LumberJocks

New mortiser! Now what?

  • Advertise with us

« back to Joinery forum

Forum topic by PLShutterbug posted 04-29-2021 03:45 AM 613 views 0 times favorited 27 replies Add to Favorites Watch
View PLShutterbug's profile

PLShutterbug

86 posts in 121 days


04-29-2021 03:45 AM

Topic tags/keywords: mortiser mortising jet mortiser jet jbm-5

Hi all – I just got a Jet JBM-5 benchtop mortiser free from someone, after first thinking I’d buy the Delta mortising jig. Can’t pass up free, right? Especially for a purpose-built tool rather than a kludge. This has been very lightly used and the only chisel/bit ever used is the 1/2” – and it is still incredibly sharp – as you can see.

Now that I’ve cleaned it up and tested it, I’m impressed. At least in soft wood.

Some questions, if you’ll indulge me.

A video from Woodworking magazine recommends setting the bit 1/16” below the highest point it can be placed up in the chisel, as here:

This puts the bit 1/16” below the top of the curve in the chisel.

The Jet manual recommends setting the bit 1/16”-3/16” below the bottom of the chisel corners, as here:

Which is recommended? The only difference seems to be that in the lower position the cut depth depth below the chisel shoulders is greater.

The mortise bottom is messy:

I’ve cut with a router before and of course the bottoms look beautiful – but does that matter? It appears that with a mortise cut with a mortising bit, the practical bottom of the mortise is at the chisel shoulders, not the actual bottom of the where the drill bit ended up – and you just ignore whatever is below the shoulders. Is that correct? Or do you recommend setting the mortise bottom to the bottom of the drill bit depth and cleaning it out with a chisel?

Penultimate – that Woodworking video recommended using some Dry Lube. Will WD40 do? That dries pretty quickly and leaves just a slick surface. Or is there a specific product recommended to lubricate the bit so it doesn’t squeal, and also doesn’t get the the mortise sides all gunky so they won’t hold a glue joint?

Finally – what do you use for chip collection? I have both a powerful Ridgid shopvac with 2¼” hoses and a single-stage 1,50cfm dust collector with 4” hoses. Are there dust collection gadgets just for mortisers, and/or do you all have any cool solutions you’ve created yourselves?

Thanks all for any advice.

-- Washington (the other WA - the state)


27 replies so far

View Aj2's profile

Aj2

3888 posts in 2916 days


#1 posted 04-29-2021 03:50 AM

I recommend you sell it for as much as you can and put the money toward a Festool domino.
Good Luck

-- Aj

View PLShutterbug's profile

PLShutterbug

86 posts in 121 days


#2 posted 04-29-2021 04:01 AM



I recommend you sell it for as much as you can and put the money toward a Festool domino.
Good Luck

- Aj2

Well … as a hobbyist who does maybe two projects per year that require mortise and tenon joints, I’m not ready to spend over $1,000.

But thanks for the quick response.

-- Washington (the other WA - the state)

View Madmark2's profile

Madmark2

2840 posts in 1706 days


#3 posted 04-29-2021 04:09 AM

Air hose mount for chip clearing on drill press, mortiser, etc. Place “big gulp” intake to 4” DC opposite and chips blow off the work into the DC intake. C’est solve’!

Used this trick when gang cutting box joints on router table. Chips blew across table into F-clamped intake scoop. Caught at least 90% of the considerable end grain router fluff.

-- The hump with the stump and the pump!

View Axis39's profile (online now)

Axis39

496 posts in 715 days


#4 posted 04-29-2021 04:17 AM

I can only answer the dry lube question, sorry. I don’t own a mortiser. But. I’ve watched a bunch of videos.

I’ve seen a few folks use wax, but, it melts out fast. I use wax a lot around the workshop, but when it comes to cutting edges/areas, etc, I do use a product actually called dry lube. I think I got the WD-40 brand. I know I picked it up at Home Depot.

I’ve found regular WD-40 can get gummy over time in a situation where you’re trying to keep wood chips and hot steel sliding smoothly.

