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Josh Doran
05-17-2015, 12:47 AM
I own an antique Miter Jack, excellent condition but I'm afraid to use it. I'm worried about ruining the surface. I've been watching the benchcrafted build and noticed that he orients the clamping blocks so that the end grain is on the outside reference surfaces. My board, however, is oriented opposite with the face and side grain on the outside. The end grain setup seems better than mine. I'm worried about tear out, running a plane across grain on mine. End grain seems more durable as well as providing a stable surface unaffected by wood movement. Any thoughts? Should I try to use it anyways, replace the jaws on an antique, or sell it and make my own like the benchcrafted one?

Thanks,
Josh

Kees Heiden
05-17-2015, 3:29 AM
Glue some thin cardboard to the faces as a sacrificial surface. I did that too, afraid to harm the nice old surfaces. Chicken, I know. In reality you hardly touch the faces with the plane anyway and a little scuffing around the edge doesn't matter.

george wilson
05-17-2015, 8:47 AM
It was the usual practice to glue a few sheets of paper to the face of the jig when in use.

Prashun Patel
05-17-2015, 9:21 AM
Dumb question alert:

How is a miter jack used? I've seen the Benchcrafted site but I can't figure out how and why I'd use one. Any help appreciated.

Kees Heiden
05-17-2015, 9:30 AM
Better then to explain in words, watch the video from Benchcrafted:


https://vimeo.com/126329537

Bill White
05-17-2015, 9:59 AM
No vid will open. ????
Bill

Robert Norman
05-17-2015, 10:36 AM
try this:

https://vimeo.com/126329537#at=0

Jim Koepke
05-17-2015, 11:29 AM
No vid will open. ????
Bill

This is my reason for having more than one browser. Most of the time Safari is my browser. Vimeo doesn't always work with Safari so then FireFox gets called into service.

Now my OS is getting pretty long of tooth and is in need of an upgrade.

jtk

mike holden
05-17-2015, 11:56 AM
Josh,
The plane is run down the face of the jack such that the blade only passes over the workpiece and some slight overlap of the jack at the clamping edges.
The main surface is touched only by the bottom of the plane, the area ahead of the blade on one side, the area behind on the other. The plane is skewed to allow this to happen.
The paper/cardboard is an insurance policy. Not really necessary.
Mike

Prashun Patel
05-17-2015, 12:08 PM
Thanks for that video. I was confused about how you avoid planing the into the fence, but i guess you just have to stop and check often.

Kees Heiden
05-17-2015, 2:43 PM
Indeed. And a little bit of damage to the faces around the opening is no problem as long as there is plenty of surface untouched for the plane to ride.

Jim Matthews
05-17-2015, 2:51 PM
At last - a woodworking video without banjo accompaniment.

Brian Holcombe
05-17-2015, 3:06 PM
The use of 18th century french tools should be accompanied by Bréval :p

Josh Doran
05-18-2015, 12:56 AM
Thanks for the replies. I'd heard of gluing cardboard before but saw that wasn't done in the video. I was concerned if the edges of the jack were planed a bit, it would affect registering the knifed edge for joinery like tenons. I guess this can be overcome by laying a chisel flat on the jack and aligning the knifed edge into the chisel. I like the benchcrafted holdfast clamping block style better than my single board which only works in a vise, so I might replace mine with that style. I like the idea of the plane riding horizontal.

Jim Matthews
05-18-2015, 7:35 AM
Modern users from Gascony would prefer something less suited to the parlor of Madame et Messieurs

https://youtu.be/dLBb4oJR_4s?t=234

Jim Matthews
05-18-2015, 7:37 AM
Finally, I can use the one I've been afraid to ruin.

As with so many of your posts, it's only obvious in hindsight.
I've got some thin plastic sheets (LV sharpening kit leftovers)
that should do the trick nicely.

Thanks again.

Brian Holcombe
05-18-2015, 7:38 AM
Well played sir.

Darrell LaRue
05-18-2015, 1:12 PM
I find it strange that everyone assumes that a mitre jack is used with a plane. Even when they all understand why it isn't a good idea, due to the damage you will inflict on the precisely made faces of the jack.

Clamp up the stock in the mitre jack, then grab a big, long, wide paring chisel and lay it on the face of the jack. Slide it across and pare off the offending bits. The chisel won't dig in, the cut will be precise, and the work will be done perfectly. I suppose you could also use a flush-cutting plane like the one LV sells, but you already have the big-*ssed paring chisel, right?

Darrell

Kees Heiden
05-18-2015, 2:54 PM
Maybe because everyone tells us so? Even Ulmia in their advertisements.

http://i290.photobucket.com/albums/ll266/Kees2351/Shootingboard/stosslade2_zps77330234.jpg (http://s290.photobucket.com/user/Kees2351/media/Shootingboard/stosslade2_zps77330234.jpg.html)

They even had a special plane for use on the mitre jack, the Vergatt hobel.

But the paring chisel is a good idea of coarse. You can also use a flush cutting saw, like the french veneer saws.


