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So . . . what's my mortiser made of?

2K views 21 replies 13 participants last post by  patcollins 
#1 · (Edited by Moderator)
I have a Grizzly mortiser I bought off Craigslist some time ago. Nice, solid generic mortiser. Looks a lot like this one.



I put on an x-y vise and it works pretty well.

I was cutting some mortises last night and the light wasn't quite right, so I grabbed my magnetic light that I use on my drill press and bandsaw.


Except that when I tried to put it on the body of the mortiser, it wouldn't hold! What's this thing made of?
 
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#3 ·
seems too cheap to have an all aluminum body. I went back and checked-there is a slight magnetic force, but not nearly enough to keep it in place. I'd say 5% of what I would expect.
 
#5 ·
I've known of pot metal, but it never occurred to me (before yesterday) that I could have a solid metal tool that wouldn't hold a magnet.
 
#6 ·
Yep…old crappy pot metal…my Delta is the same way…..Get you a light , but it has a clip on it, kind of like women use in their hair, and they are pretty strong….Just clip it on the side somewhere, and you're in business….plus it has a goose neck so you can position it where you need the light….On my band saw and drill press, I have the kind with the magnets, but the mortiser is a strange duck…....
 
#7 ·
I looked up Pot metal

Pot metal is a slang term used to refer to cheap metal alloys with a low melting point. The low melting point makes this metal very easy to cast, but the generally low quality can cause problems during casting and at a later date. There is no formal definition of pot metal, so it can be hard to determine its contents. Some common metals included in such alloys include zinc, lead, copper, and tin, among others.

The mixed contents of pot metal make it highly unpredictable, which can be a problem for people who are trying to create specific items. It has a tendency to become very soft and porous, and over time, it is subject to deformity. It also tends to break or bend easily, making it unsuitable for many tasks, and because some of the metals commonly included are toxic, this type of metal can also be hazardous to human health.

Rapid and easy casting is the primary advantage to pot metal. No sophisticated foundry tools are needed, as comparatively low temperatures are needed to turn it into a castable liquid, and specialized casts and molds aren't necessary either. Some people like to use pot metal to play around in the foundry, experimenting with molds and ideas before using metals of higher quality, and this metal can be useful in the production of some items.

This metal can be difficult to plate, because of its often unknown properties. Many people attempt to plate pot metal to protect it or to conceal its origins; it tends to be a dull gray color when left unplated. Objects made with this type of metal are also difficult to repair, as they tend to take poorly to welding, soldering, or gluing, techniques typically used to repair other broken metal objects.

Some people refer to pot metal disparagingly as "monkey metal," and it is also sometimes referred to as "die-cast zinc" or "white metal," among other names. Ingots for melding and casting are available from many metallurgical companies, and some people make their own pot metal, breaking down various scrap metal objects around the shop and melting them down into an alloy. Foundries may also sell scrap to people looking for a cheap source of metal, although such scrap sometimes contains an assortment of impurities which may prove problematic later.
 
#8 ·
I've heard of pot metal all my life…My dad was a certified welder for the gubberment, and he talked about that crappy stuff all the time…When I was home growing up, he expalined it to me, and what crappy metal it is to work with, and especially to weld…....It's not a new term…it's been around for many, many years….Now….back to our regular program…...Carry on, bros…..!!!!!
 
#9 ·
My Delta mortiser looks identical. The frame is not actually the weak point of this tool. It's the internal gear and handle hub that are prone to fracture. They too are pot metal, I'm sure.
 
#10 ·
Willie,

Does that require more finesse in using it or do you think it will just fail if it is going to fail?
 
#13 ·
The base. I made a plywood base to hold the vise. So there nothing but the tool itself that is metal
 
#15 · (Edited by Moderator)
Well, I suppose it could be something like injection
cast aluminum. INCA machines were made of this
stuff. It takes paint well and I think part of the
appeal is that it wasn't too prone to movement
after casting so the castings would come out of
the molds requiring only minimal clean-up work.
This could, for the mortiser column, save more
in processing cost than the cost difference
between iron and the aluminum alloy.

Just because it isn't ferrous doesn't mean it's
not an adequate casting alloy for the application.
 
#17 ·
The magnet is fine. Sticks to drill press and bandsaw with tenacity.

Funny enough, I was working in the shop today when I realized I have a clip on attachment for my light-totally forgot. Used it like that today.
 
#18 ·
Depending on how long ago it was made, it's likely diecast aluminum. The technology is getting less expensive and the castings better requiring less cleaning/flash removal.
 
#20 · (Edited by Moderator)
To totally beat a dead horse on this topic, here are two very short videos. The first shows the magnet base snapping to to the drill press housing. The second shows how it tepidly holds to the mortiser housing, but much more strongly holds to the mortiser base. I got some seriously high production values going on here.
 
#22 · (Edited by Moderator)
Not all steel alloys are magnetic either, it is dependent on how the atoms align, bond etc.

http://en.wikipedia.org/wiki/Austenite

I would wager that the silver part you see around the motor is an aluminum heatsink because of the fluting, the light sticks slightly because the motor inside of it is magnetic and contains magnets itself.

1000 series aluminum is really pretty cheap
 
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