-- John F. SoCal transplant, chewer uppper of good wood

View PLShutterbug's profile

PLShutterbug

86 posts in 121 days


#5 posted 04-29-2021 04:27 AM



I can only answer the dry lube question, sorry. I don t own a mortiser. But. I ve watched a bunch of videos.

I ve seen a few folks use wax, but, it melts out fast. I use wax a lot around the workshop, but when it comes to cutting edges/areas, etc, I do use a product actually called dry lube. I think I got the WD-40 brand. I know I picked it up at Home Depot.

I ve found regular WD-40 can get gummy over time in a situation where you re trying to keep wood chips and hot steel sliding smoothly.

- Axis39

Thanks, John. I was at HD today and intended to get Dry Lube but it wasn’t on my list so I forgot. I will need to go back in a day or so and will remember this time!

I waxed the face of the cast iron fence on this mortise and it now glides friction free. Paste wax is great for shop tools.

-- Washington (the other WA - the state)

View tvrgeek's profile

tvrgeek

1937 posts in 2767 days


#6 posted 04-29-2021 10:42 AM

WD-40 is NOT a lubricant. It is a Water Displacer. Good for taking off sticky labels. I do not know anything about their dry lube. There are also bike chain lubes which are dry. I use Boeing T-9 dry lube for places like that.
Anyway, after fighting too much flex in a drill press for morticing, I went back to hand. I would love to try a morticing machine, but pprobably ever will. New fangled junk like a Dominos biscuit may work fine for kitchen cabinets but not for the kinds of ffurniture Id o. Might even dump my biscuit and go back to dowels REBOOT, somefunny with my keyboard

View EarlS's profile

EarlS

4550 posts in 3466 days


#7 posted 04-29-2021 10:56 AM

Bostik makes a product that you spray on saw blades that always worked for me when I had a mortiser. Spray the drill liberally with it, as well as the interior of the chisel, let it dry and away you go. It is not cheap. BoeShield T-9 works, but it can get gummy too if you don’t wipe it down good after spraying it on.

As far as setting the drill in the the chisel, I found that the holes would have a slight rounded edge if the drill was below the lip of the chisel so I set mine so the corners of the chisel touch the wood before the drill.

I also used a drill press mortiser for years before I came across a dedicated mortising machine. The mortising machine was superior in both operation and quality of work. I sold it when I bought the Leigh FMT Pro.

Keep the chisels sharp. There are various hones you can buy (Rockler has one) to sharpen the chisels.

-- Earl "I'm a pessamist - generally that increases the chance that things will turn out better than expected"

View TechTeacher04's profile

TechTeacher04

468 posts in 2649 days


#8 posted 04-29-2021 12:00 PM

You want this stuff https://www.wd40.com/products/dry-lube/

The problem you are finding at the bottom of your mortise is part of the nature of the beast. I own a mortiser and a domino. I honestly use the domino more, but have plans to make some new pieces with the mortiser in the near future.

I make my mortises deeper than needed to account for the rough bottom edge, if that is not possible use a chisel to clean out the bottom. I am not aware of any way to adjust the bit and chisel to clean out the corners, the geometry of the parts do leave a small amount of material in the mortise.

View TechTeacher04's profile

TechTeacher04

468 posts in 2649 days


#9 posted 04-29-2021 12:01 PM

You want this stuff https://www.wd40.com/products/dry-lube/

The problem you are finding at the bottom of your mortise is part of the nature of the beast. I own a mortiser and a domino. I honestly use the domino more, but have plans to make some new pieces with the mortiser in the near future.

I make my mortises deeper than needed to account for the rough bottom edge, if that is not possible use a chisel to clean out the bottom. I am not aware of any way to adjust the bit and chisel to clean out the corners, the geometry of the parts do leave a small amount of material in the mortise.

For chip collection I vacuum between each piece, if you have or make a flexible holder for your vacuum hose you can align the hose with the open side of the mortising chisel.

View Lenny's profile

Lenny

1703 posts in 4645 days


#10 posted 04-29-2021 12:27 PM

The premise behind a mortiser is that the drill (auger) bit removes the bulk of the stock and the chisel squares up the cut. If the chisel is ahead of the drill bit, you are asking too much of it, not to mention it will not be able to penetrate or cut hardwoods. There are many theories on how much of a gap there should be between the tip of the drill bit and the tips of the chisel. I would say 1/16th inch is a good choice. Some suggest using a dime or a nickel as a guide, others suggest using a card scraper. For a more professional answer, check out the Youtube video by The Wood Whisperer on mortiser set up.