313794

george wilson
05-18-2015, 4:25 PM
They have used them with planes in the Anthony Hay Cabinet Shop in Williamsburg for years Paper glued on with hide glue gives a safety layer,and can easily be gotten off and renewed.

A tip: dampen the paper before you glue it down or it will wrinkle when the glue dries and pulls it together.

Steve Voigt
05-18-2015, 6:10 PM
I find it strange that everyone assumes that a mitre jack is used with a plane. Even when they all understand why it isn't a good idea, due to the damage you will inflict on the precisely made faces of the jack.

Clamp up the stock in the mitre jack, then grab a big, long, wide paring chisel and lay it on the face of the jack. Slide it across and pare off the offending bits. The chisel won't dig in, the cut will be precise, and the work will be done perfectly. I suppose you could also use a flush-cutting plane like the one LV sells, but you already have the big-*ssed paring chisel, right?

Darrell

I'm with Darrell. I don't have a miter jack, but I have some homemade jigs, which I use for repetitive operations, that operate on the same principle. I use a chisel and the reference surfaces have remained pristine after hundreds of cuts. I think most of the time, the chisel would be faster. For a really large surface though, the plane would be a nice option.

Simon MacGowen
05-18-2015, 7:20 PM
A tip: dampen the paper before you glue it down or it will wrinkle when the glue dries and pulls it together.

Good tip!
Simon

Hilton Ralphs
05-19-2015, 5:16 AM
Fine Woodworking had a great article about this jig in issue #190

313837

313838

You can get the screw press from Lee Valley (http://www.leevalley.com/US/wood/page.aspx?cat=1,43838,43845,31138&p=31138) or Peachtree (http://www.ptreeusa.com/clamp_brand_shop_fox.htm).

The latter is a Shop Fox version and the quality isn't the best so I may try the Lee Valley version.

ian maybury
05-19-2015, 9:38 AM
That's a nice tool/jig - i'm a big fan of anything (much like honing guides :) ) that takes the variability out of processes. So often the magic is in going for the right set up. There's other variations on the theme about too: http://www.wkfinetools.com/tMaking/miterJack/miterJack-1.asp (pardon if it's old hat to some)

One question. Depending on the details of the alignment there could be some tendency for the moving clamping block attached to the screw to ride upwards from the sloped face as it comes up tight - to cause come misalignment. There's slots in some of the pics about, but seemingly not dovetails as such. Is this a real issue/if so how is it dealt with?

Andrae Covington
05-19-2015, 2:03 PM
I'd never thought of using a chisel with a miter jack as well as a plane. Seems obvious now that I've seen it, but that's pretty cool.

george wilson
05-19-2015, 3:12 PM
You need to keep the underside of the track of the moving jaw snugged up to keep the moving jaw from rising. Also,I would not over tighten the moving jaw as the whole mechanism is made of wood,and the jaw can fairly easily be made to lift up some.

Personally,I don't have a lot of use for miter jacks. I'm mostly an instrument maker anyway. But,if I wanted one,I'd make the track parts out of metal,and just have the jaws made of wood. It would be possible to do this even if you don't have a milling machine or a lathe. A drill press would do. Just go to the scrapyard,or buy some rectangular bars of aluminum(at least). I'd use steel myself,but i have the means to saw it,etc..

I'd face the lower face of the sliding jaw with 1/8" thick steel,either precision ground,or heavy sheet. Aluminum would be a second choice,but keep it lubricated with paraffin to avoid galling. Screw the sheet to the underside of the sliding jaw.

I think a shooting board would be more reliable. But,you can't do things with a shooting board that you can with a miter jack,such as paring around tenons.

ian maybury
05-19-2015, 6:35 PM
Ta George. I hadn't seen one before, and would need to think through possible uses. My instincts regarding the tracks would tend along the lines you describe too.

Hi strength heat treated aluminium (make sure its an anodising grade) is good stuff, something like a 6061T6 - significantly stronger than mild steel - although not quite as stiff. The big advantage (as you know) is that you can cut it very nicely on a table saw - even if the flakes get a bit messy. I've been making an accessory rip fence for my saw this week for example from aluminium angle - no problem at all using a non ferrous metal blade.

Anodising is relatively widely available and not too expensive - it's a decent way of putting a reasonably wear resistant and slippery surface on the stuff...

Brian Holcombe
05-19-2015, 7:55 PM
I think a lot of the features of this can be accomplished with both an accurately made tail vise and a paring block or set of paring blocks.

george wilson
05-19-2015, 9:33 PM
Of course,the great work of the past was made with all wood miter vises(if any was used on a given piece,that is). So,with care,they do work. Being a toolmaker,I can carry things into the metal realm.

ian maybury
05-19-2015, 9:45 PM
For sure there's multiple routes to the same or similar end Brian. I'm guessing that the mitre vise/mitre jack is the sort of thing that would have been used in a fairly specialised/semi production type environment back when hand tools were used for that sort of work...

Brian Holcombe
05-19-2015, 11:07 PM
I think so too, it does look like it can make life much easier for repetitive miters.