in 666 days


#9 posted 02-24-2013 11:56 PM

Through tenons eh? do you have a process photo? I ask because I’m wondering if you don’t need the mortiser at all…consider ripping your board into strips, and reassembling with a re-sected strip? I can upload a sketch if it will help…

As for the exactor, this forum may not be the best place to discuss it- my email is arcwds@gmail.com. I’ll give you my number there, and we can discuss payment for the exactor.

-- www.arcwds.com

View sarahss's profile

sarahss

254 posts in 1398 days


#10 posted 02-25-2013 01:41 AM

@runswithscissors (cool name) we have the auger set pretty low and the points of the chisels are penetrating, but the arched area just won’t penetrate—we ordered the cones last night so hopefully we’ll have them soon….

southpaw—thanks for the tip on wood whispere’s video—i’ll watch that one. my plan sounds like what you’re describing—just worried about taking too much material during the polishing phase—don’t want to make it less than 3/4”. Don’t know why I didn’t think of wood whisperer!!

@ arcwds—no process photos yet—haven’t done the glue ups yet—wanted to test all my jigs for accuracy before committing the wood!! I thought about ripping, cutting mortises with the table saw and dado blade and gluing, but given the grain direction, that won’t work. the mortises are going up the side of the cabinet—in order to do what you suggested, I’d actually have to chop, cut and glue—sorta hard to describe but once I get all my jigs tested, I’ll start taking pix and trying to get them posted. I’ll send you an email about the exactor.

View derosa's profile

derosa

1557 posts in 1584 days


#11 posted 02-25-2013 02:07 AM

You might want to check the owners manual on this one. Most benchtop style mortisers aren’t meant to use anything bigger then a 1/2 inch which is why most have that as the biggest. Some like the powermatic can go 5/8 but bigger then that is just more then the machine may be meant for.

-- --Rev. Russ in NY-- A posse ad esse

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sarahss

254 posts in 1398 days


#12 posted 02-25-2013 02:22 AM

@derosa—it’s bigger than a benchtop—1.5 hp on a free standing base—more along the lines of the powermatic—just not as pretty!! based on the accessories they list in the manual, it will take a 1” chisel, but good thought—I’d never checked that until you mentioned it.

View SamuraiSaw's profile

SamuraiSaw

489 posts in 713 days


#13 posted 02-25-2013 02:26 AM

I have a Delta benchtop mortiser that came with a 3/4” chisel.

-- Artisan Woodworks of Texas.... www.awwtx.com

View oldnovice's profile

oldnovice

3868 posts in 2116 days


#14 posted 02-25-2013 03:38 AM

I had a real hard time “no pun intended” even with a 1/2” bit in oak with my mortiser. Just not enough leverage for a little guy.

-- "I never met a board I didn't like!"

View a1Jim's profile

a1Jim

112898 posts in 2325 days


#15 posted 02-25-2013 06:31 AM

Not sure where you are with your mortiser problem? I agree with cleaning and shinning the chisel but most of the time when your having trouble with your mortiser cutting it’s because the drill bit inside is not adjusted properly or it’s dull or both. Hickory is a very hard wood so even though your mortiser is set up right it can still be tough without pre-drilling at least the starting points of the morticer.

-- http://artisticwoodstudio.com Custom furniture

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