-- On the eighth day God was back in His woodworking shop! Lenny, East Providence, RI

View Robert's profile

Robert

4592 posts in 2598 days


#11 posted 04-29-2021 01:24 PM

I sold my Domino. Some consider that crazy, but is was 1) not the game changer for me in my work, 2) I was never satisfied with the fence accuracy, 3) it was $1000 that spend 90% of its time sitting on a shelf.

So if it were me, I’d keep the mortiser you’ll find other uses such as slots for button fasteners and square pegs.

Drill should be just below the spikes on the chisel. If its not low enough its too hard to push, the trade off is the bottom is a little raggedy, but not an issue.

I don’t use any lube. Never had an issue (see above).

Sharpen with a diamond cone and keep the outside polished. The bits can also be touched up with a saw file.

For those considering buying a mortiser, I would offer that if I had to do over I would get a horizontal boring machine or a pantarouter.

-- Everything is a prototype thats why its one of a kind!!

View Andybb's profile

Andybb

3316 posts in 1721 days


#12 posted 04-29-2021 02:06 PM

I too have a mortiser that I use once every year or two. One of those tools that I had to have then realized I didn’t really but it comes in handy when I do.

I find that once the initial plunges are made then just a quick trip across the bottom in 1/4” increments pretty much clears it out.

-- Andy - Seattle USA

View PLShutterbug's profile

PLShutterbug

86 posts in 121 days


#13 posted 04-29-2021 02:37 PM

Thanks, all. This was the advice I was looking for.

I will get the proper dry lube product, and honing material to keep the bits and chisels sharp.

-- Washington (the other WA - the state)

View WoodenDreams's profile

WoodenDreams

1317 posts in 1028 days


#14 posted 05-11-2021 09:47 AM

The type of dry lube to use is Silicone Free. If you use a Dry Lube with silicone with woodworking. The silicone will transfer to the wood and you end up with stain and finishing problems. WD40 has a couple different dry lube sprays. Make sure it’s the one without silicone…

I set my drill so it’s flush with the mortising bit. When you install the tenon into the mortised hole, the roughness on the hole bottom is not seen. For cleaner bottom. You could use a forstner bit and clean up with a chisel. Or use a router method.

View PLShutterbug's profile

PLShutterbug

86 posts in 121 days


#15 posted 05-11-2021 06:07 PM


The type of dry lube to use is Silicone Free. If you use a Dry Lube with silicone with woodworking. The silicone will transfer to the wood and you end up with stain and finishing problems. WD40 has a couple different dry lube sprays. Make sure it s the one without silicone…

I set my drill so it s flush with the mortising bit, When you install the tenon into the mortised hole, the roughness on the hole bottom is not seen. For cleaner bottom. You could use a forstner bit and clean up with a chisel. Or use a router method.

- WoodenDreams

Thanks. I got B’Laster Dry Lube with Teflon. Their FAQ says it is silicon free.

You can set a bit “flush with the bit” (actually, the chisel – the bit sits within the chisel) several ways.
- The horizontal portion of the cutter flush with the top of the saddle of the chisel.
- The horizontal portion flush with the bottom of the saddle (the chisel’s points).
- The vertical portion of the cutter (the tip) flush with the top of the saddle.
- The vertical portion flush with the bottom of the saddle.

What do you mean by “flush?”

I ended up setting the horizontal part of the bit 1/16” below the point of the chisel as in my third photo above (first: cuts on finger; second: bottom of horizontal portion 1/16” below saddle; third: top of horizontal portion 1/16” below chisel points). That made for a good compromise between being able to cut well, and draw the sawdust up the auger of the bit without jamming it. I found that if I fed too quickly, the dust built up right at the bottom of the bit and eventually stopped it. Then I had to drop the bit, clean it out and re-install it. Another example of “slow down to speed up.”

-- Washington (the other WA - the state)

showing 1 through 15 of 27 replies

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com